Simulator 23 Patches

New Features

Bug Fixes

Date

November 26, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): A new script command named TSAutoSavePlots was added. It will create and save images of the plots in the same manner as the AutoSave an image in the transient stability dialog works. The format and parameters of the script command are as follows:
    TSAutoSavePlots([PlotNames], [ContingencyNames], FileType, theWidth, theHeight, theFontScalar, IncludeCaseName, IncludeCategory);

    The script will ONLY plot the plots defined in the [PlotNames] and only will plot the result of one contingency as defined in the [ContingencyNames]. It will NOT PLOT Multiple contingencies in the same plot. If [PlotNames] is blank then it will plot all of the plots defined in the case for the contingencies defined in [ContingencyNames]. If [ContingencyNames] is blank it will plot all of the plots defined in [PlotNames] for all the contingencies in the case. Only [PlotNames] and [ContingencyNames] need to be defined, the rest of the parameters are optional. FileType options are JPG, EMF, BMP, GIF, PNG or PDF. Defaults are FileType=JPG, Width=800, Height=600; FontScalar=1, IncludeCaseName=NO, and IncludeCategory=NO.

November 25, 2024

Features and Improvements

  • Transient Stability: Added ability to read the ESURR1 USRMDL model from a DYR file and convert it to a ESURRY model.
  • Transient Stability: Added ability to read the EX21BR USRMDL model from a DYR file and convert it to a AC7B model.
  • Bug Fixes

    • Contingency Analysis: When using a linear method to solve an injection group ChangeBy or SetTo contingency action, there was an error in the calculation if the change in injection was 0. This error could prevent makeup power from being calculated correctly if there were other actions in the contingency that isolated generators or loads. This has been fixed.
    • Contingency Analysis: After defining a contingency analysis CustomMonitor that monitored a field of an actual Contingency object, if the Contingency Combo Analysis was run and CTGComboViolations were created for the CustomMonitor, a problem could occur. The problem was a CTGComboViolation refers to
      (1) the Contingency for which the violation occurs
      (2) to the object being monitored by the CustomMonitor (which is also a Contingency in this example).
      This meant that the CTGComboViolation could reference a Contingency object twice.
      When a Contingency was later deleted, errors would occur in Simulator because we were cleaning up references to the deleted Contingency twice and the second time resulted in various bugs. This has been fixed.

November 18, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Moving a percentage of a generator either with the Move script command or the Move Bus Equipment dialog was not consistent with how the regulated bus of the new generator was set. If the original generator is regulating a remote bus this bus is regulated, but if the original generator is regulating its own terminal the new generator will regulate its own terminal bus.
  • Available Transfer Capability (ATC) Tool: When running Multiple Directions ATC, the implementation of RAS with linear contingency calculations when using the Iterate on Action Status option may not have been calculated correctly for the second and subsequent transfer directions studied. This has been fixed.
  • Available Transfer Capability (ATC) Tool: When running Multiple Directions ATC and using one of the iterative ATC methods, the linear calculation of the impact of outaged generators and loads may not have been calculated correctly for the second and subsequent transfer directions studied. This has been fixed.
  • Oneline Diagrams: The addition of the new feature with the TextBox oneline object for loading AUX and AXD text in the October 29, 2024 patch caused a bug. The new feature broke another feature where a user could assign a ScriptCommand to oneline display object. This has been fixed.
  • Transient Stability: GENQEC Model was not checking the parameters correctly Tqop, Tqopp and Tdopp were big numbers (> 200) and they should be treated as zero because is a salient pole mode. Now those parameters are treated correctly and the impedances checks are done assuming it is a salient pole mode.
  • User Interface Dialogs: Moving a generator from one bus to another or changing the ID when using the generator dialog while in edit mode was not working correctly. Generators would not end up moved or data would be missing. This has been fixed.

November 11, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in parsing text in the Script command Scale(). Extra white space could cause the script to fail to run.
    This would work: Scale (Load, MW, ["CustomFloat:0","CustomFloat:1"], Zone);
    This would fail (note the space after the comma): Scale (Load, MW, ["CustomFloat:0", "CustomFloat:1"], Zone);
  • Bus View and Substation View Onelines: Breaker/Disconnect symbols were never added to a branch with BranchDeviceType = ZBR. In general this makes sense because the intent of a ZBR is to represent a branch that is never open. However, it is still possible in software to set Status=OPEN, so the BusView has been changed to always show a symbol if the ZBR branch is OPEN.
  • Optimal Power Flow (OPF): The OPF option for "Power Flow Recalculation = After each LP solution" was not being treated correctly in the code, and affected the solution sequence of an AC OPF/SCOPF solution, but had negligible or no impact on the final solution. This is corrected. This impacted both the OPF and SCOPF.
  • Security Constrained OPF (SCOPF) Tool: If an element happens to to be highly constrained during an SCOPF solution (i.e., many contingency violations), the actual number of violations for that element would exceed the value of the SCOPF option "Maximum Number of Contingency Violations Allow Per Element = N". This is not an issue, because the algorithm keeps track of the N worst violations, and keep repeating the SCOPF inner loop, provided new violations that are worse than the existing N violations are found. When the SCOPF outer loop iterations is set to a large number like 999, and the SCOPF yielded less severe than the existing N violations, the SCOPF outer loop would just keep going because it thought there were new violations being added. This would unnecessarily repeat the outer loop until 999. The fix here was to keep track of whether a new violation that is worse than the existing N was added, and only then continue the outer loop. This fix ensures quicker termination of the SCOPF solution, especially when there are several unenforceable violations, instead of giving the false impression that the SCOPF is trying hard to fix violations with many outer loop iterations.
  • Transient Stability: There was a bug in the transient stability models string grid in model explorer. The Custom Expression Strings were showing the wrong name in the column heading. The Column heading was showing the regular custom expression name. This bug was fixed.

November 6, 2024

Features and Improvements

  • Contingency Analysis Tool: Modified the loading of files when clicking the Load button on the Contingency Analysis dialog or from the Load Contingency Data under the RAS + CTG Case Info dropdown on the Tools Ribbon tab. Both of these provide access for opening various contingency-related files such as AUX files, PTI contingency (*.con ), PTI load throw over (*.thr ), GE contingency (*.otg), Areva RASMOM and Contingency (*.csv). Previously you could only open one file at a time by clicking on these options. This has been modified so you can now select multiple files in the Open Dialog and choose to open them all at once.
  • Transient Stability: If a transient contingency was set to change the parameters value "By" to be something different than the first selection it was change to the first selection of the event dialog was opened. This was only happening on Generators, VSDCLines and Injection Groups.

November 5, 2024

Features and Improvements

  • Case Information Displays: Changed the column header for a branch named "XF Auto" to instead be "Automatic Control". It was too easy to confuse this with auto-transformers which it is not related to.
  • Bug Fixes

    • Case Information Displays: When using Dynamic Formatting for any transient stability object and trying to highlight a particular field on a case information display, the dialog was not properly showing the list of available fields. This has been fixed.
    • Scheduled Actions: Fixed a bug in Scheduled Outage Action Revert operations where the Action Status was incorrectly set to INACTIVE rather than RESTORED
    • Transient Stability: Special Single Condition Filter Strings were not working when applied to transient stability objects. This has been fixed.
    • Transient Stability: When using the TSContingencyElement action to "Set Load 50 MW" or "Set Load 30%", PowerWorld would ignore the action if the load was presently not inservice. This mean that if at a time after the "Set Load" call had been made the Load was then Closed, the load would still come in at its full value. The Set Load commands are only changing an internal multiplier on the load, so it is reasonable to change this multiplier even when the load is not inservice, so the TSContingencyElement has been modified to not restrict "Set Load" commands to inservice loads.

October 30, 2024

Bug Fixes

  • Contingency Analysis: Fixed bug caused by recent bug fix of 10/17/24 that could occur when running contingencies that BOTH Open and Close(or Bypass) a branch at the same time. The angle smoothing was improved for this situation in general, however it introduced a bug if the opening of branches was completely islanding a portion of the system. The contingency analysis would report strange flow and voltage violations in the part of the system that was islanded.
  • Optimal Power Flow (OPF): This bug was introduced on 03/18/2024 while trying to fix another earlier bug introduced on 09/27/22. The current bug fix is for generators that have a negative MinMW value, and were available for dispatch during an OPF/SCOPF, and had a cost function that would allocate the MinMW as their output. These are renewable plants in the "charging mode", that are perfectly reasonable with a negative MW output with a monotonically increasing cost function. During OPF or SCOPF, these generators were erroneously being set to a value larger than the MinMW, i.e., charging lesser than their cost functions would actually allow them to. This was causing other generation to ramp down erroneously, and that severely affected the convergence of the OPF or SCOPF iterations. In addition to this issue being fixed, the earlier bug that was fixed on 03/18/2024 also remains fixed.
  • Security Constrained OPF (SCOPF) Tool: See OPF update for 10/30/24

October 29, 2024

Features and Improvements

  • Oneline Diagrams: Added ability to right-click on a "Memo Text" oneline display objects and flag the memo as "Enable Load Memo Text as AUX File" (or an AXD file). When it is flagged this way, then you may click on this memo and choose an option to "Load Memo Text as AUX File". This will then read the entire contents of the Memo Text as though it is an AUX or AXD file. It provides a clever way to embed an entire AUX file inside a oneline diagram which can then be shared with others.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Changed quick filter and advanced filter code to allow the user to right-click on a frozen column (not the first column with the record number) and have the Filtering dialog recognize that the user is choosing a frozen column to filter on, instead of the dialog defaulting to the first non-frozen column.
    • Auxiliary Files (SCRIPT and DATA Sections): Adding better error checking on Script commands for Weather and Time Step that involve datetime values.

October 25, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): The CTGWriteResultsAndOptions parameter for specifying all of the various options is supposed to allow defaults for all options, but if no options are specified at all, i.e. empty brackets, an access violation will occur. This has been fixed.
  • File Formats: The following option was not being saved with the PWB file, and is now stored correctly. "Simulator Options > Power Flow Solution > Advanced Options > Require Largest Island Solved for Successful Solution"
  • General: Fixed potential error in Finding Parallel AC branches routines when searching using zero-impedance branch groupings.
  • General: Fixed "argument out of range" error that could occur when solving the power flow after bypassing a series capacitor by changing the Bypass field.
  • Time Step Simulation: Modified scrips so ISO8601 datetimes return errors rather than default values. Added script to clear the TimeStep results and to set the save fields by object.

October 21, 2024

Features and Improvements

  • Model Explorer: It is possible on the Model Explorer to reduce the width of the Fields and Explore Pane to zero in chich case you can not see these panes. This is fine and a user may want to do that to create a screen shot without those panes for example. However when closing the Model Explorer and reopening it the Explore and Fields Pane will still be set to a size of zero which could be confusing to the user. To prevent confusing these will now be set to a minimum width of 20 so that when reopening the Model Explorer they can be seen.
  • Transient Stability: Added a new synchronous machine model GENQEJandC_Beta which is an experimental model which includes both a Kw and Kis term for compensation and saturation modeling. It is a combination of both GENQEC and GENQEJ_Beta.
  • Bug Fixes

    • Weather: Bug fix with WeatherPWWSetDirectory script command

October 18, 2024

Features and Improvements

  • Transient Stability: Added a new model named GENQEJ_Beta which has identical parameter list as GENQEC, except parameter Kw is named Kis instead. The model then implements the same structure as GENQEC but the term Kw is assumed to be 0.00. The saturation function is then modified so that the input to saturation function is (PsiAirGap + kis|Iterminal|)
  • User Interface Dialogs: When finding groups of parallel branches for the purpose of transformers tap regulation, branches that have both ends in the same ZBR group, are treated as a group of 1

October 17, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Several variablenames for Sim_Environment_Options used to specify auxiliary files to load when cases are opened were confusing. AutoLoadAUXAnyCaseNotUse and AutoLoadAUXAnyCase were used for files loaded with only the present case. AutoLoadAUXThisCaseUse and AutoLoadAUXThisCase were used for files loaded with any case. New variablenames have been added to clear up this confusion. AutoLoadAUXCaseNotUse and AutoLoadAUXCase are now used for aux files loaded with the present case, and AutoLoadAUXCasesAllUse and AutoLoadAUXCasesAll are used for an aux files loaded with any case. The old variablenames are still supported so that old auxiliary files will set the options that have always been set, but the new variablenames will be used for any new auxiliary files saved from Simulator.
  • Auxiliary Files (SCRIPT and DATA Sections): In the Sim_Environment_Options, the names of auxiliary files to load with the present case or any case can now be cleared out by loading an auxiliary files with these options having blank entries.
  • Available Transfer Capability (ATC) Tool: When changing the definition of TransferDirection objects, the multiple Directions ATC results are now deleted for modified directions
  • Contingency Analysis: When closing or bypassing a branch and then solving a power flow solution, special preprocessing Simulator calls angle smoothing is done to improve power flow convergence. This preprocessing was not working properly when closing or bypassing a branch and at the same time opening all branches in parallel with the branch being closed. This has been fixed so that the preprocessing works properly and power flow solution convergence is achieved.
  • File Formats: Fixed an access violation error that could occur under very specific conditions after opening a PWB file that had been saved using Integrated Topology Processing's Save Consolidated Case feature. There needed to be
    1. Two Switched Shunt objects labels as an SVC that were at different buses
    2. These two buses needed to become consolidated as part of integrated topology processing into the same bus as each other
    3. Then the case needed to be saved as a Consolidated case.
    Under these situations the resulting PWB would have a problem in it which may not be noticed until the user closed the PWB file after opening it again. This would cause an access violation.
  • Power Flow Solution: When closing or bypassing a branch and then solving a power flow solution, special preprocessing Simulator calls angle smoothing is done to improve power flow convergence. This preprocessing was not working properly when closing or bypassing a branch and at the same time opening all branches in parallel with the branch being closed. This has been fixed so that the preprocessing works properly and power flow solution convergence is achieved.
  • Transient Stability: Fixed a bug with Measurement Objects in transient Stability. There was an access violation if the object that was measured is removed/deleted from the case. Now, no access violation will result.

October 10, 2024

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added bus field ATC Min Trans MW to provide a field for creating heatmap contours for multiple direction ATC with buses as the source.
  • Available Transfer Capability (ATC) Tool: Made improvements to make the gathering of results faster for distributed ATC.
  • Available Transfer Capability (ATC) Tool: When using the Options for Heatmap from FERC Order 2023 option with ATC, now allow the Max Limiters Per Element to be specified and allow the reporting of Base Case Limitations.
  • Bug Fixes

    • File Formats: Fixed potential error in reading Transient Stability Measurement objects from a PWB file.

October 4, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): There is a new optional parameter at the end of the Move() script command called AbortOnError. It will default to YES in which case if the Move command can not be done the auxiliary script will be aborted. By setting it to NO you can tell the script keep running even if an error occurs.
  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command was added to perform this calculation FindRadialBusPaths(IgnoreStatus, TreatParallelAsNotRadial, BusOrSuperBus);
    IgnoreStatus = YES or NO
    TreatParallelAsNotRadial = YES or NO
    BusOrSuperBus = Bus or SuperBus
    The result of this calculation is then viewed as fields for a Bus or Branch object under
    1. Neighbors\Radial Path\End Number = returns the bus number at the end of the radial path if the bus or branch belongs to such a path.
    2. Neighbors\Radial Path\Index = returns the index within the path for the bus or branch. An index of 1 is assigned to the final radial bus and connected branch. Indexes increase by 1 when moving away from this final bus.
    3. Neighbors\Radial Path\Length = returns the total number of buses in the series bus path to which the bus or branch belongs.
    All these fields show a blank if the bus or branch does no belong to a radial path.
  • Case Information Displays: Modified the Area field for "SuperArea" so that editing the field to a blank value will remove the area from its SuperArea.
  • Difference Case Tool: When using the "Save To" feature while using the topological differences tool, the caption has been changed to display "Only Changed Elements", instead of "Only Both Elements".
  • Difference Case Tool: When using the "Save To" feature while using the topological differences tool, comments will be added at the top of the AUX file that is produced. These comments contain the executable build date, date on which the file was create, a text description of removed/new/changed elements that are included (or not included), the present case file name, and the base case file name.
  • General: Added a new feature under the Tools, Connections drop down in the Ribbon for "Find Radial Bus Paths". This opens a dialog for calculating all the series paths of buses in the case. There are 3 options for this path calculation.
    1. Traverse Open Branches (Ignore Status) when searching
    2. Treat Parallel Branches as Not Radial when searching
    3. Search by Bus or SuperBus.
    The result of this calculation is then viewed as fields for a Bus or Branch object under
    1. Neighbors\Radial Path\End Number = returns the bus number at the end of the radial path if the bus or branch belongs to such a path.
    2. Neighbors\Radial Path\Index = returns the index within the path for the bus or branch. An index of 1 is assigned to the final radial bus and connected branch. Indexes increase by 1 when moving away from this final bus.
    3. Neighbors\Radial Path\Length = returns the total number of buses in the series bus path to which the bus or branch belongs.
    All these fields show a blank if the bus or branch does no belong to a radial path.
  • Bug Fixes

    • Case Information Displays: There are several fields for series capacitors that identify if the series capacitor is bypassed or not. When the bypass status is changed the ybus needs to be updated to reflect this. This was not always being done resulting in a bad power flow solution. This problem has been fixed.
    • Difference Case Tool: When the Topological Difference Case window was open, and either "Set Present As Base" Or "Clear Base" were used, there would be some items that did not refresh correctly, and some access violations. These have been fixed.
    • Transient Stability: In Transient Stability RAS, there was a bug when setting the Switched Shunt Specific Element Type to a Bus. this was causing an access violation. the reason is that the Specific Element Type should always be set to "Specific Device". When is set to a Bus it should say it is an "Invalid Action" and also show a comment explaining why. This bug has been fixed.

September 26, 2024

Features and Improvements

  • Oneline Diagrams: Added new shape option on a generator oneline object to represent a hydrokinetic generator.
  • Bug Fixes

    • Security Constrained OPF (SCOPF) Tool: Contingency Violations reported based on the CHANGE relative to base case were erroneously being considered in the SCOPF routine. These type of violations are no longer included as a constraint in t he SCOPF routine. This bug would have been observed if reporting based on the change was enabled in Contingency Analysis > Options > Limit Monitoring > Advanced Limit Monitoring. In some situations the SCOPF would converge very slowly to a reasonable dispatch, if sufficiently large number of iterations were allowed. Otherwise, consecutive SCOPF solutions, each with a single iteration, would result in an oscillating dispatch.

September 24, 2024

Features and Improvements

  • Oneline Diagrams: Added new shape option on a generator oneline object to represent a battery storage device.
  • Bug Fixes

    • Oneline Diagrams: Fixed a bug with the Show Objects That Are Not In Oneline dialog where Series Caps were not properly filtered.

September 11, 2024

Features and Improvements

  • Case Information Displays: Added secondary filter support for LineShunt objects.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug with scripts if the initial case did not load; also when loading a case in a script with an open TSB there is no longer a prompt
    • File Formats: When saving to a PWB file, custom fields for the PWCaseInformation object type were not being stored. This has been fixed.
    • File Formats: Modified reading of RAW to catch a premature end of file in a location that did not respect the format of the RAW file. In some parts of the RAW file load processing, previously this would cause the code to get stuck in a loop and hang. It now should exit the loop, and return message to the log indicating that the RAW file is incomplete.
    • GIC: Fixed bugs with GIC analysis with the non-uniform fields when the time series is rebuilt not using the start time.
    • Oneline Diagrams: When autoinserting circuit breakers on oneline diagrams made sure that any switching device (BranchDeviceType = Breaker, Disconnect, etc.) will have only one symbol added

August 27, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): The following GIC related script commands have been added:
    GICReadFilePSLF("FileName");
    GICReadFilePTI("FileName");
    GICWriteFilePSLF("FileName", UseFilters);
    GICWriteFilePTI("FileName", UseFilters, Version);
  • GIC: The following GIC related script commands have been added:
    GICReadFilePSLF("FileName");
    GICReadFilePTI("FileName");
    GICWriteFilePSLF("FileName", UseFilters);
    GICWriteFilePTI("FileName", UseFilters, Version);

August 22, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug when ready the fields ControlType and IsXF for a branch in an AUX file. The bug was related to using an AUX file to change the IsXF field to NO for the purpose of converting a transformer to a branch.
  • Contingency Analysis: It was possible for contingency analysis to return that reserve limits had been hit when in fact they hadn't. This has been fixed.
  • Oneline Diagrams: Updated contour data symbols to work with all contour types, not just spatial data. Also, the spatial data layout has been improved.
  • Sensitivity Calculations: Fixed bug that could result in incorrect shift factor calculations when accounting for injections at buses that contain generators or loads that are part of outages in the interface and there were line outages also modeled as part of the interface.

August 15, 2024

Features and Improvements

  • Transient Stability: Modified the PlayInGen stability model to respond to the TSContingencyElement action for changing or setting the "rotor angle" of a generator so that it sets/changes the internal phase angle state of the PlayInGen. This can be used to simulate an instantaneous phase angle change in the system as described in NERC PRC-029-1
  • Bug Fixes

    • Transient Stability: Fixed a bug in where the Relay States and Other fields names were not matching the results in transient stability. When a branch has more than one relay the results shown were from the last relay loaded to the case but the field name shown in the plots and results where from the first relay loaded and available in the branch. Now the States and Other field names will match the results of the FIRST INDIVIDUAL relay loaded into the case.

August 12, 2024

Features and Improvements

  • Transient Stability: added more description to Accel factor for GENTPF, GENTPJ, and GENQEC models to indicate the field is not used by PowerWorld Simulator.
  • Bug Fixes

    • Oneline Diagrams: When copying and pasting oneline diagrams including the underlying model records, there were access violations during the paste step, and the software would need to be restarted. This bug is now fixed.
    • Transient Stability: The Auto-Save an Image of a plot during transient stability had an bug when the PNG file format was selected and the plot was loaded from an aux file. Instead of the PNG file format, the PDF format was selected in the plot. This bug has been fixed.
    • Transient Stability: I fixed a bug with the loading of the PLNTBU1 and REAX3BU1 and REAX4BU1 model from a dyr file. For example, the bug is that if the plant controller bus is at bus 1 but the REAX models are at bus 2 and 3 but are referencing to the plant controller at bus 1 it was not loading. This is a possible configuration and we write this configuration correctly in a dyr file but we can't read it. This bug was fixed and now it will be read correctly.

August 6, 2024

Features and Improvements

  • Contingency Analysis Tool: Modified the field description for the Contingency field Solved to include references to the ABORTED, RESERVE_LIMITS, and PARTIAL possibilities
  • Bug Fixes

    • Contingency Analysis: There was an access violation that could occur when deleting a contingency record if there was a contingency combination violation associated with the contingency. This has been fixed.
    • Contingency Analysis: After aborting the ctg combo analysis. The status string would briefly say 'Aborted'. However, it would change to 'Finished' after a couple of seconds. I have updated the code so that the status is not changed to ctgsetstFinished at the end of CTGComboDoAnalysis. The form is refreshed perodicly by windows messages, so changing the status to ctgsetstFinished resulted in the text changing the next time the form was refreshed.
    • General: When communication with a hardware key is lost, we now check for a restored connection every 30 seconds during the 15 minute window before program termination. If they key is reconnected during that time, the program can continue to run uninterrupted.
    • Transient Stability: Fixed a bug when reading exciter models AC7C, AC8C, AC9C and DC4C from a dyr file. It was expecting an extra parameter that is not use in PSSE. Now the dyr is read and written out correctly from PowerWorld.
    • User Interface Dialogs: In the General File Browser the column metrics were not working when there was no case open yet.

July 29, 2024

Bug Fixes

  • Contingency Analysis: After aborting a contingency analysis run, the user may choose to restart the run by clicking 'Start Run'. Doing this will prompt the user about whether to restart the run entirely or start from the last solved contingency, keeping the results already in memory. If a user closed this dialog without making a selection, then the contingency analysis would proceed with default options. This has been fixed so that closing the dialog via the 'x' will cancel the operation and the contingency analysis will not proceed. There are two dialogs affected by this change. One is shown when there are no 'SKIP=YES' contingencies. The other is shown when there are no skipped contingencies. They differ in the option to clear results for only 'SKIP=NO' records.
  • Contingency Analysis: Added ability to handle a cancel on the 'Control Contingency Combination Run' dialog that is shown if a primary contingency is flagged as SKIP=YES. The dialog allows the user to choose if all results are cleared or only the results for SKIP == NO records. If the user clicks the windows close "x", then nothing will happen -- the run is not started. Previously, the run would start with default options.

July 25, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): In the script command LoadAuxDirectory("c:\temp", , YES); the second parameter is a filter on the filenames to load. If the parameter is included but left as a blank entry, the Simulator was not loading any files. We have modifying so if that second parameter is included but left as an empty string then we automatically assume it means any file instead.
  • Auxiliary Files (SCRIPT and DATA Sections): Adding new option for OpenOneline script command. The fullscreen parameter can now have 3 values (yes, no, and max). When max is used the oneline is maximized after opening
  • Oneline Diagrams: Adding new option for OpenOneline script command. The fullscreen parameter can now have 3 values (yes, no, and max). When max is used the oneline is maximized after opening
  • Bug Fixes

    • GIC: GIC changes associated with merging large duplicate b3d files to avoid stack overflow.

July 23, 2024

Features and Improvements

  • Difference Case Tool: Added OPFFastStart field for a generator to be part of the Difference Case Tool
  • File Formats: Added the use of the RAW file option to keep duplicates with new ID's to the Loads section of reading the RAW file.
  • Bug Fixes

    • File Formats: Updated a few of the transformer configuration interpretations in the section for reading sequence data transformers.
    • Weather: Filtering wasn't working on the general file browser form when there was no case presently open
    • Weather: On Contour dialog the contour wasn't being updated on Make Contour if a custom colormap had been changed and saved.
    • Weather: Fixed bug on SuperArea display in which the total online generation field was showing the total for all the generators
    • Weather: Fixed a bug where converting a branch to a transformer would not display the transformer configuration and sequence data fields unless the dialog was closed and reopened. Additionally fixed some of the logic related to when certain sequence data fields were enabled or disabled depending on the sequence configuration selected.

July 12, 2024

Features and Improvements

  • Power Flow Solution: Modified the Generator Mvar Limit checking algorithm when (NOT using Check Immediately) AND (Using Check Backoff Immediately). For very low generator terminal voltages are see we will still force minimum Mvar limits to be checked and for very high terminal voltage we will force maximum Mvar limits to be checked.
  • Transient Stability: Added more descriptive information for transient events related to tripping of portions of the composite model induction model. The message will now make clear why the motor is tripping. The percentage and MW tripped will still show up as before.
  • Transient Stability: Added the ability on the relay model DIFFRLYS to use the parameters Fb, Sb and Ckt1. These parameters will only be used if the parameter Monitor is set to 2. Then it will look for the branch defined as Branch Fb-Sb Ckt1 and IF that branch is faulted it will open the branches defined in branch 1 - 8. If the parameters Fb, Sb and Ckt1 does not defined a branch in the case it will set the defined branch as the relay branch. If Monitor is set to 0 or 1 it will behave as before and will ignore the parameters Fb, Sb, Ckt1, Ckt2, Ckt3, Tb and TTb.
  • User Interface Dialogs: When setting up dynamically formatting for Contingency objects in the case information display, made it easier to choose a list of specific commonly used fields.
  • Bug Fixes

    • Transient Stability: Fixed a bug with measurement objects. If the object was not set to measure any object and the case was saved, it was creating an access violation. This issue was solved.

July 8, 2024

Bug Fixes

  • File Formats: When writing out a RAW file if a bus had only disconnected generators we were writing the bus as a IDE = 1 instead of a 2. This didn't impact the solution in programs reading a RAW file, but was not the intended behavior. They will now be written as a 2 instead.
  • Oneline Diagrams: Fixed bug with auto inserting lines, generators, loads and shunts; the code was not correctly enforcing the minimum nom kv voltage value, with some lower values being inserted.
  • User Interface Dialogs: Fixed an issue that could result in 0 values or random characters appearing within numerical edit boxes with up/down arrows anchored to them.

July 1, 2024

Bug Fixes

  • File Formats: Modified writing out RAW files with full-topology representation of substations to ensure IDs for switching devices are not changed.
  • GIC: For writing of transformer records to a RAW file + GIC file pair, the transformer data records will now match with the same key fields. Prior to this, a group of three 2-winding transformers connected topologically as a 3-winding transformer (but not explicitly defined as a 3-winding transformer), would have been written out as a 3-winding transformer in the GIC file, and written as separate 2-winding transformers in the RAW file. For such situations, both RAW and GIC files will now have the same the same key fields for the separate 2-winding transformers that are written out. In addition to writing out the GIC file differently, is now more robust to allow both 2-winding and 3-winding transformer records from a GIC file to be read regardless of whether it belongs to an underlying group of three 2-winding transformers or one 3-winding transformer.
  • Time Step Simulation: Improved Time Step Simulation for doing GIC calculations.
  • Transient Stability: Fixed a bug in which the Load Tripped and Load Model Tripped and Load Relay Tripped values shown wrong values in the Summary results section in the Simulation tab in transient stability. The simulation was running fine but those values were showing in correct results. Now those values match the MW Nominal Tripped values of the loads. If you add up all the field values of the MW Nominal Tripped values at the last time step and compare it with the total load tripped in the Summary results section, the results will be the same.

June 25, 2024

Features and Improvements

  • Simulator Automation Server (SimAuto): Modified the GetParametersMultipleElement type SimAuto functions so that when in DiffCaseMode = Change, we will only return objects that have input parameters which have at least one non-key field that has changed.
  • Bug Fixes

    • Case Information Displays: Fixed access violation on the list of Area or Zone Tielines when showing a Switched Shunt dialog.
    • Contingency Analysis: Update the CTG Combo Analysis form when an auxiliary file is loaded from anywhere.
    • Oneline Diagrams: Pie charts that represent values of almost exactly 100% could end up unfilled. This patch fixes the problem.
    • Transient Stability: The SCL input flag was missing from the input parameters of exciter model ST2C, ST3C, ST5C and ST7C, and the SCL signal input was not implemented for the simulation. The SCL input parameter has now been added, along with using the SCL signal during the simulation. Autocorrection for SCL + Exciter compatibility is also supported.
    • Transient Stability: Added support for modification of OEL/UEL/SCL limits during initial limit violations for exciter models ESST2A, ESST3A, ST2C, ST3C, ST7C, ST7B and ESST7B.
    • Transient Stability: Bug fix for stator current limiter SCL2C initialization. The non windup limits on both PID blocks and all four lead lag blocks were not being enforced.
    • Transient Stability: Added support for modification of OEL/UEL/SCL limits during initial limit violations for exciter models ST8C, ST9C, ST10C, ESAC1A, ESAC2A, ESAC3A, ESAC4A, ESAC5A, AC1C, AC2C, AC3C, AC4C, AC5C, AC6C, AC7C, AC8C, AC9C, AC10C, AC11C
    • Transient Stability: Improvement to the modification of SCL model limits during initial limit violation when paired with exciter ST9C with SCL input at position 2, where it expects the idle VSCLUEL signal to be zero, and the idle VSCOEL signal to be a large positive value. This is different from other models where the SCL signals are received by HV/LV gates at the same location.
    • Weather: Improving loading METAR data when loading new weather stations.

June 17, 2024

Features and Improvements

  • Power Flow Solution: Improved how bus voltages are estimated when particular types of topology changes are made. In particular, when deleting objects that affect topology (Bus, Branch, Gen, and Load), it was important to update the connected bus topology so that buses that are then in disconnected islands are marked as such. Then if new branches are added to reconnect these buses, the reconnected buses need new voltages estimates based on the new connections before a power flow solution is attempted. This greatly improved power flow performance under these situations
  • User Interface Dialogs: When showing a transient stability plot, if the there were already plots open and the form that contained the plots was minimized then the newly created plot would be added to the minimized form and it was difficult for the user to realize the plot had been generated. Now when generating a plot we force the existing form showing plots to become un-minimized to you can see the plot immediately.
  • Bug Fixes

    • Transient Stability: The SCL input flag was missing from the input parameters of exciter model ST5C and ST6C, and the SCL signal input was not implemented for the simulation. ST6C_PTI was implemented correctly. The SCL input parameter has now been added, along with using the SCL signal during the simulation. Autocorrection for SCL + Exciter compatibility, and modification of SCL limits during initial limit violations is now supported for exciter models ST5C, ST6C and ST6C_PTI.
    • Transient Stability: When writing REPC_A, REPC_B or REPC_C generator plant controller models, PowerWorld Simulator will not write the Voltage Measurement bus to the header of the DYD file even if the voltage measurement is the same as the terminal bus. Previously it was writing ! ! ! instead.

June 10, 2024

Features and Improvements

  • File Formats: Added new bus field RAWNodeBusNum. When reading a RAW file containing nodes defined in Substation data sections, this is the bus number as defined in the Bus data section associated with the node. For files with no node data defined, this is the same as the bus number. This is informational only.
  • File Formats: When reading RAW files version 34 or greater, update switched shunt continuous voltage control limits after substation data has been read. The node and switching data with substations might impact the switched shunt voltage control groups, but even if they don't the bus numbers will most likely have changed due to the node data. The bus numbers in the log should match the numbers in the case.
  • File Formats: Improved writing out RAW files containing full topology information for substations when some of the RAW file bus groupings have a mix of connected and disconnected PSS/E nodes.
  • File Formats: When writing a RAW file that includes substation data with nodes, write out node voltages if necessary. This will be done for buses that were created by traversing open switching devices. Node voltages are only written to RAW 35 and later.
  • Time Step Simulation: For Power Flow Weather wind models there is now a field to scale the used wind speed; this accounts for variation between the wind farm location and the measurement location.
  • Bug Fixes

    • File Formats: There was a bug introduced with the 6/4/24 patch that would cause a Version 23 PWB files not to load. It was possible that Simulator would just hang with no error produced. This has been fixed. This did not impact loading older PWB files. Also the PWB files did not have a problem and were proper files. After downloading this patch you will be able to load those files.

June 6, 2024

Features and Improvements

  • Case Information Displays: When adding new columns to a Case Information Display from Fields Pane or the Display/Column Options dialog, we now have internal defaults for the decimal places to show for some fields. In the past the Fields Pane would always add field with 3 decimals and the dialog would always add decimals based on the presently selected column in the dialog. It will now always use 3 decimal places unless there is a hard-coded different number specified by PowerWorld staff. For now this hard-coded list is small and consists of
    Latitude, Longitude, and Per Unit volt field: 6 decimals
    Various MW, Mvar, and MVA fields: 2 decimals.
    This is cosmetic as it only impacts the default value when adding fields in the user interface. The user can and always has been able to customize them. This was primarily done to ensure the Latitude/Longitude fields always had 6 decimals by default as the prior default of 3 decimals was not precise enough.
  • Bug Fixes

    • File Formats: Fixed bug in reading back in TSB files saved starting with the June 4, 2024 patch.
    • Sensitivity Calculations: Fixed potential access violation when doing multiple-direction PTDF calculations.
    • Transient Stability: Fixed a bug when writing the REGC_B model to a PSSE DYR file. When the REGC_B model is referencing a generator with no active machine models it was creating an access violation. That issue is now fixed.

June 5, 2024

Features and Improvements

  • Case Information Displays: Added field for Bus, Area, Zone, and Substation for showing MWRangePercent field
  • Bug Fixes

    • Transient Stability: The SCL input flag was missing from the input parameters of exciter model ST1C, and the SCL signal input was not implemented for the simulation. The SCL input parameter has now been added, along with using the SCL signal during the simulation. Also supported are t autocorrection for SCL + Exciter compatibility, and modification of SCL limits during initial limit violations.

June 4, 2024

Features and Improvements

  • Case Information Displays: Added a generator MW range percentage used (MWRangePercent). This calculates the percentage of the entire range, namely: MWRangePercent = (MW - MinMW) / (MaxMW - MinMW)
    This ensures that negative MinMW values actually expand the range instead of being ignored like with the traditional MWPercent field.
  • Oneline Diagrams: Added the ability to select an angle from which pie chart/gauge styles start filling pie charts and the direction in which they fill.
  • Time Step Simulation: In the Time Step Simulation tsb files can be saved and loaded if they have custom save fields defined even with no time points. This was added to allow a tsb file to be defined for a case and then used to load potentially many pww files. There is also now a tsb option that specifieds whether custom result fields are cleared on a pww file load; the default is to not clear them. Another new option indicates the default solution type when loading pww files; the default is Apply Only (with Weather Update).
  • Transient Stability: For exciter model IEEET2, VE is now available as a signal in the "Exciter Other" folder in transient stability plot designer.
  • Transient Stability: Added parameters ImovTup and IcapTup to the SCMOV model to provide a definite time pickup timer to the Imovlim and Icaplim pickup levels. These were added to help avoid having hte model respond to numerical simulation spikes in current that last only one timestep. Ideally these timer will be set very low, but non-zero.
  • Bug Fixes

    • File Formats: When loading in substation data in a RAW file, node voltages and angles might be specified. We had been ignoring these values, but not they are applied. This seems to help greatly with the power flow solution.

May 30, 2024

Bug Fixes

  • Contingency Analysis: When using Contingency Sensitivity Analysis on a contingency violation and choosing to calculate LODF/LCDF values for Breakers or other switching devices in a full-topology case, an access violation could occur if switching devices included in the calculation were in parallel to other switching devices not included in the calculation. This has been fixed.

May 28, 2024

Bug Fixes

  • Contingency Analysis: When including the treatment of Transient models for steady state contingency analysis, all the lists on the Result tab of the contingency dialog were omitted violations of generator or shunt models. Branch models appeared correctly. Also, on the Contingencies tab, the list of violations for one particular contingency was correct. This has all been fixed.
  • File Formats: When reading RAW files that contain transformer vector groups, Simulator will now read these columns and show them in branch records. When saving to the RAW file these are written out. Previously this information was not being maintained.
  • QV Curve Tool: Fixed QV bug that would delete the QV Tracked Quantities for all but the last scenario studied.

May 23, 2024

Bug Fixes

  • Contingency Analysis: Bug fix for contingency AC Method Options
  • QV Curve Tool: When loading a QVCurve object, the QVPoints were not being cleared correctly before loading the SUBDATA section with new points. All points should be deleted before loading the SUBDATA, but points were being appended instead. This has been fixed.
  • Transient Stability: Some initial limit violations were not being reported in the State Limit Violations tables. This has been fixed. The examples were various exciters for which Vb > Vbmax at the initial condition.
  • Transient Stability: When load was being tripped by dedicated load relays such as lsdt9, the Total Nominal MW tripped field for the loads in transient stability was giving the wrong result. It was working properly for load model tripping such as the composite load models (CMPLDW and CMLD), but when missing that load tripping with the relay tripping the result was incorrect. That was corrected.
  • User Interface Dialogs: When using Interface feature to "Modify Definition due to Isolated Elements on Selected Interfaces" it was possible for the tool to choose to choose to isolate all loads and gens in the main island. This was rare but could occur and has been fixed.

May 7, 2024

Features and Improvements

  • Case Information Displays: Changed the MouseWheel up and down behavior on Case Information Displays to better match what is done in spreadsheet software tools.
    If CTRL key is down we will zoom in and out (same as CTRL + Up/Down arrow keys)
    If SHIFT key is donw we will move the selected cell up/down (this was the old default)
    Otherwise we will scroll the viewed window up or down by 1 row.
  • Case Information Displays: Case Information Column Metrics Histograms now support Show Dialog to show the elements in a histogram bin. Also, string objects are also now supported as well.
  • Case Information Displays: When using the local pop up menu to Copy/Send to Clipboard or Spreadsheet (MS Excel, Open Office), there is now an option to always include the key field column, even if it is not currently being displayed as part of the case information display. This option is stored with the registry, and not stored with the PWB case.
  • Sensitivity Calculations: On the Shift Factors dialog, modified the Disconnected Device Options to use checkboxes for Close Breaker and Close Load Branch Disconnect instead of a dropdown. This changes functionality slightly in that you can choose Load Break Disconnects to use for connecting devices independently of Breakers.
  • Transient Stability: Added a new parameter Vpllfrz to the REGFM_B1 model. When the terminal voltage falls below this threshold then the PLL dynamics are modified to result in a frozen PLL repsonse.
  • Bug Fixes

    • Contingency Analysis: When running Contingency Analysis (non-distributed), the Summary section will now display the start time at the beginning of the run, and keep updating # processed, # unsolvable and # violations while running. Previously, all these values were only being updated after the entire run was completed.
    • Sensitivity Calculations: Fixed access violation that could occur when using the LODF tool to calculate Closure Sensitivities and attempting to close a line using breakers or load break disconnects and the line cannot be connected.
    • Transient Stability: Removed all maximum validation checks on all Tqop, Tqopp, and Tdopp parameters for all synchronous machine models. There was code to prevent very large values (> 20 seconds) from being set on these machines, but there are parameter configurations (such as Xqp = Xq) which result in time constants not being used because the states are ignore, such as when modeling a salient pole synchronous machine with only one damper winding on the q-axis. Simulator was checking for large values of Tqop when it was not useful to do so.

April 25, 2024

Bug Fixes

  • Transient Stability: Modified SCMOV model so that the EnergyMOV calculation is more accurate when the branch resistance in the power flow model for the capacitor branch has a non-zero resistance value. This is not typically the case, but if Rbranch <> 0 then EnergyMOV will be more accurate now.
  • Transient Stability: Fixed a bug in the REGFM_B1 model with the non-windup limit on the DeltaIT state when the non-windup DeltaITMax limit was active at the same time as the DeltaIT limit.

April 24, 2024

Features and Improvements

  • Sensitivity Calculations: Added fields with the TLR_Options object to specify whether Breakers and Load Break Disconnects should be used to close disconnected buses that contain generators or loads so that shift factors can be calculated at these devices. These options were only available on the user interface dialog, but can now be changed using script commands and AUX files too.
  • Bug Fixes

    • Transient Stability: In transient stability when an island was dead in the power flow solution base case because it didn't had an online generator, the island was not properly marked as dead during the initialization in transient stability. When the simulation began the island was immediately changed to a dead island and a transient result message would be added at the simulation start time saying that the number of islands was being reduced because the island was now dead, even though it should have already been dead. This was not impacting anything, but the result messages were confusing. This patch ensures these confusing messages do not appear.

April 19, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added CTGConvertToPrimaryCTG(filter, KeepOriginal, "Prefix", "Suffix") script command that converts regular/secondary contingencies to primary contingencies. All parameters are optional. Filter has all of the standard filter options and if not specified all contingencies will be converted. KeepOriginal is YES by default. If set to NO the original contingencies will be deleted after the conversion. The name of the new contingency will be "Prefix" + originalCTGname + "suffix". "Prefix" is blank by default. "Suffix" is "-Primary" by default.
  • Case Information Displays: Both v24 and v23 now support a field that shows whether the time zone offset is based on daylight savings time. This field is strictly for display purposes since the date/time is unique determined by the UTC time plus the timezone offset. The purpose of the new field is to display the timezone. For example for -5 it is either EST or CDT; this field indicates which one.
  • Contingency Analysis Tool: Changed a caption on the dialog that is used with the "Insert Special > Convert into Primary Contingencies" option found on the Contingencies tab of the Contingency Analysis dialog. The conversion options allow using the mouse to select contingencies to convert or converting all contingencies that are currently displayed in the case info due to filtering.
  • Oneline Diagrams: Added oneline option to scale the size of all the gen/load/shunt object Circuit Breakers symbols.
  • Transient Stability: Made change to REGFM_B1 to always report DeltaITmin = 0 when ESFlag = 0. Previous we were always using a 0, but it was still reporting a negative angle.
  • Bug Fixes

    • Case Information Displays: Fixed column header and variable name for Rem Regs (SVC) in the Bus and Remotely Regulated Buses case information displays.
    • GIC: Fixed memory leak that occurred when running GIC analysis.
    • Power Flow Solution: Fixed some oscillation issues with parallel transformers. After balancing taps for parallel transformers, it was possible for a single transformer to move due to being outside of limits without the other transformers parallel to it moving, This would cause the balancing to occur again and end up oscillating the same process over and over.
    • Transient Stability: Fixed an access violation when reading a Transient Limit Monitor that is referencing a Filter that is not yet created in the case.

April 4, 2024

Features and Improvements

  • File Formats: Modified reading *.otg and *.otgd files so that delimiters between fields can be either a comma OR white space (spaces, tabs, etc...). Newer OTGD files are space delimited and older ones were a mix of both spaces and commas. Changes were made to Simulator in 2023 to support reading the newer OTGD format, but older OTGD files must be read as well. This change was made to allow any of these to function.
  • User Interface Dialogs: Modified generator dialogs so that cubic cost function can not be entered which are non-convex functions between the MWMin and MWMax range of the generator. If specified that way the cost model will be changed to None and the cost function ignored for this generator.

April 2, 2024

Features and Improvements

  • Contingency Analysis Tool: Added ability to show more fields with LimitViol and ViolationCTG (All Violation) objects. New fields were numbers of Areas, Zones, BA, and Substation.
  • Oneline Diagrams: Added support for images now having a fixed aspect ratio. When this option is true, when they are resized by the diagonal handles the width and height change proportionally. The image dialog also now shows the rotation angle.
  • Transient Stability: Added and Over-frequency and Over-voltage relay similar to the under-frequency and under-voltage relay TLIN1. The name of the relay is TLIN1O.
  • User Interface Dialogs: Updated super area dialog so it now has pages to show the buses, generators, loads, switched shunts and tie lines for the super area. Currently these pages are not updated when new areas are added, requiring that the dialog be closed and reopened if the updated pages are desired.
  • Bug Fixes

    • File Formats: When saving out RAW file version 34 and greater and including substations, the node names within a substation's node data section are now unique.
    • Oneline Diagrams: CaseInfoMemo fields can now show the likely timezone abbreviation for a time field. This is just based on the timezone hour offset and whether daylight savings time is active for the date. Since there are exceptions (like Arizona not doing daylight savings time), it isn't perfect but it should be quite good.
    • Optimal Power Flow (OPF): In OPF added checks to not include generators as controls if they have a cubic cost function with a decreasing incremental cost. Note, these generators can still be changed during the initial part of the OPF solution since it does an initial participation dispatch of the generators.
    • Power Flow Solution: Modified economic dispatch to not use generators with decreasing incremental cost curves.

March 21, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command TSJoinActiveCTGs(TimeDelay,DeleteExisting,JoinWithSelf,FileName,FirstCtg);
    The parameters are as follows
    TimeDelay : Time in seconds
    DeleteExisting: YES or NO and determines if the existing TSContingency objects are deleted
    JoinWithSelf: Set to YES and the existing list will be joined with itself
    FileName: Optional parameter which needs to be specified if JoinWithSelf = NO. Specifies an AUX file that contains a list of TSContingency and TSContingencyElement objects which define a second list of TSContingency
    FirstCtg: Optional parameter which is assumed as Both if not specified.

    If FirstCTG=Active, then each existing active TSContingency object
    is joined with the Contingencies in the AUX file specified by Filename.
    All TSContingencyElement objects in the AUX file are shifted by the TimeDelay value.

    If FirstCTG=AUX, then the TSContingency objects in the AUX file have the same timing
    and they are joined with the existing Active TSContingency objects with the existing elements
    time shifted by the time delay.

    If FirstCTG=Both, then you get both options of list (A + BTimeDelay) and (B + ATimeDelay).
  • File Formats: Made some additional changes to writing out RAW version 34 and later with full topology substation information.
  • Transient Stability: Added new right-click option on the TSContingency Case Information Display to "Join Active Contingencies". This allows you to join two lists of TSContingency objects with a specified time delay in seconds. The options on the dialog that appears when choose this are the same as those for the new Script command TSJoinActiveCTGs(TimeDelay,DeleteExisting,JoinWithSelf,FileName,FirstCtg);
  • Transient Stability: Added ability to read/write the HYG3 governor model from the DYR format.

March 20, 2024

Features and Improvements

  • Case Information Displays: Added Gen fields to show the incremental cost at the min and max MW values
  • Bug Fixes

    • Oneline Diagrams: The patch on March 4 caused the area or zone fields on onelines that showed the MW or Mvar total for the entire case for either Gen, Load or Shunts to always show blanks. This has been fixed.
    • Simulator Automation Server (SimAuto): Fixed a bug where SimAuto calls to SaveCase resulted in a COM error if the case could not be written; now returns a SimAuto error message instead.

March 19, 2024

Bug Fixes

  • General: When tapping a transmission line and choosing the option to "Use Line Shunts", if existing line shunts were on the transmission line, then the shunt values were not set correctly. This has been fixed.
  • Oneline Diagrams: The patch on March 4 caused Zone fields that show MW or Mvar flow to another zone to always show as blanks. This has been fixed.
  • Power Flow Solution: If there are multiple generators at the system slack bus and not all have AGC = YES, it was possible that the slack generators could end up with very different MW dispatches with one or more with negative MW outputs. This could occur when using Island-Based Dispatch with all generators on AGC with non-zero participation factors participating and all generators hitting MW limits. This has been fixed.

March 18, 2024

Features and Improvements

  • Time Step Simulation: Changed Solar PFW model to include a parameter for the Inverter Loading Ratio. Also, reduced the assumed optical depth in the irradiation calcuation, which causes more irradiation when the sun is lower in the sky.
  • User Interface Dialogs: On the Transformer Parameters dialog the ESC key will now close the dialog without saving changes.
  • Bug Fixes

    • Distributed Computation: Fixed error in showing Custom Expression results which do not have a valid expression string specified. An access violation could occur. This was noticed due to an access violation occurring in the distributed Transient Stability simulations.
    • Optimal Power Flow (OPF): During an OPF or SCOPF solution (either AC or DC method), fast start generators (commitment and/or decommitment) were not being dispatched correctly when the MinMW of these generators is more than zero. This bug was inadvertently introduced on 9/27/22. Possibly affected users would be those with OPF and SCOPF cases with fast start generators like these, and they might have noticed odd generator dispatches and violations during an OPF solution. It is possible to not have noticed this bug, especially if the existing state of the system did not require the commitment or decommitment of fast start generators during OPF or SCOPF.
    • Security Constrained OPF (SCOPF) Tool: This bug fix addresses the incorrect dispatch of some generators and loads that are available for control during a SCOPF solution (either AC or DC mode). An example of this is when a OPEN generator action is part of contingency. A branch limit violation during that contingency would then (previously) redispatch the base case MW of that generator to alleviate the contingency limit violation. However, this was an erroneous redispatch because the generator would be OPEN during that contingency and hence the violation would not actually alleviate. More SCOPF outer loop iterations would worsen this skewed dispatch, and ultimately lead to "SCOPF Aborted with Error = Power Flow Did Not Converge".

March 6, 2024

Features and Improvements

  • File Formats: Added new Sim_Environment_Options field called UnlinkedElementsSaveForce. This option is stored with the PWB case and when set to YES it overrides the windows registry option called UnlinkedElementsSave. This can be set to YES to always store unlinked elements of Contingency, Interface, and InjectionGroup objects when saving a particular case as a PWB file.
  • Bug Fixes

    • Scheduled Actions: Corrected import of PowerWorld Outage CSV files using Custom Field headers to correctly map existing Custom Fields and append new ones as needed.

March 4, 2024

Features and Improvements

  • Oneline Diagrams: PowerWorld has a hard-coded list of objecttypes that are allowed as part of a ModelExpression. This same list is used with the Generic Model Fields added to oneline diagrams and with fields show in the Custom Case Info Displays. This patch has added the DataMaintainer to the list of objectclasses allowed.
  • Bug Fixes

    • Case Information Displays: When showing a DataCheckAggr field in a case information display it can be configured to show the string in the form of 95 / 245 where 95 is the number of objects that meet the DataCheck and 245 is the total number of object in the aggregation. This field is still considered a numerical field, but the result is a string of the format "95 / 245". When a field like this is added as a text field on a oneline diagram however this special formatting was not obeyed and instead you would see only the 95 value. This has been fixed.

March 1, 2024

Features and Improvements

  • Case Information Displays: For PartPoint object type changed the column header "Initial Value" to "AutoCalc Method" because this more accurately reflects how this field is used. "Initial Value" will continue to work as a legacy column header for pasting information from Excel or loading a CSV.
  • Transient Stability: Completed full implementation of current-dependent resistance and reactance for a Series Capacitor Metal Oxide Varistor (SCMOV) device. Previously SCMOV functioned but it either completely bypassed the device or operated in normal mode. Also added very detailed help documentation to describe how this device impacts the software simulation.
    https://www.powerworld.com/WebHelp/#TransientModels_HTML/Line%20Relays%20SCMOV.htm

February 29, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): The AutoCalc variable with IG_AutoInsert_Options and IG_AutoInsert_Options_Value used with the InjectionGroupsAutoInsert script command was being used as the opposite value when used to set the AutoCalc field with PartPoint objects. This has been fixed. The legacy variable PPntUseFixedParFac was being used correctly. A new concise variable called UseFixedPartFact has been added that is the opposite of AutoCalc.
  • Auxiliary Files (SCRIPT and DATA Sections): Added EnumerateDDLOnelines script command. This command creates a file that lists all of the oneline diagrams contained within an Areva/Alstom/GE DDL file.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): The Selected field for ViolationCTG objects was not being set correctly. This has been fixed.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug that could cause an access violation when using the ImportDDLAsTranslation() script command.
    • Transient Stability: When transferring the transient stability present state to the power flow for visualization, if a generator was configured to be on line-drop compenstation in the power flow the transferred state would appear with mismatches at the generator on line-drop compensation. This has been fixed.

February 22, 2024

Features and Improvements

  • Contingency Analysis Tool: Added new field "Reference Percent" for contingency limit violations (ViolationCTG object). This calculates (Reference State Value)/Limit*100.
  • Bug Fixes

    • Distributed Computation: When running contingency analysis using distributed computing through a script command and using screening, it was possible for the run to never complete if an error occurred during the base case power flow solution. This has been fixed.
    • File Formats: After reading ReactiveCapability objects from an auxiliary file, Simulator ensures that Mvar limits of generator records are updated immediately.
    • Optimal Power Flow (OPF): The option to "Monitor/Enforce Contingent Interface Elements" was being overwritten inadvertently with a previous value, when solving an LP OPF specifically while a user would have the LP OPF dialog open, and then altered this option either via (i) Case Information > Simulator Options > General, or (ii) Model Explorer > Optimal Power Flow > Interfaces. This would result in the newly changed value of "Monitor/Enforce Contingent Interface Elements" to be lost, and contingent interfaces would not be monitored/enforced as desired during the OPF. This bug would have only been observed by users running OPF with the user interface and editing options + solving OPF in tandem. In contrast, this bug would not be seen when setting all options upfront (in either GUI or script), and then solving an OPF.

February 20, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added NewBusName parameter at end of TapTransmissionLine script command to specify the name of the new bus created at the tap point.
  • File Formats: When saving out an equivalent system to a RAW file, substations will not be saved.
  • File Formats: Modified read of correction table records. Now if we read a tap/scale pair of 0,0 we stop reading the rest of that record, and move on to the next one. Any points read up to the 0,0 will be kept and added to that correction table. Also modified that if the tap or scaling factor are not valid numbers, we also abort and keep only the valid points read up to the errant value.
  • Time Step Simulation: New PFW model for Gen MaxMW, WindGeneral, to model a user specified power-speed curve. A few other minor changes.
  • Bug Fixes

    • File Formats: When reading Areva CSV contingency records, when reading CTGL records which pointed to a TYPE.ID = SVS then invalid ContingencyElement objects were being created resulting in an access violation when running the contingency. This has been fixed so that we now support SVS actions.
    • Transient Stability: When using "Save Plot Images for Auto-Save Options" or as part of a transient stability run, a PDF of multiple contingency plots was not being saved. This bug has been fixed.

February 9, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Add a new script command called InterfaceFlattenFilter(filtername); The filtername follows the same syntax as all other script commands in that it can be the name of an advanced filter, device filter, All, AREAZONE, or a special single-condition filter.
  • Bug Fixes

    • General: In cases with a large number of interfaces (>1000) which also have interfaces that referred to other Interfaces, adding and deleting of interface definitions could become extremely slow. Even loading the PWB file could become very slow. This was due to PowerWorld checking for circular references where you may have interfaces references that would form a circle A-->B, B-->C, and C-->A. This circular reference check is now many orders of magnitude faster so this is no longer a problem.

February 8, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command that adds one or multiple plot series to a new or existing plot definition
    TSPlotSeriesAdd("PlotName", SubPlotNum, AxisGroupNum, ObjectType, FieldType, "Filter", "Attributes");
    This command adds one or multiple plot series to a new or existing plot definition
    "PlotName" : A string to specify a certain plot
    SubPlotNum : A positive integer to specify a certain subplot of a plot
    AxisGroupNum : A positive integer to specify to a certain subplot of a subplot
    ObjectType : Specifies which objects to set. The ObjectType is the object name of supported objects such as GEN, BUS, BRANCH, etc
    FieldName : Specified a transient stability field name that can be plotted
    "Filter" : (optional) Only objects that meet the specified filter will be included. See the Using Filters in Script Commands section for more information on specifying the filtername
    "Attributes" : (optional) A comma-delimited list of other attributes for the PlotSeries. Blank by default just uses the defaults for a new PlotSeries
    A couple examples are
    TSPlotSeriesAdd("Gen 2 1 | Rotor Angle", 1, 1, Gen, TSRotorAngle, "Gen 2 1");
    TSPlotSeriesAdd("Area 2 buses", 1, 1, Bus, TSVpu, "Area 2", "ValueType=Actual Deviation, LineDashed=Dot");
  • File Formats: When writing the end of some section in a RAW file we were writing a ' 0' (space before the 0). This was causing a problem in other 3rd party software tools, so we have removed the space as it was not necessary.
  • Transient Stability: Added a new script command that adds one or multiple plot series to a new or existing plot definition
    TSPlotSeriesAdd("PlotName", SubPlotNum, AxisGroupNum, ObjectType, FieldType, "Filter", "Attributes");
    This command adds one or multiple plot series to a new or existing plot definition
    "PlotName" : A string to specify a certain plot
    SubPlotNum : A positive integer to specify a certain subplot of a plot
    AxisGroupNum : A positive integer to specify to a certain subplot of a subplot
    ObjectType : Specifies which objects to set. The ObjectType is the object name of supported objects such as GEN, BUS, BRANCH, etc
    FieldName : Specified a transient stability field name that can be plotted
    "Filter" : (optional) Only objects that meet the specified filter will be included. See the Using Filters in Script Commands section for more information on specifying the filtername
    "Attributes" : (optional) A comma-delimited list of other attributes for the PlotSeries. Blank by default just uses the defaults for a new PlotSeries
    A couple examples are
    TSPlotSeriesAdd("Gen 2 1 | Rotor Angle", 1, 1, Gen, TSRotorAngle, "Gen 2 1");
    TSPlotSeriesAdd("Area 2 buses", 1, 1, Bus, TSVpu, "Area 2", "ValueType=Actual Deviation, LineDashed=Dot");

February 5, 2024

Bug Fixes

  • Case Information Displays: When right-clicking on a list of objects in a case information display and choosing to Save Aux File with Options, if a AUX Export Format Description was chosen from the dialog that appears the filters specified in that AUX Export Format were being ignored. This has been fixed.
  • General: Added code to handle trampling of the history list, which could occur when multiple instances of Simulator are running simultaneously on the same computer. It was possible that an error stating something like "Failed to set data for 'HF6' " would appear.
  • Transient Stability: Patch note: When calling TSSolveAll(YES), a distributed run was not creating multiple-contingency plots. Note, calling TSSolveAll(NO) was working as expected, and this bug only affected distributed runs via the TSSolveAll script command

February 2, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Added code to remove quotes from user input interface name for new InterfaceAddElementsFromContingency script command.

February 1, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command: InterfaceAddElementsFromContingency(interface name, contingency name). It creates interfaces elements from valid contingency actions and adds them to the named contingency. If the interface does not exist, it will be created.

January 31, 2024

Bug Fixes

  • Scheduled Actions: When the Scheduled Actions dialog opens, the Current Statuses of all Scheduled Actions and Scheduled Action Groups will be populated based on the current View settings.

January 30, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): SaveCase script command now has an option to IncludeSubstations when saving to RAW files. SaveCase("filename", SaveFileType, [AddCommentForObjectLabels, IncludeSubstations]). This option is NO by default.
  • File Formats: When writing RAW files there is now an option on the PTI RAW File Options dialog to "Include Substations (used for full topology node breaker modeling)". This is only relevant for RAW versions starting with 34. This option is NOT checked by default.
  • Oneline Diagrams: GenericModelFields can now have a prefix, and appear larger when first created if they would otherwise be microscopic. Also GenericModelFields can show the number of weather measurements.
  • Oneline Diagrams: CaseInfoMemoFields can now show whether the PFWModels have been aplied, and also now have the ability to show a runtime local menu.
  • Bug Fixes

    • File Formats: When writing RAW files, corrected how the AREAIN option is written. This should be written as either disabled or using "tie lines and loads." When area interchange is enabled Simulator always uses tie lines and loads. When island based AGC is in use, area interchange should not be enabled in the RAW file.
    • File Formats: When writing RAW files, any bus number greater than 999,997 will be renumbered starting with 1 until an unused bus number is found to avoid bus number limitations in PSS/E.

January 25, 2024

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added built-in AUX Export Format Description for Geomatically Induced Current. This is found under the Create Format for Complete Case button.
  • Bug Fixes

    • File Formats: Modified reading of the _cmpldw2 model so that when encountering a cmp_der_a model as one of the components of the model the extra parameter in cmp_der_a for DGmbase is read and populated in the respective DGDER_A model for PowerWorld Simulator.
    • Power Flow Solution: Fixed how the "Initialize from Flat Start Values" Advanced Power Flow Solution option is applied. This is now only used when solving the power flow in the GUI, using the Auto Solve on Load option, and Animating in the GUI. It is not used when solving the power flow using script commands.
    • Power Flow Solution: Bug fix for how parallel transformers are determined for the purposes of tap balancing. This is now done by excluding their present phase and tap ratio. The patches from Aug 7, 2023 until this patch were incorrectly including their present phase and tap ratio to determine parallel transformers. This issue would have been observed by users during a full power flow solution, with some transformers' tap settings not being "rebalanced" and an operating point with higher circulating reactive power and lower bus voltages in the immediate "local" vicinity of those transformers.
    • Transient Stability: Fixed a bug when closing a generator in transient stability when no governor was available in the generator. This was causing an access violation. This bug was fixed.
    • Transient Stability: Bug fix for reading/writing the parameter SW1 in the UEL2C transient stability model for the DYD file format. As per the spec, SW1=A,B, corresponds to SW1=0,1 in DYD, but to SW1=1, 2 in PW and DYR

January 18, 2024

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Many ObjectTypes in AUX files have fields that are a string representing a reference to another object. Those strings have the format of "ObjectType KeyField1 KeyField2 etc.". For example, a branch may be represented by the following string: "BRANCH 12345 98765 '12'" . This string is the word BRANCH followed by a SPACE, then integer bus number, followed by a SPACE, and so on. The syntax calls for using a SPACE character as the delimiter between key fields. Users however sometimes edit AUX files in a text editor and may use a TAB character instead of a SPACE. PowerWorld's AUX file parser will now handle a TAB character in those locations and treat them just like a SPACE character.
  • File Formats: Fixed two bugs related to the same thing. EPC format only allows a max of 20 points in a reactive capability curve in the QTable. We were writing out more than 20 for curves that had more than 20 points in Simulator. When reading in an EPC, we were limiting the array to 20 points, but were not checking to see if we read more than 20 when trying to assign to the array, so we were getting an access violation. Both have been fixed. When writing we now limit the points written to the EPC to 20 curve points. When reading, we now can read as many points as are given, even if there are more than 20 (which in theory now shouldn't happen.)

January 16, 2024

Features and Improvements

  • Transient Stability: Added the REGFM_B1 model for modeling a Virtual Synchronous Machine grid forming machine model.

January 12, 2024

Bug Fixes

  • File Formats: Fixed a bug reading and writing two-winding transformer data from/to a RAW file when using CW=1 and the transformer base voltage differed of the To bus differed from the nominal kV of the To bus.
  • File Formats: When writing to a Substation Terminal Data section in a RAW file, fake generators used for modeling SVCs were being included. This has been fixed.
  • File Formats: When writing out inter-area transfer data, RAW files don't allow characters like ? as IDs. We now restrict these IDs for that object types a single character number or letter.
  • File Formats: When writing to a RAW file always set the Flat Start flag to false and correctly set the flag for enforcing generator Mvar limits.

January 11, 2024

Features and Improvements

  • Transient Stability: Customer had reported a long duration of Simulator window not responding, at the end of a distributed transient stability run. This was because contents of the AUX file produced during a transient contingency were ALL being loaded back into memory of the primary Simulator program. The amount of time for this can be significant, and this operation has now been threaded to allow results to be loaded back into memory as the results are returned from the distributed processes.
  • Bug Fixes

    • Case Information Displays: The Power Flow Jacobian Case Information Display was not updating if generators changed from PQ to PV. The Jacobian itself was updated correctly but the grid would leave previously populated fields populated when they should be blank. This has been fixed.
    • File Formats: Made some fixes when writing substation data to RAW files. Specifically errors were reported by a user when loading a version 35 RAW file created in Simulator into PSS/E - "FATAL: Cannot place substation switching device between nodes belonging to two different buses in the same substation." Invalid latitude and longitude values for a substations are now written as 0 instead of the Simulator internal defaults for invalid values.

    • File Formats: When writing a version 35 RAW file, switching devices that are set to Allow Consolidation = NO are written in the System Switching Device section to prevent errors when loading into PSS/E that "Cannot place substation switching device between nodes belonging to two different buses in the same substation."
    • File Formats: When writing out RAW files with substations, additional checks were added to substation names that are required in RAW files only.
      1. Substation names can not contains any quotation marks
      2. Substation names must be unique across then entire case in PSS/E.
      When exporting to a RAW file any substation name containing a single or double quote has these characters replaced with an underscore. For duplicate substation names, the substation with the largest number of buses maintains the name. Other substations have _1, _2, etc. appended to the substation name in the RAW file.
    • File Formats: When writing out the normal status of device to RAW files we were flipping the logic. This has been fixed.
    • File Formats: When writing out substation names to a RAW file the maximum number of characters is 40. We now truncate names to 40 characters.
    • File Formats: When writing out a RAW file, the load records now left justify the IDs. This was done so that the Load records would match the terminal equipment IDs in the substation portion of the RAW file.
    • File Formats: Also modified so that switching devices that are between different SuperBuses will always be written as system switching devices.

January 8, 2024

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added more options for auto inserting multiple directions for ATC and PTDF analysis. Options are now available to insert from Area, Zone, Injection Group, and Bus source objects to a specified sink object of type Area, Zone, Injection Group, or Slack. The source objects can be filtered using standard filtering methods.
  • Case Information Displays: Case Info Column Metrics dialog now has a page making it easy to get a histogram plot of the data.
  • General: In the General File Browser there is now 1) support for loading axd files and 2) an option to view the contents of the aux and axd files without loading them; with this option they are viewed in the computer's default text editor (what is associated with the *.txt files).
  • Simulator Automation Server (SimAuto): Modified the SimAuto command called RunScriptCommand2 so that the error string can include information such as "23 objects not found" while reading objects from the data section of an auxiliary file.
  • Simulator Automation Server (SimAuto): Simulator COM automation (i.e., SimAuto) distributed process threads are now assigned in a manner that prevents them from being power throttled by the Windows layer. This issue affected newer Intel CPUs that have p/e-cores technology, in which background Simulator distributed processes would get assigned to e-cores (that have lower processing speed). This did not change the quality of results from Simulator, but some users running distributed tools (like Transient Stability, ATC) would have noticed a significant increase in processing duration, because p-cores (that have higher processing speed) were inadvertently not being used. This issue only affected those users using distributed tools from a primary SimAuto instance (from VBA, Python, Matlab, etc), and not those using a primary graphical Simulator instance. It has been remedied.
  • Time Step Simulation: Added Time Step Simulation script command to store the custom results for an object type in a csv file.
  • Transient Stability: Added the ability to open the BusView from the Solution Details tab in Transient Stability. It will open the BusView of the first Mismatch Bus (Mismatch Bus 1).
  • Transient Stability: Added another parameter Vfrzhigh to REPC_D bus plant controller.
  • User Interface Dialogs: Modified GenROpt PFW/Weather page to include the ability to easy apply weather for many hours to a generator.
  • Bug Fixes

    • Simulator Automation Server (SimAuto): ChangeParametersMultipleElementRect SimAuto function would stop when encountering the first object that could not be found without processing the rest of the specified objects. All objects are now processed and all objects that cannot be found are specified in the returned output message.
    • Transient Stability: For GGOV1 model the Ldref acts as a maximum limit on the output mechanical power of the governor. PowerWorld was always modifying Ldref to ensure it was at least as big as the initial Pmechical and not reporting this in any log message or as State Limit violation. This will now be reported and we will also only change the Ldref value if the option to "Modify limits and run" is chosen regarding initial state limit violations.

December 19, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): There are now four new script commands associated with TimeStep Simulation, mostly to better support the PWW files.
    TIMESTEPDeleteAll(); // This is just like pressing Delete All from the Time Domain form
    TIMESTEPLoadPWW(filename : String); // This loads the pww, replacing any existing time step data
    TIMESTEPAppendPWW(filename : String); // This appends the pww to the existing time step data, but only works if the weather stations are the same
    TIMESTEPSavePWW(filename : String); // This saves the time step weather data in pww format.
  • Case Information Displays: In Case Information Displays the Plot Columns now allows just a subset of the rows to be plotted. If the user selects one row then all rows are plotted (as before); the new functionality is if more than one row is sleected then just those rows are plotted. The Column Plot dialog now also allows the plotted rows to be changed, with a button to easily select all.
  • Bug Fixes

    • Case Information Displays: The "Load MW IS" and "Load Mvar IS" fields with islands should return the nominal load of all loads in the island where the load status is closed but the bus status is disconnected. These fields were always returning 0. This has been fixed.
    • Time Step Simulation: Fixed bug assigning a subscription from AUX files in the time step tool. When saving and loading an AUX file with Sched Subscriptions from the time step tool, the field type (e.g. GenMW) was not being saved or loaded properly. This has been fixed.

December 15, 2023

Features and Improvements

  • Simulator Automation Server (SimAuto): Added the ability to select the addons utilized by SimAuto when using hardware keys for licensing Simulator. Using the Register SimAuto Tool (RegSimAuto.exe), the Advanced section contains buttons that let the user select which addons they'd prefer SimAuto to utilize when using hardware keys to license Simulator. When addons are selected, SimAuto will only attempt to obtain licenses for those specific features, but will not fail initialization if it cannot do so. The user will need to utilize SimAuto functionality to ensure that the selected addon licenses have been obtained or to gracefully handle errors that occur when licenses cannot be obtained, which is identical to previous behavior.
    It should be noted that using the "Clear preferred hardware key addon selection" button will cause the preference to be deleted and SimAuto will revert to the default behavior of attempting to obtain licenses for all available addons.

December 14, 2023

Features and Improvements

  • General: For Dynamics Studio added Amps per phase from and to ends of a branch.

December 13, 2023

Features and Improvements

  • Case Information Displays: Added two new fields with areas to show fields for Injection Group Slack values. Inj Group Slack MW shows to the total injection from the injection group, and Inj Grp Slack Gen Max MW shows the sum of the Max MW for all generators in the injection group. When populating these values, only online gens and loads will be included and the option for enforcing AGC will be used.
  • Oneline Diagrams: Modified oneline diagrams so that when pressing Ctrl+G while the mouse cursor is hovering above a oneline diagram, then a string is copied to the Windows Clipboard of the format "Latitude, Longitude" with 7 decimal places for the coordinates.
  • Oneline Diagrams: When loading a KML file, users have encountered ill-formed KML files that have omitted commonly used namespaces. PowerWorld will now look for errors related to 3 commonly used namespace definitions and automatically include them when reading a KML file if those namespaces are used but not declared. These namespaces are as follows.
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:gx="http://www.google.com/kml/ext/2.2"
    xmlns:kml="http://www.opengis.net/kml/2.2"
  • Bug Fixes

    • Oneline Diagrams: Fixed bug inserting substation topologies from a oneline. The starting bus number supplied by the user was not being used. This has been fixed.

December 7, 2023

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added new fields to a TransferLimit object which show results in a manner that forces a positive OTDF Sensitivity and a positive Limit Used. This added fields are under a folder "Positive" in the list of available fields. The variable names are Pos_ValuePreTrans, Pos_PercentPreTrans, Pos_Object, Pos_ObjectDesc, Pos_Limit, and Pos_Sensitivity.
  • File Formats: Modified writing to PTI *.CON contingency files so that the full name of the contingency is written out regardless of the length of the string. Various versions of CON files have had 8, 12, 32, etc... character restrictions. It will now be up to the user to truncate names appropriately for the version of PTI they are using.

December 5, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command RenumberCase. It applies the bus swap list as it exists in memory. This was needed to renumber XF correction tables without the GUI. They do not have custom fields, so the ordinary Renumber scripts won't work.
  • Available Transfer Capability (ATC) Tool: Added "Use Options for Heatmap from FERC Order 2023" option with ATC analysis. This will set the ATC options necessary for producing the Transfer Limiter results based on the FERC Order 2023 heatmap requirements. This will set the options for Max Limiter Per CTG, Max Limiter Per Element, Max Limiter MW, and Transfer Limiters to Save along with the Include Contingenecies, Report Generation Reserve Limitations, and Report Base Case Limitations. Interfaces will not be monitored and the Ignore PTDFs Below option will also be ignored. The Single Linear Step Solution Method will be used and any ATC Extra Monitors will be ignored.
  • Bug Fixes

    • File Formats: Fixed a bug saving Scheduled Actions to PWB

December 4, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Modified to make the generator field UnitTypeEPC an enterable integer field.
  • Auxiliary Files (SCRIPT and DATA Sections): Minor edits to remove the "EPCDateIn" and "EPCDateOut" field for a generator object. These are now handled by the "DateOperating" and "DateRetired" fields for a generator instead. Old AUX files using the legacy variable names GEDateIn, GEDateOut, EPCDateIn and EPCDateOut will read into these new fields.
  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command
    CustomFieldDescriptionModify(ObjectType, CustomType, Location, FieldString, HeaderString, IncludeInDiff);
    *ObjectType : the object type
    *CustomType: Either Integer, String or Floating Point
    *Location: The location number of the custom field. Remember that "Custom Integer 2" corresponds to CustomInteger:1 and for that example you would use a Location of 1. Entering a negative value for Location will increment the present CustomMaxOfType by 1 for the present ObjectType/CustomType. If a location is chosen that is too large, then the CustomMaxOfType will be increased to accommodate the location.
    *FieldString: String shown when field is displayed. Remember that a \ results subfolder being created under the Custom folder. Enter a value of "_same_" if you do not want to change the string.
    *HeaderString: String shown in column headers in case information displays. Enter a value of "_same_" if you do not want to change the string.
    *IncludeInDiff: Set to either YES, NO or "" where a blank indicates that the value is not changed.
  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command
    CustomFieldDescriptionAppend(objecttype, CustomType, FieldString, HeaderString, IncludeInDiff);
    This command behaves the same as calling ModifyCustomFieldDescription with a negative Location. This creates a new CustomFieldDescription by incrementing the CustomMaxOfType.

November 27, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new feature to the TSGetResults() script command. When parsing the portion of that script command looking for specific Object | Field pairs or Plot Names, you may now also specify the syntax "ObjectName FilterName | FieldName". For this syntax anything after the first space and before the | character is considered a FilterName. The FilterName can be All indicating that all objects of the type ObjectName are used, or it can use the syntax available for defining a FilterName in all the other script commands. Examples would include
    "Bus All | TSFrequency" : exports Frequency for all buses
    "Bus NomkV > 300 | TSFrequency" : exports frequency for all buses with a Nominal kV above 300
    "Bus My Filter Name | TSFrequency" : exports frequency for all buses meeting the filter named "My Filter Name"
    "Bus Selected | TSFrequency" : exports Frequency for all buses which have the Selected = YES
    "Bus AreaZone | TSFrequency": exports Frequency for all buses that meet the present Area/Zone filters
  • File Formats: Added error checking when loading the Areva hdbexport CSV for a case. If records such as UN, LD, CP, LN, ZBR, XF, NDPAIR, or DCCNV reference another ND record but it is an index higher than the largest ND record index then appropriate warning messages are written to the log indicating a problem in the file. If this is the ND record at which the device is connected we will ignore the device. If this is the ND record for a regulated bus, we will use the terminal bus of the device as the regulated bus. These are error in the CSV however and the user should fix these problem in the CSV export (probably by reducing the hdbexport process in the EMS). These fixed in PowerWorld Simulator however will at least allow us to load the file and see what is wrong in the CSV export.
  • General: Increased the maximum number of buses from 250000 to 400000.
  • Oneline Diagrams: Major enhancement to GDV styles so they can now be setup to automatically update the display based on the linked objects of the specified type. This means a single GDV display can be easily used with vastly different power flow cases.
  • Scheduled Actions: Added support for Custom Fields in ActionField column of PowerWorld Outage CSV format
  • Simulator Automation Server (SimAuto): Added support for single-condition filter strings in SimAuto commands
  • Transient Stability: Updated Stability saving two bus equivalents to also store the substation to provide access to geographic information. Saving two bus equivalents for all generators and buses also now supports the use of area/zone filters.
  • Transient Stability: Modified the PVD1 machine model so that it will respond to TSContingencyElement actions which change the generator "Governor" or "Exciter" setpoints. The Pref in PVD1 will be treats as the governor setpoint and the Qref will be treated as the exciter setpoints. The PVD1 model itself should be used as a stand-alone model only however without an actual governor or exciter defined. This allows TSContingencyElement to change the MW and Mvar output of a generator with a PVD1 machine model.
  • Bug Fixes

    • File Formats: Fixed bug in writing out an EPC file for changes made to a case which could occur for branch records.

November 10, 2023

Features and Improvements

  • Case Information Displays: When right-clicking in a case information display showing Gen, Shunt, LineShunt, Branch and Load objects there is now a special option under the Save As submenu for Save As "TS models AUX format (only model of selected records". This will save any stability models associated with the objects selected in the case information display.
  • Transient Stability: Added the ability for a TSContingencyElement action to ChangeBy, Set, or Ramp the Pref, QVrefFrom, and QVrefTo of a VSCDCLine stability model as part of a contingency event. This allows the user to change the MW setpoint of a VSCDCLine as part of a simulation.
  • Transient Stability: When choosing to Save to Aux on the Bus, Shunt, Generator, Branch, LineShunt, and Load dialog, the user will now also be prompted to save any stability models associated with the object as well. These will be appended to the AUX file written to.
  • Bug Fixes

    • Oneline Diagrams: Fixed access violation closing oneline with a contour applied. There was an error closing the color key, which has been fixed.
    • Oneline Diagrams: When loading the "ColorKeyShowValuePanel" from an AXD file it was not properly updating the ColorKey to remove the ValuePanel at the bottom of the ColorKey. When loading the AXD now the ColorKey will be automatically updated to show or hide the value panel based on what was read from the AXD.

November 8, 2023

Bug Fixes

  • Distributed Computation: Added the SimAuto Service; this service enables a machine to enforce a cap on the number of SimAuto instances that can be used concurrently, so multiple Distributed clients sharing a pool of computational resources can't collectively overwhelm the machine with SimAuto instances. It can be installed, started, and configured through the DistCompCfg utility. The new Limit and Limit Enforced fields in the Distributed Computer list are populated during Machine Verification to indicate what cap is set on each remote machine, and if the service is running to enforce it.
  • Scheduled Actions: Added support in the PowerWorld Outage CSV for two new columns: "Disable" and "Comment". They are applicable to both Actions and Action Groups; if a row has YES in the Disable column, it Simulator will not import it (if an Action, just that action; if a Group, the Group and all actions in it are disabled). Any text in the Comment column will be loaded into the Comment field of the applicable Action or Action Group.
  • Transient Stability: When a Plot was set to automatically appear upon execution of the transient stability simulation, the auto-sizing of vertical axis was not working properly. This has been fixed.

November 7, 2023

Features and Improvements

  • File Formats: When loading *.otg files to create either Contingency or TSContingency definitions, modified to read the Category and the Skip flag from the OTG format.
  • GIC: Modified the script command GICLoad3DEField to have an optional fifth parameter that changes the calculation mode to TimeVaryingNonUniform. The default value is to change the calculation mode.
  • Oneline Diagrams: Allowing edit mode dialogs to appear on the oneline list object display; set for background lines and text objects.
  • Oneline Diagrams: On Auto Line insert in edit mode added an option to not insert the pie charts. Also (on a more minor note), the GDV line and interface objects can now be contoured.
  • Transient Stability: Added new fields to Area and Zone transient stability result storage to show the total Gen MW loss for the area or zone. This can be caused by tripping generation or by the generation becoming separated in a dead island.
  • Bug Fixes

    • Oneline Diagrams: Fixed a bug on the Oneline Options display in which the base object background color might not have been changed correctly.
    • Oneline Diagrams: Fixed access violation that could occur when deleting a bus object from a Spatial View when deleting using the Delete key.
    • Transient Stability: The option in transient stability for "Use Distributed Computing" was stored with a PWB file. This has been changed so it is not stored with the PWB and is instead only stored in the Windows Registry tied to a particular computer. The option may also be set using the Distributed_Options_Value object such as using the script command SetData(Distributed_Options, [Option, Value], [TSUseDistributedComputing, "YES"]);
    • Transient Stability: Fixed a cosmetic bug when loading a PWB file which was saved with the UseDistributedComputing flag set true. When loading that into a version of Simulator which did not have a license for Distributed Transient, the user interface messages when calculating a stability simulation made it appear like distributed computing was being used when it was actually not being used.

October 31, 2023

Features and Improvements

  • PV and QV Curve (PVQV) Tool: Delete and DeleteDevice script commands will now work with QVCurve, PWQVResultListContainer, PWPVResultListContainer, and PVInterfaceResults object types.
    When deleting a QVCurve object the associated PWQVResultListContainer object will also be deleted.
  • PV and QV Curve (PVQV) Tool: Added Delete All Results button to the QV Curves dialog that will delete all results.
  • Sensitivity Calculations: Adding user input to choose distance metric when setting sensitivies at out of service busses from the TLR/Shift factor form.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Fixed a bug in linear ATC calculations that could result in incorrect OTDF calculations for contingencies that isolate generators or loads.

October 25, 2023

Features and Improvements

  • Transient Stability: Added a new type of controller called a Bus Plant Controller which can be assigned to a Bus Object. This controller can then talk directly to a group of generator plant controller to coordinate their outputs. The first example of this is the new model named REPC_D.
  • Transient Stability: Added ability to read HPLNTDU and REAXDU models from DYR files and create an REPC_D model from them
  • Transient Stability: Added TSContingencyElement action for changing QVRef or Pref on a Bus controller object.
  • Bug Fixes

    • PV and QV Curve (PVQV) Tool: PV and QV results for a contingency that is being deleted will now be deleted automatically if a contingency is deleted. Not deleting the results could cause access violations.
    • Transient Stability: Fixed a bug with TSSaveTwoBusEquivalent script command. The Bus Number was not processed correctly and also the filename path was not read properly causing an access violation. Both bugs were fixed.

October 20, 2023

Bug Fixes

  • File Formats: When saving a Shapefile to a network hard-drive, we now save the file to the local hard drive first and then copy the file to the network drive. This fixes problems that can occur when saving large files to a network drive.
  • File Formats: When loading a PWB that had been creating by "Saving External System" from another case, an access violation could occur when loading interface elements that were not part of the external system. This has been fixed.
  • Oneline Diagrams: When opening the "Unlinked Display Objects" list for a oneline, and then closing the oneline before the Unlinked Display Objects list, an access violation would occur. This has been fixed by closing the Unlinked Display Objects table immediately as it should be tied to the Oneline.
  • Power Flow Solution: Made modifications to how a system state is stored with regard to how angle smoothing occurs after restoring the system state. This avoids some rare situations where angle smoothing occurs in a manner that causes a bad power flow solution.

October 19, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added SetSelected field to DoFacilityAnalysis script command. This is an optional parameter that is NO by default. DoFacilityAnalysis("filename", SetSelectedField). When set to YES the Selected field for branches that are part of the minimum cut will be set to YES. Prior to running the script command the Selected field should be set to desired values for all branches. The script command only sets the Selected field for branches in the minimum cut to YES and does not reset other branches.
  • Power Flow Solution: Prevent angle rotation in an island when (largest angle > 150) and (smallest angle < -150). This is a cosmetic change and does not impact the solution.
  • User Interface Dialogs: Added "Set Selected Field for Branches" checkbox on the Facility Analysis (Minimum Cut) dialog. When this is checked the Selected field for branches that are part of the minimum cut will be set to YES. Prior to finding the minimum cut the Selected field should be set to desired values for all branches. Only the Selected field for branches in the minimum cut will be set to YES and other branches will not be reset.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed access violations that could occur when running the DoFacilityAnalysis script command
    • Auxiliary Files (SCRIPT and DATA Sections): The option to "Treat Blanks as Zero" in custom expressions and custom string expressions was not working correctly and could result in an "Unable to evaluate fields" error. This has been fixed.
    • Contingency Analysis: When running contingency analysis, any generator that is outside its MWMin - MWMax range is turned to AGC=NO during the contingency solution so that PowerWorld is not moving large amounts of generation during redispatch due to an initial generator MW violation. The was an issue however with slack bus generators which can be with a tolerance of their MW limits but still violate the limit. To fix this, during contingency analysis we do not set slack bus generators that are close to their limit to AGC=NO at the start of a contingency solution.
    • GIC: Fixed bug with script command GICTimeVaryingDeleteAllTimes that could occur if the GIC Dialog was also open.
    • Oneline Diagrams: On some computer/monitor setups the oneline image copied to the clipboard was not the correct size. This has been fixed.
    • Power Flow Solution: When dispatching MW generation when there are multiple generators at the slack bus, changed how the dispatch is done. Generators at limits will respect their limits as long as there are other generators available not at limits. If all generators are over limits, all available generators will be modified. Previously it was possible for generators to move so that they all moved within their available range even if no total change was necessary. It doesn't make sense that generators are adjusting their dispatch unless an actual MW change is required.
    • Sensitivity Calculations: When running a shift factor calculation on a full topology model and using the Use Topology Processing Option, it was possible for the system state to remain in the consolidated state if an error occurred while doing the shift factor calculation such as when a calculation is attempted on a branch that is open. This has been fixed.

October 12, 2023

Features and Improvements

  • File Formats: Both GMD data files, and GMD data in an EPC file can now filtered using the Area/Zone filters.
  • Bug Fixes

    • Bus View and Substation View Onelines: When using the Bus View option to show Consolidated Topology, an access violation could result if the case is modified by adding, deleting, or moving a branch or adding or removing a bus. This has been fixed.

October 10, 2023

Features and Improvements

  • Scheduled Actions: Added support for 'XFMR' ActionObjectType in PowerWorld Outage CSV files. Simulator will attempt to interpret the corresponding ActionObjectLabel in the following ways, stopping when it finds the first match:
    1) the Label of a 3WXFormer object
    2) the Label of a Branch object
    3) An ID in the format "SubName_XFMR_EMSLineID" for some collection of XF branches
    4) An ID in the format "SubID_XFMR_EMSLineID" for some collection of XF branches
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixes to new BranchDistMeas parameer of SetSensitivitiesAtOutOfServiceToClosest and CalculateShiftFactors script commands

October 9, 2023

Features and Improvements

  • File Formats: Modified reading of hdbexport *.CVS file for Contingency Information. If the CTG.ENREDEF=T, then CTGL records which refer to a TYPE=CB will only be read as an OPENCBS ("open with breakers") action if the CTGL.CBF=T is set. CTGL records refering to a CB record need this special permission to model a "CB failure".

October 6, 2023

Features and Improvements

  • File Formats: When reading the CTGL records which have CTGL.REDEF=T or CTGL.RAS=T, we will now indicate that this was in the CSV file by populating the Comment field of the ContingencyElement created with either REDEF=T or RAS=T.

October 5, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Modified all script commands that have a parameter "filtername" to specify an advanced filter or device filter. These parameters can now also use a special string with the syntax "MW >= 50" to do a single condition filter without actually needing to create a named filter. The syntax is Variablename Comparison Value1 Value2. Examples are
    "NomkV between 220 550"
    "MW >= 50"
  • Contingency Analysis Tool: In contingency analysis when processing an OPENCBS action, if no Breakers are found that can and need to be opened isolate the Object then PowerWorld Simulator was instead opening the Object itself. Normally that's fine, but if the reason no devices were found was because the device was already isolated from the system using the other ContingencyElement in the contingency, then there is no reason to open the Object again. This has been changed to just do nothing in this situation because the Object is already isolated. This does not impact the solution, but just the WhatActuallyOccurredDuringCTG reporting object.
  • File Formats: Added 2 new options to Sim_Environment_Options called HDBExportCTGLREDEF and HDBExportCTGLRAS. These options are used when reading an hdbexport CSV file with CTGL records. There are flags on CTGL records for
    CTGL.REDEF : indicates that the record was dynamically created in the EMS by the REDEF process which is enabled by the CTG.ENREDEF flag
    CTGL.RAS: indicates that the record was dynamically created in the EMS by the RAS process
    The 2 new options can be set to either "Ignore" or "OPEN".
    Ignore indicates that the CTGL record will be ignored.
    OPEN indicates that the CTGL record will create a ContingencyElement that is an OPEN action.
  • Transient Stability: Added the Efe value to be shown in the Other Fields for Exciter AC7C.
  • User Interface Dialogs: Modified General File Browswer to open more file types (pptx, docx, xlsx, csv, and several image/movie foramats); it also now indicates why it can't open a file type.
  • Bug Fixes

    • Contingency Analysis: When the Contingency case information list is sorted by name and the name of a contingency is changed, the order of contingencies can change just before Solve Selected Contingency is implemented resulting in the wrong contingency being solved. This has been fixed.
    • Difference Case Tool: GICXFormer objects were being written to the aux file created when saving Difference Case changes. These objects are defined from regular transformer objects and do not need to be part of the difference case changes. This has been fixed.
    • Optimal Power Flow (OPF): When running OPF or SCOPF on a case with multiple generators at the system slack bus, it was possible to get "Unenforceable Generator MW Limits" messages for generators at the slack bus. This would occur when some generators should have been dispatched exactly to a limit with other generators at the slack bus not at limits. This has been fixed.

September 27, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Modified the a script command to have an additional optional parameter
    SetSensitivitiesAtOutOfServiceToClosest("FilterName", BranchDistMeas);
    The new parameter BranchDistMeas follows the same syntax as the DeterminePathDistance command parameter with the same name. It has options of X, Z, Length, Nodes, or "VariableName". If the BranchDistMeas parameter is omitted then the old behavior of taking the closest nodes based on the number of nodes away and averaging the value will be used.
  • Auxiliary Files (SCRIPT and DATA Sections): Modified the CalculateShiftFactors() in the same way. It now has parameters as follows with the BranchDistMeas a new optional paramter.
    CalculateShiftFactors([flow element], direction, [transactor], LinearMethod, SetOutOfServiceBuses, filter, AbortOnError, BranchDistMeas)
  • File Formats: Added support for "XFMR" ActionObjectType entries in PowerWorld Outage CSV format. The corresponding ActionObjectLabel field should either be the Label of a 3WTransformer, or a string in the format "[SubName]_XFMR_[EMSLineID]" which will create actions for all XF elements with the corresponding SubName and EMSLineID
  • Bug Fixes

    • Oneline Diagrams: When loading an AXD file in a oneline diagram with many unlinked buses or substations, the process could be very slow due to attempting to anchor at the end of the AXD load. This speed of this process has been greatly increased.

September 25, 2023

Features and Improvements

  • File Formats: When reading the hdbexport CSV file, addded support for having user-specified labels for 3WXFormer object records based on the primary winding XF record.
  • Transient Stability: Bug fix for TS When running multiple contingencies, the list of transient monitor violations was being cleared, instead of being appended. This bug was introduced on January 16, 2023. Advise all TS users to install the latest patch. However, if storing to hard disk, the violations were already stored to disk, and can be retrieved by "load from hard drive ..." in Results from RAM. So there is a way to get it back without re-running the contingencies.

September 15, 2023

Features and Improvements

  • File Formats: Added ability to load Dynamic Line Rating information from the hdbexport CSV files. This reads the DYNELE, SEG, RATING, WST, and SEGWST objects and translates these into XYCurve, XYCurvePoint, WeatherStation, and XYCurveX objects along with appropriate links from the Branch objects in the case.
  • File Formats: Also added a new Sim_Environment_Options_Value option called HDBExportTempUnits which can be set to either Fahrenheit or Celsius. This determines the assumed units of temperature provided in the RATING and WST records in the CSV file.
  • GIC: Cleaned up the GIC dialog to remove features not used any more. Added concise variablenames for GICGeographicRegion, GICGeographicRegionSet, GICMagLatScalarFunction, and GICResistivityLayerObject objects.
  • Oneline Diagrams: In various places when right-clicking on a oneline diagram or on the Geography tab of the Bus and Substation dialogs there are ways to "Open Google Maps". This feature has been extended to offer a drop down to Open Google Maps, Bing Maps, or Open Infrastructure Maps. These are the websites
    https://www.google.com/maps
    https://www.bing.com/maps
    https://openinframap.org/
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): The Export Case Object Fields list could be missing some fields because fields were not written if there was no Description. A field does not require a description resulting in some fields being missing. This has been fixed.
    • Available Transfer Capability (ATC) Tool: When using one of the iterated ATC methods and using the option to Report Generation Reserve Limitations, generator reserve limitation limiters should not be iterated on during the step when all limiters are iterated on to determine the individual limiters to iterate on. If generator reserve limits are found during this initial process, the entire process should stop without iterating on individual limiters. Without this change individual limiters would be iterated on.

September 7, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new Script command as follows
    BranchMVALimitReorder(FilterName, SetA, SetB, SetC, SetD, SetE, SetF, SetG, SetH, SetI, SetJ, SetK, SetL, SetM, SetN, SetO);
    FilterName : same treatment as always
    SetA: Specify a blank to indicate MVALimitA should stay the same
    Specify a numeric value to set MVALimitA to this value
    Specify a character from A..O and we will set the MVA limit to that other limit 
    SetB...SetO: same treatment as SetA, but applies to respective limit
    Examples:
    BranchMVALimitReorder("Area 3",A,B,D,E,G,H,J,K,M,N,9999,9999,9999,9999,9999);
    BranchMVALimitReorder("My Filter Name",M,N,O,A,B,C,D,E,F,G,H,I,J,K,L);
  • Bug Fixes

    • Contingency Analysis: Fixed access violation that could occur during contingency analysis when using Custom Monitors to model cascading outages.

August 30, 2023

Features and Improvements

  • Power Flow Solution: When switching to Edit Mode, all system states are destroyed. This includes the Last Successful Solution State, State Before Failed Solution Attempt, Contingency/ATC/PV References, User State, and Named States. This patch modifies this behavior so that the "User State" and "Named States" are no longer destroyed when switching to Edit Mode. This allows you to continue using the User and Named States even after switching to Edit Mode and deleting or adding objects. These states will not be "solved states" after you have made deletions or additions in Edit Mode, but they still can be useful states.
  • Bug Fixes

    • Transient Stability: Added a new load characteristic LDVFD_A
    • User Interface Dialogs: On the time domain weather station page, added ability to go to a specified time point.

August 28, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): When specifying values for field in the SetData() script commmand, we will now look for special strings @CASENAME, @CASEFILEPATH, and @CASEFILENAME special strings. The particular user request was to add the ability to set the folder to which to store Transient stability hard-drive results to.
  • Auxiliary Files (SCRIPT and DATA Sections): With the Auxiliary File Export Format Description there is an option to build a format description for the complete case and various categories of objects can be user selected. A new selection for "Contingency Combination" is now available that will include Contingency Primary definitions and solution options with the format description.
  • Auxiliary Files (SCRIPT and DATA Sections): With the Auxiliary File Export Format Description there is an option to build a format description for the complete case and various categories of objects can be user selected. A new selection for "Scheduled Actions" is now available.
  • File Formats: When an advanced filter condition is using a field instead of a value for comparison, the field will be stored internally using the location number instead of the field name if using the option to show variablenames using names instead of location numbers. This affects fields like custom expressions, custom strings, custom integers, etc. that can be named. Previously, the internal storage could change based on the option setting and could result in the field not being found when loading a PWB with saved filters. This will keep the internal storage consistent regardless of the option.
  • Bug Fixes

    • User Interface Dialogs: Fixed a bug with the Advanced Filters dialog when using another filter as a condition, unusual filter names would break the dropdown list. In particular any filter name that started with a character that would precede < in an alphabetic search, such as a name that started with a square brace [.
    • User Interface Dialogs: Fixed access violation that would result when loading DynamicFormatting object types from an aux file and fields specified for the Context Object are not supported for that type of object. These fields are just skipped with an error message written to the log.

August 18, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added the optional parameter PreferenceFilter to the commands InterfaceRemoveDuplicates(PreferenceFilter) and InjectionGroupRemoveDuplicates(PreferenceFilter);
    Specify a filter to use when determine which object to keep when there are duplicates. If one object meets the filter and the other object does not, then the object which meets the filter will be maintained and the other removed. Otherwise, the one with a name that would occur first in an alphabetic sort is maintained.
  • Auxiliary Files (SCRIPT and DATA Sections): Renaming script command "CalculatePostCTGInterfaceMWFlows" to "InterfacesCalculatePostCTGMWFlows"
  • Auxiliary Files (SCRIPT and DATA Sections): Added CTGWriteAuxUsingOptions script command. This uses the CTGWriteAux_Options object to specify which contingency related information should be stored in the aux file and how objects should be identified.
  • Bug Fixes

    • Transient Stability: Bug fix for Transient Stability Contingency Element Dialog. There was an unwanted dependency happening between the Insert, OK and also the Delete button, which caused elements do be added that were not chosen. This has been fixed.

August 16, 2023

Bug Fixes

  • Transient Stability: When deciding when to not model an Island in transient stability there was a bug that was not opening generators and shunts in the Island using the Simulate New Island Requirements options. This bug was fixed.

August 15, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added ability to use Device filters in UseAnotherFilter conditions for Advanced Filters
  • Case Information Displays: Added ability to use Device filters in UseAnotherFilter conditions for Advanced Filters
  • Bug Fixes

    • Transient Stability: Fixed stack overflow error that was introduced in the 8/4/23 when writing REPC_A transient stability models to a DYD file.

August 11, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command "CalculatePostCTGInterfaceMWFlows"
  • GIC: Modified the b3d format to Version 5 to handle storing multiple events in a b3d file.
  • Bug Fixes

    • Scheduled Actions: Fixed a bug where Close Breakers actions in Scheduled Actions pops up an unnecessary dialog.

August 9, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added three new parameters to the CTGWriteResultsAndOptions script command: Opt20 = Save Primary Contingency Options for Combo Analysis, Opt21 = Save Primary Contingencies for Combo Analysis, and Opt22 = Save CTG Combo Results. All of these parameters are NO by default and NO when used with the CTGWriteAllOptions script command.
  • Contingency Analysis Tool: When saving options from the Save button on the Contingency Analysis dialog there are now options to Save Primary Contingencies for Combo Analysis, Save Primary Contingency Options for Combo Analysis, and Save CTG Combo Results.
  • Contingency Analysis Tool: Added buttons to Load and Save contingencies and options from the CTG Combo Analysis dialog. When saving, the same options that are used when saving from the Contingency Analysis dialog are available.
  • Bug Fixes

    • Transient Stability: OEL1 model is now allowed with exciter models that are configured for an OEL input signal at a LV gate. Only the generator trip and hard limit on Efd exciter output can be enforced in this case, and the OEL1 model would continue functioning in limited capacity when (runback <> 0) at the OEL1 model instance.

August 7, 2023

Features and Improvements

  • Transient Stability: Signal E_FE for exciter AC7B is now available for plotting in the transient stability plot designer
  • Bug Fixes

    • Power Flow Solution: When a branch had an impedance below the ZBRThreshold and also had a large phase shift or off-nominal tap ratio, it could result in bad power flow convergence. This has been fixed. It was showing up at bus number 516007 in Eastern Interconnection case.
    • Transient Stability: Fixed a bug in the parameters Qdn1, Qdn2, Qup1 and Qup2 to ensure they are treated as in per unit on the Plant MVABase for the REPC_C Model

August 4, 2023

Features and Improvements

  • Scheduled Actions: Added Bus View option to Scheduled Action records menu if the Action targets a device that can be viewed in a Bus View
  • Bug Fixes

    • File Formats: Added a new object called HDB_BRLIMS_RateSet which allows you to specify where BRLIMS ratings read are placed into the model. These decisions are made based on the fields: BRLIMS.ID field and LNLIMA.BRLIMS. The HDB_BRLIMS_RateSet object specifies a SearchString which is used to match the BRLIMS string ID. If a match is found then the HDB_BRLIMS_RateSet object specifies to either push limits into the DEF, GHI, JKL, or MNO RateSets. We would expect that only one HDB_BRLIMS_RateSet would have a SearchString that matches, but if multiple do, then the one with the lowest Order field will be used. A sample AUX file defining a choices like this is as follows.
      HDB_BRLIMS_RateSet (Order,RateSet,SearchString)
      {
      1 "DEF" "*SUM*"
      2 "GHI" "*FAL*"
      3 "JKL" "*WIN*"
      4 "MNO" "*SPR*"
      }
    • Transient Stability: Modified REPC_A, REPCA1, REPC_B, and REPC_C generator models so that the parameters for dbd, fdbd1, fdbd2 always have a fixed sign. Thus if the deadband must always be negative then any edits will automatically take the absolute value and choose the appropriate sign. Also modified so that when writing out to DYD or DYR files these deadbands are written with the sign expected by those formats.
    • Weather: When loading in new METARS data on the Weather Related Models dialog, the list of WeatherStations would be updated. There was a bug with some internal search/sort structures however which were not updated after loading the METARS data. This would cause the assignment of objects to WeatherStations to fail as the lookup of WeatherStations by Name was broken. This has been fixed.

August 2, 2023

Features and Improvements

  • Contingency Analysis Tool: Added new option with CTG_Options called "Save unlinked contingency and remedial action element objects in auxiliary files" that will enable saving unlinked action objects when saving aux files outside of the Save button on the contingency analysis dialog or the CTGWriteResultsAndOptions script command. When using the Save button on the contingency dialog the option on the resulting dialog will be used for saving unlinked objects or not. The script command also has its own input parameter to indicate this.
  • GIC: With the GIC time-varying, spatially uniform (used for the NERC TPL calculations) the code is now about twice as fast. Most of the time is associated with formating the results, and writing them to the file. There is also a field that shows the percent complete.
  • Transient Stability: Added ability to read the cmp_mo1ph model as a load component. Model is the same as a MOTORC model.
  • Transient Stability: Also added the ability to read GENQECU model from a dyr file.
  • Transient Stability: Signal E_FE for exciter AC8C is now available for plotting in the transient stability plot designer
  • Bug Fixes

    • Case Information Displays: Fixed GUI display bug which caused some LimitSet fields to show up as disabled when they should not have.
    • Transient Stability: Fixed bug in translating the LDTRPMON records from a DYD File
    • Transient Stability: Fixed bug in reading cmpldw2 model from a DYD file
    • Transient Stability: Fixed UEL2 model to be written into a dyr file with the correct name. It was showing UEL2_PTI and now will show UEL2.

August 1, 2023

Features and Improvements

  • Scheduled Actions: Added log messages when the Outage system state is stored/restored
  • Time Step Simulation: Added two time domain fields to show the TDateTime values (either local or UTC) since these can be used in Excel to show the date.
  • Bug Fixes

    • Transient Stability: Fixed a bug when reading the _CMPLDW model from a dyd file. If the DGDatno was not an integer (for example -100.0 instead of -100) was not reading creating the _CMP_DER_A corresponding model. This bug was fixed and now it will create the DER model if the DGDatno number is not an integer.

July 28, 2023

Features and Improvements

  • Case Information Displays: Adding additional geography fields to areas and zones, including min/max latitude/longitude values.
  • Optimal Power Flow (OPF): Changed the maximum LP iteration default limit from 9999 to 50000The default was too small for large cases.
  • User Interface Dialogs: Minor change of adding the ShowDialog to the superarea dialog list of areas
  • User Interface Dialogs: Added ability to show area fields in the area (really TSuperAreaArea) list display on the superarea dialog.
  • Bug Fixes

    • File Formats: When loading DYD file with LHVRT and LHFRT models we now treat all the timer parameters as optional. If they are not specified then a value of 0.0 is assumed. Previously if 0 values were now added to populate all 10 timer values then the DYD record would be ignored.
    • File Formats: EPC files allow the 3rd winding of a three winding transformer to be empty. Modified writing of the GMD data to an EPC file to handle this. We now write defaults for the 3rd winding (0,'',138) number, name and kV. Also added a slight change to the logic for calculating the neutral R to write in the EPC depending on the existence of the 3rd winding.

July 26, 2023

Features and Improvements

  • User Interface Dialogs: The Limit Monitoring Branch table now shows additional fields by default, which will help the user notice branches that are considered as "base case violations during Contingency Analysis"
    *"Limit Used", "% Limit Used", "Violated Normal" --> referring to be base/reference system state
    *"Limit Used CTG", "% Limit Used CTG", "Violated CTG" --> referring to be contingent system state
  • Bug Fixes

    • File Formats: Fixed a bug when reading the -cmp_der_a model from a dyd file. If the data ID number was not an integer (for example -100.0 instead of -100) was not reading the model. This bug was fixed and now it reads the model if the data ID number is not an integer.

July 21, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): While using the SaveCase script command, the PWB extension is now appended correctly to the saved file name, even when the "filename" variable in the script command does not contain the extension
  • GIC: Added ability to manage multiple GIC efield events.
  • GIC: In Time Step simulation allow the state to be stored when doing just a GIC solution; also fixed bud with Time Step Playback dialog when there are either no playback values or the dialog is closed while playing results.
  • Oneline Diagrams: Added ability from the Oneline Options to quickly change the fill color of the base objects (with the filled states an example). The button to do the change is right below the background color field.
  • Bug Fixes

    • Security Constrained OPF (SCOPF) Tool: When using the DC approximation and running a SCOPF solution, if you have either no contingencies specified, or all active contingencies do not make any changes to the reference state, then the SCOPF would calculate control sensitivities incorrectly and the SCOPF solution did not work. An odd situation, but Simulator will now properly calculate control sensitivities under these conditions.

July 12, 2023

Features and Improvements

  • Scheduled Actions: Added buttons to the Scheduled Actions dialog to Revert/Restore outages at the ViewTime, added Current Action Status field to Scheduled Action objects showing the action's own Current Status (separately from the governing Group Current Status)
  • Bug Fixes

    • Case Information Displays: Fixed a bug pasting DCTransmissionLine data from Excel. There was a conflict between "Circuit" being used as a variablename and a normal column header.
    • Sensitivity Calculations: PTDF calculations for interfaces did not include the impact of load outages on other branch outages within the interface or the impact of transferring the injection point from a bus to a gen or load in the interface. This has been fixed.

July 11, 2023

Bug Fixes

  • Sensitivity Calculations: Interface PTDFs are now modified due to the outage of a load that is defined as an interface element and the load is participating in the source or sink of the PTDF calculation.
  • Sensitivity Calculations: Shift factor calculations for interfaces have been modified to include the impact of a generator or load outages that are defined as interface elements.
  • Sensitivity Calculations: Shift factor, PTDF, and ATC tools now have an option called "Assumed Location of Injection for Bus" that will modify the sensitivity results to include the impact of generator or load outages if using a Bus as an injection point. The injection location can be defined as Bus, Gen, Load, or GenLoad. Choosing an option other than Bus will assume that the injection occurs at a gen or load at the bus, and if such a device is outaged due to a contingency action or action within an interface, the sensitivity will be updated accordingly.

July 10, 2023

Features and Improvements

  • Transient Stability: Added new option for Transient Stability under Options\Power System Model\Common which allows the user to specify two new options called MOD_IslandNewCountBus and MOD_IslandNewCountGen. During a transient stability dynamic simulation, any newly created island must have at least that many buses and that many online generators to continue simulating. If a NEW island is small, then it will be numerically ignored and no longer simulated.

July 7, 2023

Features and Improvements

  • Transient Stability: Added initial implementation of the REGC_D bus-based plant controller. This is a new controller that sits above a generator plant controller.
  • Transient Stability: Added ability for the REGFM_A1 model to accept inputs from a PlantController such as REGC_A.
  • Bug Fixes

    • Transient Stability: An access violation was caused when using the transient script command TSClearResultsFromRAM(ALL) while one of the contingencies did not have any results. This bug was fixed.

June 28, 2023

Features and Improvements

  • File Formats: When reading the hdbexport netmom CSV file, we now read the ND.ELIGIBLE field: if it is FALSE, then we set the respective Simulator's Bus field Monitor = NO.
  • File Formats: Added ability to read the TEID field for the records ST, ND, LD, CP, UN, SVS, LN, ZBR, XF, PS, CB, INTRFC, AUX. This field represents the "Transmission Equipment ID". We will read the field and create an object label with the syntax "TEID_12345" where the value 12345 is what is populated in the TEID field in the CSV file.
  • Scheduled Actions: Added "RevertScheduledActionsAt" script command which applies the opposite of any relevant actions (e.g. Closes breakers if an Action is set to Open them). It takes 1 to 3 arguments:
    WindowStart - The beginning of the window to evaluate
    WindowEnd (optional) - If specified, sets the end of the window to evaluate; if not specified, only actions active at WindowStart are reverted
    Filter (optional) - If specified, only Actions that meet the filter are reverted.
  • Transient Stability: Modified the INDMOT1P model to include new parameter Bpgas and Tpgas the add an additional term to the Mechanical Torque Equation equal to Bpgas*Speed/(1+s*Tpgas). Tpgas is a time constant to give a delayed value of rotor speed which is meant to represent the mechanical load due to the compressor gas pressure in an airconditioner compressor load. The value of delayed speed is then multiplied by the coefficient Bpgas to express how this load is weighted relative to the other mechanical load terms A, B, C0, D, and E.
  • User Interface Dialogs: On Gen Run Dialog added buttons on main page for access the Area and Substation dialogs. This mimics what is aleady available on the Load Run Dialog. On the Substation Dialog added a stability page to provide quick access to stored stability data for the substation. This matches what is done on the Generator and Bus Run Dialogs.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Device filtering for PartPoint and InterfaceElement object types was not working correctly when used with script commands. This has been fixed.
    • Case Information Displays: Dragging column headings allows you to reorder the columns. A bug would occur if you dragged a column heading from one case information display over to different one and dropped it there. This has been fixed.
    • General: Fixed bug in equivalencing due to not considering the load distributed MW and Mvar fields
    • GIC: Making changes to allow saving GIC supplemental data import settings in the PWB and AUX
    • Oneline Diagrams: Fixed bug with colormap not being restored correctly when saved with a view.
    • Oneline Diagrams: Increased the default contour min,middle,max resolution to match then change we made to the overall contour resolution in 2015. This will make contours have a higher resoluation.
    • Power Flow Solution: Fixed DC power flow bug for cases when there are two series phase shifters on control in series. The code now efficiently disables using one of them, but does not permanently turn it off of control.
    • User Interface Dialogs: BusPair listing of violations on the Limit Monitoring Settings was not properly using the LimitSet for BusPairPercent. The contingency analysis violation was working correctly and this only impacted the GUI in the Limit Monitoring Settings.

June 9, 2023

Bug Fixes

  • File Formats: Fixed a bug that was preventing the creaction of transient contingencies when loading an OTGD file.

June 7, 2023

Bug Fixes

  • Available Transfer Capability (ATC) Tool: When running iterated ATC analysis using injection groups as the source and sink and using the option to maintain a constant power factor for loads, the power factor wasn't always being properly cached from the start of the run and could change over the course of the run causing bad solutions if the load crossed 0. This has been fixed.
  • File Formats: When loading a RAW file using the special option "Keep all duplicates and update their IDs to make them unique", Simulator was doing this correctly for lines and gens, but was not doing this for transformers. This has been fixed so the special option is used for transformers also.
  • General: Fixed an access violation that would occur when loading cases in Dynamics Studio.
  • General: When using the Scale tool with injection groups and scaling load, the correct power factor wasn't always being used if using the option to maintain a constant power factor for loads. This has been fixed.

June 5, 2023

Features and Improvements

  • Transient Stability: Added support for PNG files when saving transient stability results to an image.
  • User Interface Dialogs: Added a new colormap named "IntegerB 16 Color (0-15 for Fuel Type)"
  • User Interface Dialogs: Added ability to see stability results on the Generator Dialog boxes. Shows Results from RAM, but only results related to the generator for that dialog.
  • Bug Fixes

    • Contingency Analysis: Fixed access violation which could occur when using Merit-Order scaling or tripping of an Injection Group in a contingency action or using system scaling if an Injection Group contained another Injection Group.
    • Power Flow Solution: Enhancements made in December 2022 were made so that the limit monitoring settings could have labels and be read/write using labels. This was incorrectly changing some default AUX file exports to write LimitSet objects assuming that the user had defined labels which in general users will not due. This has been fixed so that LimitSet objects are written as they were previously by default.

June 1, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): An existing feature in an aux file exists when using the special string “&objecttype ‘key fields’ variablename” the key fields and variablename can be specified using the ‘@variablename’ syntax that will lookup the value to use from the specified field. An example: SetData(Load, [CustomFloat], [“&Zone ‘@ZoneNumber’ LoadMW”], All). This will set the CustomFloat field for every load to the MW value of that field’s zone.
    Now the objecttype and keyfields can all be specified using a single variablename reference using &@ syntax. "&@variablename variablename1" can be used to specify both the objecttype and keyfields in variablename. If CustomString contains "Zone '1'" as an objecttype keyfield combination, the following example will do that same as the previous example: SetData(Load, [CustomFloat], "&@CustomString LoadMW"], All).
  • Case Information Displays: Added ability to specify an "ColorBackgroundAlternating" for case information displays. This will show alternating rows with a slightly different color.
  • Fault Analysis: Added FaultAutoInsert script command. This script command uses the CTG_AutoInsert_Options object to set the options. This can be done by loading an AUX file or with the SetData command. FaultAutoInsert creates faults according to the options set.
  • Scheduled Actions: Added "Fit Window To Schedules" button to automatically set the Start and End times in the Scheduled Action Dialog to fit the currently configured Schedules.
  • User Interface Dialogs: The Island Dialog now shows the DC tielines. DCLines also can now show the rectified and inverter bus island numbers.
  • Bug Fixes

    • Transient Stability: Modified the WEHGOV governor when the feedback flag is 1 to account for algebraic circular loop.
    • Transient Stability: Modified the PSSE generator relays FRQDCAT and VTGTPAT so if the high values are below the low values the high value is ignored -- this is noted as a warning message. Also for VTGTPAT if the low voltage is above 2.0 (which is is for one MMWG model) there is a validation error.
    • Transient Stability: Using Distributed Computing in conjunction with the Critical Clearing Time tool for Transient Stability was not functioning. This has been fixed.
    • Transient Stability: Fix a bug introduced in 5/17/23 changes when using SMIB Eigenvalue tool if the user select to Store into RAM and Store into Hard Drive and the HD file location doesn't exists it was creating an access violation. Now it will create an error and will prevent the SMIB Bus tool from running until the Hard Drive location is fixed.

May 26, 2023

Features and Improvements

  • Oneline Diagrams: Added more full PNG file type support.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Modified the calculation of PTDFs used in ATC calculations to include the impact of losing a participation point due to a contingency outage. If a gen or load in lost due to a contingency, the impact of this injection change will cause a modification to the PTDFs used to calculate the OTDFs.
    • File Formats: Fixed RAT file parsing for relay settings. The primary/secondary impedance calculations were wrong.
    • Oneline Diagrams: Fixed bug in Geo Data View dialog with adding user defined colormaps.

May 25, 2023

Bug Fixes

  • Transient Stability: Bug Fix for WT2G1 machine model. This bug was inadvertently introduced on May 9, 2023, which treated the first parameter as synchronous reactance, instead of stator leakage reactance. Bug fix for how WT2G is translated to WT2G1 in PSSE DYR file. The first parameter should be stator leakage reactance, instead of synchronous reactance.

May 24, 2023

Features and Improvements

  • Case Information Displays: On case information displays, the option to SetAllValuesTo so for numeric fields the user can scale and/or shift all the values.
  • Scheduled Actions: Some Scheduled Actions log messages can now link to the BusView of their target device
  • Bug Fixes

    • Contingency Analysis: Fixed bug that would not apply the Custom Monitor Pre Filter correctly when the custom monitor specifies a single object to be monitored. The Pre Filter was being ignored.
    • Fault Analysis: The Auto Insert Dialog from the Fault Analysis dialog was allowing you to choose either Load or BusGrouping which wouldn't insert anything. These extraneous dialog options have been removed.
    • File Formats: Bug fix for writing out to RAW file -- parameters R1-2 and X1-2 and WINDV2 are now written properly according to codes CZ and CW for 2 winding transformers
    • Scheduled Actions: Fixed Device Filtering for Scheduled Action Groups and Scheduled Actions
    • Transient Stability: Fixed bug that would delete existing transient stability results in RAM for contingencies set to skip when running with distributed computing.
    • Transient Stability: Fixed bug in ABBSVC1 in which the initial T1 state was being set not considering a < 0 constraint. This caused an initial non-zero derivative.
    • Transient Stability: When using WEHGOV, if the non-linear lookup function had X-values that were out of order we were omitting all the following points on the curve. We now only ignore that points that are out of order which is consistent with how other governors are handled. Regardless, models with proper intput data are not effected.
    • Transient Stability: For REEC_A and REEC_D, when the Pref input is available from a torque controller, PFlag=0 is used in the simulation. For WTGPT_A and WTPTA1 were used but no governor model present , there was an intial non-zero derivative for the the PI block. This is fixed.
    • Transient Stability: When the gain (KpLoad) is zero for the supervisory load PI control, then a non-windup limit is needed on the integral state
    • Transient Stability: Improvement for REEC_A/B/C/D/E models When the min/max limits on Iqv (i.e., Iql1, Iqh1) are not centered around zero, this is now indicated as a validation error, with an option to autocorrect. These should always be centered at zero, since the upstream deadband is also centered at zero.

May 17, 2023

Features and Improvements

  • Transient Stability: Added two new fields to a TSContingency for ResultFilename and ResultDirectory. By default these are blank and the existing behavior will remain which is that hard-drive results are stored to and read from the directory specified in the Hard Drive Result Storage options and all result files are expected to have the name of the TSContingency with the appropriate extension (TSR, AUX, image file format such as JPEG, and so on). This default behavior can now be overridden by specifying either a ResultFilename or ResultDirectory.
    The ResultFilename field should not include any file extension, so if a value of MyFile.tsr is specified in this field, then the actual files written out would have names such as "MyFile.tsr.tsr" and "MyFile.tsr.aux". So do not include an extension in ResultFileName.
    The ResultDirectory may be either an absolute path or a relative path. An empty string means the directory specified in the Save to Hard Drive Options is used. If this is a relative path, then it will be the path relative to the RSHD_Directory path set with the Save to Hard Drive Options. If this is an absolute path it will be used directly.
  • Transient Stability: Modified the dialog that opens to show TSContingency objects with the multiple transient plot settings so it can be open while interacting with other dialogs. The dialog however will remain on top of the main transient stability dialog.
  • Bug Fixes

    • Contingency Analysis: The May 3, 2023 patch broke the "Open with Breakers" features. This has been fixed.
    • General: The May 3, 2023 patch broke the "Open with Breakers" features. This has been fixed.
    • Scheduled Actions: Added an optional parameter to the ApplyScheduledActionsAt script command. This 4th parameter (Revert) defaults to FALSE, but if set to TRUE the command will attempt to apply the opposite action for any Scheduled Actions which would otherwise have been applied (e.g. Closing devices set to Open, Opening Breakers for devices set to Close Breakers)
    • Scheduled Actions: The May 3, 2023 patch broke the "Open with Breakers" features. This has been fixed.

May 16, 2023

Bug Fixes

  • File Formats: When loading a case that does not have a valid Case Time Stamp stored, default this date to 1/1/1970. This should fix the "Failed to set calendar date or time" error that would occur when opening the Case Description dialog.
  • Scheduled Actions: Added a log message when import PowerWorld Outage CSV files indicating if an unknown ActionType is encountered and cast as "None"

May 12, 2023

Bug Fixes

  • Distributed Computation: Installations now retain distributed computation security settings across patches and major releases.
  • GIC: Modified GIC Scale and Stretch command to allow 0 to be treated as 1 because a value of 0 makes no sense.

May 10, 2023

Features and Improvements

  • Transient Stability: When writing out a DYR file, added ability to translation from the models (WT2G + WT2E) to (WT2G1 + WT2E1)
  • Bug Fixes

    • Oneline Diagrams: Added fix for access violation when right clicking on unlinked lines. Recently added code to show the device data view or in the model explorer was causing an access violation when the element was unlinked. This has been fixed.
    • Scheduled Actions: Fixed an access violation if user attempts to load a blank file as a PW Outage CSV
    • Scheduled Actions: Fixed an access violation if user attempts to set a blank Distributed Master Password

May 9, 2023

Features and Improvements

  • Oneline Diagrams: Adding support of PNG graphics.
  • Transient Stability: Transient Stability model WT2G is now translated to WT2G1 when writing a DYR file. This translation is exact only when Ra=0 in the original WT2G model.
  • Bug Fixes

    • General: Added fix for memory leak in storage of LODF values with doubles

May 8, 2023

Features and Improvements

  • Case Information Displays: Modified the new feature for maintaining the selected row in view on the case information display so that this is only done when Ctrl-Clicking on a column header or when user an option available on the Advanced Sort dialog called "Maintain Selected Row in View"
  • Oneline Diagrams: The ImageDialog now has the ability to automatically update the image when one clicks on the crop/size/position fields. The functionality is fast on simple onelines, but it needs to be optional since on a complex oneline it might be too slow.
  • Transient Stability: Transient Stability model WT1P_B is now translated to/from USRMDL WT12A1U_B when writing/reading a DYR file
  • Bug Fixes

    • Transient Stability: In bug fix from May 5, 2023 for DC Line events, it was now possible for multiple events doing the same thing to show up at the same time in the ResultEvents in transient stability. This has been fixed.

May 5, 2023

Bug Fixes

  • File Formats: When loading RAS definitions from a Areva CSV file, fixed a bug where ModelResultOverride objects without associated Model Objects were causing an access violation.
  • Transient Stability: Modified DC Line transient models such as CDC1, CDC4, CDC6, EPCDC so that the timing of blocking could occur immediately upon the application of a fault. The decision to block would be made based on that immediate post-fault voltage. Previously if the voltage recovered back above the Vblock at the end of the time step it would then not block the converter.

May 4, 2023

Bug Fixes

  • Transient Stability: Changed how contingencies are named when automatically inserting contingencies based on bus groupings. It was possible for contingencies to have the same name if basing the name purely on the buses that are on the outside of the grouping. This would cause contingencies to be overwritten and not all expected contingencies were created. Now if a contingency is found with the same name and the contingency actions are different, the lowest bus number internal bus will be appended to the name of the contingency to make the name unique.
  • Transient Stability: Fixed bug when saving or loading CTG_AutoInsert_Options to or from an aux file when using the BUSGROUPING element type.
  • Weather: Fixed how the Transient Stability\Summary\Models In Use table and Power Flow Weather Models In Use table function in case information displays. If the Weather Related Models and Information Dialog was open at the same time as the Model Explorer was showing one of these tables the software would crash. This has been fixed.

May 3, 2023

Features and Improvements

  • Case Information Displays: On the Case Description page added support for an Assumed Date for Determining Inservice Devices. Currently this date is only used for determining whether generators are retired, future, or current. This date needs to be different from the case date since the case date is modified by the time step simulation. By default this date is the same as the case date.
  • User Interface Dialogs: Enhanced the File Browser to return all file dates: created and last modified
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: When attempting to ramp an ATC transfer with a negative step and the full step amount could not be achieved, the process could stop prematurely without attempting the full step in smaller steps due to a tolerance bug. This has been fixed.
    • Case Information Displays: Generally fixed issues with displaying and switching between filters when filtering display objects. Filters for display objects will now show up in the list of filters in both the Model Explorer and Display Explorer. This will allow them to be saved to and loaded from auxiliary files. All filters will be saved to PWB files, but only filters that are used with dynamic formatting, contours, geographic data view styles, and select by criteria sets will be saved to PWD files or AXD files of complete onelines.
    • Contingency Analysis: When auto inserting contingencies by bus grouping, groups with only 1 bus were not being named using the grouping convention to name based on the outside buses of the boundary lines. This has been fixed so these contingencies are named consistently.
    • Scheduled Actions: Fixed a bug in Open Breakers actions where already-isolated elements were misidentified as unable to be isolated
      Fixed the Current Status and InOutage fields to properly reflect the current state of Scheduled Action application
    • Time Step Simulation: Fixed a few bugs with loading aux files into the Time Step Simulation form, and on the Modal Analysis Frequency dialog added the ability to scale the mode values on the transfer.

April 21, 2023

Features and Improvements

  • Transient Stability: Added support for a new machine model named REGFM_A1 for a grid-forming converter model designed by PNNL.
  • Transient Stability: Improved Algebraic Network Boundary equation solutions at the time of fault or fault clearing for the REGC_B, REGC_C, REGFM_A1 and DER_A machine models.
  • Bug Fixes

    • Case Information Displays: Fixed bug with the wrong object type being used in the Advanced Filter dialog when the dialog is opened using the Find button on the Filter toolbar.
    • File Formats: When loading a DYD file if duplicate _cmp_der_a or _cmp_dgpv with the same data number (such as -103) were read an error occurred. This has been fixed so that whatever the final entry read will be maintained.
    • GIC: Fixed GIC scripting issues and added the GIC script command GICTimeVaryingClearB3D to clear out the b3D data. It has three boolean paraments. If the first is "Yes" then clear the file name, if the second is "Yes" then clear the GIC data, if the third is yes then clear the time points. All three default to yes, so the command can be called with no parameters.
    • Transient Stability: For both the PlayInGen and InfiniteBusSignalGen machine models, when Rth was not 0 there was a bug. This has been fixed.

April 19, 2023

Features and Improvements

  • Scheduled Actions: Added "Apply Only Filtered Actions" to the Scheduled Actions Options tab; if enabled, the Advanced Filter settings on the Scheduled Actions grid will determine which Actions are actually applied to the case.
  • Simulator Automation Server (SimAuto): SimAuto instances now run at Below Normal priority level to allow all cores on a machine to be used without danger of locking up the user interface.
  • Transient Stability: Added REEC_E Exciter Transient Model.

April 18, 2023

Bug Fixes

  • File Formats: Fixed a bug with reading transient stability DC Lines models from a dyd file. The DC Line was read incorrectly because it was expected the DC line id after the second bus and that was causing an error in the format and couldn't add the transient model. That issue was solved and reading the ID in the correct string order was added. Also writing the transient DC line model was corrected to follow the same format.
  • File Formats: Fixed error in reading the USRMDL relays models VTGTPA, VTGDCA, FRQTPA, and FRQDCA. Multiple instances at a single generator were not being read properly.

April 17, 2023

Features and Improvements

  • Bus View and Substation View Onelines: Forward and backward mouse buttons now work for moving backward and forward in bus views and substation views.
  • Bug Fixes

    • Transient Stability: Fixed a bug with the Transient Stability Contingency Dialog. When inserting a Generator Event with the dialog, the set By "Percentage of Start" was not working with the dialog. It was working with an aux file and during the simulation.

April 13, 2023

Bug Fixes

  • File Formats: It was possible to assign an invalid Control Mode to a Switched Shunt that would result in access violations when restoring the system state as part of contingency analysis, and possibly elsewhere. The Control Mode would make it appear that the switched shunt was an SVC, but it was really an invalid type. When loading a PWB file with this incorrect control mode the control mode is now set to Fixed. The error most likely originated from loading a RAW file with a switched shunt control mode of 6 that is not supported in Simulator. When loading RAW files with this control mode the mode is now set to Fixed.

April 11, 2023

Features and Improvements

  • Contingency Analysis Tool: Added option to use branch Normal Status when determining Bus Groupings as a standalone or as part of auto inserting contingencies.
  • GIC: Added a GIC script command for setting up the time-varying series. Also added logging when the time-varying series is setup and made functions for some of the more common script processes.
  • GIC: Added script command GICSetupTimeVaryingSeries(aStartTimeSec,aEndTimeSec,aDeltaTime) to update the time-varying values; for all time using parameters of 0,0,0,
  • GIC: added another parameter to the GICShiftOrStretchInputPoints command to update the time-varying values with a default of "YES"
  • GIC: added a log entry whenever the time-varying series is updated.

  • Bug Fixes

    • Oneline Diagrams: Fixed minor bug with TS Contour Toolbar contour dialog being opened when there is no oneline
    • Oneline Diagrams: On a oneline with a large number of Geo Data View objects, it could take a long time to delete an object. This has been fixed.
    • User Interface Dialogs: Fixed showing generator ID on the Breaker Isolated Groups generator table.

April 6, 2023

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): In script command "SendToExcel", the "workbookname" and "worksheetname" parameters will let the use of the special keywords @DATETIME, @DATE, @TIME, @BUILDDATE, @VERSION, @CASENAME, @CASEFILENAME, and @CASEFILEPATH.
  • Case Information Displays: When sorting on Case Information Displays now if the present view of the display is not near the top of bottom of the list of objects, Simulator will now automatically navigate to the presently selected object in the table after completing the sort.
  • Scheduled Actions: Added TimeProfile to Scheduled Action Groups, which can be Continuous or Daily
    - Continuous groups are active continuously between the StartTime and EndTime
    - Daily groups are active every day from the day of StartTime to the day of EndTime, between the time of StartTime and the time of EndTime
  • Sensitivity Calculations: Added a TBus field to show whether there are any connected closed generators, loads or shunts (including the fixed ones). This is a useful field by itself, but it is also now used in the alternative solution check to not say those buses have converged to an alternative solution.
  • Sensitivity Calculations: Modified the LikelyLowSolution field for a Bus so that it only returns YES if a bus meets all the following
    1. dV/dQ < 0
    2. Not connected to any branch with a negative (excluding 3-winding transformer windings)
    3. Has at least one closed generator, load, or shunt
    Criteria #3 was added to eliminate falsely flagged buses in some situations. A bus must have some load, gen, or shunt in order for those injections to push the local system to voltage collapse.
  • Sensitivity Calculations: Modified Bus field HasNegativeReactanceBranches so it always return NO if the bus is an internal star bus of a three-winding transformer.
  • Transient Stability: When using Distributed computing in transient stability and you want to change the mode to to "One Contingency at a Time" that will now be allowed to be done without the need for the user to go to the Options and unchecked the "Use Distributed Computing" Option. Once you initially checked the "Use Distributed Computing" checked box a similar option will appear below the Process Multiple contingency options. However, when running One contingency at a time, will not allow the use of distributed computing and as soon as you select the One contingency at a time option it will automatically uncheck the Use Distributed Computing option .
  • Transient Stability: Added a new Paux Controller PAUXSS1A.
  • Bug Fixes

    • Case Information Displays: Fixed secondary filtering of a ContingencyElement, RemedialActionElement, and other similar objects.
    • Case Information Displays: TSContingency and TSContingencyElement objects can now be filtered using the following secondary filter object types: Bus, Gen, Load, SwitchedShunt, Branch, Interface, InjectionGroup, DCLine, Area, and LineShunt. TSContingency objects can be filtered using TSContingencyElement filters and TSContingencyElement objects can be filtered using TSContingency filters.
    • Contingency Analysis: Fixed access violation that could result if any contingency generator actions for Move, Change By, or Set To are specified for a generator rather than a bus.
    • Contingency Analysis: Made significant changes to the Bus Grouping option when auto inserting contingencies. This option uses the Implicit Breakers field specified with buses to create contingencies.
    • Difference Case Tool: Difference Case Change Mode Tolerances for Substation Latitude, Longitude, UTM Northing, and UTM Easting were not being applied. This has been fixed.

March 29, 2023

Features and Improvements

  • Power Flow Solution: Power Flow Solution
    When EvalSolutionIsland = YES, a solution only terminates if ALL viable islands in the case fail to converge.
    Added a new option EvalSolutionIslandRequireLargest that when set to YES also requires that the island with the largest number of buses in it must converge.

March 28, 2023

Features and Improvements

  • Power Flow Solution: When automatically detecting parallel transformers to ensure taps ratios and regulated buses are consistent, PowerWorld Simulator uses the ZBRThreshold user-input parameter to determine groupings of buses considered the same electrical point. This ZBRThreshold is also used with generator voltage regulation and making the ZBRThreshold too large can cause numerical problems. Transformer tap and regulated bus tests for parallel transformers are not as sensitive to this threshold however, so a larger threshold is useful so that more parallel transformers can be auto-detected. This patch increases the impedance threshold for the purposes of transformers taps to be 4 times the ZBRThreshold. For example, if ZBRThreshold = 0.00029, then for transformers tap tests we will use a value of 0.00116 instead.
  • Scheduled Actions: Update PowerWorld Outage CSV to allow for unmapped actions with unknown device types
  • Bug Fixes

    • Distributed Computation: Fixed a bug generating an error when DistributedComputer credentials were being encrypted. This bug was only in the recently released Version 23.

March 24, 2023

Features and Improvements

  • Bus View and Substation View Onelines: Modified the Bus View edit box for show the presently selected bus to accept a PASTE action when the paste comes from a spreadsheet.
  • Oneline Diagrams: Added Case Info option in the Geographic Data View submenu to show the closest objects.
  • Sensitivity Calculations: Every object that has a geographic location (or can estimate one from the underlying objects), now has available fields named RefDistanceMile and RefDistancekm which shows the distance of an object from a user-specified reference point. The reference point can be set on a dialog available from the right-click menu of a case information display under the Geographic Data View submenu. This can be used with objects such as a generator or load which obtain their geographic location from either the bus or substation object, or from more abstract objects such as a RemedialAction or Interface that obtain their geographic location from the average value of objects that they contain.
  • User Interface Dialogs: Every object that has a geographic location (or can estimate one from the underlying objects), now has available fields named RefDistanceMile and RefDistancekm which shows the distance of an object from a user-specified reference point. The reference point can be set on a dialog available from the right-click menu of a case information display under the Geographic Data View submenu. This can be used with objects such as a generator or load which obtain their geographic location from either the bus or substation object, or from more abstract objects such as a RemedialAction or Interface that obtain their geographic location from the average value of objects that they contain.

March 23, 2023

Bug Fixes

  • Integrated Topology Processing (ITP): Fixed a bug causing a list index out of bounds error when running an SCOPF solution using Integrated Topology Processing when using the DC approximation.
  • Security Constrained OPF (SCOPF) Tool: Fixed a bug causing a list index out of bounds error when running an SCOPF solution using Integrated Topology Processing when using the DC approximation.

March 22, 2023

Features and Improvements

  • Available Transfer Capability (ATC) Tool: On the ATC dialog the case information displays that list the object changes for multiple scenarios cannot be modified to show different fields. This makes it difficult to save the individual scenario object types with the correct fields directly from their case information displays. The "Save As Auxiliary FIle (x Scenarios)" option found on the local menu for each object type will now save all objects for a scenario type along with the appropriate fields for updating and creating these objects. They are saved in the same manner as they are saved when using the Save Settings button on the ATC dialog to save all ATC settings. A prompt prior to saving the file will allow user input for which key field type to use. If Labels are being used and not all objects have labels, the resulting aux file will be split into objects using labels and objects using primary keys when labels aren't defined.
  • Case Information Displays: Added 4 more new generator fields the folder for "Mvar Output\Capability Curve Range\"
    CapCurveMvarMinAtMWMin, CapCurveMvarMinAtMWMax, CapCurveMvarMaxAtMWMin, CapCurveMvarMaxAtMWMax
  • Case Information Displays: Some additional generator fields for showing the retirements and inservice dates, and the EIA860 identifiers.
  • Scheduled Actions: Added ability to create unmapped Scheduled Actions reading in PW Outage CSV files
  • Scheduled Actions: Added a read-only Log field to Scheduled Action objects to display any issues that arise when the action is applied.
  • User Interface Dialogs: Modified the default "Dark Blue" Color Scheme to modify the color of the caption for the active form to a dark color to match the Ribbon. This make it so when a form is maximized you can better see the Minimize/Maximize/Restore/Close icons in the upper right of the form. These buttons get integrated into the Ribbon when the form is maximized so the color schemes need to match the ribbon.
  • Bug Fixes

    • Transient Stability: Patch: Bug fix. REPC_B model is now written out as PLNTBU1, REAX3U1, and REAX4U1 models in the PSSE DYR file format.

March 16, 2023

Bug Fixes

  • Scheduled Actions: Fixed a bug where assigning ScheduledActionGroup a filter could cause the software to hang.
  • User Interface Dialogs: When viewing the list of line shunts that belong to a branch when clicking the Line Shunts button on the branch dialog, all shunts belonging to that line should be displayed and no Advanced Filtering or Area/Zone/Owner filtering should be applied. Filtering had been applied and this has been fixed.

March 8, 2023

Features and Improvements

  • Oneline Diagrams: Changed GDVs to make it easier to work with large numbers of GDVs. The only user change is there is now a GDV Style option that controls the minimum pixel size of text to display. This defaults to 6 vertical pixels. This avoids spending lots of time waiting for a display to show text that can't be read.
  • Scheduled Actions: Added a new Scheduled Actions Script Command:
    ApplyScheduledActionsAtCurrentViewTime(StartTime, [EndTime], [Filter])
    This command applies any scheduled actions which meet the specified filter which are active during the window of time between StartTime and EndTime. If EndTime is not specified, only actions active at StartTime are applied; if no filter is specified, no filter is applied.
  • Transient Stability: Added a new TS Gen event that allows an event to set the playin voltage magnitude and speed values. The events is valid for the Gen, Set Values to or Change Values Type. Set the Action Type to PlayIn Voltage Mag, Speed.

March 3, 2023

Features and Improvements

  • Scheduled Actions: Added ActionAllow column to PowerWorld Outage CSV format to map to the action's AllowActive field.