Simulator 21 Patches

New Features

Bug Fixes

Date

June 2, 2020

Bug Fixes

  • Transient Stability: Improved the numerical performance of the SVSMO1, SVSMO2, and SVSMO3 to permit large values of integral gains.
  • Transient Stability: Added the ability to link SVSMO3U1, SVSMO3U2, and CSTAT1 USRFCT models to switched shunt dynamic models named SVSMO3 and CSTCNT.

May 29, 2020

Bug Fixes

  • Transient Stability: For the CHSVCT SVC model for switched shunts, when setting Bmax, Bmin, Bfmax, and Bfmin to 0.0, the software automatically determines those values from the power flow data by summing up the available capacitors and basing Bmax and Bfmax on this sum and summing up the reactors to set Bmin and Bfmin. There was a bug that resulted in an error because we were not properly converting this value to per-unit on the SVC MVABase and were instead using the system base. This error has been fixed.
  • Transient Stability: Fixed enforcement of the non-windup limit on the svsmo3 model for the Ki/s state

May 28, 2020

Features and Improvements

  • Case Information Displays: In the menu options for Generator Records on a generator case information display there is an option to "Convert Voltage Setpoint for LDC_RCC" that would only appear if particular fields associated with line drop compensation were the currently selected field. Now this option will appear regardless of the currently selected field.
  • Bug Fixes

    • Oneline Diagrams: Fixed "List index out of bounds" error that could result when using the option on a oneline background object to Show Shapefile Fields.

May 27, 2020

Features and Improvements

  • File Formats: Added support for loading matpower m files with inf or -inf fields for generator q and p max/min fields.
  • File Formats: Fixed issue reading a MatPower case setting the gens to allow AGC if Pmax > Pmin and PG is between them. If a generator is not AGCAble then the max/min values are written as Pg.
  • File Formats: Made changes to Unit Type EPC:
    -Renamed P1 (Photovoltaic, No Storage) into P3 (Photovoltaic, Fixed)
    -Renamed PD (Photovoltaic, DC Coupled) into P4 (Photovoltaic, Tracking)
    -Made FC (Fuel Cells) EPC integer = 48
    -Made SV (Static Var Compensator) EPC integer = 60
    All of this to be in accordance with the WECC 2020 Data Preparation Manual.
  • Oneline Diagrams: Added a button on the GIS Shapefile Data Dialog to "Convert X/Y to Latitude and Longitude". This will convert projected X/Y values that have been specified in the shapefile to degrees latitude and longitude using the WGS 1984 Web Mercator Auxiliary Sphere projection. This is a standard Mercator projection assuming earth radius of 6378137 meters, no flattening, and 0 for the central meridian. This conversion is required before the projection is done to X/Y values in PowerWorld's coordinates. This is an attempt at making shapefiles useful that contain values that have been projected if they have been projected using this particular projection, which seems to be fairly common, but this may not work in all situations.
  • Transient Stability: Modified the InductionMotor3P_A model to include dependence on the source voltage to the terminal bus electrical frequency in per unit.
  • Bug Fixes

    • Transient Stability: Fixed error introduced by attempts to fixed bug related to deleting TSPlotSeries, TSVertAxisGroup, TSSubPlot and TSPlot objects. This new patch introduces access violations caused by the attempted fix in the May 20, 2020 patch.
    • User Interface Dialogs: When showing a list of 2-terminal DC lines in the objects chooser, we were listing each DC line twice with the same string being shown. We have now modified so that one entry lists the rectifier bus first and the second entry lists the inverter first.

May 22, 2020

Features and Improvements

  • Transient Stability: When writing error and warning messages to the log when reading a DYR file, added addition information to show the NAME of buses related to the log messages.
  • Bug Fixes

    • General: Fixed possible access violations that could occur when deleting an object that had been initially assigned to an owner, then removed from that owner, and that owner was then deleted.
    • Transient Stability: When storing transient results to hard-drive, if the check box to use area/zone filters was not checked then all objects would be written to the TSR hard drive file regardless of the the filtering specified with the generator or load objects. Thus the filtering was not being used. This bug did not exist for branches or buses but only loads and generator.
    • Transient Stability: For synchronous machine models, removed the validation warning message that says "Tqop > 5*Tqopp is recommended". This is not a useful warning.

May 21, 2020

Bug Fixes

  • Integrated Topology Processing (ITP): Fixed a bug determining Derived Status and Derived Online. The bug would affect specific topologies where there are no breakers between one terminal of a branch and a radially connected shunt device.

May 20, 2020

Bug Fixes

  • Contingency Analysis: When using the linearized contingency solution methods, disconnected buses were not being reported as violations when requested by the user. This has been fixed.
  • General: Fixed bug that would not allow Owners to be properly updated for generators.
  • General: Fixed bug that would not allow an Owner to be deleted even though it was empty.
  • Integrated Topology Processing (ITP): When using the contingency tool to Convert to Device Contingencies it is now assumed that new energized islands cannot be created due to the actions of a contingency. Previously, the power flow solution option of "Dynamically add/remove slack buses as topology is changed" would be used, but now this option is always assumed false. This means that generators and loads that could form an energized island will now appear as devices in the resulting contingency element conversion.
  • Sensitivity Calculations: Fixed two bugs with the LODF Screening tool.
    (1) When setting the Lines to Process option to use Defined Contingencies, Remedial Action Elements were being included. This doesn't make sense for this tool. These are now ignored.
    (2) When choosing the Lines to Monitor option as Limit Monitoring Settings all lines would be monitored. This has been fixed.
  • Transient Stability: Fixed issue with closing in a synchronous machine in transient stability. This was possible if the bus was connected in the initiation coniditon, but the generator was set to status of OPEN. It is now also possible even if the bus is disconnected initially.
  • User Interface Dialogs: Fixed bug that would not show the correct Unit Type on the generator dialog when opened while in Edit Mode.
  • User Interface Dialogs: The Layers dropdown on the Oneline Ribbon tab was missing and has been added back in.

May 15, 2020

Features and Improvements

  • File Formats: Added options for how to handle duplicate generators read from a RAW file. This includes a choices on the Load RAW with option dialog on how to handle these. The default is to only keep the last duplicate read from the file which is the intended behavior of this format. The alternative the user can choose is to keep all duplicates and have Simulator set unique ID's for each one. Right now this has been added for generators. We plan on rolling this change out to each device type, so that the option will apply to all device sections read from the RAW file. Again, this is not the "correct" treatment of this format, but for some users it is a convenient treatment regardless.
  • Transient Stability: When using the user interface to choose a Horizontal Axis Object for a TSSubPlot, if the sub-plot presently only has 1 vertical axis group which has 1 plot series in it, the object will for the Horizontal Axis Object will now default to the same object as the plot series.
  • Transient Stability: When loading an AUX file that creates new TSContingency objects for transient stability, if the old default contingency named "My Transient Contingency" exists and the old contingency has no elements and no stored results then we will automatically delete the old dummy contingency. Previously it was annoying that the dummy TSContingency named "My Transient Contingency" stuck around.
  • Transient Stability: Modified the Device Type drop down on the Transient Stability Plot Designer so that it always show the entire list without the scrollbar.
  • Transient Stability: When loading a Transient Stability DYR file, if possible we now include the area and zone of the respective device if any warnings or errors string which are written to the message log.
  • Bug Fixes

    • General: In places where a simple string can be used to represent one condition (instead of referring to an advanced filter by name), Simulator was allow the user of the simple string even when the user had defined an advanced filter which used the Area/Zone filters. This has been changed so if you are pre-filtering by the Area/Zone filters then you can not use the simple string representation.
    • Transient Stability: When saving the Transient_Options to an AUX file from the transient stability dialog, we have modified the writing of this AUX file so that it also writes out any advanced filter definitions that are used by the store to hard-drive options.
    • Transient Stability: When deleting a TSPlot, TSSubPlot, TSVertAxisGroup, or TSPlot Series a case information display or from an Auxiliary File script, if the Plot Designer portion of the transient stability dialog was open then it would cause an access violation. This has been fixed.
    • Transient Stability: It was possible to create a duplicate transient contingency element on the dialog for this object. This is now properly not allowed.

May 12, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added CTGProcessRemedialActionsAndDependencies(DoDelete, Filter) script command. See Contingency Analysis section for details.
  • Contingency Analysis Tool:
    Added options is three different places that will allow Remedial Actions and any Model Conditions, Model Filters, Model Expressions, and Model Planes being used by Remedial Actions to be deleted. Model Conditions, Model Filters, Model Expressions, and Model Planes that are being used by other objects or not being used by a Remedial Action will not be deleted.
    These are the three places that options have been added:
    (1) Added "Delete Remedial Actions and Dependencies" option on the Contingency Analysis dialog under Other > Manage Contingency Definitions.
    (2) Added "Delete Remedial Actions and Dependencies" and "Delete Remedial Actions and Dependencies (only selected records)" on the local menu of Remedial Actions case information displays.
    (3) Added CTGProcessRemedialActionsAndDependencies(DoDelete, Filter) script command. If DoDelete is YES, objects will be deleted. If DoDelete is NO, the Selected field will be set to YES instead of deleting objects for all object types described above. Filter is optional, and if not specified or left blank, all Remedial Actions will be deleted or selected along with dependencies. Filter is applied to RemedialAction object type. AREAZONE is not a valid filter option.
  • Oneline Diagrams: Added support for Injection Groups with Geographic Data Views.
  • Transient Stability: Added options to create Transient Stability Contingency Elements for Switched Shunts that allow Set Values To and Change Values By as Percent of Start Nominal Mvar.
  • Transient Stability: Remedial Action Elements for Switched Shunt actions for Set To or Change By in Mvar or Percent are now translated for use in Transient Stability Remedial Actions.
  • Bug Fixes

    • Case Information Displays: On case information displays containing participation points for injection groups, Show Dialog options are now available while in Run Mode.
    • File Formats: When reading a RAW file in the non-transformer branch section, the ownership information for the branches was not being read correctly. This has been fixed.
    • Transient Stability: In Transient Stability validation, eliminated the error check on SVCs to require that the type of SVC be the same in the power flow and transient stability model.
    • Transient Stability: Added numerical checks on the Kvi and Kqi parameters for the REEC_A, REEC_B, REEC_C, and REEC_D electrical models for renewable plants to prevent numerical integration problems when values of Kvi or Kqi are too large.
    • Transient Stability: Modified how the DC line solution transitions between hitting the firing angle limits to improve algebraic network solution.

May 7, 2020

Features and Improvements

  • GIC: Added ability to show DateTime for GIC 3D Time Points.
  • Bug Fixes

    • Fault Analysis: A bug existed where we were trying to use the wrong zero sequence impedance values for Delta - Grounded Wye transformers ONLY when calculating the post-fault branch currents. This has been fixed.
    • Transient Stability: Fixed bug that would not update the Case Information Toolbar to match the correct tab when viewing Validation Errors, Validation Warnings, or Informational Messages on the Validation page of the Transient Stability dialog.

May 6, 2020

Features and Improvements

  • GIC: Added support for GMD JSON files.
  • Transient Stability: Contingency Element options have been added for Switched Shunt actions to Change Values by or Set Values to for specifying changes to Nominal Mvar.
  • Bug Fixes

    • Case Information Displays: Fixing an access violation that can occur when closing some dialogs associated with various case information displays.

May 4, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added ATCWriteAllOptions("filename", AppendFile, KeyField) that saves the same objects as ATCWriteResultsAndOptions but always uses the concise format for object fields and headers and does not save using Subdata. RAS and contingency actions are saved using dependencies.
  • Available Transfer Capability (ATC) Tool: Added option "Use Concise" on the GUI dialog that allows the saving of ATC options and results. This will save using the concise format for object fields and headers and does not save using Subdata. The option will be unchecked by default in Simulator version 21, but will be checked by default in Simulator version 22.
  • Case Information Displays: Added Number of Tie Lines field with Substation objects.
  • GIC: Added new GMD 3D functionality.
  • Bug Fixes

    • File Formats: When writing to RAW files fixed an issue where we were writing out a minimum R value for series capacitors of 1x10-7, but when reading the RAW file back into Simulator, only considering a branch with -x a series capacitor if R = 0. Thus the type assignment of series capacitor was never getting set to branches with -x from a RAW file that we created. To fix this, I first changed the code to write out 0 for R if the value of R was <= 5x10-7. I also changed reading the branches to consider a branch with -x a series capacitor if the abs(R) value is < 5x10-7 instead of = 0.

May 1, 2020

Features and Improvements

  • Oneline Diagrams: Modified contouring to allow contouring of spatial data without explicit oneline objects. This is useful for GIC electric fields.
  • Bug Fixes

    • Case Information Displays: Fixed an "Argument out of range error" that could result when including the Nominal kV Range field in a Substation case information display and there are substations with no buses.
    • Case Information Displays: Fixed an issue with case information toolbars not updating properly when selecting a record in a particular grid.
    • File Formats: Fixed bug in EPC file writing - due to an uninitialized variable, this was transferring lines shunts from the "fromEnd" to the "toEnd" or vice versa. This bug would have only affected line shunts in a multi-section line.
    • File Formats: Fixed error where we were not subtracting distributed generation amounts from load amounts when writing to older versions of RAW files. This would create mismatches and potential solution failures if the user saved to a RAW file version prior to 34.
    • Power Flow Solution: Error checking in Simulator between switched shunt and transformer control was checking that the MIDPOINT of the shunt regulation range was inside the regulation range of the transformer. For example if transformer regulation range was between 1.02-1.03 and the shunt range was 0.95-1.03, then the error check would incorrectly turn off the transformer because the midpoint of the shunt range is 0.99 which is not within the transformer range. This has been fixed by instead ensuring that there is an overlap in the shunt and transformer regulation range.
    • Transient Stability: Fixed enforcement of the current limit on an REGC_B machine model.

April 27, 2020

Features and Improvements

  • Contingency Analysis Tool: When using one of the Linearized Lossless DC Calculation Methods buses that become disconnected can be reported as violation if choosing that option.
  • Oneline Diagrams: Hidden Geographic Data View objects are not contoured.
  • Oneline Diagrams: Added Delaunay Triangulation as a Countour Method with Contour Options.
  • Bug Fixes

    • Contingency Analysis: Fixed a few bugs when using Expressions with the ViolationCTG object type. Access to LimitViol and Contingency expressions are allowed through this object and the various expressions were not always being identified correctly. There is a maximum allowed number of Expressions that can be created for ViolationCTG objects, currently 5, and this was not being enforced.
    • Distributed Computation: Distributed contingency analysis result processing performance has been improved. Long post-run stalls should be much shorter in duration if they still occur.
    • General: When writing an expression for a custom expression or Model Expression, if no function or operator correctly matches all of the parameter types passed into it (whether string, integer or float), Simulator will now give a more verbose error message that lists all of the overloaded functions or operators that match the name of the one used to give the user more information.
    • User Interface Dialogs: Simulator log messages copied to the clipboard will include the timestamp when shown.

April 22, 2020

Features and Improvements

  • General: Added Tap Step Count field with Branch objects to show the total number of tap steps for a transformer.
  • PV and QV Curve (PVQV) Tool: Added options to track loads in Quantities to Track with the PV and QV tools. MW, SMW, IMW, ZMW, Mvar, SMvar, IMvar, and ZMvar can now all be tracked and plotted.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When using the ATCWriteResultsAndOptions script command and when saving ATC results and options from the ATC dialog, Injection Groups that are used for the source and sink and Interfaces that are used with ATC Extra Monitors and multiple scenarios, along with any injection group or interface dependencies, will be saved to the resulting auxiliary file. When saving contingency settings along with the ATC options, dependencies will always be saved now. Previously all Model Conditions, Model Filters, Model Expressions, and other object types that are used to define Remedial Actions were being saved even if they weren't used as part of a Remedial Action. Interfaces and Injection Groups are now included in the dependencies for Remedial Action definitions.
    • Contingency Analysis: When setting up a contingency solution it was possible that a generator that was at it's Max or Min MW limit may appear to be violating it's limit and thus turned off AGC during the contingency solution. This has been fixed.
    • Difference Case Tool: When saving objects to an EPC file from the Difference Case tool or from case information displays, three-winding transformers were not being written. This has been fixed.
    • Model Explorer: Updated Model Explorer folder's object count for OPF Phase Shifters to match actual phase shifters, and not all branches.
    • Transient Stability: Updated the handling of the Bmax limit for SMIB calculations on several exciters.
    • Transient Stability: Fixed some issue with limits being checked during the SMIB calculations. There are now much fewer positive eigenvalues.
    • Transient Stability: An access violation could result if using a transient stability contingency action on a generator to Enable AGC or Disable AGC if the generator had no AGC model assigned. This has been fixed.
    • Transient Stability: Fixed error in REGC_B model with the DQFlag. Value of 0 means Q-priority and non-zero is P-priority. This was backwards.

April 14, 2020

Features and Improvements

  • General: New distributed computation configuration command line tool has been added to aid in scripting the automatic configuration of multiple machines across a network.
  • Transient Stability: Added new CDC1T two-terminal DC line model. This is a stripped down version of the CDC4T model.
  • User Interface Dialogs: Added two new tabs on the Contour Options dialog. Contour Data Points shows the x,y location on the oneline of the object being contoured and the value of the field being countoured along with the color of the countoured value. Contour Pixels provides details about the pixel color and location in the contour.
  • Bug Fixes

    • File Formats: Fixed access violation that could occur when loading DYR file containing SVCs.
    • File Formats: Updated Areva contingency parser to handle injection groups (LDAREA). Previously they were unhandled, which resulted in them being incorrectly treated as line open contingencies (the default). This was causing an access violation when saving the contingency list to file.
    • Simulator Automation Server (SimAuto): Fixed RegSimAuto registration check so it no longer fails when checking to see if the registered SimAuto executable and the local executable are the same files.
    • Transient Stability: Fixed significant error in the loading of PSSE User Defined GENPTJ models. We were treating the Kis field as Ra.
    • User Interface Dialogs: Disable the Area/Zone/Owner filter option on the Area/Zone/Owner filter dialog and the Tielines between Areas case information display. The Area/Zone/Owner filter is not applied here.
    • User Interface Dialogs: Enabled Advanced Filtering for the Area and Zone case information displays on the Limit Monitoring Settings dialog.
    • User Interface Dialogs: Disabled the option to Use Area Zone Filters for case information displays that do not allow Area/Zone/Owner/Data Maintainer filtering. This option wasn't doing anything but this change makes it clearer that it is not applicable.

April 9, 2020

Features and Improvements

  • Transient Stability: When using the Show Dialog option on the Transient Stability Models in Use case information display, a case information display of only a single model type is opened. Delete is now an option on this case information display.
  • Transient Stability: Delete is now an option with the Transient Stability Models in Use case information display. This will allow deleting all models of a particular type.
  • Bug Fixes

    • Contingency Analysis: When auto inserting contingencies and creating combinations of different object types, the maximum number allowed for each object type has increased from 3 to 6.
    • File Formats: Fixed bug in reading Matpower files.
    • File Formats: Fixed bug with loading a PTI DYR file that contained two-terminal DC line dynamic models. This bug was just introduced but is now fixed.
    • General: Fixed a bug that could result in calculating incorrect transformer regulation sensitivities. This would occur when doing the calculation for "Determining the side of transformer on which regulated buses are. This is needed to write to some non-PowerWorld file formats." Sensitivities could end up being calculated as NAN.
    • Power Flow Solution: Fixed access violation error that was showing up during Power Flow calculation. This would occur only when there were Interfaces defined in the case that contained contingencies like branch open/close elements, AND these open/close branches were already open/close in the base case.
    • Transient Stability: Better handling of the Model Instance field that is used with types of dynamics models where more than one of that type can be assigned to the same object.

April 7, 2020

Features and Improvements

  • Transient Stability: Improved support for loading in PSS/E idev files for transient stability.
  • Bug Fixes

    • Distributed Computation: Fixed distributed computation configuration page table alignment.
    • Distributed Computation: Fixed an access violation that could occur when selecting a user in the distributed computation configuration tool.
    • Oneline Diagrams: Fixed a bug displaying the loss field on a diagram depending on which end of the line the field was closest to. If it was closest to the Far bus, it would display the series I^2*R losses instead of the total loss. It should be displaying the total loss always, regardless of how many times displayed or which end of the line it is closest to. The series loss has its own field that should be displayed if the user wants to see the series only losses instead of the total losses.
    • PV and QV Curve (PVQV) Tool: Fixed bug with maximum mismatch information not showing up for critical PV scenarios.
    • Scheduled Actions: Fixed an anchoring issue with the Scheduled Actions dialog.
    • Transient Stability: Saving TS results out to a text file (csv, jsis, etc) was not working when results were in Hard Drive. If Transient Stability was NOT open, then nothing was being saved. If Transient Stability was open, then it would alternate between working okay and not working at all, for consecutive TSGetResults() script command, for example. If Transient Stability dialog was open, and one were to clear the time values from RAM, then it would alternate between working okay and not working at all, for consecutive TSGetResults() script command, for example. This has been fixed.

April 1, 2020

Features and Improvements

  • Transient Stability: Added a new parameter to the ATRRELAY called "LeaveOneOn". Setting this parameter to a non-zero value will force at least one generator to remain online when a tripping command is sent. The generator with the smallest initial MW output will remain on.

March 31, 2020

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): The AutoInsertBuses script command has a couple of fixes. The MapProjection parameter should take "xy" instead of "x,y" as input. The last parameter FileCoordinates, which was intended to indicate if an input file list values in x,y or lon, lat, is redunant due to the MapProjection field and is no longer required. Including this parameter will not cause an error but it will be ignored and shound not be included with new auxiliary files
  • Transient Stability: Fixed a bug in reading a WECC switch file that could result in an access violation.
  • Transient Stability: When a 2 terminal DCline has either the rectifier or inverter AC bus disconnected from the rest of the AC system, then in the steady state power flow the DC line is considered out of service. This is true even if the DC line is set to be on power or current control because obviously it can't be on if the AC system is dead. This worked fine in the steady state power flow, however in the transient stability system if the DC line was set to be on power or current control and the AC system to which it was connected was dead there were errors resulting in undefined power flow mismatches at the terminals of the DC line (even though those terminals were disconnected). This has been fixed.
  • User Interface Dialogs: Closing the Run Mode Line Dialog could take a very long time on large cases. This has been fixed.

March 26, 2020

Bug Fixes

  • GIC: An access violation could result when going from Edit to Run mode after moving the terminals of branches to different buses. This would occur even when not doing a GIC solution. This has been fixed.
  • Power Flow Solution: When generators remotely regulate a bus that can not be reached without crossing buses that have SVCs of type svsmo1 or svsmo3, then it is impossible for these generators to perform remote regulation. This data input error had been captured between generators in the past, but was not being captured for a combination of gens/SVCs. It is now properly captured and an appropriate warning message is written to the log and the generator control is not enforced.
  • PV and QV Curve (PVQV) Tool: Fixed an access violation that could result when running PV analysis. This could result if the step size could not be reduced from the Initial Step Size because the Minimum Step Size is greater than the reduced step size, i.e. (Initial Step Size/reduction factor) < Minimum Step Size.
  • Simulator Automation Server (SimAuto): Bug fix in error message management -- message indicating that required fields were missing when attempting to add a new object through SimAuto was being overwritten by a generic "Object not found".
  • Transient Stability: Added three changes to help with solving MMWG transient stability cases: 1) check on GENTPF/J XL <= xdpp, 2) check on ST6B exciter Tda small, 3) added subinterval to handle large negative eigenvalues on AC7B when Kpa*Kf1*inv(Te) is high.
  • Transient Stability: Added initial limit adjustment of the temperature limit value for the GAST2A and GASTWD turbines.
  • Transient Stability: ST6B correction of low Tda values.
  • Transient Stability: For the REPC_B model if a user does not specify any Control Device to which the output is connected, Simulator will assume that Control Device 1 is the generator to which the REPC_B model is assigned.
  • Transient Stability: Fixed initialization of Pmech for HYGOVR and IEEEG3 governor models.
  • Transient Stability: Modified the REEC_A, REEC_B, REEC_C, and REEC_D models. We will now consider the following as an initial limit violation: the Vref0 input parameter creates an initialization that results in the output of the deadband dbd1/dbd2 being non-zero. If auto-correcting initial limit violations, then the value of Vref0 will be modified to either Vinit+dbd1 or Vinit+dbd2 so that the output is at the edge of the deadband.
  • Transient Stability: Modified all machine models that use the Lvpnt1 and Lvpnt0 "low voltage power management" block that manages the current source interface to the network equations. When the Lvpnt1 input parameter is higher than the initial terminal voltage then this is now treated as initial limit violation and we always automatically decrease Lvpnt1 to be equal to the initial terminal voltage. This effects models such as WT3G, WT4G, PV1G, PVD1, REGC_A. This low voltage block should never been active in the initial condition.
  • Transient Stability: When Ke=0 for some types of Exciter models, the value of Ke is automatically calculated based on the initial Field Voltage to achieve a particular value of Vr. This automated routine is handle differently in different software tools and PowerWorld has an option called "Exciter Automatic Parameters" which is set appropriate depending on whether you have loaded a DYR or DYD file. In cases where folks merge two data sets from two different software tools however this option may be more nuanced. This patch modifies this option so that particular Exciter models that are only supported by one other software tool will always use the approach used by that software tool.

March 18, 2020

Bug Fixes

  • Case Information Displays: Fixed possible access violation that could result from changes made in the March 17, 2020 patch to not allow the Quick Filter with case information displays on the Area/Zone/Owner dialog.
  • Oneline Diagrams: Fixed a bug with the display of LineFlow and InterfaceFlow indicators, which were not properly respecting "do not zoom" format settings.

March 17, 2020

Bug Fixes

  • Case Information Displays: Quick Filtering should not be allowed for the case information displays on the Area/Zone/Owner dialog. All objects should be shown at all times. Advanced Filtering had been disabled, but Quick Filtering was still allowed with no way to remove the filter. This has been fixed and Quick Filtering is disabled as well.
  • Power Flow Solution: Fixed a problem with DFACTS regulation. It was reported that DFACTs were not regulating into a negative reactance range when capacitance is available. The problem was that the minimum injection value was incorrectly being limited at 0 because limits were not being updated after inputting the capacitance values. This has been fixed.
  • Sensitivity Calculations: Fixed the column headers for the multiple direction PTDF values. Now, the header is the direction name. Previously, it was Direction Name + "From" + Direction Name, which doesn't make much sense.
  • Sensitivity Calculations: Set processed flag on the direction when calculating multiple direction PTDFs.
  • Transient Stability: Fixed error when initializing load with distributed generation that is closed but at an open bus. We were getting a divide by zero error on the zero terminal voltage.
  • Transient Stability: The Summary > Models in Use case information display allows opening a dialog to show all models of a particular type that are currently defined. Fixed an access violation that could occur when closing this dialog.
  • Transient Stability: Fixed divide by zero error with WTGTRQ_A and WTTQA1_PTI models when the power/speed curve points are zero.
  • Transient Stability: Modified ESAC2A model so that the Vfemax value is modified if it is initially out of range.
  • Transient Stability: For WTGTRQ_A and WTTQA1_PTI models fixed interpretation of the Flag variable when determining speed dependency. This was needed to fix an issue in which this model and the WT3E1 model had different speed power curve values.

March 11, 2020

Bug Fixes

  • User Interface Dialogs: On the Injection Group dialog, the scroll buttons and dropdown to change the selected injection group were not working to change the selected injection group. This has been fixed.

March 10, 2020

Features and Improvements

  • User Interface Dialogs: Added the ability to search the Case Description using the Search Bar that can be added to the dialog.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: When using the option to create an interface from a limiting element and contingency, three-winding transformer open and bus open contingencies are now included. A three-winding transformer contingency will add the two-winding transformers as interface contingent elements, and a bus contingency will add all branches connected to the bus as contingent elements.
    • Case Information Displays: Fixed a few bugs with the case information display search bar: (1) no longer beep when enter is pressed, (2) no longer clear selected text when enter is pressed, (3) no longer disallow the first entry after hitting enter to conduct a search, and (4) unselect last selection if new search text is not found.
    • Contingency Analysis: When using the option to create an interface from a contingency and violation, three-winding transformer open and bus open contingencies are now included. A three-winding transformer contingency will add the two-winding transformers as interface contingent elements, and a bus contingency will add all branches connected to the bus as contingent elements.
    • Transient Stability: Removed special subinterval integration for GENCLS when using Euler's method on a small case (less than 200 buses).
    • Transient Stability: For the H6E Governor model if the bgvmin is greater than 1 or less than 0 this will be treated as a warning instead of an error.

March 3, 2020

Features and Improvements

  • General:
    Added a lot of new features to the distributed computation configuration tool:
    - Changed the user configuration to allow setting the user to be either
    a user or a security group. Furthermore, this allows selection of
    objects from the local machine or across an enterprise domain forest.
    - Removed the (broken) file permission checkbox.
    - Added a user privilege tester. This checks the user against the system
    limits, configured permissions and also against file permissions for
    pwrworld.exe and simproxy.dll.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When saving injection groups to an auxiliary file with participation points listed in a SUBDATA section and using labels as the key field identifier, blanks would be written instead of the primary key field for participation points where either no label or no label for the bus existed. This has been fixed.
    • File Formats: Fixed a potential bug that would cause reading the RAW file to fail if a branch, switched device, or transformer record was incomplete and stopped somewhere in the middle of the branch ratings. Now Simulator will set defaults for the rest of the ratings and all fields that should have come after the ratings.
    • File Formats: Fixed an issue with switched shunts where the RAW file read would fail if the number of shunt blocks didn't match the number of steps, i.e. the last MVAR block value in the file was missing, so Simulator was reading a value for the number of steps for a block, but the MVAR value of the block was missing at the end of the record. Now Simulator will set that value to 0 if it is missing, and move on.
    • File Formats: Fixed a bug where reading a negative from bus number for branches, switched devices, and transformers would also cause the RAW file read to fail. Since it does not appear that negative from bus numbers are intended or mean anything in the RAW format, I set it to use the absolute value of the from bus number and continue reading the rest of the record as usual.
    • GIC: Fixed retention of the Selected field for GICXFormer objects when switching between Edit and Run Mode.

March 2, 2020

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Changes made in the SendToExcel script command in the January 31, 2020 patch that allow specifying the number of digits and decimal places to use for floating point fields resulted in "format string too long" errors if digits and decimals were not specified and defaults were assumed. This has been fixed.
  • Auxiliary Files (SCRIPT and DATA Sections): When loading Generator fields for BidMW and BidMWhr, then order in which the fields mattered when it should not have. The user was required to load BidMW:5 before loading BidMWhr:5. If they were loaded in the oppositie order then the MWhr values would not be read. This has been fixed so that the order of the fields no longer matters when loading an AUX file, copy/paste or script command.
  • GIC: Fixed bug on gic validation with a full topology model.

February 28, 2020

Features and Improvements

  • Contingency Analysis Tool: Auto Insert options now allow auto inserting single loads.
  • Bug Fixes

    • File Formats: Modified reading a OTG or OTGD file so that the event syntax: "fault 4.0 30.0 30.0 3pb solid", will interpret the second and third strings as the time in cycles after the fault that the from and to end buses are opened on the branch.
    • File Formats: The new feature for having a Voltage Setpoint Tolerance with a generator was not being properly stored to a PWB file. This parameter for VoltSetTol is now stored in the PWB.
    • General: When using the White option for Ribbon Settings, window borders have been increased to make grabbing the border much easier for resizing.
    • General: When filtering gens, loads, and switched shunts by Area, Zone, or Balancing Authority Device or Advanced Filters, use the area, zone, or balancing authority of the shunt object and not the bus. Area/Zone/Owner filtering already did this.
    • General: Added 2 new fields for a Bus: EPCBusType and RAWBusType. Both the RAW and EPC file have an old concept of the user specifying the "equation type" at each bus. In Simulator this is automatically determined from the control devices you have specified in the system, but when writing out to the RAW or EPC file formats Simulator has always written out an integer code appropriate for these formats. These two new fields allow the user to see what these codes in the case information displays.

February 25, 2020

Features and Improvements

  • Transient Stability: Added "Save Plot Images for Auto-Save Options" on the Plot Designer page of the Transient Stability dialog to re-evaluate plots and auto save images after the simulation is complete. It will check for results in RAM and Hard Drive.
  • Bug Fixes

    • Transient Stability: With the Absolute Angle Deviation Generic Limit Monitor, the Rotor Angle Shift will now be used instead of Rotor Angle No Shift when determining if the limit has been exceeded.

February 21, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added LogShow(DoShow) script command to control when message log is shown. When the DoShow parameter is set to YES the message log will be displayed. When DoShow is set to NO the message log will be hidden.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug with script command TSGetResults in which the output csv time is off by one index. Start at the second time step instead of the initial time step of zero. The rest of the values were correct. It happens only when you are reading results from Hard Drive. If the values are on RAM it will give the correct order.
    • Contingency Analysis: When determining if Transient Contingency Elements, Contingency Elements, and Remedial Action Elements are the same as existing elements when pasting from Excel or loading from an auxiliary file, the time will now be checked to the microsecond. Previously a tolerance was being used based on the number of digits to the right of decimal included with the time values. This could end up considering elements the same when they really did not occur at the same time. 9.3 seconds was being treated the same as 9.2502 seconds.
    • Contingency Analysis: Time values with Transient Contingency Elements, Contingency Elements, and Remedial Action elements will always be shown with 6 digits to the right of the decimal.
    • GIC: Fixed GMD bug when there is voltage data and a new line is added.
    • GIC: Fixed code for changing the EMP E3B max value.
    • Time Step Simulation: Fixed issue in time step simulation with how the total area or zone load is assigned to the loads.
    • Transient Stability: When importing relay configuration data in the SEL 421 RDB file format, now recognize identifiers Z1MP-Z4MP in addition to Z1P-Z4P.
    • Transient Stability: While creating transient contingencies from the steady state contingencies list, there was no indication of what the software did. A message box now appears that shows how many transient contingencies were created. Also, the multiple transient contingency grid is refreshed.
    • Transient Stability: When determining if Transient Contingency Elements, Contingency Elements, and Remedial Action Elements are the same as existing elements when pasting from Excel or loading from an auxiliary file, the time will now be checked to the microsecond. Previously a tolerance was being used based on the number of digits to the right of decimal included with the time values. This could end up considering elements the same when they really did not occur at the same time. 9.3 seconds was being treated the same as 9.2502 seconds.
    • Transient Stability: Time values with Transient Contingency Elements, Contingency Elements, and Remedial Action elements will always be shown with 6 digits to the right of the decimal.
    • Transient Stability: Fixed a bug that could produce an out of memory error if storing too many transient stability results to RAM.
    • Transient Stability: Changed Distributed Computing for Transient Stability to use a temporary folder based on the current process ID to prevent clashing if multiple Simulators are running concurrently.

February 13, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added parameter Append to SaveData and SaveDataWithExtra script commands. This is an optional parameter that will be YES by default. Set to YES or NO. If YES and the specified file exists, the file will be appended with the saved data. If NO any existing file will be overwritten.
  • Transient Stability: Added new option to allow a LDTRPMON object to allow you to monitor the entire case.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug with the InterfaceCreate script command that was not doing a case-insensitive check on the specified ObjectType. If 'branch' was entered instead of 'Branch', an interface could be created with interface elements instead of branch elements.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bugs related to identifying display objects by the label of their linked model object in display auxiliary files, pasting from Excel, and display script commands. The Auxiliary ID was not being used to distinguish objects if there was more than one display object for the same model object, and the object with Auxiliary ID = 1 would always be chosen. Display script commands would not allow the use of the linked object label at all. When using labels to identify display objects, the label always refers to the linked model object and not the display object itself. Labels cannot be defined specifically for display objects.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bugs with DoCTGAction script command that would not allow spaces or allowed special characters (such as #) when identifying objects by something other than bus numbers. The brackets are no longer required around the action string, but if omitted the string must be enclosed in double quotes.
    • GIC: Modified so GIC XFormers are not rebuilt when loading aux files/doing scripts just in run mode.
    • Transient Stability: When using the LDTRPMON measurement object, if the area or zone for which summary information was being collected had a CMPLDW which had a non-zero fraction for a Motor D, but zero for the A, B, or C motor, then the the summary information for the Motor D may be shifted up one to the Motor C (or higher). This indexing error in the summary results has been corrected. Note that the input date we have seen from our customers never did this, but it could have.
    • Transient Stability: Fixed the actual values (p of something) of the ldtrpmon. Were reporting the original values.
    • Transient Stability: Cleaned up monitoring of nominal and instantaneous trip values for ldtrpmon monitoring. Also modified throughout to make the values tracked within the contingency summary results to match those in ldtrpmon. There were some strange differences in the treatment of "model trip" versus "relay trip" which have been made consistent between these two situations.
    • Transient Stability: Fixed unusual error that could occur when generating a plot when there is no underlying results to link to.

February 7, 2020

Bug Fixes

  • Case Information Displays: Fixed error with sorting Datetime values on a case information display
  • Transient Stability: Fixed error reading the ldtrpmon object from a DYD file
  • User Interface Dialogs: The Show Dialog for Object option on the Dependency Explorer dialog would not open the dialog for Remedial Actions, Remedial Action Elements, or Contingency Elements. This has been fixed.

February 6, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command EstimateVoltages("filtername") that will estimate voltages and angles at specified buses based on voltages and angles at surrounding buses. A valid filter must be specified. An error will result if a blank filter is specified.
  • Transient Stability: Added ability to read the REECCU1 USRMDL from a DYR file and interpret as a new REECC1 model that is idential to the REEC_C model.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a list index out of bounds error that could result when identifying display objects to create or update through display auxiliary files and display script commands.
    • Transient Stability: Fixed error when reading/writing from/to the DYR file a REECB1 or REECBU1 model. The Tpord and Imax values were flipped when reading/writing them. Thus the treatment inside Simulator had them flipped when reading them.

February 5, 2020

Bug Fixes

  • Case Information Displays: The option to Paste from the clipboard into the SuperArea case information display was not working. This has been enabled for the SuperArea display.
  • Case Information Displays: Fixed access violations when deleting objects from the case information displays found on the Remedial Actions tab on the Options page of the Transient Stability dialog.
  • Transient Stability: Improved numerical properties of the REGC_B machine model hitting the current Imax limit inside the network boundary equation solution.
  • User Interface Dialogs: The AUX file browser was checking for an empty path, but not for paths that don't exist. If it encountered a path that did not exist, it would error out when attempting to build the tree view. A fix has been added to check the existence of a directory before building the tree view.
  • User Interface Dialogs: The Used By list on the Dependency Explorer was limited to 6 levels deep. Now the Maximum Depth parameter that can be set from the Contains list will also be used with the Used By list.

January 31, 2020

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added another default parameter to the DiffFlowWriteCompleteModel script command called IncludeClearPowerFlowSolutionAidValues. By default this is YES. When set to YES the ClearPowerFlowSolutionAidValues script command is included in the auxiliary file saved from the case differences.
  • Difference Case Tool: When saving the Complete Model from the Preset Topological Differences from Base Case dialog, there is now an option to "Include ClearPowerFlowSolutionAidValues Script Command" that is checked by default. When checked this script command is included in the auxiliary file saved from the case differences. This script command was always included prior to this option being added.
  • Difference Case Tool: Modified the following generator fields so they are part of the Difference Case tool comparison: FuelType, FuelTypeCode, FuelTypeInteger, and FuelTypeEPC, UnitTypeInteger, and UnitTypeEPC.
  • File Formats: Added ability to read the H6E governor model from a DYD file. Removed the ability to define H6B and H6BD models from DYD models as those models are obsolete and were never used in any cases PowerWorld had previously seen. The H6E replaced this model.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Allow fields specified with the SendToExcel script command to include user-specified digits and rod.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug reading ATC Extra Monitor records from auxiliary files if the objects are identified by label.
    • Difference Case Tool: When using an AUX Export Format when saving a difference case auxiliary file, the section for renumbering three-winding transformer star buses was being included even if the three-winding transformer object type was not included in the AUX Export Format. This has been fixed so that this section will be excluded if choosing not to include three-winding transformers.
    • General: Fixed a bug where advanced sorting was not properly parsing date-time strings.
    • GIC: Fixed bug in the calculation of the GIC line voltages using a non-uniform field.
    • Transient Stability: Modified plots so that when hovering over the legend entries it doesn't highlight them.

January 27, 2020

Bug Fixes

  • Case Information Displays: Fixed bug in showing super area OPFReferenceObject field in the case information display.
  • Case Information Displays: Contact, Phone, Email, Company, and Location information for a Data Maintainer can now be set back to blank once they have been specified.
  • General: Dynamic Formatting and Data Check objects allow picking Transformer as an Object Type to include in the formatting or checking. This will no longer be allowed. Transformers are just a special kind of Branch and now the Branch object type will need to be used to represent Transformers. Dynamic Formats or Data Checks using the Transformer type will be deleted when loading a PWB or auxiliary file with this type.
  • General: User Defined Case Information displays can no longer be created for Transformer object type. The Branch object type will need to be used instead. When loading a PWB file or auxiliary file, a Transformer User Defined Case Information display will be converted to a Branch type.
  • General: AUX Export Format Descriptions can no longer be specified to save out the Transformer object type. The Branch object type will need to be used instead. When loading a PWB file or auxiliary file with an export format that includes the Transformer object type, this object type will be converted to Branch.

January 23, 2020

Features and Improvements

  • File Formats: Added ability to read a more recent version of the PSLF *.otg format for defining transient stability contingency events.
  • Bug Fixes

    • General: Fixed bug with new option added to Model Plane to extend the inside region beyond a single quadrant. The bug would not correctly identify that the current point was in the region beyond the defined quadrant.

January 20, 2020

Features and Improvements

  • Case Information Displays: Added new fields for Branches to show loading percentages based on Limit Monitoring Settings using Contingency Ratings. These new fields are Used % at From Bus CTG, Used % at To Bus CTG, Used % CTG, Used Limit CTG, and Violated using CTG Limits.
  • General: Added option to Model Plane to choose whether the Inside Region of the plane is contained in the single quadrant in which it is defined or it extends to infinity in the other quadrants. The default is to contain the plane in a single quadrant.
  • User Interface Dialogs: When right-clicking on a generator in a oneline or an area in a case information display there is an option to bring up plots for "All Area Gen IC Curves". This dialog will now contain a legend showing indicating which generators are being shown.
  • Bug Fixes

    • General: Data Check and Dynamic Formatting would not allow the use of secondary filtering. This has been fixed.
    • General: Interfaces could not be filtered by unlinked Interface Elements. This has been fixed.
    • Oneline Diagrams: Fixed a bug causing background objects to display incorrectly when saved to an image file.
    • Transient Stability: Made sure that the Show Block Diagram button is always enabled on the various transient stability object dialogs even when showing the present transient state.
    • Transient Stability: Modified the GICCoreType so that those columns in the case information display are disabled when the GICModelType <> Default.
    • Transient Stability: Changed the default Imarg parameter for EPCDC and CDC6 models so that it is 0.15.
    • Transient Stability: Fixed a bug that when switching from One to Multiple contingencies and vice versa in Transient Stability it was initializing the simulation.
    • Transient Stability: Added "Re-set Min and Max Values" button will only work when the simulation is paused. The values will be re-set to new values only after pressing Continue button in the simulation.

January 13, 2020

Features and Improvements

  • User Interface Dialogs: Modified Island Dialog to 1) allow shifting all the island bus angles by a specified amount of degrees and 2) a list display showing the Island AC tielines (which would obviously be open given that they span two ac islands).
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: An access violation could result when running ATC analysis while using one of the iterated solution methods and using a full topology case while using the option to close breakers to energize switched shunts. This has been fixed.
    • Distributed Computation: Fixed distributed user configuration.

January 3, 2020

Bug Fixes

  • Transient Stability: Greatly improved the network boundary equation solution convergence for events near DC line and Multi-terminal DC line terminals.

January 2, 2020

Features and Improvements

  • Case Information Displays: Added Nominal Tap Ratio field with Branch objects.
  • Transient Stability: Added options to plot and store results for the Meets Criteria field for Model Plane objects in transient stability. This value is reported as 0 for NO and 1 for YES.
  • Transient Stability: Added transient contingency element option that allows the generator delta and delta speed values to be directly changed. The application would mostly be system testing, such as phase angle for generator reclosing.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When creating interface elements through the InterfaceElement object type in an auxiliary file, better error messages will be provided in the log when elements cannot be found in the case.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in SetSelectedFromNetworkCut script command that reversed the order of the LowerMinkV and LowerMaxkV values. This was reversed even if using the defaults. This would result in branches not being selected.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixing issues to allow AXD support for Model Expression pie charts.
    • File Formats: The ability to add DistMW and DistMvar (distributed generation MW and MVar) to a load record was added in Simulator Version 19. A bug was fixed in Simulator Version 20 on September 18, 2018 related to performing area generation control in areas that contained this distributed generation. For cases in Version 20 and Version 19 created before this change however and then stored to a PWB file, some internal solution variables were stored slightly off. This could cause strange behavior when opening a PWB file stored in version 19 into Simulator 20 and 21. The behavior would result in a bunch of generation moving immediately when solving a power flow. Assuming the inner power flow solution worked Version 20 and 21 would move the generators right back to where they started and from that point on never exhibit this behavior.
    • File Formats: When loading RAS in the Areva hdbexport format the VALID field will now be used for RAS, TRIGCON, GATE, RTRIG, RSTG, and RPACT objects.
    • General: Corrected some bugs with unlinked interface elements that would not correctly identify the original element or allow them to be relinked.
    • Oneline Diagrams: Fixed a bug with the area/zone/substation swapping not working with onelines.
    • Transient Stability: Added the ability to only operate one relay at a time in a load. It follows the same order as before just only added the first or relays found first at any level.

December 17, 2019

Features and Improvements

  • General: Added ability to define "CustomFieldToggleChoice" objects which allow you to define a user-defined list of toggle choices for the CustomSingle, CustomFloat and CustomString fields for object. For toggleable Custom Fields we will only allow them to set the field to one of the choices. Otherwise we set the entry to blank. For custom integers or floats we will set it to the "closest" match. Modified so if custom fields are given toggle choices, then the user may not type in the value on the Custom Tab of various object dialogs. Instead the user must use a drop-down button to choice from among the choices.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): The filename for saving the oneline when using the ExportOneline script command will now support the special keywords starting with @ and the PROMPT functionality.
    • Oneline Diagrams: When auto inserting line pie charts and choosing not to insert pie charts on lines where pie charts already exist, pie charts would not be inserted if Line Flow Objects existed on the lines. This has been fixed so that only line pie charts are considered when adding new pie charts.

December 12, 2019

Features and Improvements

  • General: Added many new FuelType options to the generator field for FuelType. Also added fields for FuelTypeCode (shows only a 2 or 3 character code) and FuelTypeInteger and FuelTypeEPC which show integer versions of these field. The options are taken from the Form EIA-923 annual US Department of Energy filing. The EPC integer codes are taken from the WECC Data Preparation Manual. Also moved the FuelType and UnitType fields into a separate folder named "Type Unit Fuel\" as they were previously stored in the cost folder.
  • Bug Fixes

    • Simulator Automation Server (SimAuto): When clearing all registration type library information wasn't properly being cleared for both 32 bit and 64 bit entries. This has been fixed.
    • Transient Stability: Modified so that special plotting attributes based on a particular TSContingency are only applied to the plot series when creating a plot for multiple contingencies.

December 6, 2019

Features and Improvements

  • Sensitivity Calculations: Modified "Set Sensitivities At Out Of Service Buses To Closest" now enabled to work with Multiple TLR calculations. ETLR and WTLR not recalculated.
  • Transient Stability: Adding a new induction motor model named "InductionMotor3P_A_Beta". Traditionally, detailed induction motor models used in transient stability simulations have not modeled the frequency dependence of the electrical equations. As a result the induction motor model with a constant mechanical torque would return to a new steady state that was a similar constant power instead of scaling with the system frequency. This new InductionMotor3P_A_Beta model will include the frequency dependence.
  • Transient Stability: Added new fields for TSContingency objects to show totals for "Load Relay Tripped" and "Model Tripped" MW Fields.
  • Bug Fixes

    • Transient Stability: The CMPLDW and CMPLDWNF models had hard-coded the Trst field for single-phase air-conditioner models to be 0.4 seconds. This was a mistake as the input data included this value.

December 2, 2019

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added @CASEFILENAME and @CASEFILEPATH as special keywords that will return just the case name without path and extension and just the case path. These can be used anywhere that @CASENAME can be used.
  • Transient Stability: Added the tripping of the LDELEC to the IncrementTotalLoadMWTripped for Load Tripped total in Transient Stability.
  • Transient Stability: For WT3E and WT3E1 models, now modifying IpMax limit on the IpCmd output signal, when there is an initial limit violation.
  • Bug Fixes

    • Contingency Analysis: When using Merit Order Open dispatch on an Injection Group that is part of a contingency action, the amount of injection change might not occur correctly if the injection group contains a combination of generators, loads, and switched shunts. The objects that are not needed for dropping are supposed to be ignored, but this was not being done. This has been fixed.
    • GIC: Corrected GIC bug associated with the pxf.VECGRP_PSSE having a different configuration than what is being used. This could occur if the user changed a configuration. Now the pxf.VECGRP_PSSE is 1) set to blank on a pwb load and 2) set to blank when loaded from a *.gic file. However, the value in the *.gic file is used. Also fixed a bug in which we were not writing out our calculated VECGRP value to a *.gic file, just what had been stored.
    • Simulator Automation Server (SimAuto): SimAuto functions that take a filtername as input would return data even if the filtername that was specified was not valid. This has been fixed. Now an error message will result and no data will be returned.
    • Transient Stability: Fixed potential initialization problem in the CMPLDW and CMPLDWNF models when FmA + FmB + FmC + FmD + Fel = 1.00000 exactly. This could cause simulator to spit out an error indicating that the summation was > 1.0 when actually it was just exactly equal to 1.0.

November 25, 2019

Features and Improvements

  • Case Information Displays: Added three new generator object UnitTypes.
    'P1 (Photovoltaic, No Storage)' (maps to EPC Turbine Type 32)
    'PD (Photovoltaic, DC Coupled)' (maps to EPC Turbine Type 33)
    'P2 (Photovoltaic, DC Coupled No Storage' (maps to EPC Turbine Type 34)
  • Case Information Displays: Added new fields to a VoltageDroopControl object for Pmax and Pmin. These allow the user to monitor a total MW output coming from a group of generators involved in Voltage Droop Control together. Along with these two new user-enterable fields, added several MW fields to the Voltage Droop Control to show MW flows arriving at the regulated bus, MWs coming from generators, and percentages of the new Pmax/Pmin values. Also added percentages of the Qmax/Qmin values too.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When loading an "AUX format export description" from an auxiliary file, if an objecttype was encountered that did not exist it would cause access violations. This has been fixed so that these blocks within the format description are just ignored instead and not read.

November 18, 2019

Bug Fixes

  • Transient Stability: If a fixed switched shunt is assigned to a transient stability model it is allowed to move based on the model. This might require that shunt blocks be defined. Shunt blocks are not always defined for a fixed shunt. During a transient stability run if a fixed shunt has no blocks defined, has a non-zero nominal Mvar output, and zero Min Mvar and Max Mvar, a single block of the initial nominal Mvar output will be created and the limits will be set based on the nominal Mvar output.
  • Transient Stability: Fixed a bug with initializing the GroupMSS transient stability injection group model that could result in switched shunts not moving even though they should based on the enabling criteria and voltage conditions.

November 14, 2019

Features and Improvements

  • Transient Stability: Added validation check on the parameter T1 for IEEEG1 to ensure it is not too small.
  • Transient Stability: Previously for the WT3E and WT3E1 electrical control wind turbine models, setting both Kip AND Kpp would be treated as a validation error. We have modified this to only be an information message indicating that Kip will be treated as a very small positive number instead to allow proper model initialization.
  • User Interface Dialogs: Added the Model Planes to be seen in the Model Filter Visualizations. Also the dialog for model planes will open with a right click on the model plane just as the model conditions do.
  • Bug Fixes

    • Case Information Displays: When using SendToExcel features and trying to push the results to an existing open instance of Microsoft Excel, Simulator would sometimes return and "Operation Unavailable" error. This could happen inf Microsoft Excel was busy doing something. We have modified it so that if this happens we will now wait 1.0 seconds and try again. If it then fails, we will instead just automatically open a new instance of Excel and push the data to this instance.
    • File Formats: When loading three-winding transformers from an EPC file, only the first three ratings are specified in the file for the secondary and tertiary windings. There was a bug where the ratings beyond the first three were not being initialized correctly to 0 and instead were being set to numbers in the e-40 range. This would result in very large % of Limit Used calculations and very negative ATC results. This has been fixed when loading an EPC file. When loading a PWB file that had been saved with this issue, this incorrect limits will now also be set to 0.
    • PV and QV Curve (PVQV) Tool: Added ability to identify QVCurve results by label.
    • Transient Stability: Fixed an initialization bug with REGC_A when internal XFMR StepX and/or StepR are specified in the power flow case. Intended modeling of REGC_A is with StepX and StepR as zero and StepTap = 1, and now these are set before initialization.

November 12, 2019

Features and Improvements

  • Case Information Displays: Added new field to InterfaceElement object called "NearBusRetain". This field is the same as NearBus, however it will retain the string that is entered here and write it back out later. The other NearBus field just uses the string to populate the appropriate near bus, but then throws the string away.
  • Transient Stability: Added support for new model named IEEEG1PID. This governor is very similar to IEEEG1, except that it replaced a lead-lag controller with a PID controller instead.
  • Transient Stability: When reading a DYR file, modified to convert the USRMDL model named "RAVGOV" so that it is translated to the new governor IEEEG1PID.
  • Bug Fixes

    • Case Information Displays: An access violation could result when opening the Jacobian case information display if area/zone/owner filters were applied. This has been fixed.
    • Transient Stability: Removed option to show Bus View from transient stability injection group models case information display. Bus views are not relevant for injection groups.
    • Transient Stability: Option to Pan to Object on Open Onelines on transient stability model case information displays should now work to pan to the object to which the model is assigned.
    • Transient Stability: Allowed the GP3 Relay Model to propagate to all generators in the case even when the generator to which the GP3 relay is attached does not have an active machine model
    • Transient Stability: Fixed potential numerical problem when using a CSVGN1 model which could occur with a particular set of input parameters.

November 7, 2019

Bug Fixes

  • File Formats: When opening a PWB file containing a Model Filter that includes a Model Plane, the Model Plane was not always being linked to the Model Filter Condition. This has been fixed.
  • Optimal Power Flow (OPF): Removed the field OPF_SolutionType on the object OPF_Options. This does not do anything.
  • Transient Stability: When reading a switched shunt model from a DYR file, if the bus did not exist it would cause an error. This has been fixed and the model is properly skipped then.
  • Transient Stability: Fixed bug with initializing the Pref-Controller WTGTRQ or WTTQA1 when the MVABase of the PrefController did not match the MVABase of the generator.

November 6, 2019

Features and Improvements

  • Transient Stability: When reading a DYR file, the OLTC1T and OLTC1 models are now automatically converted to an LTC1 model.
  • Bug Fixes

    • Power Flow Solution: Further refined the power flow solution when multiple continuous switched shunts are remotely regulating the same bus together.
    • Transient Stability: Fixed error when defining a MeasurementObject in transient stability to does not have an associated object with it. This doesn't make sense, but was causing an error. It will now just be ignored.

November 1, 2019

Features and Improvements

  • Transient Stability: Added the reading of USRMDL model SVSMO1U1 which is read as an SVSMO1 model.
  • Transient Stability: Added the reading of USRMDL model SVSMO1U2 which is read as an SVSMO1 model.
  • Transient Stability: Added the reading of USRMDL model SVSMO2U2 which is read as an SVSMO2 model.
  • Transient Stability: Added ability to read the SVSMO1T2 model from a DYR file which is read as an SVSMO1.
  • Transient Stability: Added ability to read the SVSMO2T2 model from a DYR file which is read as an SVSMO2.
  • Transient Stability: Added a new CHSVCT dynamic model for switched shunts.
  • Bug Fixes

    • File Formats: When reading an Areva RASMOM file, an access violation could occur if encountering an unknown TRIGCON GATE field. This has been fixed so than an error message is produced instead.
    • Power Flow Solution: Improved transformer tap switching consistency after a failed solution.
    • Transient Stability: Fixed duplicate event messages that could appear saying that the loss-of-field relay portion of a GP3 model can not be used with a GENCLS model.
    • Transient Stability: Modified to read USRMDL IEEEG1CDU and convert to a IEEEG1D model.
    • Transient Stability: Correctly normalizing the PrefInput into WTGTRQ_A_WTTQA1_PTI, if it has a Plant Controller, and if it is just an initialized constant.
    • Transient Stability: An access violation could result if creating a Measurement Object without an associated object. This has been fixed.

October 29, 2019

Features and Improvements

  • Transient Stability: Added a button on the Transient Limit Monitors tab of the transient stability dialog to "Re-evaluate to Get Limit Monitor Violations." This will re-evaluate stored results to determine limit monitor violations. First the results in RAM will be searched, and if not found, results in TSR files will be searched. If in Multiple Contingencies mode, all contingency results will be evaluated.
  • Transient Stability: Added support for a new relay model named LDS4 which is identical to LDS3 except that it includes two extra parameters Vthresh and Tv. When the voltage at the measured bus of the relay drops below Vthresh, then the relay will not respond until the voltage goes back above Vthresh for at least Tv seconds. While the relay is inhibited from acting this way it will also reset any stages of the relay that may have started their timer. Note however that if a stage had already made a decision to trip something then dropping below Vthresh will not stop this from happening.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Updated the script command TSLoadPTI() so that a 5th option parameter for MOD_REMOVE filename is now available.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed error in parsing fields from AUX files which had consecutive single quote characters embedded inside the string.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed how TSPlotSeries read from an AUX file are when the plot series referred to fields of a Measurement Model such as LDTRPMON.
    • Available Transfer Capability (ATC) Tool: When allowing users to specify the names of multiple ATC scenarios, prepend an underscore on the name if it matches a default name and the name is not in the appropriate order. The default names of generator scenarios are G0, G1, G2, etc. If a user decides that the names should be G1, G2, G3, etc., the resulting names will be _G1, _G2, _G3, etc.
    • Transient Stability: In the measurement object LDTRPMON which monitors the composite load model, the reported Other field values of Pld, xshn, and Pdg were being shown in per unit instead of in MW (off by a factor of the system MVABase and thus by default 100 times too small). As a result values for these 3 fields would show 2.5 instead of 250. This has been fixed. Also, the field name "xton" was showing up as "ston" which was a typo that has been fixed now too.
    • Transient Stability: Bug fix for WTTQA1, which was initializing Pref0 on the wrong base, and hence causing the initialized PI Input value to be non-zero.
    • Transient Stability: Added validation of the Ta parameter on the ESST1A exciter model to ensure it is not too small.
    • Transient Stability: Only generators with synchronous machine models can have a meaningful non-zero value for the power angle.
    • Transient Stability: Fixed bug reading zonedef for distrel when reading from a dyd file.

October 23, 2019

Features and Improvements

  • GIC: Added ability to show the substation input electric field values.
  • Bug Fixes

    • Transient Stability: Modified WT3E, WT3E1, and WT4E1 to better handle user-input in the Kip = 0 (gain on integrator PI Controller).
    • Transient Stability: Typically in PSLF the Extra Object or Extra Devices used the "! ! ! ! !" but it seems that the repc_a and repc_b used only the "! !". Fixed this.
    • Transient Stability: Added VKlr as an other field for EXST1_GE.

October 21, 2019

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added a new script command LoadPTISEQData(filename, version); The filename is the file being opened. Version is an integer representing what version of the SEQ file to open.
  • Transient Stability: added VPERHZ1 generator relay model that implements a Volts per Hertz definite time relay model. It has 5 zone (V/Hz and Time) settings, a measurement delay for per unit voltage and per unit speed (Note: model uses speed as a proxy for frequency), and a breaker delay.
  • Transient Stability: Modified the meaning of the "rrpwr" rate limit on real current for many renewable energy machine models. Previously this rate limit only applied to real current that was increasing in the positive direction. It will now apply to increasing the ABSOLUTE value of real current instead. Thus if the present real current is negative it will be a negative rate limit and if present real current is positive it will be a positive rate limit. This has become necessary as these machine models are being used for energy storage devices which can initialize real current as a negative value to represent charging. This impacts the models GEWTG, WT3G, WT4G, WT3G2, WT4G1, PV1G, REGC_A, REGC_B and REGC_C. The DER_A model had always been coded in this manner.
  • Bug Fixes

    • Transient Stability: Fixed a bug with the auto insert DISTRELAY feature. The auto insert feature was incorrectly placing the relay at the opposite end of the line from what the user indicated. This has been fixed.

October 18, 2019

Features and Improvements

  • Transient Stability: Adding support for changing GMD induced dc line voltage as a transient stability (really ds) event.
  • Bug Fixes

    • Transient Stability: Modified DGDER_A and DGPV load distributed generation models so that when defining their MBase as a negative value, we do not always base the MVABase on DistMW/abs(Mbase). It will now take the absolute value of the DistMW and DistMVar fields and take the larger of those two values and then divide by abs(MBase). This was done for the situation where DistMvar is much larger than DistMW. In extreme example, DistMW = 0, DistMvar <> 0. This is potentially possible if someone were modeling distributed energy storage, but the more likely situation is inadvertent user input. Regardless it will no longer cause software errors for this situation.
    • Transient Stability: Modified filtering associated with applying complex load model. Normally the filtering applies only to the load MW/Mvar portion of the load object and not the DistMW/DistMvar. If however there is not a dynamic model for the distributed generation then DistMW and DistMvar are substract from MW and Mvar and the Net values are used with the load characteristic. Simulator has been changed so that when the NetMW and NetMVar are being used then NetMW and NetMVar are used in the filtering features of the load characteristic

October 16, 2019

Features and Improvements

  • Transient Stability: Modified the LD1PAC (and thus LD1PAC_CMP which derives from this model and also CMPLDW, CMLD, and CMLWDWNF that contain this model). When the Tstall parameter is set to a negative number, then a hard-coded inverse time characteristic is implemented which replaces the definite time Vstall/Tstall characteristic. The curve implemented uses the following table to lookup a Tstall from the terminal voltage of the model (with a linear interpolation between points). Also the inverse time internal state is automatically reset whenever the terminal voltage goes above 0.565 per unit.
    Vterm Tstall (in cycles)
    0.000 2
    0.450 2
    0.490 3
    0.550 12
    0.565 15
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed error in Move script command that was not allowing the change of CircuitID for one leg of a 3 winding transformer
    • File Formats: When loading PTI RAW files for Branches, LineShunts that were 0 MW and 0 MVar were being created. This did not impact the simulation but was strange, so has been fixed.

October 11, 2019

Features and Improvements

  • Fault Analysis: Added option on the fault analysis dialog to open and save a version 34 PSS/E sequence data file.
  • File Formats: Added code to abort hdbexport reading when the fields in the records don't match the expected fields in the header. This is in response to several files with string fields without quotes. These fields contained commas, which was causing an access violation attempting to access the header for a field that doesn't exist.
  • Simulator Automation Server (SimAuto): Changing RegSimAuto.exe program so that the dialog that appears shows the currently registered executable
  • Transient Stability: Reads PTI DYR model SVSMO2T2. Converts to SVSMO2. Writes out PTI DYR model SVSMO2T2
  • Transient Stability: Added a new synchronous machine model GENQEC which has the following features that improve upon the GENROU/GENSAL models. This GENQEC model can be used with both salient pole and round rotor synchronous machines. The purpose of this model is to replace GENROU/GENSAL and GENTPF/GENTPJ type models.
    1. Ignoring saturation, model has the same as differential equations as GENROU/GENSAL
    2. Saturation treatment is similar to GENTPF/GENTPJ in that saturation is modeled by applying multiplicative term to the machine input parameters as appropriate
    3. Allows Xqpp <> Xdpp (allows sub-transient saliency), which GENROU/GENSAL did not.
    4. Added a flag to indicate what saturation function to use. Choices are 0: exponential, 1: scaled quadratic, 2: quadratic
    5. Added a Kw compensation term which can model the impact of stator current on the steady state relationship between field current and terminal voltage relationship. This models the fact that the linear relationship (slope) between steady state field current and terminal voltage changes with stator current.
    (Also Removed the test synchronous machine models GENPWS and GENTPW.)
  • User Interface Dialogs: Added new fields for Area and Zone for a Injection Change in LineLoadingReplicator
  • User Interface Dialogs: Update in Line Loading Replicator Tool - Now able to choose multiple injection groups, instead of just one. Participation factor is not relevant, because the injection group is just being used as a basket of sink/source elements (gens and loads)
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed access violation that could occur with the SetData script command if no fields are specified.
    • Auxiliary Files (SCRIPT and DATA Sections): Added optional fieldlist parameter to the ATCWriteToText and ATCWriteToExcel script commands. If the fieldlist is specified, the results will be saved with these specified fields. If not specified, the results will be saved with the fields that are specified with the TransferLimiter DataGrid. It is possible that the results could be blank if the TransferLimiter DataGrid has not been initialized by either opening the ATC dialog or loading the DataGrid settings from an auxiliary file. To make sure that results are stored and the desired fields are included, it is suggested that the fieldlist option be used.
      The format of the script commands are now:
      ATCWriteToText("filename", filetype, [fieldlist]);
      ATCWriteToExcel("worksheetname", [fieldlist]);
    • Time Step Simulation: Fixed error check when Kpp = 0 on the WT3E1 model. It was supposed to check if Kip was also 0.0 and return this as an error, but this was not working properly.
    • Time Step Simulation: Fixed error in implementation of ABBSVC1 model when no transformer branch has been specified.
    • Time Step Simulation: If specifying a distributed generation model for the entire case, we were including this transient stability model in the list of states even for loads which do not have any distributed generation (DistMW = 0 and DistMvar = 0). This did not effect the numerical simulation, but was strange and has been removed.
    • Time Step Simulation: On the Transient Stability Plot dialog, when selecting a multiple devices we automatically update the strings underneath folders such as "Exciter State" or "Machine State" to reflect the names of fields for the objects which have been selected. If "State 2" for all the selected devices where the same string we would show that string, and otherwise we would just show "State 2" instead. When selecting a very large number of generators or loads (> 500) this was making the user interface sluggish. This has been modified so if more than 500 devices are selected we always only show the "State 2" or the equivalent.
    • Transient Stability: Fixed a bug with run validation in TS. It was creating an Item not found message when a generator dot no had an Island. This only occurred on machine models that could be closed.

October 3, 2019

Features and Improvements

  • Bus View and Substation View Onelines: The information stored in the system registry for Bus View settings will now include the name of the Custom View if one is chosen to be the current view. This will be retained when Simulator is closed and will be applied when reopening Simulator and used with any PWB if the named custom view is saved with the PWB.
  • Contingency Analysis Tool: Added options on the local menu of the contingency case information display under the Save As menu entry for "PTI Contingency File..." and "PTI Contingency File (only selected records)...".
  • File Formats: When reading an hdbexport CSV file, modified how we read multiple XFLIM records which have pointers to the same XF record. Normally this won't happen, but users are able export a CSV file with multiple XFLIM records. Previously we would read all of them an continue overwriting the ABC limits and thus the final XFLIM record encountered would override all others. In talking with customers the preference was to read them into limits DEF and beyond instead. Now when reading
    1. The first XFLIM record will take parameters LIMIT1_XFLIM, LIMIT2_XFLIM, LIMIT3_XFLIM and put them into limits A, B, and C.
    2. The second XFLIM record will populate D, E, F
    3. The third XFLIM record will populate G, H, I
    4. The fourth XFLIM record will populate J, K, L
    5. The fifth XFLIM record will populate M, N, O
    All subsequent XFLIM records for the same XF record would then be ignored.
    The same logic was added taking LNLIM and assigning limits to LN records, and for taking ZBLIM records and assigning limits to ZBR records.
  • Transient Stability: Reads PTI DYR model SVSMO1T2. Converts to SVSMO1. Writes out PTI DYR model SVSMO1T2
  • Bug Fixes

    • File Formats: When changing switched shunt data within the Simulator GUI or through an auxiliary file for GE specific fields that are associated with EPC files, fields that can be associated with both SVD and Shunt data in an EPC file, such as GE In Service Date and GE Retirement Date, may not have been set correctly. This has been fixed. Information was correct if it was read directly from an EPC.
    • File Formats: When reading PTI sequence data the circuit IDs of transformers were not always being identified correctly resulting in sequence information not being read. This has been fixed.
    • User Interface Dialogs: Removed unused options from the local menu of the LODF Screening Summary case information display.

September 30, 2019

Bug Fixes

  • Distributed Computation: Fixing distributed computation when hardware key licensing fails
  • File Formats: When setting the EPC datein and dateout fields through an auxiliary file, trim any extra spaces. These fields are supposed to be integers and conversion to an integer can fail with extra blanks. Trim these fields when writing to an EPC file to prevent invalid integer errors.
  • File Formats: Fixed bug reading in SUBDATA for contingency elements. When a generator was referenced by a label, which happened to be a numeric value, it was matching to a bus number instead of the generator label. This has been fixed. This is detected by the missing ID value in the generator key fields.

September 26, 2019

Features and Improvements

  • Contingency Analysis Tool: Added the 'Disable D-FACTS' option to the contingency solution options.
  • Bug Fixes

    • Contingency Analysis: Fixed access violation that would result if starting a contingency analysis run while the All Violations case information display is open and contains violations.
    • File Formats: Fixed a bug that would save a PWD file as blank.
    • Transient Stability: Made changes to user defined models in TSUserDefined.pas, so that validation errors are not produced when using a user-defined machine model with any (library or user-defined) exciter model.
    • User Interface Dialogs: On the Simulator Options dialog fixed the mouse over hint for the Disable D-FACTS Control option.
    • User Interface Dialogs: When dialogs were maximized inside the main Simulator window and a dialog was already open but hidden behind other dialogs, clicking on the option to open that dialog would bring the dialog to the front but not display it properly as maximized. The top caption of the dialog would be shown and some option buttons and the bottom of the dialog could be hidden behind the bottom of the main Simulator window. This was happening with the Scale dialog and Limit Monitoring Settings dialog and various others. This has been fixed.

September 25, 2019

Bug Fixes

  • File Formats: Fixed a bug that would produce an error when saving a PWD file.

September 24, 2019

Features and Improvements

  • File Formats: When loading PTI MON file now support loading an interface when specified in this format: MONITOR flowgate 3 'My Flowgate' biratings -10000 10000
  • Transient Stability: Implemented SignalStabStabilizer to provide reference signals into a stabilizer input. Inputs are similar to the InfiniteBusSignalGenerator.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in the LoadCSV script command. The command was crashing when the specified file did not exist. Now, it checks for the file's existence and returns an error message when it's not there.
    • File Formats: Fixed a bug that would not allow the same PWB or PWD file to be loaded at the same time by different processes.
    • Sensitivity Calculations: Fixed access violation when trying to calculate a TLR on an open branch.

September 21, 2019

Bug Fixes

  • General: Fixed an error that resulted if trying to save a PWB or PWD file that already existed.

September 20, 2019

Features and Improvements

  • Transient Stability: Added ability to read the CMLDxxU2 composite load model. This is the same as CMLDxxU1 except that it includes the frcel (fraction of electronic load the reconnects). This will be read into a CMLD model which now also includes this additional input parameter frcel.
  • Transient Stability: Added new ModalAnalysis button on the Ribbon.
  • Transient Stability: Modified Modal Analysis to have option of storing results; default is false.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Fixed access violations that could occur when running one of the iterated ATC methods when oneline diagrams are open.
    • Contingency Analysis: When using the contingency option to specify Generator Maximum MW Response, the Max MW and Min MW limits are adjusted for generators with a maximum response specified. The change in limits will restrict how far the generator can move during the post-contingency solution. At the end of the contingency solution the limits are now restored to their original values. Previously they were kept at the reduced limits and this could result in incorrect generator responses if applying additional contingencies on top of the first contingency.
    • Power Flow Solution: When checking switched shunts in the voltage control loop of the power flow solution, a tolerance is now included so that shunts will only move if the voltage at the regulated bus is different than the target voltage by this tolerance. This will help prevent switched shunt oscillations especially in situations where generators are regulating the same bus as switched shunts.
    • Transient Stability: Fixed the caption on the Stability > Terminal and State > Bus/Setpoint Values page of the generator dialog from "Polar" to "Rectangular" for one of the "Terminal Voltage and Current into Bus" fields.
    • Transient Stability: Changed the order of fields on the case info display showing the CompLoad load characteristic objects.
    • Transient Stability: When loading a DYR file and loading a machine, exciter, governor, or stabilizer we now make sure that if an existing model of a different name exists at the generator, then the newly created and loaded model from the DYR file becomes the active model.
    • Transient Stability: Prevent errors by preventing generator relay from being included in calculations if its generator is not inservice.
    • User Interface Dialogs: Reduced the amount of window flicker that occurs when moving or resizing windows.

September 16, 2019

Features and Improvements

  • Contingency Analysis Tool: (1) Added new option under the Other > button and then Manage Contingency Definitions called "Set Selected Field for Remedial Actions and Dependencies."
    (2) Added two new options on the local menu of the Remedial Action case information display: (a) "Set Selected Field for Dependencies" and (b) "Set Selected Field for Dependencies (only selected records)".

    All of these options are meant to help identify the Model Filters, Model Conditions, Model Planes, and Model Expressions that are being used by user specified Remedial Actions and NOT used by other objects. If for example a user specified Remedial Action is using a Model Filter and a Transient Stability Contingency Element also is using that Model Filter, that Model Filter will NOT have its Selected field set to YES. At the beginning of the implementation of each of these options the Selected field is set to NO for all Remedial Actions, Model Filters, Model Conditions, Model Planes, and Model Expressions. In the descriptions below "dependencies" will mean objects of type Model Filter, Model Condition, Model Plane, or Model Expression.
    Option (1) will check all Remedial Actions in the case and set the Selected field to YES for any dependencies of the Remedial Actions. The Selected field for Remedial Actions will also be set to YES.
    Option (2a) will check all Remedial Actions that are shown in the Remedial Action case information display. This might be a subset of all Remedial Actions if filtering is in use. The Selected field will be set to YES for any dependencies of these Remedial Actions and the Selected field for these Remedial Actions will also be set to YES.
    Option (2b) will check only the Remedial Actions that have been selected in the Remedial Actions case information display by using the mouse. The Selected field will be set to YES for any dependencies of these Remedial Actions and the Selected field for these Remedial Actions will also be set to YES.
  • User Interface Dialogs: Added dropdown on Model Expression dialog to change the key field identifier to use for variables on the dialog. This option only affects the key field identifier to use for this dialog and does not impact the setting used with case information display options.
  • Bug Fixes

    • File Formats: Fixed a bug that would prevent a PTI CON file from loading.
    • GIC: Allowed XFConfig to work with primary and secondary fields, both for display and pasting.
    • Oneline Diagrams: Added options with right-click menus to format oneline fields while in Edit mode if only a single field is selected. Previously this could only be done if more than one oneline object was selected.
    • Transient Stability: Fixed change from August 8, 2019 patch that was preventing the modal analysis signal dialog from showing.
    • Transient Stability: Fixed bug that was preventing the modal analysis Iterative Matrix Pencil from working.

September 10, 2019

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): SendToExcel Script Command now validates to ensure that the workbookname is not an empty string.
  • File Formats: Fixed access violation when reading contingency records from an Areva EMS file.
  • General: Fixed installation to properly register SimAuto.
  • GIC: Fixed bug when pasting GICXFORMER info by primary and secondary bus numbers.
  • Oneline Diagrams: Fixed an access violation that would occur when closing a oneline for which a Display Explorer is also open.
  • Optimal Power Flow (OPF): In OPF solution when using the minimum control change option, the phase shifters and DC Lines controls were not working properly and instead were using a cost function centered around zero instead of the present operating point. This has been fixed.
  • Transient Stability: Fixed treatment of damping on the WTGT_A model.
  • Transient Stability: Modification of WTGT_B mechanical model for wind turbines.
  • Transient Stability: When reading a DYR file which contains the USRMDL with the name DERAU1, Simulator will automatically convert that to the DER_A model.
  • User Interface Dialogs: When trying to change the ID of a branch from the branch dialog while in Edit mode, an error for "Cannot make a visible window modal" could result. This has been fixed.

September 4, 2019

Features and Improvements

  • Case Information Displays: Added new case information display option regarding whether to "Show prompt about saving SUBDATA to AUX". This impacts the Generator and Load case information display which previously had prompted the user regarding whether to store the ReactiveCapability or BidCurve information as a SUBDATA section of each object. The user will now be able to choose "Never" and this dialog will no longer appear, though it can be added back by changing the new Simulator Option to show these again.
  • User Interface Dialogs: On dialog/window system menus found by left clicking on the PowerWorld logo in the caption of a dialog, there are now options for "Export" and "Copy to Clipboard" that export or copy images of the dialog.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug that would not allow the LoadAXD script command to load an AXD file into a oneline that doesn't already exist.
    • Case Information Displays: When listing the Areas, either by Name or Number, that are assigned to a Zone, include gens, loads, and shunts along with buses. Previously only buses were being included.
    • Case Information Displays: When listing the Zones, either by Name or Number, that are assigned to an Area, include gens, loads, and shunts along with buses. Previously only buses were being included.
    • Case Information Displays: Added Case Info Customizations for the following contingency related case information displays: Generator Post-Contingency AGC, Bus Load Throw Over, Generator Maximum MW Response, Generator Line Drop and RCC, and Switched Shunt Post CTG.
    • General: Closing a case containing many injection groups that include other injection groups could be very slow. This has been fixed.
    • Power Flow Solution: Fixed log messages regarding the AGC changing generator MW outputs. They should have been listing the area that was resulting in the change in MW.
    • PV and QV Curve (PVQV) Tool: Removed extra dialog that pops up briefly before opening the PV dialog.
    • Transient Stability: When transferring the Transient Stability operating point to view inside the case information displays in Simulator, errors were appearing related to setting generator voltage setpoints that should not have been appearing. This has been fixed.
    • User Interface Dialogs: The plotting of a reactive capability curve from user-specified points was not working properly. This has been fixed and diamonds have been added to the display to show the points.
    • User Interface Dialogs: On the bus dialog while in Run mode the Selected checkbox and other options on the Custom tab were not being updated to reflect the values associated with the current bus when the dialog was opened unless the Simulator license key included the OPF add-on. This has been fixed. The values set on the dialog were being transferred to the bus when the dialog was closed with the OK button or Save was clicked.

August 29, 2019

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in CalculateLODFMatrix script command. There was a bug using the ALL qualifier to monitor ALL of the interfaces. The code was accessing the monitor filter incorrectly.
  • General: Fixed a bug where the impedance correction table was not working properly. The table was using the range of the values in the table to determine whether to use the phase or tap ratio to lookup in the table. Now, the type of value is determined correctly before looking up the impedance in the correction table.
  • User Interface Dialogs: On the Auto Insertion of Injection Groups dialog the Custom Field dropdowns were not being updated if the Element Type changed. This has been fixed.

August 28, 2019

Features and Improvements

  • User Interface Dialogs: When defining Model Conditions and Model Expressions and using the Choose a Field dialog to select a field for the condition or expression, there is now an option "Show Transient Stability Remedial Action Fields". When this option is checked, only the fields that are valid for being evaluated each time step during transient stability analysis will be shown.
  • Bug Fixes

    • Contingency Analysis: Certain categories of contingency violations could not be loaded from an auxiliary file or correctly returned when using distributed contingency analysis. These include the Change Bus dV/dQ, Change Bus Disconnected, and Bus Neg dV/dQ violation categories. This has been fixed.
    • Contingency Analysis: An access violation could occur when deleting contingency violations from the following categories: Change Bus dV/dQ, Change Bus Disconnected, and Bus Neg dV/dQ. This has been fixed.
    • Distributed Computation: For Distributed Contingency Analysis an error would occur when including the Advanced Limit Monitoring options to "Report changes in bus dV/dQ sensitivity" or "Report as a violation if a bus becomes disconnected." This has been fixed.
    • General: Updated autoload function. Now the files are renamed with an underscore '_' character before being loaded. This allows us to check for files that need to be deleted before loading a new file.
    • Sensitivity Calculations: Fixed access violation when calculating interface sensitivities on the Flow and Voltage Sensitivities dialog under Single Meter, Multiple Transfers.

August 26, 2019

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): When loading Contingency Elements, Remedial Action Elements, and Global Actions from an auxiliary file it was possible that the Model Criteria field could be set to an incorrect entry if the Model Criteria field was not specified in the field list in the auxiliary file. The Model Criteria should have been set as blank instead of an entry. This has been fixed.
  • Auxiliary Files (SCRIPT and DATA Sections): When loading Remedial Action Elements from an auxiliary file it was possible that the Arming Criteria field could be set to an incorrect entry if the Arming Criteria field was not specified in the field list in the auxiliary file. The Arming Criteria should have been set as blank instead of an entry. This has been fixed.
  • Auxiliary Files (SCRIPT and DATA Sections): It was possible that blank names could be specified for Model Filters, Model Conditions, Model Planes, and Model Expressions when loading from an auxiliary file. A non-blank name must be specified for these objects. This has been fixed.

August 23, 2019

Bug Fixes

  • Transient Stability: Handled strange input data for WTGT_A when Ht=0. Modified to automatically assume this represents a single-mass model and internally H=Ht+Hg. Previous expectation was that the user would set Ht and then make Hg=0. This handles situation when the user does the opposite and sets Ht=0 while giving a value for Hg.
  • Transient Stability: Fixed bug when REPC_B was assigned to a generator and then not connected to any generators. This was causing inconsistent results. The expectation is that the REPC_B model must connect its output to itself.
  • User Interface Dialogs: When editing the MVABase of the winding of a three-winding transformer on the Three-Winding Transformer Information dialog it was not taking any edits of the MVABases. You were only able to edit those values on the case information displays and NOT on the dialog. That has been fixed.

August 19, 2019

Features and Improvements

  • Transient Stability: Added a button on the Options > Remedial Actions page of the transient stability dialog to "Show Valid Remedial Action Fields" that will display a case information display with all fields that can be evaluated each transient stability time step.
  • Transient Stability: Added REGC_C model.
  • Bug Fixes

    • File Formats: Modified how the System-Wide settings of the RAW version 34 file are read so that we properly read files even when particular parameters are omitted in that format. Previously we were failing to read the file when values are omitted. The values are all entered as "Key=Value" strings, so we can just parse these and lookup the keys that we fine.
    • Transient Stability: Renamed governor model GGOV1DU to GGOV1D.
    • Transient Stability: When including remedial actions in transient stability, the remedial action definitions would be ignored if not using the option with contingency analysis to "Save contingency analysis definitions/results in the case PWB file." This has been fixed.
    • Transient Stability: Fixed TSAutoInsertDistRelay script command. Added parameters for AddTo, AddFrom, Transfer Trip, and Shape. The format is now:
      TSAutoInsertDistRelay(0.9,InsertRelayAtFromBus, InsertRelayAtToBus, DoTransferTrip, Shape, filtername).
    • Transient Stability: Improved validation of remedial actions used in transient stability.
    • Transient Stability: Added fields that are allowed to be evaluated at each transient stability timestep: Branch MW From, Branch MW To, Branch Mvar From, Branch Mvar To, Branch MVA From, Branch MVA To, Branch Amps From, Branch Amps To, Bus PU Volt, and Bus Volt (kV).
    • Transient Stability: Fixed a bug that would not correctly identify line relay models when loading from an auxiliary file.

August 13, 2019

Features and Improvements

  • General: Added ability to automatically load a PWB, AUX, RAW, or EPC file whenever a new file appears in a directory. The file will immediately be opened and then the file will be deleted!
  • Bug Fixes

    • File Formats: Modified the Save RAW with Options dialog to allow Version 34 RAW files to be opened and saved.
    • File Formats: When reading an EPC file load record a climate zone of " " (double quote, space, double quote) was being read and a climate zone created without stripping of the double quotes resulting in a very strangely named LoadModelGroup in Simulator. Then on a subsequent export of the load record to an EPC it would encase that entire string inside double quotes resulting in "" "". This then appeared to be two strings on the next import of the EPC file messing up entries after the climate zone in the EPC file. This has been fixed.
    • Integrated Topology Processing (ITP): Added checks for the ITP add-on when using the 'When using Integrated Topology Processing, monitor only the primary bus for each superbus' option. This option was being used when the user did not have the ITP add-on and when the case was not marked as a full topology case. This was causing the contingency analysis to give confusing results: they were being limited to primary buses when this was not the expected behavior. Now, the option will check that the user has the ITP add-on and that the case is marked as a full topology case before filtering the results. In addition, the checkbox will be hidden if the user does not have the ITP add-on.
    • Transient Stability: When testing to see if the Intermountain Power Project (IPP) DC Line should be automatically included in the stability model, modified so this model is not included if the actual device is out of service in the initial case. This was causing access violation.
    • Transient Stability: Fixed bugs with initializing a DC line that is out of service in a transient stability simulation.
    • Transient Stability: Fixed error when initially energizing a bus with a ZIP load by closing in branches to energize the bus during a transient stability run.

August 9, 2019

Bug Fixes

  • Transient Stability: Fixed a bug where Plot images were not being saved properly during Distributed TS runs.

August 8, 2019

Features and Improvements

  • Transient Stability: Added a new Injection Group transient stability model named GroupMSS.
  • User Interface Dialogs: Modified the dialog that appears offering the user the ability to add "Case Comments" when choosing options to Save Case, Save Case As, Save Case with Comments, or Save Case As with Comments. Previously once you got to that dialog there was no way to "Abort the Save". Hitting the X in the upper right would just skip adding the comment but you would still save the case. There are now separate buttons to Add a comment, Skip adding comment, and Abort Save all together. Also removed the X in the upper-right of this dialog to force the user to choose one of the buttons making it very clear what is desired.
  • Bug Fixes

    • Case Information Displays: Fixed an access violation that could result when using the option to Export Case Object Fields related to the new ModelPlane object
    • Transient Stability: Bug fix in Modal Analysis for catching exception during floating point overflow, which happens rarely, but typically while using a large time window, or a time window which has a "discontinuous" signal (like when a generator opens up, causing a sudden change)

August 6, 2019

Features and Improvements

  • Transient Stability: Added WTGT_B mechanical model for a type 4 wind turbine.
  • Bug Fixes

    • Case Information Displays: Fixed error in calculating the amps of a load when the load is disconnected.
    • Transient Stability: When an IEEEG1 or CRCMGV were configured with the low pressure generator online AND the high pressure generator off-line, this resulted in an access violation. The governor model is assigned to the high-pressure generator which is off-line in this situation and was causing bad behavior. For now this has been fixed by ignoring the governor and thus the low pressure genenerator will be simulated without a governor.
    • Transient Stability: Added storage of the option to Include Remedial Actions in Transient Analysis to PWB files which will also allow this option to be included with distributed computing. Remedial actions had not been included with the distributed computing runs but this has been fixed.

August 2, 2019

Features and Improvements

  • File Formats: Added bad data handling when reading an EPC file with a generator with cont_mode = 4 if the Vcsched is set to an unreasonable value. (We were seeing cases where value was set to 24.000 as user entered value in kV mistakenly). When Vcsched is specified outside the range 0.85 - 1.15 we will instead assuming cont_mode = 0, the regulated bus is the terminal bus, and the VoltSet is the present terminal voltage.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Fixed Access Violation that would occur when using the Available Transfer Capability tool when using the Iterated Solution Methods. This bug only impacted Version 21.
    • File Formats: Added ability to read the cont_mode = 4 from a generator in an EPC file. This then uses a field "Vcsched" field. When reading cont_mode = 4, the generator is set to as follows
      VoltSet = Vcsched
      UseLineDrop = YES
      Rcomp = RcompEPC * SBase/MVABase
      Xcomp = XcompEPC * SBase/MVABase
    • Time Step Simulation: Fixed bug when using a file Data Source on the Model Analysis Form when no plots have been defined. Even though the plots is not being used as the source an error would occur. Now a file can be specified without needing plots defined as well.