Simulator 21 Patches

New Features

Bug Fixes

Date

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.