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What was new in Version 17?

What’s New in Version 18

The following is a list of many of the most noticeable changes in Simulator Version 18, which builds on PowerWorld Corporation’s dedication to creating powerful, easy-to-use analysis software. Version 18 contains many new features and enhancements to improve the performance and convenience of the package.

Auxiliary Files and Display Auxiliary Files

  • Added a special SUBDATA section “BusRenumber” to a multi-section line records which allows you renumber the dummy buses in the multi-section line by using the same format as for specifying the dummy point.
  • Added ability to write out the “REVERSE” bids for a StudyMWTransactions object. Previously you would only see the area-to-area MW bids from the lowest area number to the highest when saving out to an AUX file.
  • If loading in an auxiliary file with REMOVED object types, i.e. REMOVEDBUS, REMOVEDBRANCH, etc., the corresponding objects will be deleted in you are in Edit mode. REMOVED object types that are supported are any object that can be compared in the topological differences as part of the Difference Flows tool.

Auxiliary File SCRIPT and SimAuto

  • Can now use the keyword ALL instead of using the location number of a field when specifying variablenames as part of a field list used with select script actions. This will return all fields with the same variablename. This is intended to allow easier access to fields when the exact number of fields is not known such as with multiple TLR (MultBusTLRSens:ALL) or PTDF (LinePTDFMult:ALL) results. This can be used with SaveData, SaveDataWithExtra, SaveObjectFields, and SendToExcel script actions.
  • Can now use the keyword ALL instead of a variablename as part of a field list used with select script actions. This will return all fields for a particular objecttype. This can be used with SaveData, SaveDataWithExtra, SaveObjectFields, and SendToExcel script actions.
  • Added new script command SetInterfaceLimitToMonitoredElementLimitSum(filtername) where the filtername is a filter that applies to interfaces that should be adjusted by the command.
  • Added script commands RenumberBuses, RenumberAreas, RenumberZones, and RenumberSubs, each with a parameter denoting the number of the Custom Integer field containing the new numbers.
  • Added script command ConditionVoltagePockets(VoltageThreshold, AngleThreshold, Filter). The goal of this script command is to find groups of radial buses that may have bad initial voltage estimates and to get a better voltagestimate of these buses based on assuming that the voltages on buses outside of the radial group are good. It will identify pockets of buses bounded by branches that meet the condition that the absolute value of the voltage difference across the branch is greater than VoltageThreshold or the absolute value of the angle difference across the branch is greater than AngleThreshold and the branch meets the specified filter. The buses contained within these pockets will have their voltages estimated based on the assumption that the voltages at buses outside these pockets are good. The Filter is optional and determines which branches will be examined. If not specified all branches are considered.
  • Added script action CTGRelinkUnlinkedElements. This does exactly what they name implies.
  • Added a new script command ExportAreaSupplyCurves(“filename.csv”, “User Defined String”, NumPoints); The first parameter is the name of the CSV file to which results will be written.  The second parameter is an optional parameter for specifying a user defined string written to each entry in the resulting CSV file.  If the second parameter is omitted, a blank will be assumed.  The third parameter is optional and is related to converting a cubic cost model into a piece-wise linear model.  If you omit the second parameter we assume 5.  The output of the file will have 7 entries for each area for Fixed Gen MW, Fixed Load MW, Fixed Shunt MW, Losses MW, Variable Min MW, Variable Max MW, Variable Present MW, followed by a set of Bid MW/Price entries representing the supply curve for the variable MWs.
  • Added new script command InitializeGenMvarLimits. This initializes all generators in the case so that they are appropriately marked as being at Mvar limits or not. This could be useful if manually setting the Mvar output of generators or changing their limits.
  • Added new script command SaveGenLimitStatusAction(“filename”).  Use this action to save Mvar information about generators in a text file.  The information saved includes the generator bus number, generator ID, Mvar, Max Mvar, Min Mvar, AVRable flag (user specified), and internal AVRable flag (set by Simulator).  This information is useful for debugging.
  • Added a new script command: TSResultStorageSetAll(objecttype, YES/NO). The first parameter is the objecttype such as GEN, BUS, BRANCH, etc. You may also use ALL to signify to do this for all classes. The second parameter is a YES or a NO. Using this command will toggle all the “Save All” fields to YES/NO. It will also toggle all the “state” fields (such as exciter, machine, governor, etc.) to YES/NO.
  • Added new script command CTGJoinActiveCTGs(InsertPowerFlow, DeleteExisting, JoinWithSelf, “filename”); that will join the current contingency list with itself or another list of contingencies contained in a file.
  • Added script command DiffFlowRefresh that will reset the links between the Difference Flows Base case and the Present case. This should be used after a topology change has been made before any results are saved indicating elements that have been added or removed. It would especially be a good idea to use this before using the ContainedInDiffFlowsBC field to determine if an element has been added.
  • Added new script command LoadCSV(“filename”, CreateIfNotFound); that will load a CSV file that is formatted the same as the data sent to Excel in the Send All to Excel option found within a case information display, or by choosing Save As CSV.
  • Allow special keywords @DATETIME, @DATE, @TIME, @BUILDDATE, and @VERSION to be used as part of the filename for SaveDataUsingExportFormat, SaveData, SaveDataWithExtra, SaveObjectFields, and WriteToTextFile script commands. These special keywords will be replaced with their actual values when the file is saved.
  • Within all script commands related to opening or saving files, added a new ability to specify a filename of a special form that instructs PowerWorld to bring up the Open or Save dialog for the user to choose a file.  This will not work when using the SimAuto Add-on.  The special syntax of the file name is generally “<PROMPT ‘Caption’ ‘FileTypes’>”.  The entire string must start with <PROMPT and end with >.  After the word PROMPT there may optionally be a space delimiter followed by a special caption to be placed at the top of the file dialog that appears (this caption must be enclosed in single quotes).  If the special caption is omitted then either Save or Open is assumed.  After the special caption there may optionally be a list of File Types and extensions specified.  This list must be enclosed in single quotes.  The list itself is composed of a pipe-delimited string (|) with the first string representing the first file type, the second string representing the first file extension, the third string representing the second file type, the fourth string representing the second file extension and so on.  If no File Types are specified then ‘All Files (*.*)|*.*’ is assumed.  An example string might be <PROMPT ‘Choose an Aux File’ ‘Auxiliary Files (*.aux)|*.aux|All Files (*.*)|*.*’>.
  • The Scale script command now allows specifying the new value or scale factor through a field with the object type to scale. To use this option, the [parameters] input should contain variablenames instead of numeric values. When using a field rather than value, the scaling will be done by individual object rather than the aggregation of all objects selected for scaling.
  • The DetermineBranchesThatCreateIslands script command will now allow you to enter a blank for the filename. If the filename is blank, the selected field will be set for lines that create islands regardless of how you have that option set.
  • The SendToExcel script command will now allow the saving of .xlsm filetype if using Excel 2007 or later.
  • Modified the CloseWithBreakers script command to allow input of a single object instead of a filter. The second parameter can now be the name of an advanced filter or the identifier for a single object of the objecttype that is specified as the first parameter. The single object identifier must be enclosed in square brackets and use the relevant key fields for the objecttype specified. The format for identifying a single object is the same as that used with the Move script command except that the objecttype should not be specified as part of the object identifier. Example: CloseWithBreakers(Gen, [1 “1”], YES);
  • Added two new SimAuto functions: GetSpecificFieldList and GetSpecificFieldMaxNum.
  • New OpenCaseType(FileName, FileType, Options) SimAuto function. This function behaves the same way that the OpenCase script command works with FileType and Options being the same as those specified with the script command. The Options parameter is optional.
  • Can now use the keyword ALL instead of using the location number of a field when specifying variablenames as part of a field list used with select SimAuto functions. This will return all fields with the same variablename. This is intended to allow easier access to fields when the exact number of fields is not known such as with multiple TLR (MultBusTLRSens:ALL) or PTDF (LinePTDFMult:ALL) results. This can be used with SendToExcel and WriteAuxFile SimAuto functions.
  • Can now use the keyword ALL instead of a variablename as part of a field list used with select SimAuto functions. This will return all fields for a particular objecttype. This can be used with SendToExcel and WriteAuxFile SimAuto functions.
  • Added new script command TSRunUntilSpecifiedTime(ContingencyName, [StopTime, StepSize, StepInCycles, ResetStartTime, NumberOfTimeStepsToDo]).
  • Added ability in TSGetResults() script command to use a file type of “JSIS” which will write out desired results in a format used by the WECC JSIS group.
  • Added new script command TSAutoCorrect. This script command has no parameters. If there are still validation errors after running this script that would prevent the stability simulation from running, then the remainder of a script will be aborted.
  • Added script command TSGetVCurveData(“filename”,filtername).

Available Transfer Capability (ATC)

  • When using the iterated methods, new Iteratively Found strings (CTG_ABORTED_LINEAR, CTG_ABORTED_AFTER_LINEAR, CTG_ABORTED_IN_FULL, and CTG_ABORTED_ITERATED) are possible if a contingency fails to solve because an Abort action has been implemented.
  • Added Iterated Linear Analysis Method.  This will more accurately model conditional actions during the linear methods.  This can be used as part of linearized contingency analysis and also as part of the linearized contingency calculation used in the ATC tool.
  • Generator Economic Merit Order Dispatch can now be used with the iterated methods.
  • When generator MW limits are being enforced, the linear calculations used as part of the iterated solution methods will not include generators that are already at their limits.
  • Allow Generator MW Limit Enforcement in Single Linear Step option added to not include generators that are already at their limits when using the Single Linear Step Method.  For generators to be excluded, appropriate options to enforce generator MW limits must also be set.

Bus View and Substation View

  • No changes

Case Information Displays

  • Added new branch fields which allow you to edit line limits in Amps instead of MVA. This only works for non-transformer branches. We only store one set of limits, so this only allows you to edit those limits in different units.
  • Added a field with generators, Mvar Capability Curve Is Defined, to indicate if the generator has a curve and not if the curve should be used. No longer create a default curve when setting the Use Mvar Capability Curve option to YES through the generator case information display and a curve does not already exist. A default curve will only be created if setting this option through the generator dialog and a curve does not already exist. A curve can only be used if one has been created and the option to use it is set.
  • The GE Ohmic Data Flag field for branches can now be viewed in branch case information displays.
  • Added a read only field “In Outage?” to various objects to indicate if the object is referenced by a current Scheduled Action.
  • When using the option to display column headers as variable names, the upper left cell in case information displays will now show the objectname of the objects in the table.
  • Modified to display a column in a case information display for a transient model showing you information if the stability model has all default data. For models for which there is only one set of defaults it will show “Default”, while for other models such as TIOCRS, GEWTG, WNDTGE, EXWTGE, and EWTGFC it will show the name of the default data set.
  • Added option to load data from a CSV file similar to how data is loaded from an auxiliary file.  The data must be in the same format as the data that is sent to Excel using the Send All to Excel option or when saving a CSV file from the Save As CSV option on a case information menu.

Contingency Analysis

  • Added Iterated Linear Analysis Method.  This will more accurately model conditional actions during the linear methods.  This can be used as part of linearized contingency analysis and also as part of the linearized contingency calculation used in the ATC tool.
  • When auto-inserting two-winding transformer contingencies, now have options on how to treat two-winding transformers that are part of three-winding transformers. The options are to insert the individual two-winding transformers, insert only the three-winding transformer, or to ignore these transformers completely and insert nothing.
  • Added option to auto insert three-winding transformers.
  • Added new solution type RESERVE LIMITS to contingency results. If there is not enough make-up power and the slack needs to be used, this will appear in the Solved fields. Violations will still be recorded.
  • Added the ability on the Contingency Analysis Element dialog to choose a branch OPEN or CLOSE event by choosing a multi-section line.
  • Modified so that the OPF solution can be solved after each contingency is applied.
  • Added ability to auto-insert single switched shunt outages.
  • Enhanced the ability to auto insert based on the distance from a particular bus. Previously the measure of distance was always “Number of Nodes”, thus each branch was treated as having the same distance measure. We now allow X, Z, and Length as well. This allows integrated use of the features available from the ConnectionsDetermine Path Distances to Buses on the tools menu of Simulator.
  • Modified to allow auto-insert of contingencies based on nominal voltage level without requiring that an advanced filter be created.
  • Added contingency Abort action. If this action is implemented the contingency will immediately stop processing. No violations or Custom Monitors will be recorded.
  • Do not count Aborted contingencies as unsolvable. They are treated as their own category when reporting the final status with the number of violations and unsolvable contingencies.
  • Global Actions that are skipped will no longer be reported in What Actually Occurred.
  • Improved the descriptions in the popup hints shown with options on the contingency analysis dialog.
  • Added the ability to specify a list of Categories with contingencies and Custom Monitors. Categories determine which custom monitors are active for a contingency. For a monitor if no categories are specified, the monitor will be active for all contingencies. For a contingency if no categories are specified, all monitors will be active for the contingency. Otherwise, a monitor will only be active for a contingency if it has at least on category that matches one of the contingency’s categories.
  • Two new fields were added to the contingency summary that count how many GLOBAL and TRANSIENT actions were applied as part of the contingency.
  • Added support for using the transient shunt model MSC1 inside the power flow based contingency analysis processor.
  • Added a field with a contingency to report the total amount of generation drop that occurred during the contingency. This includes generation the is online in the reference state and become offline after the contingency for any reason. Reasons include islanded gen, gen opened from a gen or injection group action, and gen dropped from injection group merit order open action.
  • Created a new option for “Compare Contingency Definitions”. This option will compare the presently defined contingency list against an AUX file (which contains another set of contingency definitions). The output will be a CSV file that lists contingencies that match one another. Note that this comparison only compares the actions in each contingency definitions. It does not compare the model criteria or actions status, thus it may report two contingencies as the “same” even though the conditional checks make them function slightly differently.
  • Added more options to the Join Active Contingencies tool: (1) Join the active list to itself, (2) insert solve power flow action between contingencies that are being joined, and (3) delete existing contingencies.
  • Added a contingency-specific solution option to disable SVCs independently of other switched shunts.
  • Added options to include transient stability relay models, TIOCRS, LOCTI, TIOCR1, and MSC1 as part of the power flow contingency solution. Models can act during the solution if their conditions are met. Transient models will be evaluated after POSTCHECK actions are implemented.
  • Added new contingency generator actions to Set To or Change By Mvar. When this action is used the generator will be turned off AVR.
  • Added Line Shunt contingency actions.  Line shunts can be either opened or closed.
  • Solve Power Flow actions impose an order in which actions are applied. Groups of actions that are applied together are separated by Solve Power Flow actions. TOPOLOGYCHECK actions will ignore this order and be checked and applied as necessary with each group of actions. Any CHECK actions that are part of global actions will be checked and applied if necessary in the first group of actions. POSTCHECK actions will be checked and applied if necessary after all groups of actions have been applied.
  • New concise contingency and remedial action scheme format initially developed for use among entities in WECC.
  • Added Remedial Actions object. Each Remedial Action can be comprised of any number of contingency actions. Each Remedial Action is applied for all contingencies.

Difference Flows

  • Added multi-section lines to the difference flows tools
  • Switched shunt Min Mvar, Max Mvar, Shunts Blocks, and Shunt Steps will now show differences between the Present and Base case.
  • The bus nominal voltage field can now be compared between the present and the base case.
  • When using the Difference Flows options for showing Difference Case and Base Case, Custom Float values will now be shown correctly in user dialogs.

Fault Analysis

  • Cleaned up ability to auto insert fault analysis to match the power flow contingency auto insert.

File Formats

  • The GE Voltage Checking Limit Min and Max fields for buses are now stored in PWB files.
  • When writing out an EPC file and the GE Ohmic Data Flag field is 1, R and X will be written in ohms and B in microMhos.
  • Saving a removed multi-section line in the EPC format should correctly write the sections of the multi-section line with a status of -4. GE flagged for delete flag for multi-section line will be true if any section is flagged for delete.
  • When reading switched shunt records from a RAW file, a mode of 3 will now be interpreted as controlling the Mvar output of generation. Mode 4 and 5 to not correlate to features in Simulator, so these are treated as shunts with a constant Mvar.
  • When loading a RAW file, we now automatically flag any non-transformer branch with R=0, B=0, and X&lt;0 as a series capacitor. This is especially important when using the Geomagnetically Induced Currents Add-on (GIC) as series caps will block the DC GIC flows.
  • Added ability to read in three-winding transformer records from the hdbexport CSV files using the XF record’s ID_XFMR field.
  • Added support for reading NDLIM records from an hdbexport CSV file. Entries are read into a bus record’s bus-specific limit monitoring settings allow there to be specific high/low voltage for particular nodes.
  • Converted times for contingency actions in WECC switch files to cycles.
  • Added file parser to read in EMS exported case as a text file from ABB EMS systems.
  • GE OTG format contingency files can now be loaded into contingency definitions.

General

  • When defining expressions for objects, a new option has been added to treat blank entries as zeros in the expression instead of treating the entire expression as invalid.
  • For Model Conditions, modified the fields that identify the object used in the condition. Old Object File Format should be used with Simulator version 16 and earlier. Object File Format uses a more friendly format that will identify the object by primary, secondary, or label key fields depending on the user’s choice. Old Object File Format is able to load the object description in the old format that uses “&lt;KEY&gt;” identifiers as well as the more friendly formats for primary, secondary, or label key fields, but it will write out in the old format for compatibility with older versions of Simulator.
  • Injection groups now have their own set of options that define how they should be scaled. There is also an option that determines if these options should be used. When set to be used, appropriate injection group-specific options will be used instead of tool-specific options. Tools that now allow use of injection group-specific options are PV, ATC, Island-Based AGC, Injection Group Area Slack, Time Step Simulation, and Scaling.
  • Injection groups can now have buses defined as injection points.  Only standalone sensitivity tools that by the nature of their linear calculations do not require injection from specific devices can use bus injection points.
  • When using the tool to renumber multi-section line dummy buses, either through the GUI or script, a new bus that does not exist no longer needs to have a bus name specified. By default the bus name will be the same as the bus number.

GIC Analysis

  • Added handling of YDD transformers.
  • Replaced GIC transformer display with new unified display.
  • Added GIC transformer field to show if buses are in different substations.
  • Added a dialog for specifying values for a GIC transformer dialog to make user entry easier.
  • Added GIC fields to show the driving point resistance calculation at a substation. This helps in determining the sensitivity of the GIC currents to a change in the substation grounding resistance.
  • On the unified GIC Transformer display, added the ability to High, Medium and Tertiary winding configurations and added ability to edit them from this display.
  • Added the ability to edit a special record called the Unitified Transformer in the GIC dialog. This record provides one place to edit all the GIC-related inputs for both two-winding and three-winding transformers so that you do not have to navigate through the internals of the three-winding transformer model or the various ambiguities introduced by auto-transformers. Also added copy/paste support from case information displays, and AUX file support for doing these edits.
  • The unified transformer refers to the terminology “high”, “medium” and “tertiary” bus instead of primary/secondary/tertiary.
  • The Transformer Per Phase Effective GIC field now works with the Difference Flows features.
  • The layout of the GIC portion of the branch dialog has been updated.
  • Modified to show “GIC” in the Simulator status bar when GIC calculations are being included in the power flow.
  • Added ability to write G Matrix in Matlab sparse format.

Integrated Topology Processing

  • Added ability to monitor the flow on consolidated branches (Breakers, Disconnects, ZBRs, etc.) during contingency analysis.

Oneline Diagrams

  • Added Find Text in Oneline Tool.
  • Added more message descriptions to error checking for GPU contouring to include error messages in the log.
  • Added option to resize buses based on the stub size when using the feature to automatically add lines when inserting connected buses. This option is found under Insert Connected Buses –&gt; Then Auto Insert Lines… from the right-click menu of a bus while in Edit Mode. A dialog prompts the user about whether or not to automatically resize the buses. If user clicks NO, then it will resize the bus based on the number of incident lines. If the user clicks YES, the buses will be resized based on the stub size. This is the default and could, but could cause the buses to get excessively large.
  • Now when pressing Insert Connected Buses | Then Auto Insert Lines from a bus in a oneline the dialog will have an option to “Do this for all future edits”. This will disable the dialog and will automatically do the previous selection to automatically Re-size the Bus Size by Stub-size or interconnected lines to the bus every time you do Insert Connected Buses | Then Auto Insert Lines without asking again in the dialog.
  • Added ability to import KML files in the format used by MISO. The lines will link to lines in the RAW file, if they exist. There are no substations in the RAW file, so it will create them (but they will be empty) if desired.
  • Modified some size thresholds at which labels appear when exporting to the KML file.
  • KML importer now has the ability to import KML files in the specific format that ERCOT uses.
  • Changed the look of field arrows to be more discernible.
  • Flow arrows based on Custom Float 1 will now work with the Difference Flows options showing Difference Case and Base Case.
  • Added some features to translation files used when importing Areva/Allstom oneline diagrams. Also increased error reporting during import.
  • Edit boxes that have up/down arrows will automatically increase the number of digits to ensure that at least 2 significant digits are shown.
  • Added the ability for a Generic Model Field to show the “Case Information” object to show summary information about the entire case.
  • Added ability to link to a bus view or substation view from a Oneline Link. To use the feature, populate the File or Action string with the keyword BUSVIEW or SUBVIEW along with the number, name_kv, or label of the bus or substation that should open in the appropriate view.
  • Added ability to open bus or substation view onelines from oneline fields and other oneline objects. The bus view oneline will open to the bus that the device is connected to. The same ability has been added for the Quick Power Flow List.

Power Flow Solution

  • Modified the flat start routine when applied to a system which contains many 30 degree phase shifts related to Delta-Wye transformer connections. The new flat start routine will set voltage angles in a manner that handles these phase shifts.
  • Added error checking for parallel transformers so that if they do not regulate the same bus (actually ZBR Bus group), then the transformer will be turned off control automatically and an appropriate message written to the log.
  • Added a power flow solution option to disable SVCs independently of other switched shunts. The area option for shunt control only applies to non-SVCs. SVCs can only be enabled/disabled globally or at the individual device level.

PV and QV Curve

  • ‘Aborted Contingency’ is a new PV critical reason if a contingency fails to solve because an Abort action has been implemented.
  • Added a new feature on the PV curve to specify an interface on which you desire to increase the MW flow. You then configure the OPF settings in Simulator appropriately and the PV Curve will move optimally move OPF controls (generator, loads, dc lines, etc.) to ramp up the loading on your interface.
  • Added a new feature on the PV curve to specify 2 interfaces on which you desire to increase the MW flow and an angle (Angle of zero means increase only the first interface, Angle of 45 degrees means increase each interface equally, Angle of 90 degrees means increase only the second interface). Again the OPF controls must be configured appropriately.
  • Added a new feature on the PV curve to specify a third interface on which you additionally desire to maintain a constant MW flow.
  • Added option to open Bus View for an object associated with a data series on the PV plots the same as you could already do with the transient stability plots.
  • Added ability to have PV plotting based on actual value, deviation, percent of the initial value, or percent deviation from the initial value.
  • ABORTED will be reported in the QV overview results if a contingency fails to solve because an Abort action has been implemented.
  • A new field with Buses called QV Selected is now used to determine for which buses QV curves are calculated during QV analysis.

Optimal Power Flow (OPF)

  • No changes

Scheduled Actions Analysis

  • Added a read only field “In Outage?” to various objects to indicate if the object is referenced by a current Scheduled Action.
  • Added ability to use a “Scheduled Action” filter on a case information display showing a list of “Scheduled Action Groups”.
  • Added the Type field to Scheduled Actions to indicate the type of outage: transmission, generator, or generator adjustment.

Sensitivity Calculations

  • No changes

Time Step Simulation

  • Added a button on the Results tab that will allow you to send all results to Excel. The format and data that gets sent will be the same as when sending each table to Excel one at a time. Only the results tables that actually have objects defined will be sent to Excel. All results will be sent to a new workbook in separate worksheets.

Transient Stability

  • Modified captions and descriptions for fields showing min/max statistics for generator “Frequency” to instead say generator “speed”. They are showing the electrical speed of the generator. Values will typically be close to nominal frequency (normally 60) for synchronous machines, but may be much higher or lower for asynchronous generators such as wind turbines.
  • Modified to display a column in a case information display for a transient model showing you information if the stability model has all default data. For models for which there is only one set of defaults it will show “Default”, while for other models such as TIOCRS, GEWTG, WNDTGE, EXWTGE, and EWTGFC it will show the name of the default data set.
  • Transient Models
    • Made the “MOTORX” model available for use in Simulator. It’s a stripped down version of MOTORW use with CPMPLDW.
    • Added special treatment for wind turbine models which specify a low voltage active current management as a piecewise linear function. It was possible for the network boundary solution to oscillate when the voltage solution was very near the corner points at Lvpnt0 and Lvpnt1. This will not happen now.
    • Added LTC1 tap changing model for transformers.
    • Added support for new overcurrent relay TIOCRS using standard curves. TIOCRS is identical in all respects to the TIOCR1 model, except for how the time to close is specified. TIOCRS allows the specification of curve parameters according to the IEEE C37.112-1996, IEC 255-4/British BS142, or IAC GE Curves standards.
    • Added DIFF (Differential Relay)
    • Added LOADEN (Load Encroachment Relay)
    • Added DIST (Distance Relay)
    • Added more stability data validation for the CIM5, CIM6, and CIMW motor models which specify induction motor parameters using the equivalent circuit R and X values. During Validation, Simulator will now calculate the Tp0 and Tpp0 parameters and check them against the integration time-step. If the resulting time constants are too fast, then appropriate validation messages will appear. When auto-correcting values, the R1 or R2 parameters may be reduced to increase the time constants.
    • When validating stability data, we will now also validate models which are presently out-of-service, but can be closed in during the simulation. An example of this would be the induction motor models which include Generator Machine Models MOTOR1, CIMTR1, CIMTR2, etc., and Load Characteristic models CIM5 and CIM6.
    • Added speed voltage to GENTPF machine model.
    • Added frequency dependence to constant impedance load models.
    • Added the implementation of the w2301 velocity limit.
    • The switched shunt SVC power flow model has a Xc parameter. There dynamic model also has an Xc parameter. If these are different this will cause a problem when running a stability simulation. Validation will change the transient stability model to match the power flow model Xc.
    • If a switched shunt model is NOT marked as an SVC in the power flow, but has an active transient stability SVC model (svsmo1, svsmo2, svsmo3), then this will be treated as a validation error and the stability run will not be allowed to run.
    • Added 7 new default curves for the TIOCRS overcurrent relay model.
    • Cleaned up the Unified GIC Transformer table features. Also added 3 separate fields to set the winding configuration on High, Medium and Tertiary winding.
    • For the DISTR1 line relay model, added additional tripping messages so you still see “Entered Zone” result events when the delay is zero. Also added “Trip Initiated” result event for DISTR1.
  • Transient Plots
    • Added ability in the Plot portion of the transient stability dialog to export the plot information to a text file of the format used in the TSGetResults() script command. Also added ability to export in the JSIS format in the same location.
    • Added ability to use the special string @CTGEvents in transient stability plot definition strings. This string will be replaced with a list strings showing the transient result event strings which are written to the message log during the simulation.
    • Added ability to have plotting based on actual value, deviation, percent of the initial value, or percent deviation from the initial value.
  • Transient Stability File Format Support
    • When reading in a DYD or DYR file, we now set the option regarding how to treat saturation functions for which the magnitude of SE1 and SE2 are backwards. This option is set to “Flip Values” when reading a PSSE DYR file to match that treatment. This option is set to “Ignore Saturation” when reading a PSLF DYD file to match that treatment.
  • Transient Stability Contingency Definitions
    • Added the ability to specify a list of Categories with a Transient Contingency and Transient Limit Monitor. If no categories are specified for a limit monitor, the limit monitor will apply to all contingencies. If no categories are specified with a contingency, all limit monitors will apply to this contingency. Otherwise, a limit monitor will only be active for a contingency if it has at least one category that matches one of the contingency’s categories.
    • Added a local menu option on the list of transient contingencies called Time Shift Contingency Elements. This will allow you to time shift all contingency elements of selected contingencies by a specific amount of time in seconds.
    • Support new contingency types DB (delete bus), MBL (modify bus load), and RL (reinstate lines) in WECC switch files.
    • Added the ability to auto insert Transient Contingency definitions in a manner similar to what is done for Power Flow Contingencies. Presently there are 4 choices described in separate items.
  • Transient Stability User Dialogs and Auxiliary File Support
    • Modified the device dialog to show the name of the default data set if the model has all default parameters.
    • Modified the Transient Stability Generator and Load Summary case information displays so that the Paste option is available.
    • For Transient Stability Limit Monitor Violations, extra columns are now available to show the area, zone, owner, substation, nominal kV, labels, bus numbers, bus names, and circuits associated witht he respective violations. This is the same functionality as has always existed in the power flow contingency analysis tool.
    • Added a message to the log when the minimum and maximum B values for switching and min and max continuous B values are switched for SVCs.
    • Added additional user interface features for ZPOTT, ZLIN1, ZDCB, and ZQLIN1 line relay models when the Far Bus is not the same as the To Bus. This shows the appropriate % coverage of the impedance relay based on the sum of series impedances between the From Bus and Far Bus. Previously it was only based on the impedance between the From and To Bus of the line relay.
    • Modified DISTR1 so that it will base the GUI features of showing the “% reach” in columns and on the various relay zone pictures so that it will look through a series of branches that end in the TransferTripLine#1 as long as this creates an island (similar to the “farbus” specified with other relays).
    • Added a feature with induction motors (loads) and induction machine (generators) so that whenever the per unit speed drops below 0.1, then the entire integration time step will be reduced. A multiplier will be defined that is 0.05 at 0.0 per unit speed and increases linearly up to 1.0 at 0.1 per unit speed. The time step used by the integration will be equal to the user-specified time step multiplier by this value. If multiple motors/machines are operating in this region, then the smallest multiplier in the case will be used. This is intended to improve induction motor starting studies without the user having to manually reduce the time step for the entire simulation. It will be a very rare event when this occurs.
    • Added ability on a generator case info display to show and edit the transient stability input data for Rcomp and Xcomp (compensating impedance). This data can be specified on many different transient stability records. The Rcomp and Xcomp can be specified with special Other generator models (COMP, COMPCC, IEEEVC), with the generator machine models (GENROU, GENSAL, GENTPF, GENTPJ, etc.), or with some exciter models (the BPA type “F” exciters BPA_FA…BPA_FV). Values in the generator table are shown in the system MVA base, while the individual stability records may show them on the machine MVA base.
    • Generator “H (system base)” field is now enterable on generator tables. This edits the appropriate field for the corresponding active Machine Model. If there is no machine model or the machine model does not have interia, the field will be blank and nothing can be entered.
    • For governor G2WSCC and GPWSCC, modified to allow BTurb*TTurb to be zero with both set to zero if their product is less than 4*local_MinDelt.
    • For governor G2WSCC, added validation/error correction for field Td, Tt, Tf, and Tp to match what was already done for G2WSCC
    • Added ability in TSGetResults() script command to use a file type of “JSIS” which will write out desired results in a format used by the WECC JSIS group.
    • Added new script command TSRunUntilSpecifiedTime(ContingencyName, [StopTime, StepSize, StepInCycles, ResetStartTime, NumberOfTimeStepsToDo]). The script command emulates what is done in the user interface. A time or number of steps may be specified and the transient stability will run until the specified time or for the specified number of time steps. StopTime should be entered in seconds. StepSize should be entered in either seconds or cycles depending on the StepInCycles field. StepInCycles should be YES if the stepsize is specified in cycles and NO if specified in seconds. ResetStartTime is either YES or NO and indicates if the simulation should be reset to the start time of the contingency. If the NumberOfTImesStepsToDo &gt; 0 then only the specified number of time steps will be done regardless of the StopTime.
    • Added new script command TSAutoCorrect. This script command has no parameters. If there are still validation errors after running this script that would prevent the stability simulation from running, then the remainder of a script will be aborted.
    • Added script command TSGetVCurveData(“filename”,filtername); where “filename” is the name of the file where the curves should be stored and filtername is a generator filter that specifies for which generators the curves should be created.
    • Added the ability to create a V Curve for a generator. This can be done from the generator dialog on the Stability page, generator case information display, and through script command TSGetVCurveData. The curve will use the actual MW, Max MW, and Min MW with 50 points of Mvars between Min Mvar and Max Mvar for each of the MW points.
  • Transient Stability Storage
    • Added log message warnings when parsing a TSR file to warn if objects in the TSR file do not exist in the present power flow case. Only 20 log messages will be written regarding objects that are not in the present case.

User Interface Dialogs

  • Edit boxes that have up/down arrows will automatically increase the number of digits to ensure that at least 2 significant digits are shown.
  • Added the ability to use dynamic formatting on any case information display.
  • Quick Filters can now be used on dialogs when choosing objects.
  • Case Information object type is now available with Model Conditions and Custom Monitors.
  • The Scale tool now allows specifying the new value or scale factor through a field with the object type to scale. When using a field rather than value, the scaling will be done by individual object rather than the aggregation of all objects selected for scaling.
  • Modified the list of recently open files so it will dynamically increase the visual width when file names become extremely long so that the entire file name can still be viewed.
  • Advanced filters have new condition operations “equal to about” and “not equal to about” that allow filtering based on a value being within a specified tolerance of a specified value.