Simulator 22 Patches

New Features

Bug Fixes

Date

December 21, 2021

Features and Improvements

  • Case Information Displays: Add a right-click option on all case information displays called "Show Field Descriptions". When clicking on Show Field Descriptions, a dialog will appear listing all the fields that are presently shown as columns in the case information display, along with the description of those fields. This is the same description that appears in the hover hints when moving the mouse over the column headers as well as the string that appears in the Export Case Object Fields option from the Window Tab in Simulator.
  • Transient Stability: Added a button on the Model Explorer when showing transient stability models called "Parameter Descriptions". This button is adjacent to the "Show Block Diagram" button that was already there. When clicking on Parameter Descriptions button a dialog will appear listing all the dynamic model input parameters for the class of model being shown, along with the description of those fields. This is the same description that appears in the hover hints when moving the mouse over the column headers as well as the string that appears in the Export Case Object Fields option from the Window Tab in Simulator.
  • Transient Stability: Modified the CMLD and CMLPDW model so that if a loading factor for a motor is set as 0.0, then we simply interpret as 1.0 instead. 0.0 causes divide by zero errors which don't make sense.
  • Bug Fixes

    • Oneline Diagrams: Fixed various issues with being able to update generator field objects on a oneline using an AXD file and selecting specific generator display fields based on the field that they are displaying using the Select by Criteria tool.
    • Oneline Diagrams: Fixed a bug specifying the most commonly used load display fields when using the Select by Criteria tool.
    • Oneline Diagrams: Fixed a bug specifying the most commonly used transformer display fields when using the Select by Criteria tool.
    • Transient Stability: When storing to result to RAM, if a plot contains a value Simulator will automatically store that value to RAM. This was not working properly for the VSCDCLines so that these results were not stored to RAM automatically. One could choose to store them in the Result Storage options but they were not automatically stored. This has been fixed.
    • Transient Stability: Fixed defaults for the CMPLDW load model -- the values for the single phase motor model were being set as though it was a three-phase model.
    • Transient Stability: Bug fix for DISTRELAY line relay model to prevent relay operation during load encroachment.
    • Transient Stability: Fixed initialization issue with OEL4C

December 16, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command PVDataWriteOptionsAndResults("filename", AppendFile, KeyField) that will write out all options and results associated with the PV tool to an auxiliary file. This writes out the same information as PVWriteResultsAndOptions except that it will ALWAYs use the concise variablenames and headers and use DATA sections instead of SUBDATA sections.
  • Auxiliary Files (SCRIPT and DATA Sections): Added Use Concise Format checkbox to the PV saving options dialog when saving to an auxiliary file using the Save Auxiliary button on the PV Curve tool dialog. This will always use the concise variablenames and headers and use DATA sections instead of SUBDATA sections.
  • Auxiliary Files (SCRIPT and DATA Sections): Added script command QVDataWriteOptionsAndResults("filename", AppendFile, KeyField) that will write out all options and results associated with the QV tool to an auxiliary file. This writes out the same information as QVWriteResultsAndOptions except that it will ALWAYs use the concise variablenames and headers and use DATA sections instead of SUBDATA sections.
  • Auxiliary Files (SCRIPT and DATA Sections): Added Use Concise Format checkbox to the QV saving options dialog when saving to an auxiliary file using the Save button on the QV Curve tool dialog. This will always use the concise variablenames and headers and use DATA sections instead of SUBDATA sections.
  • Auxiliary Files (SCRIPT and DATA Sections): Added parameter AppendFile to the QVWriteResultsAndOptions("filename", AppendFile) script command. This is an optional parameter that can be omitted and will be YES by default.
  • Auxiliary Files (SCRIPT and DATA Sections): When saving ATC settings to an aux file either using script commands or the Save Settings button on the ATC dialog, any injection groups that are used with transfer direction definitions will also be saved.
  • Available Transfer Capability (ATC) Tool: Added TransferLimiter field called Report Limit that is YES for the limiter that has the lowest overall Trans Lim value if there are no limiters that were iteratively found or the lowest Trans Lim value for the limiters that were iteratively found. This is the same limiter that is reported in the results table for multiple scenarios.
  • Case Information Displays: For Switched Shunt Case Information Displays added AutoControl field as a default column
  • Time Step Simulation: Time Step Simulation input now has an option to input a values are the scaled based on a combination of the initial value and the variation in another (selected) column. A common example is scaling load in which the desire is to make the load conforming say between areas.

  • Bug Fixes

    • Transient Stability: Fixed a bug with VTGTPAT timers. If the Relay Pickup Time (RelayTP) is more than 30 seconds there were some errors in the timer. This was fixed and now the relay will act in the correct time.

December 9, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): PVWriteResultsAndOptions script command will now save interfaces and injection groups that are part of the PV options or part of remedial action dependencies. Objects that are dependencies of contingency and remedial action definitions will also be saved. These changes also apply to Save Auxiliary button on the PV Curve dialog.
  • Auxiliary Files (SCRIPT and DATA Sections): QVWriteResultsAndOptions script command will now save objects that are dependencies of contingency and remedial action definitions. These changes also apply to Save... button on the QV Curve dialog.
  • Power Flow Solution: On the Power Flow Solution Options, Advanced Options page, added an option in the Control (Middle) Loop Options called Var Limit Backoff Voltage Tolerance (VarLimitBackoffVtol). This parameter had always been hard-coded to 0.00005 per unit previously. This is the tolerance on when to backoff generator Var limits based on how far the regulated the bus voltage is beyond the voltage setpoint. This controls the transition from a PQ back to a PV bus (backing of a Var Limit).
  • Time Step Simulation: In the Time Step Simulation there is now a local-menu item to delete all the input columns. This is a common operation, and the new commands saves the time of having to select all the columns.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed issue with editing the Weight field for InterfaceElement when loading from an AUX file. This field was not being updated when loaded from an aux file.

December 8, 2021

Features and Improvements

  • User Interface Dialogs: General File Browser added support for searching for *.tsb files.

December 7, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Renamed ATCWriteAllOptions script command to ATCDataWriteOptionsAndResults to better reflect what this is actually doing - writing both options AND results while using the concise format without SUBDATA. ATCWriteAllOptions can still be used as a legacy name.
  • Transient Stability: Added transient result events for the REEC_D model when it blocks and unblocks the machine model.
  • Transient Stability: Changed the name of the model InductionMotor3P_A_Beta to instead by INDMOT3P_A. PowerWorld will still read old models with the name InductionMotor3P_A_Beta in as INDMOT3P_A however.
  • Bug Fixes

    • Transient Stability: Fixed an error in that could occur when using the REEC_D electrical control model in combination with the REGC_B machine model when the REEC_D model blocks the machine model.

December 6, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Updated the removed duplicate interfaces feature to handle limits. Previously, the interface limits of the first interface encountered in a series of duplicates were kept. This has been updated so that the limits will be updated to keep the most restrictive set of interface limits.
  • Case Information Displays: Updated the removed duplicate interfaces feature to handle limits. Previously, the interface limits of the first interface encountered in a series of duplicates were kept. This has been updated so that the limits will be updated to keep the most restrictive set of interface limits.
  • Case Information Displays: Added new available fields for an Island to show DistMW and DistMvar across the island.
  • Case Information Displays: Added the DistMW and DistMvar as default columns on the Case Information Displays for Areas and Zones.
  • Transient Stability: Modified plots so that various colors can be specified to make it easier to create plots with darker backgrounds. This added the following fields to various plot objects.
    TSPlot: TitleFontColor, TitleFontColorUse
    TSSubplot: BackgroundColor2, AxisColor, GridLineColor, LegendColor, BackgroundColor2Use
  • Transient Stability: Modified plots so that you may specify whether fonts appear in bold. This added the following fields to various plot objects.
    TSPlotVertAxisGroups: TitleFontBold
    TSPlot: TitleFontBold
    TSSubPlot: AxisTitleFontBold, TitleFontBold, FooterFontBold
  • Bug Fixes

    • Case Information Displays: Fixed out of range error that could result when saving Model Filters to an auxiliary file using the local menu option to Save As Auxiliary File on the Model Filter case information display.
    • Oneline Diagrams: Right clicking on an unlinked bus display object could result in an access violation. This has been fixed.

December 1, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script commands
    CTGCloneMany(filter, "Prefix", "Suffix", SetSelected);
    CTGCloneOne("ctgname", "newctgname", "Prefix", "Suffix", SetSelected);
    See the help documentation for more information.
    https://www.powerworld.com/WebHelp/#Other_Documents/Auxiliary-File-Format.pdf
  • Case Information Displays: Limit Groups now have a Memo field for user-specified memos.
  • GIC: The Time Step Simulation has been modified to better support time-varying GIC calculations. This includes the ability to enter an delay on the start of the GIC waveform. Also, in the GIC with the time-varying waveform times before the start of the waveform now return zero GIC voltages; previously they returned the starting values (this shouldn't matter much since the starting point is usually all zeros anyways).
  • Transient Stability: Added the ability to plot a generator's apparent impedance R and X on the machine MVABase.
  • Bug Fixes

    • PV and QV Curve (PVQV) Tool: When saving cases as part of PV state archiving, do not store any PV, QV, or ATC results to the cases.
    • Transient Stability: When closing and reopening a plot inside the PowerWorld User Interface, the default height of the plot was shrinking by several pixels each time. This has been fixed to maintain the previous size of the plot dialog.
    • Transient Stability: Some transient stability result fields for plotting and reporting are calculated from other values. For example, the Bus V in kV is calculated from the Vpu value. These calculated fields could be used, but they were not working properly when used as the horizontal axis value on a plot. This has been fixed.
    • Transient Stability: Fixed an issue with SCl2 and OEL2C models. With the time inverse functions: K[(Ipu/ITPF)^C -1], when the Ipu is negative that will lead to an undefined solution. When Ipu is negative it is treated as zero and the exponential function (Ipu/ITPF)^C will return 0 and basically the output of the inverse function is set to -K.

November 22, 2021

Bug Fixes

  • Power Flow Solution: Fixed error that can occur in rare situations when solving the power flow on a case that contains breakers, not using Integrated Topology Processing, and a portion of the system is islanded.

November 19, 2021

Features and Improvements

  • Case Information Displays: Added more column plotting options
  • Simulator Automation Server (SimAuto): In SimAuto command GetSpecificFieldList, modified to return the Enterable information in array index 4
  • Bug Fixes

    • Transient Stability: For the REPC_A and REPC_B model, added features on August 31, 2021 to handle bad user-input when a branch is NOT specified in the input parameters. When this occurs, then previously we always treated P, Q, and I inputs to the model as 0.0. This was changed to instead use the output of the generator. However, there was a bug when PUFlag<>0 meaning the inputs were assumed on the model MVABase and the inputs were the PUFlag was not being handle properly when the branch was not specified and values of generator output were not scaled by MVABase. This has been fixed.

November 18, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): New script command CTGComboSolveAll(DoDistributed, ClearAllResults). This will run the contingency combination analysis for all primary and secondary contingencies that are set to not be skipped. DoDistributed is optional parameter that is NO by default. Set DoDistributed to YES to use distributed computing for the combination analysis. ClearAllResults is optional parameter that is YES by default. If YES all existing results will be cleared even if a primary contingency is marked to be skipped. If NO only those primary contingencies that are marked to not be skipped will have their results cleared.
  • Auxiliary Files (SCRIPT and DATA Sections): New script command CTGComboDeleteAllResults that will delete all results that are associated with combination analysis including violations, what occurred, combination summary results, and injection sensitivities.
  • Case Information Displays: added column to the Export Object Fields to show whether a particular field is Enterable in PowerWorld. The field with either be
    Yes : means the field can be edited
    AUX/Paste: means the field can be edited via an AUX file or via copy/paste features on a case information display
    Blank : means the field can not be edited
    Yes/Always: This means a field that can even be edited when other fields can not be (such as when in Difference Mode). An example is the Selected Field or the Area and Zone Shown field for filtering
  • Case Information Displays: On the Display/Column options dialog for a case information display, modified to allow you to show whether the field is enterable or not by using the font color of the field.
  • Contingency Analysis Tool: Distributed computing can now be used with Contingency Combination Analysis. Each distributed process will analyze 1 primary contingency and as many secondary/regular contingencies as specified by the Number of Contingencies to Process.
  • Simulator Automation Server (SimAuto): In the SimAuto command GetFieldList(), added an additional entry in the output for each field which shows information about whether the field is "Enterable". The value will be blank if the field is not enterable, otherwise an appropriate string will appear indicating when it is enterable.
  • Bug Fixes

    • Case Information Displays: When show the Area Tielines and adding fields to show the Zone information for the tieline, if the table contained a lot of Load tielines it could be very slow. This was because PowerWorld was returning a list of "ALL zones that belong to the Area of the load" or the "Area of the bus". This could be a long list and would be repeatedly calculated. This has been changed so that instead we return the "Zone of the Load" and the "Zone of the Bus" instead as this is more in keeping with what is done for AC branches which return the "Zone of the Near Bus" and the "Zone of the Far Bus"
    • Contingency Analysis: The contingency solution option to "Dynamically add/remove slack buses as topology is changed (Allow Multiple Islands)" CANNOT be set to allow multiple islands if it has previously been set to not allow multiple islands. This will be enforced when the contingency specific solution options are applied.
    • Contingency Analysis: Abort button on the contingency combination analysis dialog should function correctly now.

November 17, 2021

Features and Improvements

  • Case Information Displays: Added fields to store switched shunt summary fields for buses, areas, zones, and substations. This includes the Mvar range and the Mvar percent of range.
  • Case Information Displays: Enhanced the StringGrid Column Plot to provide more flexibility.
  • Contingency Analysis Tool: On the CTGComboResults object, modified to make the following fields enterable which then pass the enter to the appropriate Contingency or ContingencyPrimary object: CTGPRI_Skip, CTG_Skip, CTGPRI_CustomInteger, CTGPRI_CustomFloat, CTGPRI_CustomString, CTG_CustomInteger, CTG_CustomFloat, CTG_CustomString
  • Oneline Diagrams: Added a new oneline display object for a Background Triangle.
  • Oneline Diagrams: Made the option when importing a KML File to add the Points as Ellipse, Squares or Triangles.
  • Time Step Simulation: Added warning messages in the log when specifying to store PWBs to a directory that does not exist.
  • Time Step Simulation: Added ability to do DeleteColumns from the right to the left column. This can be faster for some case information displays.
  • Time Step Simulation: Added option in Time Step Simulation to initialize load values from the current power flow case.
  • User Interface Dialogs: Clicking on the Modify Transformer Parameters button will now open the three winding transformer dialog if the transformer is part of a three winding equivalent.
  • User Interface Dialogs: When plotting generator reactive capability curves there is now a footnote at the bottom if AVRAble or Use Capability Curve are false. There is also a note if what is drawn is a default curve and not one that has been explicitly defined.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): For 3-winding transformers there was a misspelling in the variable name for
      3WXFMagnetizingG and 3WXFMagnetizingG which were spelled
      3WXFMagetizingG and 3WXFMagetizingG instead (notice missing n).
      These misspelling were fixed in Version 22, but Version 22 will also read the old misspelled variable names. In Version 21 the misspelling was left, but patches of Version 21 after this date will also read the correct spelling so AUX files written in Version 22 can be read in Version 21.
    • Auxiliary Files (SCRIPT and DATA Sections): When loading an AUX file or editing a case information display the 3WXFormer fields for RegBusNumSec and RegBusNumTer, the setting of regulated bus number was not being processed correctly. This has been fixed.
    • Contingency Analysis: The contingency solution option to "Dynamically add/remove slack buses as topology is changed (Allow Multiple Islands)" CANNOT be set to allow multiple islands if it has previously been set to not allow multiple islands. This will be enforced when the contingency specific solution options are applied.
    • Distributed Computation: Fixed an issue with distributed transient stability where transferring large result files could cause distributed transient stability to crash or hang.
    • QV Curve Tool: The QV solution option to "Dynamically add/remove slack buses as topology is changed (Allow Multiple Islands)" CANNOT be set to allow multiple islands if it has previously been set to not allow multiple islands. This will be enforced when the QV specific solution options are applied.
    • Time Step Simulation: Fixed a bug that could sometimes occurring when inserting new time points.
    • Transient Stability: modified the CHATGY model to not accept a DC Auxiliary Controller input. This model has the parameters for a CHAAUT as part of it so accepting a different Auxiliary Controller was not appropriate.

November 9, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added new Iteratively Found string CTG_FAIL_ITERATED_OVERLOAD that indicates that the contingency failed to solve at some point during the Iterated Linear Step (IL) then Full CTG method and using the option to iterate on failed contingencies. The Transfer Limit that is reported is the accumulated amount that is possible for which the contingency solves, but the monitored element is overloaded, as determined by a linear step calculation, at this transfer level. Using the iterated method attempts to get as close as possible (within specified tolerances) to the highest transfer amount at which the contingency will solve. This is very similar to a PV nose point.
  • Transient Stability: Added "MW Nominal Tripped" field for tracking and plotting results for loads in transient stability. It will also be recorded for Areas and Zones as a field. This field tracks the Nominal MW Tripped during the entire simulation.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Removed the change made in the 6/22/21 patch for the ATC (IL) then Full CTG solution method that set the new stepsize to (stepsize + stepsize/2) when the stepsize is negative and the monitored element is overloaded. This change does not work in all situations. This was instead fixed by improving the ATC (IL) then Full CTG solution process when iterating on a failed contingency to better handle negative stepsizes and stepsize changes needed to find a solution for the contingency and attempt to reduce the loading on the monitored element to its limit.
    • Sensitivity Calculations: Update the algorithm to determine unnecessary interface element line open elements to also catch buses isolated by contingent interface elements. The isolated buses cause numerical problems in the sensitivity calculations. The algorithm fixes this by removing one of the contingent interface elements. This has no effect on the interface flow because the flow through the bus is still zero, but fixes the numerical problems.

November 8, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Modified so the following objects can return information about any SupplementalData that contains the object referred to by the Violation or Signal: ViolationCTG, LimitViol, TSLimitViolation, TSResultAnalysisSignal, TSResultAnalysisViolation, TSResultAnalysisModeMagAngle
  • Case Information Displays: Modified so the following objects can return information about any SupplementalData that contains the object referred to by the Violation or Signal: ViolationCTG, LimitViol, TSLimitViolation, TSResultAnalysisSignal, TSResultAnalysisViolation, TSResultAnalysisModeMagAngle
  • Case Information Displays: For switched shunts, Mvar only, added fields to show the range (Max - Min) and the percentage of range. Both of these values are based on the nominal Mvar fields. On the range, since a switched shunt is ultimately switchable, zero is always a valid entry. So if switchedshunt has a fixed value of 100 Mvar, its range would be 100 since it could be opened. On the percentage there are two options. The first is the percent in the range. This value is always >= 0. The second is the percent about zero. This value can be negative if the shunt allows for negative values. For example, with a switchedshunts with limits between -100 and 100 Mvar, if its nominal output is -50 Mvar, the first percent would be 25%, and the second would be -50%.
  • Case Information Displays: For buses added fields to show the generator reactive power reserves up and down and also the range.
  • Case Information Displays: For Areas, Zones, and Substations, added the generator reactive power range as a field.
  • Transient Stability: Added new fields for Transient Nominal Tripped Load for Area, Zones and Injection Groups.
  • Transient Stability: For the Transient Result Analyzer, modified the Statistics for the ResultAnalysisSignal to also include the Final Value in the time period being studied
  • Transient Stability: Modified TSResultAnalysisSignal and TSResultAnalysisViolation to show the first 9 custom float values for the object of the Signal or Violation. This makes it easy to copy values to the underlying object like a bus, load, etc... to then use for some user purpose.
  • Transient Stability: When writing out a DYD file, modified the writing of CMPLDW models to write a #1 instead of a #9 to avoid hitting the maximum number of channels enforced in PSLF.
  • User Interface Dialogs: Added a tab showing the list of switched shunts in the area; this matches what has long been available for Zones and Substations.
  • User Interface Dialogs: Added fields to Switched Shunt dialog to show the terminal per unit voltage and the nominal voltage.
  • Bug Fixes

    • Contingency Analysis: If a new Custom Monitor was created after contingency analysis had already been run, the results for the Custom Monitor would not always show up if using the Solve Selected Contingency option. This has been fixed.
    • General: In TransLineCalc, fixed the conductor database to have the proper number of significant digits for the various conductor parameters.
    • Transient Stability: When tracking the Percent field of a transmission branch, the value in transient stability is always the percentage of the MVA Limit. Previously it was not clear that this was the case.

November 1, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added special processing for ISO-New England for reading an entire case as an AUX file (called by choosing File\Option Case or when using the OpenCase script command). Previously, special processing was occurring whenever any AUX file Branch DATA section was read, but this was removed in the May 10, 2021 patch because the old behavior was causing bugs in some new ISO-NE processes. Dating back to 2006, ISO-NE had expected the PowerWorld would automatically populate the BranchDeviceType field when reading an AUX file that has Branch objects with CustomString, CustomString:1, or CustomString:2 fields with entries of "line", "zbr", "breaker" etc. The patch for today has brought back that behavior but ONLY when loading an entire case as an AUX file and when the BranchDeviceType field for a particular branch was not populated anywhere else in the AUX file. This new patch brings back the old behavior desired by ISO-NE, but prevents the problem with general AUX files found in May 2021.
  • Available Transfer Capability (ATC) Tool: Script commands have been added to access these features: InterfaceRemoveDuplicates; and InjectionGroupRemoveDuplicates. (See Case Information Display patch update below for an explanation)
  • Case Information Displays: When working with data that has been collected from multiple organizations, it is possible to have duplicate interface and injection group definitions that have the same elements but different names. Previously this was difficult to detect. We have added a feature to detect and remove duplicate injection groups and interface definitions. This is implemented with the 'Remove Duplicates' button which can be found in the local (right-click) menu for both objects. The 'Remove Duplicates' feature applies to all injection groups or interfaces. Any duplicate definitions are deleted from the model. For comparison purposes, an injection group participation point is considered to be the same if it is for the same object, has the same AutoCalc value, initial value, and participation factor. An interface element is considered to be the same if it references the same object with the same monitored and weighting. The order of the participation points or interface elements does not matter for the duplicates check.
  • Oneline Diagrams: Added two new discrete 21 color maps that are suppose to work well in color blind situations.
    Added a 34 color discrete contour that is similar to what is used by ERCOT for their LMP map.
  • Oneline Diagrams: Added an object list for KML File Imports objects. Also now can read lines and points that are not in PowerWorld Format. Points will be drawn as an ellipse.
  • Bug Fixes

    • File Formats: Fixed a bug that could under very rare circumstances cause Simulator to hang or fail when opening older supported text file formats. This was not a problem with AUX files.

October 27, 2021

Features and Improvements

  • Oneline Diagrams: On the Format Dialog, Display/Size page the X and Y values for the selected objects are shown, and can be changed. The dialog also shows the range of the X an Y values for all the selected objects.
  • Oneline Diagrams: Made a minor change to the Align Group Objects function. Previously when taking a vertical group of objects and doing a horizontal align it would set the horizontal position based on the average of their x locations.  Now it sets their position based on the horizontal location of the top one in the group.  The same is true when aligning horizontally, except it uses the left one in the group.
  • Bug Fixes

    • Contingency Analysis: If Contingency X resulted in a partial solution (some islands are solved while others are not) and the very next Contingency X+1 did not do anything (for example it opened a branch that was already open in the reference case), then Contingency X+1 would also report as a "Solved=Partial" instead of the correct "Solved=YES". This has been fixed.
    • File Formats: When loading a case saved using the Save Two Bus Equivalent option with Transient Stability that contained Supplemental Data containing objects that are not saved with the two bus equivalent, an access violation could result. This has been fixed.
    • QV Curve Tool: Fixed access violation that could occur when running QV analysis and no buses are selected for analysis.

October 25, 2021

Features and Improvements

  • Time Step Simulation: Added a few more fields for showing the TimeDomainOPF input field counts, including a total input field count.
  • Bug Fixes

    • Transient Stability: Bug fix for Line Relay models DISTRELAY and DISTRELAYITR.
      When using TransferType = DUTT/PUTT/POTT/DCB, the communication signal was not obtained correctly from the companion relay.
      This was affecting both tripping and reclosing of transfer trip lines (i.e. RecloseWithFault=0).

October 22, 2021

Features and Improvements

  • Contingency Analysis Tool: Added local menu option to the Primary Contingency case information display to Insert Special > Auto Insert Primary Contingencies.
  • Bug Fixes

    • Time Step Simulation: Fixed bug with pasting data into the Time Step Simulation. The issue is the paste was ignored for if the data did not already exist for the particular time point.
    • Transient Stability: Bug fix for Line Relay models DISTRELAY and DISTRELAYITR.
      When using TransferType = DUTT/PUTT/POTT/DCB, the communication signal was not obtained correctly from the companion relay.
      This was affecting both tripping and reclosing of transfer trip lines (i.e. RecloseWithFault=0)

October 21, 2021

Features and Improvements

  • Contingency Analysis Tool: Fixed an issue in Contingency Analysis. When Storing Results into Hard Drive if the file location didn't exist it was setting internally the file directory to nothing and it was causing the results to be lost when finishing the analysis. Now it will prompt an error for the user to fix the file directory before continuing with the analysis.
  • Transient Stability: Added new Transient Contingency Action for a Shunt object to change the "Vsig or Vref" on the dynamic model. This can be used to perform a step-test in transient stability on a model such as SVSMO3 which has a Vsign that is initialized as part of the model.

October 18, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added new Iteratively Found string "INIT_RESERVE_LIMIT" that indicates that a reserve limit has been hit in the initial part of the iterated process when all limiters are iterated on. Hitting a reserve limit here will cause the entire process to stop and it wasn't obvious from the results that this had occurred; this was being reported in the ATC log but not with the TransferLimiter records.
  • Transient Stability: Added parameter check for min and max in PF1 and VAR1.
  • User Interface Dialogs: Previously when clicking on the button to change transformer parameters, if the branch was a three winding transformer section, we would just display a message telling the user to go to the three winding transformer table and open the three winding record to modify the parameters. I changed it so that now when you open the branch dialog of a transformer that is part of a three winding transformer, and click the button to modify the transformer parameters, the three winding transformer dialog is automatically opened (as a Modal form) so the user can edit the three winding parameters. When they click OK, it goes back to the branch dialog and calls SetInfo to update the two winding transformer displayed with any changes that were made to it from the three winding dialog.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): In Version 22 there is now an option to "Save As\Auxiliary File with Options" when right-clicking on a case information display. This gives you more features to choose to save related objects (InterfaceElements with the Interface objects for example). Because of this feature it was easier to save Gen object along with their bid curves and as a result we removed a prompt asking you what to do when saving a list of generators. This was working, but it had inadvertently been written to ALWAYS write extra data sections for the generator bid curves and capability curves when saving a gen table. This has been fixed so it will not store those unless choosing to features in "Auxiliary File with Options"
    • Auxiliary Files (SCRIPT and DATA Sections): When storing Extra Data sections as part of saving an AUX file (for example InterfaceElements with Interface objects), modified so that the default is 6 decimal places for the sub objects. Previously it was only 3 which was sometimes not enough to maintain precision.
    • Available Transfer Capability (ATC) Tool: The ATC Multiple Scenario Results table is populated with information from the limiter with the lowest Trans Lim value from all limiters that have been iterated on. If none have been iterated on then it is populated from the limiter with the lowest Trans Lim value. It was possible if a reserve limit was hit during the initial part of the iterated process when all limiters are iterated on that the limiter chosen was the first one in the list and not necessarily the one with the lowest Trans Lim if none of the limits had been marked as being iterated on. This has been fixed.
    • Available Transfer Capability (ATC) Tool: When attempting to get a failed contingency solution to solve using SOLUTIONFAIL actions, remaining SOLUTIONFAIL actions would not be applied if the last action made no changes. This has been fixed.
    • Transient Stability: Modified how numeric fields of the PlayInInfo and PlayInSignal object are shown in the GUI and written to an AUX file.
      Now, no matter what is specified for the number of decimal places, we will write at least 4 significant digits to ensure the user doesn't accidently truncate the digits too much.

October 13, 2021

Features and Improvements

  • Case Information Displays: Added columns to LoadModelGroup objects which show the LoadMW, LoadMvar, DistMW, DistMvar, DistMWMin, DistMWMax, LoadNetMW, and LoadNetMvar. These fields show the summation of these quantities across all the loads assigned to the LoadModelGroup.
  • Transient Stability: Added new exciter model ESURRY (from DYR) and exac1m (from DYD). These are the same exciter model and will be named ESURRY in PowerWorld Simulator, but when written out to a DYD file as an exac1m.
  • User Interface Dialogs: Modified so the General File Browsing form is not closed when someone opens a case using the form.
  • Bug Fixes

    • Contingency Analysis: Injection group contingency actions for Change By or Set To that are Persistent could cause excessive POSTCHECK iterations to occur when no changes are being made. This has been fixed.
    • File Formats: Modified how fault impedance is specified when loading a type of fault from an OTGD file
    • Transient Stability: Fixed a how parameter checks on values exceeding the maximum value allowed for the parameter was handled when validating data in transient stability.
    • User Interface Dialogs: Fixed a bug in the line length field where entering a value string that was not a properly formatted number would result in a weird value inserted in the field instead of resetting the field value back to the previous valid value, as it should have been.
    • User Interface Dialogs: Also modified the File Browser so that the Advanced Filter and Advanced Sort features work even when opening the File Browser dialog before open a case of any kind. Previously nuisance access violations could occur.

October 6, 2021

Features and Improvements

  • Contingency Analysis Tool: AutoInsert of Primary Contingencies was added to the CTG Combo Analysis tool.
  • Transient Stability: Added option to transient stability load modelling "Trip Extra Mvars from initialization when individual load components are tripping". By default this is set true. When true, then the Extra Mvars (Bf1 and Bf2 in the distribution equivalent model) calculated to balance the load components for complex loads such as CMPLDW, CMLD, CLOD, and LoadComp will be tripped as individual load components trip during the simulation. If this is set false, then all Extra Mvars will remain in service even as load components trip.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): An error message will now appear in the message log when loading a blank interface element from an auxiliary file.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in new feature added on September 30, 2021 to "Modify Definition due to Isolated Elements on Selected Interfaces". When run repeatedly on the same case it was adding duplicate actions for opening the same generator. This has been fixed.
    • File Formats: Fixed access violation that could occur when loading a PWB file that contained blank unlinked interface elements.
    • User Interface Dialogs: Fixed bug on the interface definition portion of the Model Explorer. When choose a particular interface the subtabs for Load Open and Gen Open were not properly showing the list of actions.
    • User Interface Dialogs: Added a option for saving unlinked interface elements to an auxiliary file when using Save As Auxiliary File with Options when saving to an auxiliary file from the Interface case information display.

October 1, 2021

Features and Improvements

  • Contingency Analysis Tool: Added Convert regular contingencies into Primary contingencies. The new option is located under the Insert Special menu by the option: "Convert into Primary Contingencies..."
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug where changing the SVC type of an SVC to type 2 or appending an SVC of type 2 using the AppendCase script command in an AUX file would cause an access violation.

September 30, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Also added a new script command to do the same with the syntax
    InterfaceModifyIsolatedElements("filtername");
    The filtername is an optional input parameter and if not specified that this is done on all interfaces. The filtername uses the common syntax for specifying either SELECTED, AREAZONE, Filter Name, or Device Filter.
  • User Interface Dialogs: Added a new right-click menu option on a list of Interface Definitions to "Modify Definition due to Isolated Elements on Selected Interfaces"

September 28, 2021

Bug Fixes

  • Optimal Power Flow (OPF): fixed potential oscillation in the solution of the DC OPF solution when using a case with 1000s of contingency interfaces defined on a larger case.

September 27, 2021

Bug Fixes

  • Case Information Displays: Fixed error with using Difference Flows with CustomFloats and CustomIntegers.
  • File Formats: Fixed bug when saving version 33 or less RAW files that could add a blank line at the start of the load records.

September 21, 2021

Features and Improvements

  • File Formats: Added FaultType for BusFault and LineFault when reading a Transient OTGD file.
  • Transient Stability: Added support for the model WTGIBFFR_A. This model is a Paux controller which is initiated for under-frequency events and plays into the Paux input on various governor and exciter (electrical control) models. In particular it is intended to be played into the REEC_D model for wind turbine models. The model can also be read and written to the DYD format.
  • Bug Fixes

    • File Formats: When reading an OTGD transient file for elements that happened at the same time but a parameter (for example in a branch opening then NEAR and FAR End at the same time) was different it was not adding the event correctly. This has been fixed.

September 17, 2021

Features and Improvements

  • Contingency Analysis Tool: On the Contingency Analysis dialog under the Results tab, there are tables show summary information about Branches, Buses, Interface, BusPairs, etc indicating how many different contingencies cause a violation on the respective object. Add a new option on the right-click menu under the object-specific sub menu to "Delete Associated Violations". This will delete all the violations associated with that object.
  • Bug Fixes

    • Transient Stability: Fixed a bug that when adding a new field in transient stability in a new version, when loading the results from hard drive into RAM was showing an empty column corresponding to that field in the TimePoint Results Table.
    • Transient Stability: Fixed initialization error when using an REGC_B machine model in combination of a type 3 wind turbine model using a WTGTRQ_A (or WTTQA1) model.
    • User Interface Dialogs: Fixed field translations on the Display Explorer.

September 16, 2021

Features and Improvements

  • Transient Stability: Modified REEC_D model so that the Thld2 parameter acts to freeze the value of Ipcmd instead of the value of Ipmax as is done in REEC_A model.
  • Transient Stability: Added the ability to read and write models ESST1C and ESST4C to a dyd file. The equivalent models in PowerWorld are ESST1C = ST1C and ESST4C = ST4C.
  • Transient Stability: Added support for REPC_C plant controller model
  • Bug Fixes

    • Transient Stability: There is a bug that resulted in an Access Violation if you try to right click the Signals table with no signals in the table in the Modal Analysis Form in Transient stability.
    • Transient Stability: Removed harmless but confusing event reporting in transient stability for out-of-service DC transmission line dynamic models.
    • User Interface Dialogs: Fixed inconsistencies when changing between per unit and percentage voltage changes when using the options to never report or always report voltage violations with contingency analysis.

September 10, 2021

Bug Fixes

  • Optimal Power Flow (OPF): In very rare situations for Interface definitions that contain many BRANCHOPEN InterfaceElements that result in the complete isolation of parts of the power system the calculation of the interface flow could become inaccurate. This could mess up calculations such as an OPF solution which uses the Interface MW flow to calculate the OPF solution. Internally, a numerical summation of very large values is done and that calculation was incorrectly using single-precision floats (7 significant digits). A user encountered an example where the equivalent of the subtraction of (123456789 - 123456789) was not returning 0.0 but instead what appeared to be random 2 digit number. This has been fixed by using double-precision instead to maintain enough significant digits to prevent this bug.
  • Transient Stability: Fixed the option on the Transient Stability dialog when processing multiple contingencies to choose whether to show results by a single contingency or multiple contingencies on the Results from RAM tabs.

September 8, 2021

Bug Fixes

  • Oneline Diagrams: Left-clicking and dragging on top of a background line when in Run Mode should simply pan the oneline in the direction of the dragging. This worked for most background lines, but not if the background line had been created by loading from a Shapefile. This has been fixed.

September 7, 2021

Bug Fixes

  • GIC: Fixed some errors with trying to get results for a transient stability run of the transformer GIC.
  • Transient Stability: Fixed some errors in VHVDC1 implementation.

September 3, 2021

Features and Improvements

  • Transient Stability: Adding new REPC_C plant controller model for testing
  • Bug Fixes

    • File Formats: Changes made in August 20, 2021 patch for storing information read from an EPC file regarding VSC DC Line objects caused a bug with saving out a PWB after loading a RAW file for a case that includes a VSC DC Line. This has been fixed.

September 2, 2021

Bug Fixes

  • Transient Stability: Fixed a bug where distributed results were not being saved to hard drive.
  • Transient Stability: When creating an open transient contingency action for a branch, the One Phase Open option will no longer appear on the GUI dialog. This option has not been implemented and an action defined as this would act the same as an Open Both action.

August 31, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command LineLoadingReplicatorCalculate with the syntax
    LineLoadingReplicatorCalculate([Branch 1 2 1], [InjectionGroup ig1], Yes, 50.0, NO, DC);
    LineLoadingReplicatorCalculate([Branch 1 2 1], [InjectionGroup ig1], Yes, 50.0, NO, DC, No, 0.5, 2);
    The parameters are
    1. Identifying string for the branch
    2. Identifying string for the injection group
    3. YES or NO for whether to only include AGC=YES devices
    4. Number representing the desired MW flow on the Branch
    5. YES or NO for whether to implement the changes after performing the calculation
    6. DC, AC, or DCPS for the linear solution method to use to perform calculation
    7. Optional, YES means to use the fields MWMax and MWMin for limits on load changes. NO means to use a multiples of the existing load for the minimum and maximum, with the multiplies as next 2 parameters
    8. Optional, If parameter 7 is NO, then this is the multiple of the existing load to use a minimum value (should be less than 1.00)
    9. Optional, If parameter 7 is NO, then this is the multiple of the existing load to use a maximum value (should be greater than 1.00)
  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command LineLoadingReplicatorImplement. This command has no parameters. The command will implement the control changes found by the LineLoadingReplicatorCalculate() command, so it is important to run that command before this.
  • File Formats: Added ability to store values read from EPC file for a 2-terminal DC line for values not used in power flow solution:
    Rectifier Gamma Min, Rectifier Gamma Max, Inverter Alpha Min, and Inverter Alpha Max. While these values are not used with the power flow solution, the value Inverter Alpha Min is used in the recently added CHVDC2 model. That value is not included in the DYD record for the CHVDC2 model, so we must carry it around with power flow data to properly read EPC/DYD file pairs.
  • Bug Fixes

    • Oneline Diagrams: Fixed how substation display objects use Default Drawing Values to highlight voltage limits. If showing the "Min kV of Highest Nom kV" or "Min PU of Highest Nom kV" fields within a substation display object, the color of this text will be the Limit Highlight Color specified with the Default Drawing Values if at least one bus in the substation is outside its voltage limits. If there is dynamic formatting in effect the dynamic formatting color will be used instead. The Limit Highlighting Used field was being ignored, but it is now being used to determine if the Limit Highlight Color should be used. The default color for the substation text will be used when the Limit Highlight Color is not used and in the absence of any dynamic formatting.
    • Power Flow Solution: Fixed bug that could prevent the DC converter equations from solving to a solution very close to the minimum firing angle at the rectifier. The solution may instead setting a transformer step 1 stepsize away a solution near the mimimum firing angle.
    • Transient Stability: Cleaned up the network boundary equation for the converters of a VSCDCT VSCDCLine dynamic model.
    • Transient Stability: Modified the bad input data treatment when the branch P, Q, or I measurement are needed for an REPC_A model but a branch is not specified. Previously we just assumed all flow measurements were 0.0, but this has been changed so that in this situation we use the output of the generator instead.
    • Transient Stability: Fixed a bug with Result Analyzer that was giving the wrong data value in some data points if the results were loaded from Hard Drive. For example a field that is scaled by SBase.

August 27, 2021

Bug Fixes

  • Transient Stability: Modifying how blocking is treated in the VHVDC1 voltage source converter DC line model. Also cleaned up the network interface equations for the VHVDC1 VSC DC Line dynamic model
  • Transient Stability: Fixed a bug where plots from a Distributed TS run were not being generated correctly when other results were not being stored

August 25, 2021

Features and Improvements

  • Case Information Displays: Updated description for the Int MW field for areas, zones, etc. to better reflect how it is calculated.
  • Oneline Diagrams: Improved the handling of Case Information Memo oneline fields.
  • Transient Stability: Added ability to load the VHVDC1U user-written model from a DYR file and load it into a VHVDC1 model in PowerWorld. This is a voltage-source converter DC line model (VSCDCLine)
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When interpreting interface elements for loads using a single string meant to represent the label of the load, it was possible for it to mis-identify the load if the user was using a label for a load that was exactly the same as either a bus number or "name_kv" of a bus in the system and that bus had a load. This has been fixed.

August 24, 2021

Bug Fixes

  • File Formats: Fixed access violation that was introduced in previous patch on 8/20/21 which would occur when loading a RAW file with a DC line record. Bug only existed in 8/20/21 patch.

August 20, 2021

Features and Improvements

  • File Formats: Added ability to read "vs converter data" from EPC files and then parse the records to create 2-terminal VSC DC Line objects. Also added the ability write the "vs converter data", "dc bus data", "dc line data" to an EPC file.
  • Oneline Diagrams: Added a new feature called a Spatial View which can be used for temporarily laying out a part of the system using geography if available. Intent is for this feature to work like a temporary Bus View, though you will also be able to save the spatial view as a stand-alone oneline after building it.
  • Power Flow Solution: Added 2 new options to modify the algebraic equations used to model line-commutated DC converters. Both options are not recommended, but when reading an EPC file PowerWorld will set these 2 options to YES so that the DC converter solutions will match the equations used by PSLF.

    Use Approximate DC Converter Power Factor Equations:
    Sim_Solution_Options VariableName = UsePSLFConverterApproximatePowerFactor
    Set to YES to use an approximate calculation (to match what PSLF does) for DC converter power factor of
    cos(Phi) = 1/2*(cos(FiringAngle) + cos(FiringAngle + mu))
    instead of the more accurate equation
    tan(Phi) = (2*mu + sin(2*FiringAngle) - sin(2*(mu + FiringAngle)))
    /(cos(2*FiringAngle) - cos(2*(mu + FiringAngle)))

    Use PSLF treatment of Fixed Tap in DC Converters:
    Sim_Solution_Options VariableName = UsePSLFConverterIncorrectFixedTap
    This only impacts DC converter transformer equations.
    NO - Uses the correct equation of TotalTap = VariableTap + FixedTap - 1
    YES- Uses the incorrect equation of TotalTap = VariableTap*FixedTap (implemented by PSLF).
  • Transient Stability: Added ability to read from a DYD file VHVDC1 models for 2-terminal VSCDCLine records.
  • Bug Fixes

    • Transient Stability: Bug fix for generating plots of fields only if they are stored in Hard Drive (storing to RAM is okay). Users might have observed that incorrect values were being plotting fields of certain devices. For example, plotting the "OEL Other 1" field for a Generator which does not actually have an OEL Active. The correct behavior is to not show any plot series on the generated plot, because the field itself does not exist for that generator. This issue is now fixed.

August 18, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: For the TransferLimiter object type, the variables for ATC_ExtraMonitor and ATC_ExtraMonitorSens can now be identified by the object identifier for the object they are monitoring instead of the location number. Example: ATCExtraMonitor:"Branch '1' '2' '1'".
  • Bug Fixes

    • File Formats: Fixed a bug where when reading an EPC file with multiple Shunt sections, we would only process the shunts in the last section read, and the previous sections of shunts would be lost.
    • Oneline Diagrams: After the file save is complete when using the ExportOneline script command, the oneline will now be returned to the options and view that were in place prior to issuing the command.
    • Transient Stability: Any OEL connected to Exciter ESST4B now has the ability to automatically modify the VOEL output so that initial limit violation can be prevented when the "Modify Limits" option is chosen in Transient Stability options. This modification will only occur if an OEL can initialize to Activation Status = Idle.
    • Transient Stability: When Qref=0 for OEL4C, internally the program sets Qref to current Qmax from the power flow records. This was already being done. However, for generators that have an internal step up transformer, Qmax needed to be transformed to the generator terminal-side. This modification has now been made.
    • Transient Stability: Fixed the Exciters EXAC1, EXAC1A, EXAC2, EXAC8B and REXS to work properly when the Hard Limit is implemented with the OEL1 Over excitation model. Previously the EFd limits were calculated without taking into effect of the function Fex in the output of the Exciter.

August 16, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): For ATCWriteToText script command, messages will appear in the log if any invalid field variable names are specified.
  • Available Transfer Capability (ATC) Tool: Added new option for handling branch and interface limit violations in the PV tool. There is now an option called "Stop in Base Case Only" that can be applied to either type of violation. When this is used, only base case limit violations can cause a scenario to be critical. Any limit violations that occur for contingency scenarios will be ignored.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When loading a Custom Monitor from an auxiliary file or pasting from Excel and the Object Name is not specified as blank and cannot be found, set the Enabled field to NO so this custom monitor is ignored. When the Object Name is blank this means that all objects of the specified type will be monitored. Do not want all objects monitored by default if the particular object cannot be found.
    • Transient Stability: Fixed a bug when the loads do not have a distributed generation model but do have distributed generation load defined with the load and the total load was negative. It was causing some transient solution problems. Also a warning will be presented when the distribution generation do not have a transient model but have distributed generation with the load.
    • Transient Stability: Fixed a bug with the Result Analyzer Time Window dialog. When setting the Maximum number of violations to store, if a number greater than a 100 was set with the dialog, the value was set to a 100. In the Result Analyzer time window table the maximum number of violation to store was working fine.

August 9, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command named RotateBusAngleInIsland. The first parameter is the identifying information for a bus between square brackets and the second parameter is a numeric value for a new angle. The script command will rotate all the angles in the island to which the bus belongs by the same shift such that the specified bus ends up with a bus angle specified by the second parameter.
    RotateBusAnglesInIsland([BUS num], Value);
  • Case Information Displays: Added a right-click option on a case information display of buses to "Rotate Bus Angles in Island". You then choose what angle you would like at the bus you have chosen and then all angles in the island to which this bus belongs are rotated by the same angle to achieve the desired angle at the chosen bus.
  • Case Information Displays: Added fields to branches in Neighbors\Parallel Branches with Flipped Terminals to indicate if there are parallel branches with flipped terminals. This could indicate a modeling error, particularly for transformers.
  • Transient Stability: In VHVDC1 the Pacref is treated as equal to 0.0 when either converter is blocked. This modification also changes it so that Idcref is also treated as 0.0 when either converter is blocked. This only mattered when using the dPmax and dPmin values to enforce a rate limit on the change in Pacref.
  • Transient Stability: Added the signals 'Iact', 'Ibias', 'Terr', 'IERRinv1' and 'IERRinv2' for the OEL2C model Other Fields.
  • User Interface Dialogs: Added button to the Edit Mode Branch dialog to allow the easy flipping of the from and to buses.
  • Bug Fixes

    • File Formats: Fixed an access violation that could occur when during saving/loading primary contingency records.
    • File Formats: Fixed access violation that would occur when loading an EPC file which contained no Shunt record section.
    • Transient Stability: More robust initialization for OEL2C.
    • Transient Stability: When an OEL model was getting VFE from generators as an input it was not getting the VFE correctly.
    • User Interface Dialogs: Fixed bug when entering the branch Length on the Branch Options dialog while in edit mode. The edit box was being updated with a conversion to the selected miles or km unit while typing a new value making it impossible to enter the desired value.

July 30, 2021

Features and Improvements

  • File Formats: Adding features to load RAW Version 35 files

July 29, 2021

Bug Fixes

  • GIC: On GIC, Time Varying Electric Fields added error message is someone tries to load an upsupported file type. Previously this was causing an exception error.
  • Transient Stability: Fixed a bug in where the Result Analyzer wasn't working when needed to load results from Hard Drive. Now it loads results from hard drive and also works to load some results from RAM and Hard Drive at the same time.
  • User Interface Dialogs: Fixed a bug with the Generator Display dialog in Edit Mode when modifying the Voltage Tolerance it was setting the Voltage Setpoint to the Voltage Tolerance when you close the dialog or hit the Save button.

July 23, 2021

Features and Improvements

  • File Formats: Fixed a bug with the MBL in the WECC switch file that wasn't creating the transient contingency. Now it will create the MBL transient contingency.

July 22, 2021

Features and Improvements

  • General: On the Tools, Connections, Determine Shortest Path Between
    1) added a tab that shows the lines that are in the path
    2) corrected the order in which the buses are shown to start at the start bus and go to the end bus, 3) on the list displays for the buses, substations, areas and zones added a local menu entry to get access to this form. Because the Buses list display already had local menu entry to another form for showing the shortest path it now has two options with the original (older) approach labeled as old. A difference with the older approach is it did include DC lines show some folks might prefer that. This old form also now shows lines.
  • Transient Stability: Changed the transient stability so when a generator is closed by default its MW setpoint is not set to zero. However the generator is taken off of AGC control.
  • Bug Fixes

    • Transient Stability: Changes associated with closing a generator in transient stability. Now they work correctly when closed at off-nominal speed. Also, AGC control is disabled when a generator is reclosed.
    • Transient Stability: Cleaning up captions for transient events when specifying to close generators.
    • Transient Stability: Fixed a bug where TS plots in a Distributed run were showing up blank if other results were not saved.
    • Transient Stability: Fixed a bug with the OEL2C that was creating an initialization problem for the exciters derivatives because it was setting the OEL output to the incorrect initial value.
    • User Interface Dialogs: Fixed errors on the Direction dialog

July 16, 2021

Features and Improvements

  • Oneline Diagrams: When auto inserting buses or substations on a oneline diagram based on geographic coordinates stored with data records and the coordinates are not valid, messages will now appear in the log indicating that objects could not be added to the oneline.
  • Transient Stability: Changed the defaults for the TTSGenOther_AGCControlModel_BASE to all zeros to emphasize by default they are automatically set.
  • Transient Stability: Improved network convergence when CHVDC2 model uses the commutation failure features.
  • Transient Stability: Added ability to feed in the auxiliary current signal into the CHVDC2 model

July 15, 2021

Features and Improvements

  • User Interface Dialogs: On BusesShortestPath added showing the lines. This can then be used with GDV displays.
  • User Interface Dialogs: Removed the Close button on the Keyboard Shortcuts dialog because it didn't do anything. The X to close the dialog does everything that needs to be handled before the dialog is closed.
  • Bug Fixes

    • General: Improved performance when deleting GICXFormers.
    • General: Fixed an issue where downgrading from a later patch release to an earlier patch release would break the Simulator installation causing the main executable to not be replaced by the earlier version executable.
    • Transient Stability: Temporary disabling the Result Analyzer when using the State Manual Control tool button pressing of One Time Step or Until a Specific Time. You can do it after the simulation stops is just that the default is to check for the Analyze Time Window option and if it is checked then it will do it right after the simulation stops and sometimes we do not have enough points and create access violations and other issues.
    • User Interface Dialogs: New features from July 7 for directly specifying a Custom Detail were not working properly and caused the CustomDetail dialog to appear when opening the oneline display options dialog. This has been fixed.

July 9, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added LoadAXDFromAXD("filename", CreateIfNotFound) script command that will allow a display auxiliary file (AXD) to be loaded via this script command that is part of another display auxiliary file (AXD).
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug that when the the script command was using a space in the string for a file type it was causing an error in the script command. Now if the user put a space in the file type of the script command it will not cause an error for the script.
    • Available Transfer Capability (ATC) Tool: When doing an ATC calculation, a contingency that completely isolates either the buyer or seller will be ignored by the ATC calculation.

July 8, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): FixFlowArrowLineEnds and FixFlowArrowPosition script commands now have both input parameters as optional. When the Oneline name is not specified the script commands will be applied to the oneline for which the AXD file was applied. When the LayerName is not specified any flow arrow objects in any layer will be modified.
  • Bug Fixes

    • Transient Stability: For stability added an offset field to the Area AGC to that all the area agc dispatch does not occur at the same time. Ideally this field is a random value that is between -0.5 and +0.5 of the update time.
    • Transient Stability: Fixed a bug that when loading Advanced Options in Transient Stability plots, if the chart have more than one subplot it was causing an error. That error was fixed and the advanced options are loaded for the entire chart.

July 7, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added script command ATCWriteScenarioLog("filename", AppendFile, filter) that will write the detailed log information for ATC Multiple Scenarios.
  • General: When a case has been modified a prompt to save the case will appear by default if opening another case, open a new blank case, or closing Simulator. If this happens while the contingency dialog is open and the system state is not in the contingency reference state, another prompt appears asking if the contingency state should be saved. There is now an option to Cancel so that the original action that led to the prompt will be abandoned and allow the case to be saved as the modified base case and not the contingency state.
  • General: Added an option on the Simulator Options Environment page to "Prompt for saving modified case." This is checked by default. This is only stored in the registry and does not have auxiliary file support. When not checked the prompt for saving a modified case when opening a new case, opening a new blank case, or closing Simulator will not appear.
  • User Interface Dialogs: Added ability to access saved custom Display Detail levels both through the Options ribbon tab and through the local menu on onelines.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed an "ID collision" error that could occur when trying to move a three-winding transformer to different buses or change the ID.

July 1, 2021

Features and Improvements

  • Optimal Power Flow (OPF): Previously it was possible to attempt to solve the OPF/SCOPF with the Island-based AGC enabled. This should not have been allowed since it is using two different algorithms to dispatch the same generation. The code has been modified to present an error message 'Error: cannot solve OPF with Island-based AGC enabled.' when an OPF/SCOPF solution is attempted with Island-based AGC enabled.
  • Security Constrained OPF (SCOPF) Tool: Previously it was possible to attempt to solve the OPF/SCOPF with the Island-based AGC enabled. This should not have been allowed since it is using two different algorithms to dispatch the same generation. The code has been modified to present an error message 'Error: cannot solve OPF with Island-based AGC enabled.' when an OPF/SCOPF solution is attempted with Island-based AGC enabled.

June 30, 2021

Features and Improvements

  • Power Flow Solution: Added Message Log warning messages when a VSC DC Line is not properly configured to alert the user that the VSC DC Line is being ignored. As an example, if both converters are configured for MW control and error message will be generated that says "DCMode at From and To Converter are both the same. One side must be set to Power and the other to Voltage for the VSCDC Line to operate."
  • Security Constrained OPF (SCOPF) Tool: set hints for the SCOPF form options, and added longer descriptions for them
  • Bug Fixes

    • Contingency Analysis: Fixed bug properly displaying contingency injection sensitivity results in the Contingency Violations Display (LimitViol object type).
    • Distributed Computation: Fixed distributed computation computer verification so that when no machines are defined, verification no longer causes Simulator to freeze.
    • Optimal Power Flow (OPF): In some cases MWMarginalCostValues was not being saved as subdata when saving an AUX file
    • Power Flow Solution: If a generator had a negative MW output and it was using Boundary Power Factor control to set the Mvar limits, the Mvar limits would end up switched with the minimum being positive and the maximum being negative. This has been fixed.

June 28, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: When storing ATC Extra Monitor flow values in the base case for use when estimating extra monitor flows at various transfer levels when using the iterated ATC methods, an extra flow value will now be included when contingencies are being iterated on at the base case transfer level at which the contingency last solved.
  • Power Flow Solution: Added option to "Use Loss Factor For DC Line tielines". This will use the two-terminal DC line aLoss term to assign the metered point a fraction of the way along a two-terminal DC line. This term was always maintained previously but not used in the solution. This feature is supported in EPC files but not RAW files. PowerWorld Simulator now has a global option regarding whether to use this Loss Factor. When not using the Loss Factor (aLoss) we will default back to the MeteredEnd specification instead.

June 25, 2021

Features and Improvements

  • Case Information Displays: Exposed multi-section line ID field in the branch table under the Multi-Section Line folder with the name MS Line ID.
  • Bug Fixes

    • GIC: Modified so the GIC Analysis Form, Field/Voltage Input the Non-Uniform Input Field (usually a b3d) field is enterable with the result saved.
    • Transient Stability: When reporting total load for the entire case in transient stability when load models include a distribution equivalent, the totals were not correct. They were correct for individual loads, areas, zones, substations, etc... but not for the entire case. This has been fixed.
    • Transient Stability: Fixed an access violation when Saving Data from the Show/Save Selected Plot Data option in the Plot Designer. The error was happening when the plot included a PlayIn Signal. It was preventing the data from been saved. This error was fixed.

June 22, 2021

Features and Improvements

  • Contingency Analysis Tool: Added code to keep unlinked contingency elements when reading OTG contingency files. Previously unlinked contingency actions were discarded.
  • Oneline Diagrams: The Text Object dialog now has a format button to give direct access to the format dialog. This matches what has long been done with the line dialog.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: In ATC when using the (IL) then Full CTG solution method, corrected how a negative stepsize is handled when iterating on a failed contingency and the limiting element is overloaded at a step when the contingency does solve. When iterating on a failed contingency the stepsize is reduced by half if trying to find a transfer where the limiting element is not overloaded. This is incorrect if the stepsize is negative because the stepsize needs to become more negative to reduce the loading on the limiting element. The new stepsize is now (stepsize + stepsize/2) to make it more negative.
    • Available Transfer Capability (ATC) Tool: Fixed a couple of inconsistencies with the ATC solution when using the (IL) then Full CTG Solution.
      (1) When iterating on individual limiters with a contingency implemented, use the OTDF cutoff threshold instead of the PTDF cutoff threshold.
      (2) When iterating on individual limiters with a contingency and an infinite transfer level is reached during the step where the limiter is iterated on by linearly modeling the contingency, no longer continue to the step where the contingency is actually implemented. The result will report Iteratively Found as YES_INFINITE.
    • Contingency Analysis: Fixed infinite loop that might result when using Best Fit actions for contingencies and remedial actions.
    • Transient Stability: Fixed a divided by zero in HYG3 when (fRelec = 0) and (fRGate = 0).
    • Transient Stability: There was an access violation bug when no results are saved into RAM or Hard Drive but saving plots as a file. The problem is fixed.

June 17, 2021

Bug Fixes

  • Difference Case Tool: Fixed an access violation that would occur when saving present case topological differences over an entire model when some of those changes include new or changed three winding transformer star buses.
  • File Formats: When loading a FACTS device from a PTI RAW file which was translated to a switched shunt SVC with svsmo3 there was a divide by zero error occurring. This has been fixed.

June 15, 2021

Features and Improvements

  • Oneline Diagrams: Enhanced ability for finding objects on a oneline diagram
  • Bug Fixes

    • Case Information Displays: Fixed a bug with Limit Monitors when creating a limit monitor the user puts a bus pair limit greater than A, B, C pr D. It was creating an access violation. This is now fixed.

June 11, 2021

Bug Fixes

  • Oneline Diagrams: Added error message to InsertConnectedBusesAction when trying to insert buses connected to a display bus based on it being linked to the specified data Bus object if no display objects can be found. This is not considered a fatal error.

June 10, 2021

Bug Fixes

  • Oneline Diagrams: In the AutoInsertBorders_Options object more than one border file can be specified to be applied at one time. This would not work if the specified borders included spaces before or after the comma delimiter. This has been fixed.
  • Oneline Diagrams: Fixed access violation that could occur when auto inserting interfaces on a oneline diagram.
  • Transient Stability: Fixed an access violation that happens when the transient simulation is aborted because of limit monitors and there are not enough points to do the result analyzer modal analysis. Now it will not have the access violation and the modal analysis will not be done.
  • Transient Stability: When auto-inserting transient contingencies the multiple contingency grid was not refreshing and showing the new inserted contingencies. You needed to get out of the multiple contingency option and return back in order for the grid to refresh. That was fixed and now will refresh after auto-inserting contingencies.

June 9, 2021

Features and Improvements

  • Case Information Displays: Fixed bug that was making the Bus Fields LoadNetMW and NetMW conflict with one another resulting in the NetMW field (showing the net injection at the bus) to not work properly. (Same fix for LoadNetMvar and NetMvar).
  • Bug Fixes

    • Optimal Power Flow (OPF): Fixed OPF initialization problem.
    • Security Constrained OPF (SCOPF) Tool: Included two additional SCOPF options when saving the options to an AUX file: "Set Solution as Contingency Analysis Reference Case" and "Basecase Solution Method"
    • User Interface Dialogs: The Close and Help buttons on the SCOPF dialog would move to the right when increasing the size of the dialog. This has been fixed.

June 7, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added AXD file support of GeoDataViewSummaryObjects and SummaryLineObjects.
  • Bug Fixes

    • Transient Stability: Added code for Critical Clearing time to work with result window analyzer and eliminated the messages from appearing when running the analysis in other than the result analyzer gui.

June 4, 2021

Features and Improvements

  • Power Flow Solution: Continued improvements with handling switched shunt ranges voltage setpoints that may conflict with generator setpoints.
  • Bug Fixes

    • Oneline Diagrams: When showing the oneline option to show out-of-service elements as dashed lines, the symbols for a transformer and series cap/reactors were not showing as dashed. The line segments up until the symbol were dashed, but not the symbol. This has been fixed so that the symbol also appears as dashed.
    • Security Constrained OPF (SCOPF) Tool: Included two additional SCOPF options when saving the options to an AUX file: "Set Solution as Contingency Analysis Reference Case" and "Basecase Solution Method"
    • Transient Stability: Added exciter ESST1A_GE to be able to set a Hard Limit with the over excitation OEL1.
    • Transient Stability: UEL2C now allows parameter KUI = 0
    • User Interface Dialogs: Fixed a bug with the Switched Shunts dialog that when the shunt is an svsmo3 was showing the current pu values multiplied by the Sbase for the Continuous Range and the Switching Range. Now it will show the values in pu value of the current. A better caption was inserted for making explicitly that the Continuous Range and the Switching Range is in pu of the current.

June 2, 2021

Bug Fixes

  • File Formats: ZBR Threshold value used when determining regulated buses for generators, switched shunts, and transformers was not being saved to PWB files. This has been fixed.
  • General: Added more error checking when copying and pasting so that errors don't result in access violations.
  • Oneline Diagrams: When showing the oneline option to show out-of-service elements as dashed lines, the symbols for a transformer and series cap/reactors were not showing as dashed. The line segments up until the symbol were dashed, but not the symbol. This has been fixed so that the symbol also appears as dashed.
  • Power Flow Solution: ZBR Threshold value used when determining regulated buses for generators, switched shunts, and transformers was not being saved to PWB files. This has been fixed.
  • User Interface Dialogs: When using an SVC type svsmo3 the Switching parameters are in Amps. We were using them in Amps in our code but the dialog was displaying the Switching parameters as Mvar. Now it shows Amps in the dialog for the switching parameter.

June 1, 2021

Features and Improvements

  • Transient Stability: modified treatment of D term for the new MOTORC to be the exponent for mechanical power.
  • Transient Stability: Added ability to read/write the ESAC8C model from a DYD record.
  • Bug Fixes

    • Case Information Displays: Fixed fields displaying improperly when in base case or difference display mode.
    • Case Information Displays: Fixed access violation that could occur when loading auxiliary file with DataGrid section that contains an empty ColumnContourInfo subdata section.
    • Contingency Analysis: Bug fix for access violation during saving a case with contingency results and then deleting a transmission line. This would happen if one of the terminal buses was referenced in the Contingency Elements as a Bus open or close.
    • Distributed Computation: Fixed an issue where distributed transient stability didn't return result analysis violations. This is now fixed.

May 27, 2021

Features and Improvements

  • Transient Stability: Added a new load model named MOTORC which is a combination of the INDMOT1P with the same contactor, under-voltage, and thermal relays added as used in LD1PAC.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Transfer Limiter case information displays for specific types of limiters were not displaying the correct column headers when viewing Normal headers. This has been fixed.
    • Contingency Analysis: Fixed access violation that would occur when saving primary contingencies without any results. The code was attempting to access the results without first initializing them.

May 26, 2021

Features and Improvements

  • Contingency Analysis Tool: Modified the Best Fit Open contingency and RAS actions for Interfaces and Injection Groups. The algorithm attempts to find the smallest number of devices that can meet the desired amount. The more devices there are to consider the more time it takes to determine all of the possible combinations. If there are more than 20 devices, the devices will be sorted from high to low impact and examined in blocks of 20. If the entire 20 devices are needed to meet the desired amount all will be opened and then next block of 20 devices will be used to meet the remaining amount. This process continues until it is not required that a set of 20 devices are all required to meet the remaining amount. This block will use the combination algorithm to fine tune which devices are opened.
  • Transient Stability: Internal modifications to the LD1PAC model to split up the features of the under voltage, contactor, and thermal relays into pieces so that these can be applied to other load models
  • Transient Stability: modified SVSMO3 so that values of Kdbd < 1.0 are treated as Kdbd = 1.0

May 25, 2021

Features and Improvements

  • Available Transfer Capability (ATC) Tool: With iterated ATC methods added two new Iteratively Found strings: YES_INFINITE and FULL_INFINITE. These indicate that the PTDF/OTDF have become too small in the process of iterating on an individual limiter, and the transfer limit is treated as infinite. This had previously been indicated by the Trans Lim value being set to a very large number, and now these new strings give another clearer indication of this. Additionally, the highlight color for these types of limiters are lighter versions of yellow and blue used to indicate YES and FULL limiters, respectively.
  • Contingency Analysis Tool: Added script command CTGVerifyIteratedLinearActions that takes a single parameter, filename, for an input. This action will save a file that identifies which fields and conditional actions (remedial actions) are valid for use with the iterated linear analysis method for contingency and ATC analysis.
  • Transient Stability: For some exciters added checking when E1=E2 and SE1 <> SE2 <> 0.
  • Bug Fixes

    • Distributed Computation: When running distributed contingency analysis the Selected field for Contingency objects was being set to NO after the run. This has been fixed.

May 24, 2021

Features and Improvements

  • GIC: Updated GIC code to better handle intermediate buses of multi-section lines. If the intermediate bus does not have any latitude/longitude specified then we will estimate the location using branch resistance values.
  • User Interface Dialogs: Updating the multi-section line dialog. There is now a regular listing of the buses in the object.
  • Bug Fixes

    • Contingency Analysis: When saving a PWB file and the contingency analysis dialog was open, the options as set on the dialog were not always being saved to the PWB file. This has been fixed.
    • File Formats: When reading an EPC file and SVCs are allowed to control fixed shunts the linking to the fixed shunts was not being done correctly. This has been fixed.
    • Oneline Diagrams: Fixed a bug where the Snap To Grid setting was continually being reset to True
    • Power Flow Solution: When multiple lines that are not in series are closed and they have common bus terminals, angle smoothing does not work correctly. When this situation is encountered voltage estimates will be done instead on the buses that are involved in the line closures

May 19, 2021

Features and Improvements

  • User Interface Dialogs: Updated the Multi-Section Lines dialog to include geography and GIC field support. Also added buttons on the Branch dialog to provide access to the Multi-Section Line dialog. Also also added fields to a branch to show if there are in-service or bypassed series capacitors on lines.
  • Bug Fixes

    • File Formats: Corrected some fields written for SVD devices in the EPC format export.
    • Oneline Diagrams: Fixed a bug where some display elements were not properly linking to their intended anchors when loading a PWD file
    • Transient Stability: Fixed error in how the short-term Rating Curve is applied to the SVSMO3 model. This was not allowing the SVSMO3 to supply a current a multiple of Ishrt higher for a short period of time when configured to do so.

May 18, 2021

Features and Improvements

  • Transient Stability: Modified how network boundary equation solution is handled when bypassing a DC line using the CHVDC2 model. It now ensures that an extra solution occurs and bus frequency calculation is updated to prevent strange bus frequency calculation spikes when bypassing and unbypassing.

May 14, 2021

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): SaveData script command will now produce an warning message if an empty fieldlist is specified.
  • Available Transfer Capability (ATC) Tool: Fixed access violation bug when deleting transfer directions from multiple direction ATC analysis. This only happened after ATC analysis had been run (i.e., transfer limiter results were present).

May 13, 2021

Features and Improvements

  • Case Information Displays: Added new summary information for the summation of Load Dist MW Max, Load Dist MW Min, Load Net MW, and Load New Mvar for the following aggregations: Bus, Area, Zone, Substation, Owner, InjectionGroup. Previously you could only get information about the Min/Max and Net values for loads by looking at individual load records or by creating your own calculated field.
  • Bug Fixes

    • Distributed Computation: Fixed an issue in distributed contingency analysis where contingency violation injection sensitivities may be dropped when the controlling Simulator program is running on a computer under high load.
    • Distributed Computation: Added the ability to gather worst overload data over all contingencies for all branches when running distributed contingency analysis. Previously this data was only available through non-distributed contingency analysis.
    • File Formats: Bug fix for RAW file reading. Angle value was not being set correctly for node data read from a "SUBSTATION NODE DATA" section.
    • Transient Stability: Modification to help with numerical integration of the INDMOT1P and INDMOT1P_PTR load models

May 11, 2021

Features and Improvements

  • Case Information Displays: When creating a new Case Comment through script or aux file, a blank Time can be specified. Time is used as a key field so the current time will be increased in second increments until a unique time is found when loading multiple comments at the same time.
  • Bug Fixes

    • Transient Stability: In PowerWorld parameters T1, T2, T3 and T4 are in seconds in DISTRELAY and DISTRELAYITR but in DYD files those parameters are in cycles in DISTREL. These paraemters are now properly converted accordingly when reading and writing those parameters from the DYD format
    • Transient Stability: Exciters DC4B, ESDC4B and DC4C modification of Max limits at initialization.

May 10, 2021

Features and Improvements

  • Transient Stability: Modified so that if the State Pitch (output) of WTGPT_B is stuck at a non-windup limit, then if the PitchControl state has a derivative pushing the output further against its limit the PitchControl state derivative will also be set to 0.
  • Transient Stability: Modified so that if the State Pitch (output) of WTGPT_B is stuck at a non-windup limit, then if the PitchComp state has a derivative pushing the output further against its limit the PitchComp state derivative will also be set to 0
  • Transient Stability: Modified the REEC_D electrical control model so that when it goes into a blocking mode it instantaneously forces the currents at the network boundary equations of the generator to go to zero.
  • Transient Stability: Added a way to store DYD extra records in the pwb. Records like for a vscdc line or a dcmt model can be read. The strings can be saved with the pwb case and the user can see the string in a case info table and can delete them if desired. Then you can save the dyd file and those extra records will be also in the file.
  • Transient Stability: On the Modal Analysis Form there is now an option to Always Reload Signals from Source. If checked then the modal analysis signals are always reloaded from the source, as opposed to using the signals already in Modal Analysis. This option is most useful when the source is changing and the user would like Modal Analysis to always use the new source value. An example is when the source is the TS plots. This option is useful when the user is changing the TS and rerunning, and then looking at how the modal analysis results have changed.
  • Bug Fixes

    • File Formats: Removed old process that would update BranchDeviceType for a branch based on entries in CustomString:0, CustomString:1, or CustomString:2 after loading any aux file with branch data or using a SetData command on branch data. (This dated from 2006 and should have been removed years ago)
    • File Formats: Fixed failed power flow solutions that might occur when opening an EPC file while in edit mode.
    • GIC: Bug fix for reading PSLF *.GMD supplemental data file for (i) rdcsw/common parameter of 2 winding transformer, and (ii) kfactor for 3 winding transformer.

May 3, 2021

Features and Improvements

  • Transient Stability: Added the ability to read and write ESST5C model to a dyd file.
  • Transient Stability: Added the ability to read and write ESST6C model to a dyd file.
  • Transient Stability: Added stator frequency dependence on the CIM5_PTR model
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): In the SendToExcel script command the ClearExisting parameter was not being read correctly if enclosed in double quotes. This has been fixed.
    • Contingency Analysis: When using transient stability models with power flow contingency analysis no changes should be attempted if the device or the device's bus is disconnected. Not checking the bus connection status could cause excessive POSTCHECK loops. This has been fixed.

April 30, 2021

Features and Improvements

  • General: Made modification to load ID assignment when merging buses. Previously the next unused ID was used even when the default was available. Now the default ID will be used if there is not already a load at the bus using the ID. This is consistent with how other objects like generators work.
  • Transient Stability: Added a new dynamic phasor model of a single-phase induction motor model named INDMOT1P
    https://www.powerworld.com/WebHelp/Default.htm#TransientModels_HTML/Load%20Characteristic%20INDMOT1P.htm
  • Transient Stability: Added a new motor model named INDMOT1P_PTR which is a simplified version of INDMOT1P, but includes the concept of progressive tripping and reconnecting
    https://www.powerworld.com/WebHelp/Default.htm#TransientModels_HTML/Load%20Characteristic%20INDMOT1P_PTR.htm
  • Transient Stability: Added a new motor model named CIM5_PTR which is the same as CIM5, but includes the concept of progressive tripping and reconnecting
    https://www.powerworld.com/WebHelp/Default.htm#TransientModels_HTML/Load%20Characteristic%20CIM5_PTR.htm
  • Bug Fixes

    • File Formats: Fixed a bug where Simulator will save a modified case to an incorrect location when opening a different case. Simulator would save the case to the same folder containing the newly opened case instead of the folder where the case was originally stored.
    • Transient Stability: Fixing reading, writing and setting MWCap from a dyd file for governors PIDGOV and WT4T.

April 29, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added column contour to the AUX format as a SUBDATA section on the DataGrid (string grid customization) object.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: When using iterated ATC methods the ramping is done relative to load and generator outputs in the base case so that generators will hit and back off limits consistently if transfer stepsizes change sign. When using injection groups as the source and sink it was possible that the ramping was being done relative to the total transfer already achieved rather than this base starting point. This could result in oscillatory behavior. This has been fixed.
    • Transient Stability: Fixed a bug in which the reading a dyd file a certain dc branch wasn't loading the dynamic ecpdc model. Now this is corrected and the epcdc model is read into transient stability.
    • Transient Stability: Fixed a bug with writing cmpldwg DGMBase parameter. When saving into dyd file and the load object DGMBase value is zero it was writing the load object DGMBase value as zero and not the transient model value.
    • Transient Stability: Corrected UEL model MNLEX2. The other fields: Activation Status and PQSig values were being output incorrectly.

April 27, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added support for a Selected field with QVCurve object type. Added support for the Bus Selected field for the bus associated with the QV scenario.
  • QV Curves: Added script command QVWriteCurves("filename", IncludeQuantitiesToTrack, filter, Append) that will save a comma-separated text file with the QV curve points. Set IncludeQuantitiesToTrack to YES to also include any Quantities to Track along with the curve QV curve points. Filter is applied to the QVCurve object type. Set Append to YES to append results to an existing file or NO to overwrite an existing file.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): The special keywords for @DATE and @TIME used with script commands were providing the opposite replacement. @DATE was giving the time and @TIME was giving the date. This has been fixed.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed access violation that would occur with SendToExcel script command if Header_List was not defined.

April 23, 2021

Features and Improvements

  • QV Curves: When running QV analysis, saving Quantities to Track while the analysis is running is now optional. This can slow down the processing. There is now a button on the Output tab of the QV dialog that allows saving Quantities to Track after the run is complete. There are also options on the local menu of the Results > Listing case information display that allow saving QV curve points with and without quantities to track.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed writing out auxiliary files so that they honor non-US regional Windows settings (i.e. using commas or periods as the decimal separator).

April 20, 2021

Features and Improvements

  • File Formats: RAW file reading for version 34 is now more lenient and allows the use of whitespace as a field delimiter.
  • Transient Stability: Vfe is available for ESAC5A Exciter model.
  • Bug Fixes

    • Contingency Analysis: When loading a PTI CON file with contingency elements specified with WND for opening or closing a single winding of a three-winding transformer, the elements read after this entry could end up being incorrectly specified. This has been fixed.
    • Power Flow Solution: Fixed an access violation that would occur when loading a case with more than 8 buses in islands without generation attached to DC lines.
    • QV Curve Tool: When rerunning QV analysis delete all quantities to track even if not rerunning particular scenarios so that the values in the file will have consistent headers.
    • QV Curve Tool: QV results for Quantities to Track were not being stored in PWB files. This has been fixed.
    • QV Curve Tool: When rerunning QV analysis existing results should be overwritten when rerunning a scenario instead of creating multiple results for the same scenario. This has been fixed.
    • Transient Stability: Changed default parameters for VHVDC1 so that Iqmin2 and Iqmin3 are both negative values (as these should almost always be negative!).
    • Transient Stability: Fixed divide by zero when simulating VHVDC1 when Rdc = 0 in the power flow model and also L = 0 in the dynamic model.

April 13, 2021

Features and Improvements

  • QV Curves: On the QV dialog fixed the location of the browse button that allows selection of an output file.
  • Bug Fixes

    • Transient Stability: Made initialization of SCL2C more robust.

April 8, 2021

Features and Improvements

  • File Formats: Device status of <= -3 when reading an EPC file now means to delete the element. Previously we had been using status = -4 to delete an element. Devices are not actually deleted, but the Flag for Delete in EPC will be set to YES.
  • Transient Stability: modified log message that says something like "1012 more ..." to say "1012 more MVABase changed" instead to make it more clear.
  • Bug Fixes

    • Oneline Diagrams: Fixed an access violation when Auto Inserting buses.
    • Transient Stability: Bug fix for OEL5C. State IntegratorTOEL was not being set.

April 7, 2021

Bug Fixes

  • Oneline Diagrams: Fixed bug saving oneline diagrams. The program appeared to hang when saving oneline diagrams because of some unnecessary calculations for groups. We've fixed the problem by only doing calculation once.
  • Transient Stability: SCL1C is now more robust during initialization
  • Transient Stability: If Modify Limits is chosen in Transient Stability Options, and if a UEL1 model feeds into a exciter's HV gate, then UEL1 limits VUImin and VULmin are modified to prevent initial limit violations
  • Transient Stability: When choosing to either Copy or Print All Charts and Title Block, the Title Block was chosen then the bottom and right gray boundary edge on the image created was missing. This has been fixed.

April 2, 2021

Bug Fixes

  • File Formats: Fixed a bug that would cause contingency violations stored by violated element to not appear properly after loading a PWB file. The PWB file still contained them, and after this patch they will be properly shown after loading the same PWB.
  • Transient Stability: Fixed a bug with PSS3C not passing the correct parameters and causing an access violation.

April 1, 2021

Bug Fixes

  • Sensitivity Calculations: Fixed bug that was causing inconsistent TLR results after sequential power flow TLR calculations. The issue was the inconsistent inclusion of phase shifters in the TLR matrices. This has been fixed by checking if the matrices have been built with phase shifters and rebuilding if needed.

March 31, 2021

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): When specifying a Source or Sink that cannot be found for a Direction object when loading from an auxiliary file, put error message in the log that the Source or Sink will be set to Slack instead.
  • Case Information Displays: Added TSContingency string grid table to the customizable tables. Now the customization of the Transient Contingency table can be saved.
  • Case Information Displays: Added nine superarea voltage fields showing min/max/avg for pu voltage, voltage angle (degrees) and voltage angle (rad).
  • Case Information Displays: Added ability to specify generator voltage setpoint and setpoint tolerance in kV. Added generator field to show the RegBus Nom kV.
  • Case Information Displays: Added TSContingency string grid table to the customizable tables. Now the customization of the Transient Contingency table can be saved.
  • Case Information Displays: SendToExcel script command will no longer change the workbookname and worksheetname to uppercase.
  • File Formats: Added optional parameters filtername and AppendFile to the CTGWriteFilePTI script command. The filter is applied to the Contingency object type to specify the contingencies that should be saved to file. All contingencies are saved by default. Set AppendFile to YES to append to an existing file or NO to overwrite an existing file. File is overwritten by default.
  • File Formats: In various places where contingency files in the PTI CON format are saved in the GUI a prompt will appear if the file already exists asking the user if the file should be overwritten or appended.
  • Oneline Diagrams: Added an InjectionGroup field.
  • Time Step Simulation: Changed time domain simulation so a reset actually resets the time to the start time.
  • Transient Stability: New transient stability fields for UEL/OEL/SCL. UEL/OEL dynamic models now have a transient stability integer field called "Activation Status". SCL dynamic models now have two transient stability integer fields called "UEL Activation Status" and "OEL Activation Status". Possible values are 0 (Idle), 1(Engaged) and 2 (Saturated).
  • User Interface Dialogs: Added ability to show all area supply or demand curves for a super area.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Corrected generator variable name RegVoltkVError to RegBuskV (it has always showed the actual kV)
    • Oneline Diagrams: Fixed bug associated with the display of multiple grouped objects, mostly when at least one of the objects is not a text object, like a background rectangle.
    • Oneline Diagrams: Fixed a bug where Snap To Grid was not being returned to its previous value after being temporarily set to True
    • Sensitivity Calculations: When using consolidation with a full topology case, calculations for shift factors and PTDFs may not have been correct when using injection groups containing bus participation points as the source or sink. This has been fixed.
    • User Interface Dialogs: Fixed bug with TGen.MWLambda when fuelcost + extrafuelcost = zero. This would only affect economic dispatch or the code showing a supply curve so the bug would not be common.
    • User Interface Dialogs: Modified generator, area and superarea charts to handle negative marginal costs; also provide access to options so curves can be customized, though right now the change are not stored.

March 24, 2021

Features and Improvements

  • Difference Case Tool: Custom integer, custom float and custom string fields can now be included or excluded when in difference or change mode. This allows a user to populate these custom fields with values they want to be seen under all Difference Case Modes so that the custom fields act like an identifier for the object. Previously if a custom integer had not changed then in difference mode it would show a zero and in Change Mode it would say _same_.
  • Transient Stability: Transient contingencies now have an option to Include RAS for individual contingencies. Previously RAS was always included.
  • Bug Fixes

    • Difference Case Tool: Expanded and corrected functionality for saving Difference Case elements to EPC file format. Interfaces and injection groups can now be saved as difference case elements. Corrected use of Aux Export Format for saving only records that have changed.
    • File Formats: Modified MATPOWER format read to correctly handle more than double circuit lines. MATPOWER itself does not support line circuit numbers, but does allow multiple circuits. The issue was when PowerWorld was not correctly assigning unique circuit IDs when loading a MATPOWER case when their were more than two circuits.
    • Time Step Simulation: Fixed some issues associated with Area ED control, including adding support for negative marginal costs. On the Time Step Simulation 1) added an option to not scale the area and zone load based on out-of-service loads, and 2) added the ability to save a pwb file at the end of each time step. Both options are available on the Time Step Simulation, Options page.
    • User Interface Dialogs: Fixed bug associated with showing the Switched Shunt dialog from a quickpout in the edit mode when the case has not been in the run mode.

March 5, 2021

Features and Improvements

  • General: Fixed a bug with line length not been saved when inserting a new branch.