What was new in Version 21?

What’s New in Version 22

The following is a list of many of the most noticeable changes in Simulator Version 22, which builds on PowerWorld Corporation’s dedication to creating powerful, easy-to-use analysis software. Version 22 contains a number of major new features and hundreds of smaller enhancements to improve the performance and convenience of the package.

Installation and Simulator Executable

  • Only the 64-bit version is installed.

Automation Server

  • Added RunScriptCommand2, which is a more usable version of RunScriptCommand. It returns a Boolean for success or failure and a status string that contains information about what just happened (such as an error message, warning, etc.).
  • Added a property called ProgramInformation, which provides version, addon and the currently running SimAuto executable in an array of arrays. The first dimension selects the record desired, and the second dimension chooses fields from the record. Each record starts with an identifier (such as “version”, “addons”, or “executable”) in the first field, followed by all the fields containing data for that kind of information.

Auxiliary Files, Display Auxiliary Files and Script Commands

  • For syntax and usage details, please refer to the latest Auxiliary File Format PDF, available at: https://www.powerworld.com/knowledge-base/auxiliary-file-format-10
  • When reading an AUX file, modified to support the ConditionType field of “!=” to mean “not equal” in a Condition or ModelConditionCondition object. PowerWorld will still always write out “<>” for this ConditionType but we now support reading “!=”.
  • Added an optional parameter at the end of the special PROMPT section when specifying a filename in a SCRIPT command. That value can either be Continue or Abort. If not specified, it this will be Abort (present behavior). If Continue is used, then we will simply skip the script command and continue reading the AUX file. If that is omitted or anything else is in that location, we will Abort the entire read of the AUX file as is done now.  Example syntax is as follows: LoadAux(“<PROMPT ‘Choose an AUX file’ ‘Auxiliary Files (*.aux)|*.aux|All Files (*.*)|*.*’ ‘c:\temp’ ‘Continue’>”, YES);
  • Added support for reading future concise variable names that will be used in Version 22 for the following objects. These only impacts reading AUX files as Version 21 will continue to write the legacy variable names. CTGResultStorage, QVCurve, PVInterfaceResult, PWQVResultListContainer, PWPVResultListContainer, CTG_AutoInsert_Options, Equiv_Options, Fault_Options, IG_AutoInsert_Options, Limit_Monitoring_Options, LODF_Options, MessLog_Options, PTDF_Options, Scale_Options, Sim_Environment_Options, Sim_Simulation_Options, TLR_Options. Also, all the difference case tool objects representing Removed*** objects.
  • The following special keywords were added for use with Script Commands. Typical uses could be to assign meaningful names while saving out CSV or AUX files, for example.
  • The following Script Commands were added:
    • ATCDeleteAllResults;
    • ATCDeleteScenarioChangeIndexRange(ScenarioChangeType, [IndexRange]);
    • ATCDetermineMultipleDirections(DoDistributed, DoMultipleScenarios);
    • ATCDetermineMultipleDirectionsATCFor(RL, G, I);
    • ATCWriteAllOptions(“filename”, AppendFile, KeyField);
    • CTGProcessRemedialActionsAndDependencies(DoDelete, filter);
    • EstimateVoltages(filter);
    • InsertConnectedBuses(“BusIdentifier”);
    • InterfaceFlatten(“InterfaceName”);
    • LoadPTISEQData (filename, version);
    • LogShow(DoShow);
    • FaultMultiple(UseDummyBus);
    • TSClearResultsFromRAM(ALL/SELECTED/”ContingencyName”, ClearSummary, ClearEvents, ClearStatistics, ClearTimeValues, ClearSolutionDetails);
    • TSSaveDynamicModels(“FileName”, FileType, ObjectType, Filter, Append);
    • TSSetSelectedForTransientReferences(SetWhat, SetHow, [ObjectType List],[ModelType List]);
    • WriteLimitMonitoringSettings(“filename”);
  • The following Script Commands were enhanced with additional input arguments:
    • ATCDetermine(…, DoMultipleScenarios);
    • ATCWriteToExcel(…, [fieldlist]);
    • ATCWriteToText(…, [fieldlist]);
    • CalculateLODFScreening(…, CustomFieldOrigCTGName);
    • DiffCaseWriteCompleteModel (…, IncludeClearPowerFlowSolutionAidValues, DeleteBranchesThatFlipBusOrder);
    • OpenCase(…, PTI, […, HowToKeepDuplicates]);
    • SaveData(…, Append);
    • SaveDataWithExtra(…, Append);
    • TapTransmissionLine(…, UpdateOnelines);
  • The following Script Commands were renamed: (For backward compatibility, the older names will continue to be recognized)
    • CalculateShiftFactors (previously CalculateTLR)
    • CalculateShiftFactorsMultipleElement (previously CalculateTLRMultipleElement)
    • DiffCaseSetAsBase (previously DiffFlowSetAsBase)
    • DiffCaseClearBase (previously DiffFlowClearBase)
    • DiffCaseMode (previously DiffFlowMode)
    • DiffCaseShowPresentAndBase (previously DiffFlowShowPresentAndBase)
    • DiffCaseKeyType (previously DiffFlowKeyType)
    • DiffCaseRefresh (previously DiffFlowRefresh)
    • DiffCaseWriteRemovedEPC (previously DiffFlowWriteRemovedEPC)
    • DiffCaseWriteNewEPC (previously DiffFlowWriteNewEPC)
    • DiffCaseWriteBothEPC (previously DiffFlowWriteBothEPC)
    • DiffCaseWriteCompleteModel (previously DiffFlowWriteCompleteModel)
    • FaultClear (previously ClearFault)
    • FaultMultiple (previously MultipleFault)
  • The following Display-related Script Commands were enhanced with additional input arguments:
    • AutoInsertBuses(…, InsertSelected);
    • AutoInsertSubStations(…, InsertSelected);

Available Transfer Capability

  • Multiple directions can now be specified with the ATC tool so that they can be run in sequence rather than having to launch tool separately for each direction to be studied. Distributed ATC computing available for calculating ATC on a list of directions.
  • ATC calculations can now be distributed by multiple directions, multiple scenarios, or multiple directions and multiple scenarios combined.
  • Added concise variable names for ATC related objects: TransferLimiter, ATCScenario, ATCExtraMonitor, ATCFlowValue, ATCGeneratorChange, ATCLineChange, ATCLineChangeB, ATCInterfaceChange, ATCZoneChange. Also added these to Version 21 so they can READ files written with new names in Version 22. However, Version 21 will NEVER write these new variable names.
  • 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.
  • More complete validation of transfer directions is done before running various ATC functionality.
  • Solution options and results for ATC are now stored with the PWB file. An option exists to enable or disable storing results.

Bus and Substation View Onelines

  • Name of the currently chosen “Custom View” is now stored in the system registry for Bus View settings. This is retained when Simulator is closed and applied when reopened. It is used with any PWB, if the custom view is saved with the PWB.
  • The Bus View option to “Show Only Breaker for Consolidate Branch” will only be checked by default if opening an EMS case. This will no longer be checked by default if simply opening a case that contains breakers.

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
    • Violated using CTG Limits
  • Changed the positioning of Quick Fill in cells of a grid. If text is right-aligned, then both the drop-down button and quick-fill handle are to the left, and vice versa.
  • Added new Row Metrics and string-grid Column Metrics. This can be accessed through a right-click on the grids, and then navigating to Set/Toggle/Columns. Added an option to “Use Excluded Values to Limit Range”, and buttons to Pan to Maximum and Minimum Row, Column.
  • Added an option to “Save As Auxiliary with Options”. This provides more flexibility to save using DATA instead of SUBDATA sections and choosing which contained objects to save. It will also include options to save using Auxiliary Export Format Description. The default option in version 22 will be to save using the DATA section, and the default in version 21 will be to save using the SUBDATA section.
  • Changed searching in the Model Explorer to allow pattern matching when the “Find entire cells only” option is selected. Also changed searching in chooser dialogs so that if a wildcard is used within the search string, searching will still find partial matches.
  • Remedial Actions can now be filtered using advanced filters defined for Remedial Action Elements.
  • Injection groups can now be filtered using advanced filters defined for the PartPoint object type.
  • Added a new field “CountLoadDistGen” for Area, Load, and Substation objects. These values return a count of the number of load record in the respective grouping which has a non-zero DistMW OR a non-zero DistMvar value assigned.
  • Pasting from Excel is now allowed for User Defined Case Information Displays.

Contingency Analysis

  • Contingency Combination Analysis is now available for studying what is known as N-1-1 contingencies. Previously, this analysis was already possible in Simulator, but required the upfront creation of a list containing all contingencies in a combinatorial fashion, which was memory intensive. The new tool maintains an additional list of “Primary Contingencies”, and each N-1-1 contingency is internally managed by combining one primary contingency and one item from the normal Contingencies list. This significantly reduces memory requirements. Improvements have also been made to the user interface for user friendly viewing, filtering, or saving results produced by Contingency Combination Analysis.
  • Contingency Element Dialog now allows multiple elements to be added to the same contingency without closing the dialog.
  • Model Plane object as another tool to use with defining remedial actions along with Model Conditions and Model Filters.
  • Disconnected buses are now be reported as violations when using a linear calculation method or in DC power flow mode when also choosing the option to report these types of violations.
  • Loads are now included as objects for which contingencies can be auto inserted.
  • 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:
    • Added “Delete Remedial Actions and Dependencies” option on the Contingency Analysis dialog under Other > Manage Contingency Definitions.
    • 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.
    • 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.
  • 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.
  • 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)…”.
  • The Summary table on the LODF Screening dialog now shows the “Original Contingency Name” field. If processing lines based on Defined Contingencies, this field will show the name of the contingency from which the single line outage originated. Otherwise, this field will be blank.
  • Added branch field called Status Change Order. This field can be used during contingency analysis with conditional actions to check the order in which branches changed status. The order is dependent on the contingency element Status group (CHECK, TOPOLOGYCHECK, POSTCHECK, etc.) in which the action is applied. This value is 0 by default, which indicates that a branch did not change status during a contingency. Branches that change status during the same group will have the same order value. Once a contingency has finished processing this field will be reset to the default of 0 for all branches.
  • Dynamic Relay Models DistRelay and DistRelayITR are now supported in Power Flow Contingency Analysis. Only tripping is supported based on the operating time (pick up time) of zones; reclosing is not supported. Dynamic Load Encroachment Models (that are helper models for relays), like RELODEN, are also supported in Power Flow Contingency Analysis.

Difference Case

  • 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.
  • Added another default parameter to the DiffCaseWriteCompleteModel 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.
  • Added an option to “Show Only Changed”, which can be applied in Difference Mode or Change Mode. When enabled, this will hide any rows that do not contain any changed values. This is currently only available for user-defined grids.
  • Modified the Section field of a Branch to properly show a Section difference treating the Section as an identifying string. Thus, if a section changed from 3 to 4 then previously it would have displayed a “1” (because it increased by 1). Now it will show “4|3” instead which is more useful.
  • When using an Aux Export Format to save Difference Case changes to file for objects that have at least one field that has changed, all objects were being saved if certain fields were included in the list of fields to save. Now only fields that are enterable and included in the difference case comparison will be considered fields that can change. These fields will still be written to the file but will not be included in the filtering.
  • Added an option to Add/delete branches that flip the from/to bus number using difference case tool. The option is on the dialog where the Key Field can be selected. Also modified the script command DiffCaseWriteCompleteModel to include the option AddDeleteBranchesthatFlipFromToBusNumber as an option to the inputs of the script command.
  • Added ability to allow Aux Export Format to be used when saving a difference case to EPC format.

Distributed Computating

  • Updated the Distributed Computation Configuration tool, which now allows a user or a security group. Command line tool has also been added to aid in scripting the automatic configuration of multiple machines across a network.

Fault Analysis

  • A new column has also been added to the multiple fault results table to indicate if the location of branch faults occurred at the specified percent location, or at one of the two terminal buses of the branch.

File Formats

  • When using “PTI RAW Files Open file with options”. This now has an additional option to handle duplicate devices – either to keep duplicate devices by changing them to a unique ID, or to keep only the last read item from a RAW file.
  • Improved support for reading of Transient Stability Contingency Events from PSLF OTG files.
  • Added support to read interfaces specified in this format from PTI MON files: “MONITOR flowgate 3 ‘My Flowgate ‘ biratings 10000 10000”
  • Improved support for loading status of Transient Stability models from PTI IDV files.
  • When writing out an EPC file, no longer check to see if there is a generator with a closed status at a bus to identify it as type 2 or -2.
  • When writing out buses to an EPC file and specific voltage ratings for a bus have not been specified, write 1.1 as the default for max ratings and 0.9 for min ratings.
  • When loading a PWB the second line now also tells the patch date. As in: Opening Case AGL37_HW5.PWB Reading PWB File, Version 22 BETA (build 527, patch date 2020_12_18)

Geomagnetically Induced Currents

  • Simulator can now read a 3D E field input time series represented in the GeoJSON format (file extension *.json)
  • Simulator can now read and write the supplemental PSLF GMD file that has data sections for: Substations, Branches, Transformers and Shunts. For now, Constant_Efield, Efield sections are ignored.
  • Added “Spatial Data” Object to Contour Type. This allows contouring of spatial data without explicit one-line objects. This is useful for visualizing GIC Electric Fields.


  • Added a new “File Browser” which bring up a list of all the PWB, PWD, RAW, EPC, AUX, and TSR in a user defined search path.
  • Added the ability to search the Case Description using the Search Bar that can be added to the dialog.
  • In a Model Expression Dialog, there is now a dropdown menu to choose the key field identifier to use while viewing each expression in its definition – Primary, Secondary, or Label. Option only affects the key field identifier used in this dialog and does not impact the setting used with Case Information Display options.
  • The right-click menu of a Dialog’s caption bar now has options for “Export” and “Copy to Clipboard”, which export or copy images of any specific dialog with Simulator.
  • Added “CustomFieldToggleChoice” objects for CustomSingle, CustomFloat, CustomString fields.
  • 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.
  • Calculated fields now have an Extra Identification Option. This is available for Min and Max operations and allows displaying any field associated with the chosen object. This is useful for using calculated fields with a combination of filtering to return specific results.
  • Added data maintainer to Area/Zone/Substation section of the Bus, Shunt, Gen, Line, and Load dialogs.
  • Added tool to flatten interfaces. This modifies an interface by bringing all the elements from any included interfaces into the interface that has been selected to be flattened. The tool is available in the right click menu. This was added to work around the limitation of not being able to calculate Shift Factors (TLRs) on nested interfaces.
  • Adding ability to remove an Area Slack Bus designation by deleting the Slack Bus number from the field. If AGC is enabled in the area, designating an empty slack bus will also turn of AGC.
  • Enhanced the log so that objects can be associated with the messages, and then links to the object dialogs are available from the log.
  • Added an option to the Auto Tap Transmission Line dialog and TapTransmissionLine script command to allow the user to choose to replace the original line object with the tapped line objects on all open oneline diagrams.
  • Added a new column for a Branch called “Transformer\Tap Ratio Change to Balance”. When parallel taps are balanced properly, this field is blank. If this entry is not blank, then it shows the tap ratio which will balance parallel transformers. This is the same calculation done when solving a power flow and having the “Tap Balancing” enabled in the power flow solution options. Regardless of that solution option though, this field will show you the troublesome transformers.

Oneline Diagrams

  • Added another contouring method called Delaunay Triangulation, which provides faster contour rendering. This is particularly useful when animating wide-area frequency or voltage contours from a Transient Stability run.
  • Added an option to navigate to the object from Contouring Data Points > Right Click> Show Dialog in the Contour Options Dialog.
  • The GIS Shapefile Data Dialog can now Button to “Convert X/Y to Latitude and Longitude”. This converts projected X/Y values (specified in the shapefile) to degrees latitude and longitude using the WGS 1984 Web Mercator Auxiliary Sphere projection. Conversion is required before projecting to PowerWorld’s X/Y coordinates.
  • Add GeodataviewStyle field to allow “area” scaling to proportionally scale the dimensions (like size) rather than their product (area). This is needed for 1D object like arrows.
  • Modified the GDV style so the GDVs object display lines can show any type of field value for the object. Previously they were restricted to just numeric values.

Powerflow 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.
  • Added ability to specify as input the RegBus with a VoltageDroopControl object. If the value is specified, then all generators assigned to that VoltageDroopControl will automatically use this regulated bus. If the value is unspecified, Simulator will continue to create a unique Voltage Drop Control equation for each set of generators within the voltage droop control which share a regulated bus (or buses connected by low impedance branches).

Transient Stability

  • Added new form to Save GE Transient Stability Data with Options.
  • “Show/Save Selected Plot Data > Show in Case Information Display” in the Transient Stability Plots tab, is now able to show signals from multiple plots. If duplicate signals are found, then they will be added only once to the grid.
  • Added Generic Branch Limit Monitors to monitor the Apparent Impedance at both ends of branches, by using a simple impedance relay within a reach circle. This can be applied to all AC branches in the case, or to only those branches that meet a filter. This is known as an Out of Step Monitor in other software.
  • Added the ability to plot the Apparent Impedance X vs. R at the same end of an AC line. This will automatically show an impedance circle at 100% of the branch series impedance. If impedance relay models are present, then their specific impedance zones will be shown, instead.
  • Added new fields for TSContingency objects to show totals for “Relay Tripped” and “Model Tripped” Load MW values.
  • In the Transient Contingency Element Dialog, added options for Switched Shunts that allow Set Values To and Change Values By (Mvar or Percent) as Percent of Start Nominal Mvar.
  • All Exciter Models and Excitation Limiter (OEL/UEL/SCL) Models now have compatibility checks.
    • Errors will be shown during Validation before running Transient Stability, along with Auto-Correction that will disable the ill-configured OEL/UEL/SCL instances.
    • The Compatibility information can also be viewed in a table by viewing Exciter fields – “OEL Input Used”, “UEL Input Used” and “SCL Input Used”, and OEL/UEL/SCL fields – “Output Used”.
    • If an OEL/UEL/SCL output signal feeds into a Summation Point of the Active Exciter, the min/max parameters of the OEL/UEL/SCL are validated, along with Auto-Correction to ensure an output signal of zero when operating within the bounds of the OEL/UEL/SCL.
  • For Remedial Action Elements, Switched Shunt actions for Set To and Change By (Mvar or Percent) are now translated for use in Transient Stability Remedial Actions.
  • Added a “Show Valid Remedial Action Fields” button in Transient Stability > Options > Remedial Actions, which will display a case information display with all fields that can be evaluated at each time step. Support continues to grow with more fields and objects types. Model Expression allow time derivatives and filter times to be specified for expression variables.
  • Redesigned the Auto-Insert Distance Relay Tool. Now Supports inserting either DISTR1 or DistRelay, and to specify whether to Monitor or Trip.
  • Added a button to “Save Plot Images for Auto-Save Options”. For the plots that are marked to AutoSave, this option will now allow plots to be batch-saved at a time after the simulation has been run, if results are available in RAM or Hard Drive.
  • Plots can now also be saved directly to a PDF file – one file per Transient Contingency, plus one additional file if plotting for multiple contingencies.
  • Added a button to “Re-evaluate to Get Limit Monitor Violations” to go through the stored results and get the Transient Limit Monitor Violations. First it will look at the results stored in RAM and then, if no results are found, look in the Hard Drive *.tsr file. If the button is pressed under Multiple Contingencies mode it will re-evaluate all the contingencies results.
  • A new tool called Result Analyzer has been added. This can calculate statistics, modes and damping information from Transient Stability time-series values. Multiple user-specified time windows can be added. These calculations can be integrated directly into a Transient Stability run so that they are completed after each Transient Contingency, or calculations can be initiated manually as a post-processing step.
  • Frequency Analysis has a new Signal Summary tab. The start and end times can be adjusted to get metrics on just subset of time duration.
  • Changed the “Rotor Angle No Shift” to “Rotor Angle Shift” for the Angle Deviation generic limit monitor.
  • Improved initialization of all Over Excitation Limiter (OEL), Under Excitation Limiter (UEL) and Stator Current Limiter (SCL) models across a variety of possible initial conditions.
  • Distribution Equivalent Models can now be made “Active” or “Not Active”, depending on whether to include or exclude from a transient simulation. When they are set to “Not Active”, then they are not used, and a particular load model will move up the object hierarchy to find an active Dist Equiv Model. For instance, if LoadModelGroups were assigned to a Dist Equiv as well as assigning a Dist Equiv model to areas. If a load’s LoadModelGroup had a Dist Equiv set Not Active, then it would move up to the Area Dist Equiv model instead.
  • Added more descriptive messages to Transient Events for LHVRT, LHFRT, LHSRT models configured to be in Alarm Mode. They will now show the MW of the generator from the initial condition to provide information about how much generation would have tripped if a model were not in alarm mode.
  • Added a new field that can be added as a column to the Transient Stability Events for “MVA Base”. This field will show the generator MVA Base, load MVA, Branch Limit MVA Normal, and Switched Shunt maximum Mvar value. Events for other object types will return a blank.
  • Added ability for a TSResultEvent object to show the custom fields for the object to which the result event refers. Under the folder Object Fields\Custom, there will be 5 custom integer, 5 custom floating points, 5 custom strings, and the memo field. In addition, we have exposed under the folder Custom, the Custom Expressions, Custom Strings Expressions, and Selected field for the TSResultEvent itself.
  • Added a right click option to a list of multiple transient contingencies to “Set into One Contingency at a Time”. This switches the dialog back to the process one contingency at a time and choose the contingency that had been right clicked on.
  • Added a new option to specify whether “Non-user events split integration timesteps”. This was always done previously. Regardless of this option, non-user events will not force the storage of time value results during the simulation. Again, previously results were stored for the time of any event occurring.
  • Added @CTGEVENTSUSER keyword that can be used in transient stability plot title block to display the transient events that are user defined, i.e., the Transient Contingency Elements. Events with other event levels will not be displayed.
  • The following models were added:
    • Machines: GENQEC, REGC_C
    • Governors: WTGT_B
    • Generator Relays: VPERHZ1
    • Load Relays: LDS4
    • Switched Shunts: CHSVCT
    • DC Line Auxiliary signals: CHAAUT, PAUX1T, PAUX2T, PAUX12T, FCWDPT, CFCAUT, SQBAUT
    • VSC DC Lines: VSCDCT, VHVDC1
    • PAux Controllers: WTGIBFFR_A, PROBOOST These are a new category of controllers that allow for inertial-based fast frequency response (IBFFR). The PAux signal feeds into augment the effect of a Pref signal.
    • Plant Controllers: PF1, PF2, VAR1, VAR2 The output of these controllers is an incremental value that feeds forward into the voltage reference of an excitation system or electrical controls model.
    • Exciters: AC1C, AC2C, AC3C, AC4C, AC5C, AC6C, AC7C, AC8C, AC9C, AC10C, AC11C

PV QV Curves

  • During the QV solution process, the solution options for QV curve power flow are now loaded AFTER the contingency solution, so that they are used when tracing the QV curve after a contingency. Previously they were always loaded at the beginning of the QV curve run BEFORE the contingency solution. Because of that, the Contingency solution options would always overwrite the QV curve options when PowerWorld went to trace the QV curve after a contingency. There is now an option called “SolutionOptionWhen” that can be set to either “Before” or “After”. The default option is “After” in version 22 and will remain as “Before” in version 21.
  • Solution options and results for both PV and QV are now stored within the PWB file. Options exist to enable or disable storing results.