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Retriever 18 Patches

New Features

Bug Fixes

Date

November 13, 2015

Bug Fixes

  • Contingency Analysis: Fixed a bug that would not always correctly evaluate Model Conditions that are meant to be evaluated in the contingency reference state.
  • File Formats: When loading a PWB file that was saved with interfaces that contained no interface elements, we were deleting the interface. We will no longer delete an empty interface on PWB load.
  • Oneline Diagrams: When auto-inserting transmission lines, the breakers were being drawn on the terminal buses instead of the stubs. This has been fixed.
  • Scheduled Actions: Fixed some bugs importing Scheduled Actions and Scheduled Action settings.

November 3, 2015

Bug Fixes

  • Fault Analysis: Fixed a bug when using Pre-fault profiles of IEC-909 or Flat Classical. The internal voltage of generators was always being calculated using the solved power flow bus voltages, when the internal voltages should instead have been set to the IEC-909 voltage or flat start voltage, respectively.
  • File Formats: Fixed bug reading generator ownership percentage from PWB file.
  • File Formats: Labels were not being assigned to Switched Shunt records when reading hdbexport file. This has been fixed.
  • General: Fixed error in editing the "Enforce Current Limit" field for a MTDCConverter through a case information display or auxiliary file.
  • Power Flow Solution: Fixed calculation of the transformer sensitivity when using line drop compensation control on a transformer. It was not properly taking into account the effect of changing the tap on PQ flows on the transformer and propogating this sensitivity to the controlled point.
  • Sensitivity Calculations: On the Line Loading Replicator dialog, the Selected field in the injection change grid now goes to the element in the grid and not the grid object itself. The Object ID field has been added to allow identification of the element by any key field.
  • Transient Stability: Added hard-coded minimum values of the following for use in a transient stability simulation.
    0.3 for Minimum Per Unit Voltage for Constant Power Loads
    0.2 for Minimum Per Unit Voltage for Constant Current Loads
    If input values are below these thresholds, Simulator will include a validation warning indicating that we will assume values equal to these threshold.
  • Transient Stability: When using the option to only include generic limit monitors for synchronous generators without relay models, relay models will not be considered unless they are active. GP2 relays will always be ignored in this check.

October 26, 2015

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Modified reading the BusSlack field of an Area and the Voltage Controlling Converter Bus for a multi-terminal DC line so that they can also read the bus by label.
  • General: Evaluating Model Expressions that are interlinked could become very slow. This will make it impossible to view the expressions or do any calculations with them like contingency analysis, ATC, PV, and QV. This evaluation process has been sped up.
  • General: A change was made in the September 23, 2015 patch to AND and OR operators in Expressions and Model Expressions that could cause them not to evaluate correctly. This has been fixed.
  • Transient Stability: Fixed error when writing out REGC_A models to the DYD file format. The following values are now always written Khv = 0.7 and qmin = -1.3. These values are not used by PowerWorld Simulator and these represent typical used (nearly universally used) value in DYD files.
  • Transient Stability: Modified REGC_A to contain Khv and Qlim parameters. These parameters are NOT used by PowerWorld Simulator, but they are part of the DYD file so we read and maintain them for users with DYD files to avoid confusion.
  • Transient Stability: Modified the REGC_A to contain an Xe parameter to represent generator effective reactance in per unit. If this value is zero then we will divide the value Iq by this amount and also model an impedance of (jXe) at the bus in the network boundary equations. This mimics what is done for WT3G type 3 wind turbines.

October 7, 2015

Features and Improvements

  • Case Information Displays: When saving to a CSV file from a case information display, now have the option to save using Variable Names or Column Headers.
  • Contingency Analysis Tool: modified so that Version 18 can properly read contingency actions that refer to expression and fields using a string that contains the special or tags. This will be the new convention used in Version 19 always.
  • File Formats: Added code when reading OTG format files that will look for the keyword "newbase" in the file, and treat the rest of the contingencies in the file as n-1-1 contingencies that get combined with the first contingency read after the newbase keyword, until another newbase keyword is encountered to signify the base contingency will change from that point to the next newbase.
  • Transient Stability: Added option for CSVGN5 to change limit on Bmax/Bmin for initial limit violations.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug with SaveDataWithExtra not writing out blank user specified field values.
    • Contingency Analysis: Fixed potential bug with not writing DC Line contingency actions to file versions less than version 18.
    • Transient Stability: For the CMPLDW and CMPLDWNF model only, there was an error when using SimAuto or the Export Case Object Fields to dump out a list of available fields for the CMPLDW and CMPLDWNF models. The MotorA, B, C, D parameters were missing. This has been fixed.
    • Transient Stability: When saving or printing a plot that includes a Title Block, any Left or Right memo text may not have appeared with the correct carriage returns. This has been fixed.
    • Transient Stability: Fixed problem with reading the repc_a model from a DYD file when specifying the branch and monitored bus.
    • Transient Stability: Fixed error with how the CLOD model was being initialized.

September 23, 2015

Bug Fixes

  • Contingency Analysis: SolvePowerFlow actions were causing actions with non-zero time delays to not be applied correctly. This has been fixed.
  • Oneline Diagrams: Fixed a bug where two breakers were auto-inserted on top of one another; also revised breaker placement on bus ties to prevent single breakers from being placed in the center of the tie if a pie chart is being inserted there as well.
  • Security Constrained OPF (SCOPF) Tool: The contingency option to solve an OPF after each contingency is now ignored when running contingency analysis as part of the SCOPF.
  • User Interface Dialogs: The substation filter was not included when saving the Auto Insert Contingency options to an auxiliary file from the dialog. This has been fixed.

September 17, 2015

Features and Improvements

  • Sensitivity Calculations: Interfaces can now be monitored with the LODF Matrix tool.
  • Bug Fixes

    • Contingency Analysis: Fixed an access violation that could occur when closing Simulator. This was due to a RAS element containing an Inclusion Filter.
    • Distributed Computation: In some situations, a distributed computing run may hang at completion.  This has been fixed.
    • File Formats: 1. Added button to clear hdbexport cbtype mapping table.
      2. Updated hdbexport file parser so that it will use the TYPE_CB record to set the cb type when it's available (rather than following the P__CBTYP and using the information on the CBTYP records).
    • Power Flow Solution: Made a correction to SVSMO2 SVC model to use a look-up table with all of the possible combinations of B MVARS to determine the B output to the closest step.
    • Transient Stability: Fixed memory leaks associated with Area and Zone objects and LSDT3 relay model.
    • Transient Stability: Made a correction to SVSMO2 SVC model to use a look-up table with all of the possible combinations of B MVARS to determine the B output to the closest step.
    • User Interface Dialogs: When using the Save Case As option from the file menu, the directory will default to the location where the present case was opened.

September 11, 2015

Features and Improvements

  • File Formats: For the hdbexport file reader, the changes made to support reverse direction pointers on August 20, 2015 introduced a bug in reading the impedance correction tables values (which use the TABVAL/TABPT/TAB records). This was resulting in the impedance correction factors being off by a factor of 100. This has been fixed.

September 9, 2015

Features and Improvements

  • Transient Stability: When saving transient stability settings to an auxiliary file, the dialog that allows you to select what to save has been modified. There is now an option that allows you to Save Transient Limit Monitors.
  • Bug Fixes

    • File Formats: If using the option to Append a Case with an EPC file with Options, the dialog was not properly allowing you to specify an EPC version. It was interpreting the selected version as one less than selected, meaning that a version 18 file was read as a version 17 file. This could result in information that was added at the end of records for version 18 not being read correctly. This has been fixed.
    • Power Flow Solution: Fixed a bug with how a SVC of type SVSMO2 operates when there is non-zero compensating reactance.
    • Power Flow Solution: SVC of type SVSMO2 previously would not move if the same High and Low voltage regulation settings were specified. This has been fixed.
    • Power Flow Solution: Fixed some problems with slow control for SVC type SVSMO2.
    • Transient Stability: Fixed a bug with the SVSMO3 model.
    • User Interface Dialogs: Fixed the advanced/quick filter dialog so that when using the keyboard to select the variablename a correct variable would be chosen.
    • User Interface Dialogs: When editing a Model Expression on the Model Expression dialog, after defining a new variable the expression function would always reset back to the function that existed when the dialog was opened. This would occur even if you had just changed that function. This has been fixed.

August 28, 2015

Features and Improvements

  • Sensitivity Calculations: Added the ability to store the display/column option settings for the grids on the Flows and Voltages Sensitivities dialog under the "Self Sensitivity" and the "Multiple Meters, Single Control Change" tabs. Previously these could be modified but after closing the dialog and reopening it, Simulator would not maintain display/column options on those.
  • Transient Stability: Added support for reading the REEC_C model from a DYD file.
  • Transient Stability: Modified the Validation message about treating generators with no machine model as negative load to make it clear that we treat the generator as constant current in this situation.
  • Transient Stability: Added ability to open the Bus View from the Transient Limit Monitor Violation case information display.
  • Transient Stability: Added ability to open the Bus View from case information displays of transient stability models.
  • Transient Stability: Modified to bring the transient stability dialog back up in multiple contingency mode if it was in that mode the last time the user open the dialog.
  • User Interface Dialogs: Modified the Recent Cases list so that the file extension is included.
    Also now include the file path in situations that duplicate entries are shown in the Recent Cases List (This can occur with the same file name, but different file path).
  • Bug Fixes

    • File Formats: Fixed an error reading in a PWB file if there were any Model Conditions referencing three-winding transformers when the file was saved.
    • Oneline Diagrams: Fixed bug in applying oneline emphasis filter.
    • Oneline Diagrams: Fixed a bug with properly drawing dashed lines while in Run Mode.
    • Oneline Diagrams: Additional modifications to prevent any dialog boxes or onelines from being dragged to a part of the screen that will prevent the user from clicking on the title bar of a form such that they can't move it again.
    • Power Flow Solution: Improved DC line tap calculations to avoid controller oscillations in the power flow solution.
    • Transient Stability: Fixed access violation that could result during the initialization of a case containing Load Distribution Equivalent records.
    • Transient Stability: Fixed a bug with auto-correcting the Xc value for SVCs. It was setting the value to 0 if the user selected to Auto-Correct the values in the validation dialog.

August 20, 2015

Features and Improvements

  • Contingency Analysis Tool: Contingency violations can now access the Monitor field for their elements so that this can be set directly from the contingency results instead of going to the Limit Monitoring Settings.
  • File Formats: Changed the parser for hdbexport files so that it supports the reverse direction of some pointers, namely:
    LNLIM -> LN
    XFLIM -> XF
    ZBLIM -> ZBR
    LNSEG -> INTRFC
    XFSEG -> INTRFC
    ZBRSEG -> INTRFC
    TABVAL -> TABPT -> TAB

    Added support for PRIO field on CP records (putting it in the VarRegulationSharing property).
    Added support pointers in either direction from XFs to PSs or PSs to XFs.
  • Bug Fixes

    • File Formats: A log warning message is written if duplicate generators are encountered when reading a RAW file.
    • File Formats: Made some WECC Switch file changes:
      1. Parse fault impedance with FB record
      2. Use OPEN BOTH action when parsing FL record that opens both ends of the line at the same time
      3. Use solid fault if impedance values are all 0.0
    • Oneline Diagrams: Fixed bug with pasting Geo Data View Style colormaps.
    • Transient Stability: Fixed bugs when deleting transient switched shunt and line relay models.

August 12, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command CTGClearAllResults that does what the name implies. This does the same thing as the Other > Clear All Contingency Results button on the contingency analysis dialog.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Fixed access violation that could occur while running ATC analysis and defining Monitoring Exceptions for contingencies.
    • File Formats: Always ignore the Auto Solve on Load option when loading an hdbexport file.
    • Transient Stability: Fixed error in reporting with a BUS record what the total load was at the bus if it contained a distribution equivalent.
    • Transient Stability: Fixed an error that could cause a network solution failure when closing back in a disconnected island during a transient stability simulation. This error would not always occur, but could sometimes.

August 3, 2015

Features and Improvements

  • Transient Stability: Added MEXS Exciter model.
  • User Interface Dialogs: On the Scale dialog, hitting Enter after changing a number would sometimes trigger the scaling instead of just changing the value to be used in the scaling. This should no longer happen.
  • Bug Fixes

    • File Formats: Fixed error when reading in the ##R records from a UCTE file. If the du% value for a phase shifter was negative we were not properly reading the phase shifter. This has now been fixed.
    • Transient Stability: Modified the transient stability dialog so that if you load an AUX file or in any way edit the list of transient contingencies it will automatically rebuild the drop-down showing the list of transient contingencies. Previous this drop-down was maintained if you modified the transient contingency list by interacting with the Transient Stability Dialog itself. The drop-down will now also be properly maintained even when you Add, Delete, or Rename transient contingencies in any other manner (such as loading an AUX file from the file menu.)

July 24, 2015

Features and Improvements

  • File Formats: For UCTE format, added reading the regulated voltage for tap-changing transformers and regulated MW flow for phase shifting transformer. For tap-changers regulated voltage is read as the value specified +/- 0.01 per unit. For phase-shifting transformers regulated MW flow is read as the value specified +/- 5 MW.
  • Transient Stability: On the Transient Stability Dialog, we were finding that the button on the Result Storage page called "Load from Hard Drive File into RAM results specified by Store to RAM Options" was causing confusion. Users were assuming that in order to plot results or use the Transient Contour Toolbar that results must first be loaded into RAM. This has never been the case as these features simply obtain data directly from the TSR file without requiring you to load results into RAM. The same button is available at the bottom of the "Results from RAMTime Values" and in practice the only place that you see these results from RAM is on this page. To avoid continued user confusion, we have removed the button from the Result Storage tab and it is now only available on the Time Values page.
  • Transient Stability: When loading in transient stability data from an AUX, DYD, or DYR file, Simulator would prompt you asking "Do you want to clear the existing transient stability data first?". Feedback from many users was they would NEVER want to do this and it was a dangerous dialog to continually show users. We have removed this prompt and the clearing of stability data when loading a file.

    If a user still wants to delete all stability models from their case, this can still be done under the AddOns ribbon tab under the drop down Stability Case InfoClear All Transient Stability Data.
  • Transient Stability: In the Transient Stability dialog, modified the drop-down showing all the transient contingencies in the so that the strings also show the categories of the contingency (if any categories have been assigned)

    In the Transient Stability dialog, added a Find button next to the drop-down showing all the transient contingencies. The Find button allows you to find by either
    1. Name of the Transient Contingency
    2. Find the first transient contingency that has a transient contingency element that acts on a generator, load, bus, or switched shunt.
  • Bug Fixes

    • Contingency Analysis: Improved the processing complex contingencies which involve several POSTCHECK iterations to ensure that large generation changes are handled efficiently.
    • File Formats: More changes to reading the Min/Max phase shift values from a UCTE file format to ensure that the Max value is the positive one and the Min value is the negative phase.
    • File Formats: Fixed error in how Generator records were being read from the UN records in an hdbexport file.
    • File Formats: Fixed error in loading in RAW file which contained an VSC DC Line if the remotely regulated bus was not specified.
    • File Formats: When reading in a 2-winding transformer in a RAW file, the cosmetic storage of the Fixed Tap ratio on the to-bus side was not being done properly when the flag CZ=2 and when the nominal kV of the secondary winding was different than the nominal kV of the bus. This has been fixed so that you can see the values on the transformer base correctly inside Simulator. Note, this did not effect the solution as we were still converting and storing everything in Simulator on the System MVA base correctly. This only effecting viewing input data on the transformer base.
    • General: When saving a case it is possible to configure Simulator bring up a dialog asking you to add a comment to the case. It is also possible to configure Simulator to automatically save a case every so many minutes. This was bringing up the case comment form constantly. The Auto-Save feature has been changed to never show the case comment box.
    • Power Flow Solution: Made a change to how the Mvar limits are enforced by switched shunts operating as SVCs.
    • Transient Stability: modified how error messages are reported when we write out a model which can not be found in the case when reading a DYD file so that the error messages work when the DYD file contains labels as well.
    • Transient Stability: For a GENTPF/GENTPJ model when setting Tdopp or Tqopp to 0.0, this indicates that a transient model should be used for the generation model. The model should then be configured such that Xdpp=Xdp and Xqpp=Xqp=Xq to function appropriately. If the model was not setup this way from the start, then Simulator will change the parameter inside the simulation automatically to be treated in this manner. There was a bug however such that this wasn't properly handled which could cause generation to initialize incorrectly. This was occurring at the LITFAL generation in a WECC case. Simulator will now properly handle this without user-intervention.
    • Transient Stability: For GENTPF/GENTPJ models which had Tqop=0 to indicate special handling of a salient pole machine with a single amortisseur winding, we were not performing any validation checks on the magnitude of Xqpp relative to Xdpp. As a result, invalid data such as Xqpp=0 was not being flagged as an error and was not being auto-corrected. We now perform the same check on Xqpp as we do for all other GENTPF/GENTPJ model and thus if the value is very small (Xqpp<0.01*Xdpp, basically zero) then we set Xqpp=Xdpp.

July 20, 2015

Features and Improvements

  • File Formats: Added FRQ as a field type identifier to map to frequency when loading a DI/DINAME file.
  • Bug Fixes

    • File Formats: Adding some error handling code to handle missing records more gracefully. Missing KV records were causing the problem.

June 18, 2015

Bug Fixes

  • Case Information Displays: Fixed a bug that prevented entering negative blocks for Switched Shunts.
  • Case Information Displays: Made some changes to impedance correction table fields with a transformer. Now have two fields: Correction Table Used and Correction Table Specified. The Used value might be different than the Specified value if the table that the user specifies cannot be found. If the user changes either of these fields as input to a case information display or through an auxiliary file, the Specified value will change. This should allow the retention of what the user specified but still notify if that table cannot be used. This will allow transformers to keep their impedance correction table settings if they are set prior to the impedance correction tables themselves actually being created.
  • File Formats: When writing out contingency containing any section of a multi-section line in the PTI CON format, write out the from bus, to bus, and circuit of the multi-section line rather than the section.
  • General: On the Scale dialog, maximum New Value fields were limited to abs(9999). This has been increased.
  • Transient Stability: Fixed a bug that was causing multiple events to occur for the same under voltage motor trip.

June 11, 2015

Features and Improvements

  • Retriever: Added a folder for the field list to the Alarm information for Areas, Zones, and Substations.
  • Retriever: Added complete support to SuperAreas for the Alarm informational fields.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Made some changes to how the user-specified extra headers and values are read when using the SaveDataWithExtra script command. Any strings enclosed in double quotes will be stripped of the enclosers. Any strings containing double double quotes will have them replaced with single double quotes. The input should be formatted in a manner to indicate how it should be written to the CSV.
    • File Formats: Fixed an access violation that could occur when appending a PWB file.
    • File Formats: When loading three-winding transformers from a PTI CON file, all three winding buses must be specified. If not, there is an error and the contingency element will be unlinked.
    • File Formats: When loading unlinked elements from a PTI CON file, keep the unlinked element with the contingency definition. This will NOT be able to be relinked, but a record of the error will exist.

June 9, 2015

Features and Improvements

  • Case Information Displays: Added new Injection Group fields to show the "Number of Gens Online", "Number of Loads Online", and "Number of Shunts Online".
  • File Formats: Added special parsing when reading text descriptions of a branch to recognize special versions for an individual winding of a three-winding transformer or an individual section of a multi-section line. This is done when reading:
    1. INTERFACEELEMENT objects or when reading
    2. Various objects that refer to a specific object (Model Condition, Model Expressions, Custom Monitor, etc.)
    3. ObjectID of a BRANCH
    Normally a branch is identified with the string "BRANCH num1 num2 ckt" or "BRANCH 'name_kv1' 'name_kv2', ckt".
    For a multi-section line section we can now accept "BRANCH msnum1 msnum2 ckt sec" or "BRANCH 'msname_kv1' 'msname_kv2' ckt sec" where the msnum1 and msnum2 represent the terminal of the multi-section line aggregation and the sec represents which section of that aggregation to use.
    For a three-winding transformer, we can now accept "BRANCH num1 num2 num3 ckt" or "BRANCH 'name_kv1' 'name_kv2' 'name_kv3' ckt" where the identifiers represent the three-winding transformer key fields, but we interpret this as the BRANCH which is attached to the first terminal listed (num1 or name_kv1).
    Also note that when reading these special interpretations for an interface, the order of the multi-section line terminals will determine the direction being monitors and for three-winding transformer windings we will always monitor in the direction going into the transformer.
  • General: Three-winding transformers can now be used as part of Model Conditions and Model Expressions.
  • Transient Stability: Added ATRRELAY model.
  • Transient Stability: Added OOSMHO Line Relay Model.
  • Bug Fixes

    • File Formats: Fixed bugs when reading WECC switch files: (1) Fixed bug stripping quotes from generator ID values and (2) When reading contingeny names on two lines concatenate into one line.
    • General: Fixed bug when opening the Model Condition dialog if the class of the filter was different than the class of the object. This worked correctly on the dialog while defining the Model Condition, but when choosing Show Dialog on an existing model condition it was not properly populating the dialog.
    • Power Flow Solution: Made some corrections to the balancing of parallel transformer taps when the parallel transformers were defined in opposite directions in regards to the from and to buses.
    • PV and QV Curve (PVQV) Tool: Removed options from the Load button at the bottom of the QV dialog. There is no reason to load options and results separately and this was causing problems by skipping DATA sections necessary for the QV setup. Clicking the Load button now will load all contents of an auxiliary file.

June 4, 2015

Features and Improvements

  • Case Information Displays: Added new field to Switched Shunts, "Controlling SVC Object ID", that will allow identifying an SVC that controls a fixed shunt by any of the available key fields. Previously, the controlling SVC could only be identified by a bus number and shunt ID.
  • Contingency Analysis Tool: Modified the layout of the Contingency Definitions folder on the Options tab of the Contingency Dialog. Previously entries for All Contingency Elements, Remedial Actions, Contingency Blocks, Model Filters/Conditions/Expressions, etc. were all under one folder. They have now been split up into folders to make "Remedial Action Definitions" more prominent and also to add Contingency Blocks and Global Actions to a "Legacy Definitions" folder to discourage their future use.
  • Transient Stability: Expanded on the "Solved" field for a transient contingency. Previously this field said "YES" if the transient contingency had been been attempted at all regardless of whether it was successfully finished. There are now 3 fields:
    1. Processed: This will say YES if the transient contingency solution was attempted
    2. Solved: This will say YES only if the transient contingency solution was run and successfully finished
    3. Reason Not Solved: When Solved = NO, this will be a string indicating why the solution was not finished
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Scale script command now allows you not to scale LOAD MW or Mvar while scaling the other value. The [parameters] entries can now be specified as NO. Scale(LOAD, MW, [-250, NO], AREA) will only scale MW and will not scale Mvar. Scale(LOAD, MW, [NO, -250], AREA) will only scale Mvar and will not scale MW.
    • Case Information Displays: Fixed the folder listing the multiple direction PTDF fields for the Branch object. These values were appearing under the folder for "LODF Multiple" in the field list and now correctly appear under the "PTDF Multiple" instead.
    • Contingency Analysis: Fixed bug when using contingency actions with non-zero time delays in a full-topology case using "Open with Breakers" or "Close with Breakers" actions. The actions with the non-zero time delays would never be implemented.
    • Contingency Analysis: Modified the caption on various tabs that said "Contingency Definition" and changed them to say simply "Definition". These same dialogs were used for Contingency Blocks Elements, Contingency Elements, and Remedial Action Elements and this caused confusion.
    • Contingency Analysis: Fixed a bug with Distributed Contingency Analysis caused by quote characters being part of contingency names. This bug would cause the results from distributed runs to not be processed correctly. This has been fixed.
    • Contingency Analysis: Fixed bugs with load throwover not being done correctly during a linear dc contingency calculation in which the load is thrown over to another bus that is also being disconnected during the contingency.
    • File Formats: Fixed a problem when opening a valid PWB file associated with a PWD file that cannot be opened. Previously, the case would be cleared. Now the case will remain open without a oneline diagram.
    • General: When creating an auxiliary file from the Aux Export Format Description tool, the file extension would not be set by default. This has been fixed.
    • General: Several bugs were fixed with the Scale tool:
      (1) Generators could not be scaled to a New Value that was negative.
      (2) Loads could not be scaled to a New Value that was negative using the Scale dialog because the dialog prevented entering a negative value.
      (3) Script command now allows you not to scale LOAD MW or Mvar while scaling the other value. The [parameters] entries can now be specified as NO. Scale(LOAD, MW, [-250, NO], AREA) will only scale MW and will not scale Mvar. Scale(LOAD, MW, [NO, -250], AREA) will only scale Mvar and will not scale MW.
      (4) Generators with a negative Original Value could not be scaled regardless of the scaling direction.
    • Power Flow Solution: If a generator's MinMW < MaxMW then it was possible for a generator on MW control in the power flow to oscillate between it's MinMW and MaxMW output. This has been fixed so that the generator will just not move instead of causing oscillations.
    • Sensitivity Calculations: Redo the injection group sensitivity calculations for TLR results after setting the sensitivities of out-of-service buses to the values of their closest in-service bus.
    • Transient Stability: Modified GENCLS so it sets its field current equal to the initial field voltage.
    • Transient Stability: When using filters, the Buses and Generators tabs on the Results from RAM --> Minimum/Maximum Values page were not indicating that a filter was applied. This has been fixed.
    • Transient Stability: Fixed error that was not showing the "Finished at XX.XXX seconds" text in the edit box showing the status of a transient contingency analysis run at the top of the Transient Stability dialog.
    • Transient Stability: Added scroll bars to the Control tab on the Simulation page of the Transient Stability dialog. This will allow access to the Simulation Time Values for varying screen resolutions.

May 19, 2015

Features and Improvements

  • File Formats: Added process to check the voltage magnitude and angle of star buses at the end of the RAW file read, and evaluate the mismatches at the three terminal buses of the three winding transformer. If we determine that our own estimate of what we think the voltage and angle should be at the star bus results in improved mismatches at the three terminal buses, we will apply our estimated voltage values to the star bus, otherwise we will keep the voltage magnitude and angle as read from the RAW file for the star bus.
  • Bug Fixes

    • File Formats: When reading the XF regulation parameters in a UCTE file, a bug existed such that the relevant transformers could not be found. This has been fixed so that the regulation parameters are correctly applied.
    • File Formats: The last line of a UCTE file was not being processed. This has been fixed.
    • PV and QV Curve (PVQV) Tool: Fixed access violation that could occur at the start of a PV run when using the interface ramping option.
    • PV and QV Curve (PVQV) Tool: When using the interface ramping option with the PV tool, do the full OPF solution always rather than trying to speed things up by doing only a single outer loop. This will ensure that the results are within the desired tolerance if a solution is found.
    • Transient Stability: Modified the DC Line calculation when considering mode 3. Mode 3 is the constant Beta mode which is used as a gradual transition between Mode 1 (full current) and Mode 2 (current reduced by the current margin). Mode 3 uses the Beta from the previous network solution which it had in a Mode 1 or 2 solution. Immediately after a network event however, Mode 3 can not use the Beta from the previous solution because the entire network state had a discrete change and the Beta from that solution is not reliably reasonable for the new network state. Doing so could lead to a solution failure. This has been fixed so that Mode 3 operation is not allow in the timestep immediately following a network event.

May 6, 2015

Features and Improvements

  • File Formats: Lshunt actions, which cause a line shunt to be opened or closed or have a new susceptance value, are now supported when reading the OTG format.
  • File Formats: Isolate actions, which cause a bus to be opened, are now supported when reading the OTG format.
  • General: ViolationCTG and LimitViol object types can now be filtered using secondary object filters.
  • Bug Fixes

    • Case Information Displays: When showing a list of Line Shunts associated with a particular line from a the Line Dialog, previously it was possible to have that list filtered by area/zone/owner or advanced filters. This never necessary as this list is very short and could cause confusion as it would hide a line shunt.
    • File Formats: Fixed bug with specifying a start bus number for three-winding transformer star buses when loading in a RAW or Auxiliary file. The bus numbers would not increment properly and the same bus number could be used multiple times.
    • File Formats: Fixed a problem with owners stored with EPC extra data for switched shunts storing too many owners and incorrectly writing out in the EPC file.

May 1, 2015

Features and Improvements

  • Case Information Displays: Added new fields with branches to show the from and to MW and Mvar flows calculated from voltages and also ignoring the branch status. Fields will contain "(Calculated from voltages ignoring status)" in their name. If either of the terminal buses is disconnected, nothing will be calculated.
  • Bug Fixes

    • File Formats: When reading a PTI CON file, the keywords MACHINE and UNIT are now read correctly along with the REMOVE keyword for actions that open a generator.
    • General: Fixed a bug that would cause a case to freeze when attempting to set the Difference Flows Base Case. This could occur in cases with only a few branches defined as Breakers.

April 28, 2015

Features and Improvements

  • Case Information Displays: Added fields for displaying Near Bus, Far Bus and Element ID for interface elements.
  • Contingency Analysis Tool: Added new field with branches, "Contingency ResultsMax % Ld Loading Direction", that shows the direction of flow for the branch at the maximum loading level under all contingencies for which this branch is a violation.
  • Sensitivity Calculations: For TLR calculations, determine the island in which the calculations occur based on the island of the TLR element. If the element's terminals are in different islands, no calculation is done. When doing the calculations, only the buses in the transactor object that are in the same island as the TLR element will be used. Previously, we would not do the calculation and notify the user that the transactor spanned multiple islands. When doing the weighted calculations for areas and injection groups, we also only include the buses that are in the same island as the TLR element.
  • Transient Stability: Added reading of the AMETA record from a DYD file to indicate storage of angle information to transient stability results.
  • Transient Stability: Added ability to read DYD file containing devices identified by label.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bugs created by loading unlinked bus participation points from an auxiliary file.
    • Contingency Analysis: Fixed bug with linear DC contingency analysis if a contingency causes the system slack to be islanded. The results would show very high flows and overloads on branches that are in the island when they should really be zero.
    • File Formats: Fixed a bug reading the UCTE files where blank lines in the description comments at the beginning of the file caused an access violation.
    • General: When creating a new branch that connects to a dummy bus of an existing multi-section line, remove the multi-section line record. If attempting to create a multi-section line through an auxiliary file and at least one dummy bus connects to other buses than the terminals of the MSline or other dummy buses, do not allow the multi-section line to be created. Messages are written to the log indicating MSLines are being removed or not created.
    • Transient Stability: Fixed bug with Modal Analysis input grid.

April 20, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Cleaned up how the creation of a star bus is handled when creating a three-winding transformer from an AUX file. Previously you had to input a star bus that was an existing bus in the case, and thus had to bother create this bus ahead of time and know its number. Now the user may optionally enter special strings for BusIndentifier:3 as follows:

    Number : enter an unused bus number and Simulator will create this bus as part of creating the three-winding transformer
    STAR : enter this and Simulator will create a star bus by starting at the primary bus number and incrementing by 1 until a unique number is found
    STARMAX : enter this and Simulator will create a star bus with a number equal to the maximum bus number plus 1
    STAR98765 : enter this and Simulator will create a star bus by starting at the number given after STAR and incrementing by 1 until a unique number is found

    Syntax Note: You may optionally put a spaces between "STAR MAX" or "STAR 98765”. If the string starts with STAR but doesn’t match this syntax we default to treating it as though it said STAR only.
  • PV and QV Curve (PVQV) Tool: With the QV Curve Tool added an option to allow specification of QV Make-Up Power. Previously, any MW changes during the QV curve tracing were made up at the system slack bus. Now can choose to use the system slack bus or the same option that is set as the Contingency Analysis Make-Up Power option.
  • Bug Fixes

    • Contingency Analysis: Fixed bug that prevented you from creating a Custom Monitor for Contingency objects using an auxiliary file.
    • Contingency Analysis: In the Contingency Violation List, change the column header to "CTG: Category" for the category list that originates from the contingency to distinguish between the Category of the limit violation.
    • Integrated Topology Processing (ITP): Fixed an access violation caused by creating branches through a Post-Contingency Auxiliary file while the case is consolidated. Objects are not allowed to be created from an auxiliary file while the case is consolidated.
    • Transient Stability: Added error message when a NAN value is encountered in the network solution to show the bus at which this occurs.

April 10, 2015

Features and Improvements

  • File Formats: Added support for reading and writing version 19 EPC files.
  • File Formats: When loading in Areva HDBExport files, the EMS ID and EMS CBTyp fields are now in their own fields with branches instead of being added as custom strings.
  • Oneline Diagrams: Added ability to re-load active display in the Oneline Viewer by double-clicking on its tree node.
  • Bug Fixes

    • File Formats: Fixed bug in writing out a PTI SEQ data file that was causing all load records to be written on the same line.

April 8, 2015

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Fixed "Percent" variablename for BRANCH objects for the more concise file format to represent the "% of Limit Used". Previously it was representing the "% at To Bus". Added variables "PercentFrom" and "PercentTo" to the concise file format
  • Case Information Displays: Fixed bug for filtering BRANCH objects by the owner in the Area/Zone/Owner filters. The problem was that we were checking both the owner of the terminal buses and the owner assigned to the branch. If both bus owners did NOT meet the owner filter, even though the branch owner did meet the filter, the branch would not be displayed. This has been fixed. This effected the use of filtering on branches everywhere in Simulator including locations like Auto-Insert Contingency definitions which make use of filtering.
  • File Formats: Added writing out voltage high/low normal/emergency limits with RAW format >= version 33. Previously we were reading this input but were not properly writing it back out. to the RAW format.

March 31, 2015

Bug Fixes

  • General: Fixed an access violation caused by deleting objects that are in contingency violation records. We were only checking for the object to appear once as a violation, but the same object could appear as different violation types. This was causing an access violation when trying to save the case to PWB.

March 23, 2015

Bug Fixes

  • Oneline Diagrams: Fixed access violation when opening the contouring dialog.
  • Transient Stability: Fixed a bug with setting only one load model active at each bus.
  • Transient Stability: Fixed the Transient Limit Monitor dialog so that the fields to monitor can be selected. This problem was introduced with the Feb. 23, 2015 patch.

March 20, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added two optional parameters to the SendToExcel script command, [Header_List] and [Header_Value_List]. These allow user specified headers and values to be included with the object fields.
  • Transient Stability: Added a new REEC_C model that permits modeling of a battery storage device allowing a negative Ipmin (to represent charging) and providing a charging state which can result in a modification of the limits of the Ip.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Return an appropriate error message when the CalculateTLR script command fails.
    • Auxiliary Files (SCRIPT and DATA Sections): Return an appropriate error message when the CalculatePTDF script command fails.
    • Auxiliary Files (SCRIPT and DATA Sections): The SaveYBusInMatlabFormat script command has a parameter to indicate if voltages should be included or not in the file. This wasn't being applied so the voltages were always saved. This has been fixed.
    • GIC: Fixed bug in which transformer configuration changes made on the GIC Transformer case information display were not getting updated on the GIC Transformer dialog that can be accessed from the Branch dialog.
    • Transient Stability: After a severe event, do not perform optimization on the network solutions until a fixed number of time steps have passed.
    • Transient Stability: Made changes to the LHFRT and LHVRT machine models to include the alarm parameter.

March 16, 2015

Features and Improvements

  • Contingency Analysis Tool: Added support with LHVRT transient stability model to trip generators in the power flow (steady state) contingency analysis if the voltage thresholds of the LHVRT are met during the contingency process.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed error with ":ALL" qualifier returning the number of fields for the Bus object BusMCMvarValue field. Also fixed and access violation associated with returning these values.
    • Case Information Displays: The field (Contingency ResultsMaximum Loading) that reports the highest loading of a branch over all contingencies should be reported as a percentage. This has been fixed.
    • File Formats: The number of Limit Groups that can be stored to a PWB file is limited to 127 in Simulator version 18. Reloading a PWB that was saved when more than 127 Limit Groups existed would result in objects being assigned to seemingly random Limit Groups. To correct this, any Limit Group beyond 127 will not be saved to the PWB and objects using these Limit Groups will be assigned to the Default Limit Group. Messages will be written to the log indicating which Limit Groups are not being saved to the PWB. Simulator version 19 will correct this problem completely and any number of Limit Groups can be saved.
    • GIC: Fixed GIC bugs associated with pasting in electric field time points.
    • PV and QV Curve (PVQV) Tool: Modified so that the name of the contingency is not included in the plot legend captions when creating a plot that only shows information for one contingency.
    • Transient Stability: Modified so that the name of the contingency is not included in the plot legend captions when creating a plot that only shows information for one contingency.
    • Transient Stability: Modified TLIN1 model so that multiple TLIN1 can be assigned to the same end of a branch. The Device ID must then be unique.
    • Transient Stability: Modified how reading line relays assigned to sections of multi-section lines is done. Previously for any line relays for which the end of the branch to which the relay is assigned matters, Simulator would always assign the relay to either the first or last section of the multi-section line and the section number in the DYD file was ignored. This has been changed so that the section number is now read and the relay can be assigned to any section of the multi-section line. Note: this probably is not good practice in general as the tripping any section of a multi-section line will trip all of them so having a separate relay for every section is unnecessary.

March 6, 2015

Features and Improvements

  • Case Information Displays: Added a new field for branch objects to the "MWSurge Impedance Loading". This will show the surge impedance loading on the line.
  • File Formats: When reading the hdbexport CSV file, fixed SVS parsing code so that AVR status is used properly.
  • PV and QV Curve (PVQV) Tool: Added a new button with PV plots to save plot images to file.
  • Transient Stability: Added support for the LSDT3 load relay models
  • Transient Stability: Added support for the LSDT7 load relay models
  • Transient Stability: Added support for GP2 relay model.
  • Transient Stability: Modified reading of the DYD file so that when the IFMON record is encountered we modify all our options regarding storing results to include the MW and Mvar flows on interfaces.
  • Transient Stability: Added a check at the end of reading a DYD file to determine if there are loads which do not have any static/algebraic stability models assigned to them. If this is the case, then a dialog would previously appear asking the user to choose a default load model. This dialog caused more confusion than clarity, thus it has been modified so that instead messages are written to the log notifying the user that all loads that do not have static load models will default to a "Constant Current P, Impedance Q". Also checking is done to see if there are ALWSCC models assigned to some areas but not others, and if this is the case then log messages are written to notify the user that some areas do not have ALWSCC models and list those areas.
  • Bug Fixes

    • PV and QV Curve (PVQV) Tool: Made fix so option to only save plots of critical scenarios is included when saving the aux file with all PV settings including plots.
    • Transient Stability: Modified treatment of Exciter Saturation which involve the calculation "VFE = Ve*Sat(Ve)". The trouble was with the Scaled Quadratic function: Sat(Ve) = [B*(Ve-A)^2]/Ve. In highly anomolous situations in which Ve --> 0, Simulator's calculation of Sat(Ve) was resulting in a floating point error due to a divide-by-zero. This has been fixed by instead simply evaluating the entire function "Ve*Sat(Ve) = B*(Ve-A)^2]".
    • Transient Stability: When reading in a branch relay (such as LOCTI, TIOCRS, TLIN1) from a DYD file, if the branch is not found then Simulator will also look to see if the terminal buses specified are the terminal of a three-winding transformer with the appropriate circuit id. If they are, then we will assume that the model is assigned to the winding of the three-winding transformer specified as the first bus in the DYD file.
    • Transient Stability: When reading CCOMP model from a DYD file, only the first 2 parameters are now required. Additional parameters if omitted are assumed to be zero.
    • Transient Stability: Fixed reading the last 2 parameters of the WNDTGE from a DYD file
    • Transient Stability: The user could configure options to storage of Injection Group results to hard-drive, but this was not actually being done when chosen. This has been fixed.

March 4, 2015

Features and Improvements

  • PV and QV Curve (PVQV) Tool: Added option with PV plotting to specify how the objects on the plots are identified, i.e. number, name_kv, or label.
  • Bug Fixes

    • File Formats: Added error checking when loading in a UCTE file to detect parallel branches that have the same circuit ID. This is not allowed in PowerWorld Simulator, but we were still adding the second branch resulting in inconsistency in Simulator. This is now handled by processing the list of branches after loading the UCTE file and automatically assigning a unique circuit ID if duplicates are found.
    • Integrated Topology Processing (ITP): When using the option to save a consolidated case and convert shunts to blocks, an incorrect nominal Mvar value could result for the consolidated shunt if composed of original fixed shunts that contained no blocks. This has been fixed. Now also correctly sum up the total Nominal G.
    • Optimal Power Flow (OPF): When trying to obtain bus information on the MW price details in the OPF solution using script commands and access the filed BusMCMWValue:1, BusMCMWValue:2 and so on, the values were not being returned properly. These values were only being calculated when the OPF dialog was opened to the tab which shows these values. It has been fixed so that these values are always calculated now so that they can be obtained when using scripts or SimAuto.
    • Transient Stability: modified throughout to handle FEX() exciter rectifier function when the Ve values falls toward zero. Previously for some models (REXS, REXSYS, REXSY1, EXAC1A, EXAC1, EMAC1T, and ESAC5A) this could cause a problem when Ve went to zero because the input the FEX function would go to +/- infinity.

March 3, 2015

Features and Improvements

  • PV and QV Curve (PVQV) Tool: Added new option with PV plots to only save a specified number of critical scenario plots to file. This is done on a plot-by-plot basis. When plotting critical scenarios, the options with contingencies that determine if scenarios should be plotted are ignored.
  • Bug Fixes

    • Fault Analysis: Modified reading sequence values for transformers from an SEQ file so that there is a check on the value existing in the record being read before trying to read it, otherwise it will default the value to 0. This applies to all of the sequence impedance values read for each record.
    • File Formats: Fixed error in loading in Generators from the UCTE file format
    • File Formats: Fixed error when loading a RAW file if the first entry in a line of text was a comma indicating that the first parameter of that line of text was supposed to be the default value

February 27, 2015

Features and Improvements

  • File Formats: Added ability when loading the KML file for ERCOT to have it create parallel transmission lines between the same 2 buses if there are duplicate entries in the KML file.
  • Transient Stability: Added support for PV1G machine model and the PV1E electrical model.
  • Transient Stability: Added option with LOCTI Relay to trip the entire three-winding transformer or only the monitored winding.
  • Transient Stability: Added more parameters to WNDTGE governor model.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Update the actual MVA limit stored with transfer limiters as individual limiters are iterated on. The limit could change from the original value due to contingency actions that change line ratings.
    • File Formats: When loading in a RAW file, estimate voltages at dummy buses of multi-section lines. Even though the buses are explicitly in the file the voltages might not be good depending on the process that created the RAW file.
    • File Formats: When loading in a RAW file, estimate the voltages at three-winding transformer star buses if the voltage is given as 1 pu and 0 deg. angle. This most likely indicates just a default value and could cause solution problems.
    • PV and QV Curve (PVQV) Tool: Fixed a bug with PV analysis that would not calculate dV/dQ sensitivities correctly under certain circumstances if a contingency did not actually implement any actions.

February 23, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added optional parameter, SetOutOfServiceBuses, to the CalculateTLR script command. If set to YES, this will set the sensitivities of out of service buses to the sensitivity of the closest in-service buses. Default value is NO.
  • Auxiliary Files (SCRIPT and DATA Sections): Added CTGApply("ContingencyName") script command to apply the actions in a contingency without solving the power flow.
  • Auxiliary Files (SCRIPT and DATA Sections): Added two new script commands, StoreState and RestoreState, that will allow user to store and restore a system state while in Run Mode.
  • PV and QV Curve (PVQV) Tool: Added options to allow saving PV plots to file at the end of a PV run.
  • Sensitivity Calculations: Added option when doing TLR calculations for injection groups that will allow offline devices to be included in the calculation.
  • Bug Fixes

    • Transient Stability: Modified column headings for options to specify what to save to RAM and column headings showing the actual transient results in case info displays. This was done to ensure column headings were unique so that copy/paste from Excel still functioned properly.

February 16, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): OpenWithBreakers and CloseWithBreakers script commands now allow the specification of any branch device type that can be switched in the SwitchingDeviceTypes parameter.
  • Auxiliary Files (SCRIPT and DATA Sections): The SendToExcel script command now allows an optional parameter SortFieldList to specify the order in which the fields should be sent to Excel. The script command parameters are now SendToExcel(objecttype,[fieldlist],filter,UseColumnHeaders,"workbookname","worksheetname",[SortFieldList]).
  • File Formats: Added the Simulator software version number and build date to a comment at the top of an exported PTI RAW file.
  • General: The number of limits that can be defined with branches has been increased to 15.
  • Bug Fixes

    • Contingency Analysis: The Text File Report Writing option could produce an error. This has been fixed.
    • Contingency Analysis: Fixed a bug when using the iterated linear CTG method and the Amount of a line rating change is specified using a model expression or field. These values were not being used correctly during the iterations.
    • Contingency Analysis: Fixed a bug when changing the rating of a line with one of the DC methods and setting the Limit Set line percentage to something other than 100%.
    • Sensitivity Calculations: The TLR sensitivities on interfaces containing phase shifters while using the Lossless DC with Phase Shifters option might not calculate the correct results. This has been fixed.
    • Sensitivity Calculations: When using DC method for TLR calculations, DC options for ignoring r or g, ignoring transformer impedance correction tables, and ignoring phase shift angle effects were not properly being included when doing a calculation on a line. This has been fixed.
    • Transient Stability: During a transient stability run hitting the Pause button and changing the simulation End Time could result in the simulation staying paused even after it was started again. This has been fixed.
    • Transient Stability: In Transient stability models REEC_A and REEC_B, fixed bugs when pasting from Excel into a case information display.
    • Transient Stability: Modified REEC_A and REEC_B record to have additional choices for the PQFlag parameter. Previously only choice 0 and 1 where available. Additional choices 2 and 3 were added. The choices are now: 0 = Q priority and Ipmin=0; 1 = P priority and Ipmin=0; 2 = Q priority and Ipmin=-Ipmax; 3 = P Priority and Ipmin=-Ipmax.
    • Transient Stability: Modified the transient contingency event so when you choose to "Set or change PRef", the following precedence is now followed (1) Use Plant Control model that accepts a Pref signal such as REPC_A, (2) Use a Pref controller such as WTGTRQ_A, (3) Use an exciter such as REEC_A, (4) use the Governor model. Previously the exciter was missing so REEC_A could not have it's Pref changed by a contingency action.

February 4, 2015

Features and Improvements

  • Case Information Displays: Added field called Limit Group Percentage to branches and interfaces to return the percentage that is being used in each object's Limit Group settings.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Enable use of injection groups as seller and buyer with the ATCIncreaseTransferBy script command.
    • File Formats: Fixed reading/writing load and shunt contingency actions to PTI CON files.
    • General: Fixed access violation that occurred when clicking on a condition on the filter logic visualization diagrams.
    • Oneline Diagrams: Fixed access violation that could result when attempting to add a new multi-section line to a oneline and then hitting Cancel on the Multi-Section Line Information dialog to not actually insert the new multi-section line.
    • PV and QV Curve (PVQV) Tool: Fixed the list of available fields for better reporting of the PV and QV results when using Track Limits.

January 29, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command CalculateLODFAdvanced(IncludePhaseShifters, FileType, MaxColumns, MinLODF, NumberFormat, DecimalPoints, OnlyIncludingLinesIncreasing, FileName) to mimic what is done on the Advanced LODF Calculation dialog in the GUI.
  • Transient Stability: Added an event in the Events table to indicate that the network solution failed during the simulation.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When loading in a display auxiliary file (*.AXD), identifying objects by label, and empty labels exist, an access violation could occur. This has been fixed.
    • Contingency Analysis: The contingency SETTO actions might not set the output to the specified value if multiple actions were applied to the same device. This has been fixed.
    • Integrated Topology Processing (ITP): Subnets were being defined based on the user specifiable field of Allow Consolidation for a branch. Subnets should only be based on whether a device is a switching device or not. This has been fixed.
    • Integrated Topology Processing (ITP): The process that would merge superbuses together if they were connected by a radial open breaker was causing open breakers to be lost during the consolidation process if the open breakers were marked to not be consolidated by setting the Allow Consolidation field to NO. This has been fixed.
    • Transient Stability: Reset the Solution Time Total for a contingency at the beginning of a run.

January 21, 2015

Features and Improvements

  • Contingency Analysis Tool: Injection Group contingency actions using Merit Order or Merit Order Open now include loads in addition to generators. If using Merit Order Open and both gens and loads exist in the injection group, only loads will be opened if the change is to increase injection and only generators will be opened if the change is to decrease injection. When using Merit Order, both gens and loads will move to their appropriate limits. Loads where both the Min and Max limit are 0 can only move to 0 MW. If using Merit Order Open and the change is to increase injection and no loads exist in the injection group, generators will be moved toward their max limits instead. If the change is to decrease injection and no generators exist, loads will be moved toward their max limits instead.
    *** You may need to modify your injection groups if you have been using Merit Order with injection groups containing both loads and generators and you want to maintain the same functionality. ***
  • General: If using the Scale tool to scale an Injection Group and using Merit Order Dispatch, loads will now be included in the dispatch. Previously, any loads in the injection group were ignored. Loads will move towards either their minimum or maximum MW limit as appropriate. If both the minimum and maximum limits are 0, loads will only be allowed to decrease to 0 MW. Mvar load will be adjusted by keeping a constant power factor.
    *** You may need to modify your injection groups if you have been using Merit Order with injection groups containing both loads and generators and you want to maintain the same functionality. ***
  • PV and QV Curve (PVQV) Tool: When using Injection Group Ramping option for Merit Order Dispatch, loads will now be included in the dispatch. Previously, any loads in the injection group were ignored. Loads will move towards either their minimum or maximum MW limit as appropriate. If both the minimum and maximum limits are 0, loads will only be allowed to decrease to 0 MW. Mvar load will be adjusted by keeping a constant power factor.
    *** You may need to modify your injection groups if you have been using Merit Order with injection groups containing both loads and generators and you want to maintain the same functionality. ***
  • Time Step Simulation: When changing the injection of an Injection Group and using Merit Order Dispatch, loads will now be included in the dispatch. Previously, any loads in the injection group were ignored. Loads will move towards either their minimum or maximum MW limit as appropriate. If both the minimum and maximum limits are 0, loads will only be allowed to decrease to 0 MW. Mvar load will be adjusted by keeping a constant power factor.
  • Bug Fixes

    • Transient Stability: Fixed a bug in Distributed TS. When an error occurred with COM, it was obscured by a secondary access violation; this is now resolved.
    • Transient Stability: Fixed bug with governor model W2301 when K <> 1.
    • Transient Stability: Fixed network reference frame for infinite bus machines.
    • Transient Stability: Fixed limit issue with exciter model ESDC4B.
    • Transient Stability: Fixed initialization of exciter model ESST4B if Vgmax is active during initialization.
    • Transient Stability: Fixed error in setting up governor model GGOV1 if Kpload = 0.

January 9, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added the Time Delay field for ContingencyElement and RemedialActionElement to the WECC Contingency AUX format.
  • Auxiliary Files (SCRIPT and DATA Sections): Added the Time Delay field to the SUBDATA format for Contingency Elements, Global Actions, and Remedial Actions.
  • Auxiliary Files (SCRIPT and DATA Sections): Added DoDistributed parameter to the TSSolveAll(DoDistributed); script command.
  • Bug Fixes

    • Sensitivity Calculations: Fixed errors with the Multiple Meter, Multiple Control Change calculations when calculating using Integrated Topology Processing. Removed limitation that would only allow up to 500 controls to be selected.
    • Transient Stability: Fixed potential error in a wind turbine model when a fault is applied at its terminal. Under rare circumstances, this error prevented the wind turbine's real power from recovering after a fault.

January 7, 2015

Bug Fixes

  • Available Transfer Capability (ATC) Tool: Fixed an access violation that could result when running ATC analysis with contingencies containing multi-section lines that have shunt devices at dummy buses.

January 6, 2015

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command CTGCreateStuckBreakerCTGs(filter, AllowDuplicates, PrefixName, IncludeCTGLabel, BranchFieldName, SuffixName, PrefixComment, BranchFieldComment, SuffixComment).
  • Auxiliary Files (SCRIPT and DATA Sections): Added script command CTGCreateExpandedBreakerCTGs.
  • Contingency Analysis Tool: Added option to create stuck breaker contingencies. This will process each contingency that has explicit breaker outages defined and create new contingencies by treating each breaker as stuck in turn. The new contingencies will be comprised of all existing elements, minus the stuck breaker outage, plus open actions for breakers that are identified to isolate the stuck breakers.
  • Contingency Analysis Tool: Added option to create expanded breaker contingencies. This will convert any "Open with Breakers" or "Close with Breakers" contingeny actions into Open actions on explicit breakers. This will permanently modify the contingency definitions.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When updating a ContingencyElement using a DATA section instead of a SUBDATA section, all of the parameters that are specified as part of the action but not used uniquely to identify an element were not being updated. This has been fixed.
    • Case Information Displays: Fixed bug with Interface Element advanced filtering.
    • Fault Analysis: Modified the calculation of the internal voltage for a generator.
    • File Formats: When writing out sequence data to the PTI file format for versions 33 and greater, now write ouf end of section kesy for zero sequence fixed shunt data and zero sequence machine data.
    • GIC: Fixed bug with display of transformer GIC Model Type parameter.
    • Transient Stability: The option to show the logo in the Title Block of a plot was being read in the opposite of how it was saved in a PWB file. This has been fixed.
    • Transient Stability: The Tripped Gen and Tripped Load values shown with contingency summary information could not be loaded from AUX files. This meant that this information was not available when using Distributed Computing for transient analysis. This has been fixed.

December 22, 2014

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Changing alarm options to look at new AlarmOptions object instead of the real time global options. This lets the alarm options be shared between Trainer and Retriever.

December 22, 2014

Bug Fixes

  • File Formats: When loading a RAW file if a bus is marked as a slack bus, but does not have any generators connected to it, Simulator will now automatically remove the slack bus designation and write a warning to the message log.
  • Transient Stability: Modified function for handling low voltage reactive current injection for wind turbines and solar panels to improve network boundary equation convergence.
  • Transient Stability: Modified function for handling low voltage P/Q injection for DC lines and converters to improve network boundary equation convergence.
  • Transient Stability: Prevent access violation when saving to hard drive and the full drive is not specified in the name of the path.
  • User Interface Dialogs: Made some changes to the multi-section line dialog to update properly if the multi-section line being displayed somehow changes while the dialog is open. This could happen if a terminal of one of the branches within the multi-section line is moved.
  • User Interface Dialogs: When right-clicking on a list of generators, shunts, or transformers and choosing to save to an EPC file snippet, a dialog appears asking if you would also like to save the bus records for the regulated bus in addition (to ensure you're saving any changes in regulated bus voltage correctly.) Unfortunately this prompt would appear for every object selected, so if you selected 600 generators to save the dialog would appear 600 times. There is now the ability to choose "Yes to All" and "No to All".

December 17, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Adding command line parameters to write out the machine ID and also to load a license. Allows for scripting.
  • Case Information Displays: Also added the ability to use filtering across other object types for the InterfaceElements. They can now use Branch, Gen, Load, Interface, Injection Group, and MSLine filters directly.
  • Power Flow Solution: When reading in an EPC or RAW file which contained multiple slack bus designation for one electrical island, Simulator picks on of these as the slack and removes the other. An appropriate message is then written to the message log alerting the user of this. This message was then being repeated every time a power flow solution was done. The ongoing annoying messages were removed and only the first message will be shown now.
  • Transient Stability: Added ability on Transient Stability Plot titles and axis titles to use the special string "@CTGMemo" to include the memo of the transient contingency in the plot
  • Bug Fixes

    • Case Information Displays: Fixed the "Selected?" field of an interface element. It was getting the results from the object to which the interface referred. For example, an interface element which was for a Branch would return the branch's selected field. It should return the Selected field of the interface element itself.
    • Integrated Topology Processing (ITP): A bug was introduced when adding the improvements to consolidation on November 17, 2014 to more completely consolidate unnecessary open switches. This has been fixed.
    • Transient Stability: Fixed a bug with initialization of user-defined load models

December 15, 2014

Features and Improvements

  • Model Explorer: Show the "Branches By Type" folder in the Model Explorer regardless of whether the Integrated Topology Processing add-on has been purchased.
  • Transient Stability: When choosing a generator as the Angle Reference in the Result Options which is presently out-of-service and choosing to use an angle reference which uses that generator, Simulator will now create a validation warning alerting you of this problem. The simulation will still run, but the angle reference will be the synchronous reference frame (no shift) instead of your choice.
  • Transient Stability: When choosing a generator as the Angle Reference in the Result Options which is not a synchronous machine and choosing to use this generator internal angle, Simulator will now create a validation warning alerting you of this problem. The simulation will still run, but the angle reference will be the synchronous reference frame (no shift) instead of your choice.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: ATC option to enforce generator MW limits with linear step is now used when using the iterated methods instead of just automatically enforcing the limits if all other options are set to enforce limits. This will allow users the option to use the same functionality that was used in version 17. This option is not applicable if using the Economic Merit Order option with injection group ramping. In this case limits will always be enforced if other options are set to enforce limits.
    • Contingency Analysis: When doing Quick Insert of Single Element add the new element to the end of the list of contingencies. Trying to add to the selected location doesn't make sense if there is any sorting applied to the list and this could royally screw up the linking of the contingencies. This will prevent a situation in which existing contingencies appear to disappear when doing a Quick Insert.
    • GIC: Fixed access violation that could occur when using the GIC scalar regions
    • Oneline Diagrams: Fixing odd behavior storing dynamic formatting settings.
    • Oneline Diagrams: Fixing problem with the undo of oneline drawing objects introduced in October 14 2014 patch. This was making the undo feature disabled when it should have been available.

December 8, 2014

Features and Improvements

  • General: Added button to open Monitors dialog so that they can a now be defined in Simulator. Monitors are used with the Trainer tool and allow for the triggering of alarms when specified events occur.
  • Transient Stability: Added support for the PVD1 Photo-Voltaic Distributed Generation model.
  • Retriever: Moved settings for alarm fading from the data model to the real time global options, and added fields (sgAlarmBackgroundFading, sgAlarmFadeColor) to store them.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): The Title Block Height and Right Memo Width for a plots created from the Plot Designer could not be set from an auxiliary file. This has been fixed. This affected the Transient Stability and PV tool plots.
    • Oneline Diagrams: Fixed bug in which when a saved contour was initially displayed its saved brightness and reverse colors were not being used.
    • Oneline Diagrams: Changed the default setting to false for the contouring option to use the GPU to accelerate the contour calculation.
    • Optimal Power Flow (OPF): Fixed potential access violation that would only occur in an OPF solution if all three of the following conditions were met for a generator that was configured to be on OPF control.
      1. (MaxMW < MinMW)
      2. abs(MaxMW-MinMW) < 0.02 MW
      3. abs(PresentMW-MinMW) < 0.02 MW
    • Transient Stability: Changed the ordering of the MOTORX parameters to match the ordering of parameters in the CMPLDW model. We had fixed the CMPLDW a year or more ago to have the following order: Vtr1, Ttr1, Ftr1, Vrc1, Trc1, Vtr2, Ttr2, Ftr2, Vrc2, Trc2. This had not been fixed in MOTORX. As a result when using the feature to expand the Composite Load Model into the power flow case we were not properly populating the MOTORX models.
    • Transient Stability: Fixed bug on loading the SIMPLEOC model.
    • Transient Stability: Fixed bug in Induction Motor TotalQ reporting. This only affected the reporting and did not affect the simulation.
    • Transient Stability: Fixed access violation when you delete all of the contingencies showing in the multiple contingency table.
    • Transient Stability: Fixed access violation that could occur when closing a case containing a FACRISC model.
    • Transient Stability: Fixed error in autocorrect of the R parameter of the GPWSCC model.
    • Transient Stability: Fixed numerical precision in message log text indicating the load bus voltage at the end of a distribution equivalent is too low. Values such as 0.9477 were appearing as 0.95.

November 21, 2014

Features and Improvements

  • Case Information Displays: When using the Find Text in Oneline tool, the case information table listing all of the display objects found with the specified text now has the Layer Name available for the objects.
  • Contingency Analysis Tool: Time Delays can now be specified with power flow contingency actions. This serves as a relative ordering for the implementation of actions. Actions with the smallest time delay will be applied first during the TOPOLOGYCHECK and POSTCHECK solution steps.
  • Sensitivity Calculations: Provide access to the Loss Increase % value found on the PTDF dialog through the PWCaseInformation objecttype and LinePTDFLosses variablename.
  • Bug Fixes

    • Case Information Displays: An access violation could occur or the status change might not register when using the Toggle feature to change the status of Line Shunts in Line Shunt case information displays. This has been fixed.
    • Integrated Topology Processing (ITP): Fixed a consolidation error that could result in a dead bus being picked as the primary node if it is a regulated bus. This could result in a failed power flow solution.

November 17, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save settings to an auxiliary file from the Contingency Analysis Dialog, we now automatically append ", AUXDEF, YES" to the DATA section headers of the following objects so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this: LimitSet, ModelExpression, ModelCondition, ModelFilter, CustomMonitor, various Contingency Definition objects
  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save settings to an auxiliary file from the Transient Stability Dialog, we now automatically append ", AUXDEF, YES" to the DATA section headers of the following objects so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this: TSLimitMonitor, TSContingency, TSContingencyElement, TSPlotSeries, TSPlotVertAxisGroup, TSSubPlot, TSPlot
  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save the PV Curve Plot definitions to an auxiliary file from the PV Curve Dialog, we now automatically append ", AUXDEF, YES" to the DATA section headers of the following objects so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this: PVPlotSeries, PVPlotVertAxisGroup, PVSubPlot, PVPlot
  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save Limit Monitoring setting to an Auxiliary File from the Limit Monitoring Dialog, we now automatically append ", AUXDEF, YES" to the DATA section header of the LIMITSET object so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this.
  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save settings to an auxiliary file from the Available Transfer Capability Dialog, we now automatically append ", AUXDEF, YES" to the DATA section headers of the following objects so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this: TransferLimiter, ATCLineChange, ATCLineChangeB, ATCGeneratorChange, ATCZoneChange, TATCInterfaceChange, ATCScenario
  • Auxiliary Files (SCRIPT and DATA Sections): When choosing to save settings to an auxiliary file from the Default Drawing Values for New Objects Dialog, we now automatically append ", AUXDEF, YES" to the DATA section headers of all the option objects so that those objects are always created when loading the auxiliary file and a dialog does not appear prompting the user about this.
  • Auxiliary Files (SCRIPT and DATA Sections): Added script command CalculateLODFScreening(FilterNameProcess, FilterNameMonitor, IncludePhaseShifters, IncludeOpenLines, UseLODFThreshold, LODFThreshold, UseOverloadThreshold, OverloadLow, OverloadHigh, DoSaveFile, FileLocation, CustomFieldHighLODF, CustomFieldHighLODFLine, CustomFieldHighOverload, CustomFieldHighOverloadLine).
  • Auxiliary Files (SCRIPT and DATA Sections): Added Left, Top, Width, and Height parameters to OpenOneline script command to specify form position when opening one line diagram. Syntax of script is now OpenOneline("filename", "view", FullScreen, ShowFull, LinkMethod, Left, Top, Width, Height).
  • File Formats: Added a new pop-up message to question the user it they want to save the bus records when saving an individual shunt, gen or transformer to an EPC file.
  • Integrated Topology Processing (ITP): Modified consolidation of superbuses to iteratively remove superbuses that contain ONLY switching devices that are connected to other superbus only by open switching devices. These are of no significance so merging into a superbus removes the clutter.
  • Integrated Topology Processing (ITP): Modified consolidation so that if a switching device that is directly in parallel (between exact same buses) with a non-switching device then the switching device is internally flagged to prevent consolidation due to this switch. This is done to prevent series capacitors from being removed from the model when they are bypassed by their bypass circuit breaker. Note that the series cap can still be completely consolidated if the more complex network typically involving a disconnect causes their terminals to be at the same super bus, but prevent the obvious parallel switch is helpful.
  • Transient Stability: Min/Max, Events, and Summary information are now saved to a PWB file if not storing the Time Values to PWB.
  • Transient Stability: Added cross-current compensation model CCOMP which is an equivalent model to the COMPCC but with slightly different algebraic expressions. CCOMP specifies a Zc and Zt value instead of Z1 and Z2. The can be converted as follows however.

    When Flag=1 in CCOMP, then
    Z1 = (-2*Zc) * System Base/Machine Base
    Z2 = (-2*Zc - Zcomp) * System Base/Machine Base
    Where Zcomp = Rcomp+jXcomp specified in the generator data record

    When Flag=0 in CCOMP, then
    Z1 = -2*(Zt - Zc) * System Base/Machine Base
    Z2 = (-2*Zc) * System Base/Machine Base
  • User Interface Dialogs: Added a Populate button on the LODF Screening dialog to populate Branch custom fields from the summary results after the analysis is complete. This is useful if you forget to set the options ahead of time or want to change the key fields used to identify branches in the summary.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug in FixFlowArrowLineEnds script command. It was flipping the pointers, but not the bus numbers so the changes were not being stored to file.
    • File Formats: Fixed comment character check for intraline comments in OTG files.
    • File Formats: Fixed checking for MS line segment when reading OTG file line contingencies.
    • File Formats: Fixed checking for -1 as an alternative ending character for an OTG file.
    • Optimal Power Flow (OPF): Prevent an infinite loop in the OPF calculation if trying to enforce phase shifter MW regulation limits in the OPF.
    • Simulator Automation Server (SimAuto): Return an error message when using the OpenCaseType function with an ArevaHDB export file and the file load fails due to an unexpected error in the file.
    • Transient Stability: Prevent storing transient limit monitor violations twice to a PWB file. If older files are read where there is the possibility of multiples of the same violation being stored, check for and remove any duplicates.
    • Transient Stability: When choosing to save settings to an auxiliary file from the Transient Stablity Dialog, we were not saving the Transient Limit Monitor objects. This has been fixed so they are now saved.
    • Transient Stability: Fixed error in keeping track of the transient contingency results for "Total Gen MW Tripped". Value was being calculated by multiplying the generator per unit power by the SYSTEM MVABase instead of the machine MVA Base.
    • Transient Stability: Fixed potential error when using a negative END time in a transient stability simulation.
    • Transient Stability: The Transient Stability Dialog was preventing a start or end time which was negative. You could specify a negative time in the case information display showing multiple contingencies, but the edit box for Start and End Time on the dialog was always limiting those values to between 0 and 9999. This has been fixed so negative times may be entered.
    • User Interface Dialogs: Fixed incorrect setting of the caption on the Transient Stability Analysis dialog.

November 10, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added script command OpenWithBreakers(ObjectType,filter or [object identifier], [SwitchingDeviceTypes]).
  • File Formats: When saving selected generator records to an EPC file, bus records will also be saved so that the generator setpoint information is available.
  • Integrated Topology Processing (ITP): When saving a Consolidated Case or when viewing the Consolidated Superbus in the Bus View, generally open switching devices are maintained in the model to show where they are. We have modified it so that if a CLOSED switching device is parallel with a open switching device we do not display the open switching device. CLOSED switching devices in this situation are unusual as they must be specified as Consolidate=NO or part of an interface or tie-line, so this is a special situation.
  • Integrated Topology Processing (ITP): Modified so that we consolidate a dead bus to its neighbors if all three of the following conditions are met:
    1. It has no gens, loads, or shunts
    2. It is connected to the rest of the system only by open AC branches
    3. It is only connected to ONE other SuperBus through these AC branches
    The objective here is to consolidate a disconnect and dead auxiliary bus.
  • Oneline Diagrams: Added the ability to search for text inside Background Text.
  • Oneline Diagrams: Added the ability to convert multi-section line display objects to background lines.
  • Sensitivity Calculations: On the LODF Screening dialog added the ability to store the summary results to custom fields with Branch records.
  • Bug Fixes

    • General: Fixed access violation that could occur if deleting an island slack bus that was selected by Simulator.
    • Power Flow Solution: We will no longer turn control off for a transformer or switched shunt that is regulating the same bus as either a generator or an SVC that are on line drop control and there are voltage regulation setpoint conflicts. In this case it is up to the user to rectify any potential control conflicts. Enhanced the error messages to give a better idea of where there could be voltage control conflicts.
    • Sensitivity Calculations: Corrected the LCDF values that are displayed when using the LODF Matrix and LODF Screening tools. The LCDF values had previously been showing values used internally in Simulator to calculate the impact of line closures rather than the actual LCDF values.
    • Transient Stability: For GGOV1 governor, a when Ka = 0 the governor doesn't make sense because in this situation the output of the governor will NEVER go up. Even as it swings down during a simulation it is then stuck at the lower value forever. Ka=0 is rarely entered in input data but when it is, the intent is clearly to disable the rate limiter, so the Ka term is now ignored if Ka<=0. Also modified GGOV1 to ignore the rate limiter if Ta=0.
    • Transient Stability: Fixed bug with Pelec not being on the Trate (turbine rating) base for governor models.
    • Transient Stability: Fixed an access violation that could occur when showing transient Events results for all contingencies.
    • Transient Stability: The start time for a single transient contingency can now be specified as less than 0. Negative start times were allowed in the case info display, but the dialog was limiting time to a minimum of 0.
    • User Interface Dialogs: Fixed a bug with the Bus View opening from the Owner Dialog Generators tab.

October 31, 2014

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): When getting Injection Group Generator MW Max Decrease or MW Max Increase values via an auxiliary file, the Generator MW Min Total and MW Max Total values were returned instead. This has been fixed.
  • Contingency Analysis: When loading a contingency element involving a change_by or set_to action for a generator in percent from an auxiliary file, this would erroneously show up as an unlinked element. This has been fixed.
  • General: When renumbering Multi-section Line dummy buses, either through the special text file or through a SUBDATA section, the default will now be to keep the original bus name instead of renaming to the new bus number if no bus number is specified.
  • Transient Stability: Modified the case info displays for Transient Contingency Elements so that we show time out to 6 decimal places by default because Time in simulator is precise to exactly 1 microsecond.
  • Transient Stability: Modified the reading of Transient Contingency Elements so that the string being read in will determine the precision of the Time used to look for that same event. Time in Simulator is precise to exactly 1 microsecond. Thus if an event occurs at 1.083333 and someone pastes in or reads from an AUX file an event at 1.0833 seconds, then previously Simulator would flag that as a NEW event. Now, Simulator will look at this string and determine that it is only precise to 100 microseconds. Therefore when searching for an already existing contingency event we will use a precision of one half that (50 microseconds). As a result we will treat 1.083333 = 1.0833 because they are within 33 microseconds of one another.
  • Transient Stability: Modified the list of all transient contingency elements definitions so that you can advanced filter this display, you can paste data into the case info display, and you can delete elements.
  • Transient Stability: Fixed bug in storing the Other field for the TIOCRS line relay model of the Current stored in amps. It was always storing a value of zero.

October 30, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added the MergeMSLineSections(Filter); It does the same as the Merge Lines right click in Model Explorer.
  • Auxiliary Files (SCRIPT and DATA Sections): Added the ability to use the special string @ to the file name to the deletefile script and to any script that uses the function InterpretFileNameIsOpenDialog to interpret the filename.
  • Auxiliary Files (SCRIPT and DATA Sections): Also added the script command: RenameInjectionGroup("Oldname","Newname");
  • File Formats: Added the ability to not generate the default labels when using custom labels in hdbexport.
  • File Formats: Modified reading of the RAW file format so that if comments are found for data records of the format /* [ my label, my second label ] */, then labels will automatically be created for the object. The string parsing removes all leading and trailing /, *, or space characters. Then if the remaining string starts with a [ and ends with a ], we assume that what is inside the bracket is a comma-delimited list of strings representing labels.
  • General: Speed increase in expression parsing.
  • Power Flow Solution: Added option with a VSC DC Line to specify whether the DC MW Setpoint is interpreted as the MW flow on the "AC side" or "DC Side" of the converter. If there are not any converter losses modeled then this does not matter. Modified reading VSC DC Lines from a RAW file so that the DC MW Setpoint is interpreted as the "AC side" MW. When writing out to the RAW format, if the option in Simulator is set to "DC Side", then the appropriate AC flow will be calculated and written out to the RAW file instead.
  • Transient Stability: Adding simplified line OC model.
  • Transient Stability: Made a slight modification so the SET Power command for transient contingencies will interpret an actual MW value and convert it to a delta MW value if necessary instead of treating everything like a delta MW value.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed a bug that when in the dialog you were renaming the IG it was adding a copy of the IG that was "Renamed".
    • Contingency Analysis: When adding the ability to include a substation outage in the contingency record in the Oct 2, 2014 patch, a bug was introduced on the Contingency Element Dialog which caused the dialog to malfunction for the special elements listed AFTER Substation. These include Abort, Solve Power Flow, and Contingency Blocks. Elements would still function properly when defined by loading from an AUX file or loading PWB files. The bug only effected the dialog box and made it impossible to define Abort, Solve Power Flow, or Contingency Block elements.
    • General: Fixed an ambiguity with the math parser regular expressions that caused a syntax ambiguity between "<>" and "<". The less than operator regular expression has been amended to "<[^>]" while still retaining a token length of one. Also fixing the ambiguities between ">" and ">=" and "<" and "<=".
    • Power Flow Solution: The power flow might fail to converge if an SVC is located at a disconnected bus. This has been fixed.
    • Transient Stability: Fixed two issues with reading of JSIS format for modal analysis tool. If a comma was at the end of the lines in the csv files, it wouldn't read those lines. Also in RawTimeRangeCount, local_LastTimeSec was getting checked but was never being set which was causing errors.
    • Transient Stability: Bug fix associated with local_HasAMachineModel being set incorrectly.
    • Transient Stability: Bug fix to DC line parameter checking.

October 16, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added new ability when pasting a string into a field (or by using the SetData() script command). The string can start the character & and then be followed by the objecttype, key fields, and then a variablename. When using a string of this type Simulator will parse to find the object referred to and then evaluate the variable name for that object and convert the string to the result of this evaluation. This feature can also be used in the Extra Strings in the SaveDataWithExtra() script command. An example of such as string is

    "&Gen '563' 'ab' GenMW:0:8:3"

    This would instruct that the MW output of with 8 characters and 3 decimal points for the generator at bus 563 with an genid 'ab' be used.
  • Auxiliary Files (SCRIPT and DATA Sections): When using the special string &ModelExpression or &objecttype key key variable:loc:digits:decimals,, if no digits or decimals are specified then we use 7 decimal places. We will now also remove any trailing zeros if no decimals are specified.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When using the script command OpenCase() and the file loaded was invalid, then after completing the script command the power system case will be empty. This was causing an access violation which has been fixed. In addition to fixing the bug, we also added additional error messages to help the user notice that the opening of the case failed.
    • Case Information Displays: Modified case information displays so that the background color outside of the region occupied by rows and columns would obey the color of the background of normal cells in the table. Previously these parts of the grid would appear as white regardless of the colors chosen for the displays.
    • File Formats: There as an error in writing out VSC DC Lines to the RAW file format. This has been fixed.

October 14, 2014

Bug Fixes

  • Retriever: Fixed error with subscribing an alias to the FGSecondaryMW field of an interface.

October 10, 2014

Features and Improvements

  • Contingency Analysis Tool: Added accounting of Total Dropped Load during a contingency. This shows the MW amount of load that was islanded due to a contingency action or opened due to a direct contingency action to the load.
  • Transient Stability: Added Level designation to Transient Events. Options have been added to easily display Events by specific Levels: Error, Info, Skipped, User, Transition, Model Trip, and Relay Trip. Result Event Reporting options have been added to specify if events are reported to the Message Log in addition to the Event table. These new options are especially useful when using the CMPLDW composite load model which has many possible events associated with it.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Before doing an iterated ATC method or using the ATC tool to increase the transfer AND the transfer is between areas/super areas AND the case AGC control is disabled, a check is done to see if the ACE values for areas and super areas that are on control is greater than its AGC tolerance. If the ACE values are too great an error will result and the study cannot continue. The user will have to reconcile the ACE problems in the case before the study can proceed.
    • File Formats: Bug fix for saving CROW import file settings to AUX.
    • Transient Stability: Fixed error in LHVRT and LHFRT models which could cause the generator to trip inappropriately.
    • User Interface Dialogs: Fixed bug in Model Condition dialog that would change the selected object after the Save As button was clicked. This could cause the wrong object to be saved with the Model Condition if the OK button on the dialog was then clicked.

October 8, 2014

Features and Improvements

  • Transient Stability: Added color to log text when loading in DYD files. "Missing" notes are written in gray. "Error" in red.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: When using Distributed ATC, the ATC Extra Monitor results were incorrect. This has been fixed.
    • Case Information Displays: When using a piecewise linear cost function for a generator, Simulator continues to use the the "Cost Shift" and "Cost Multiplier" fields to determine the cost function. The case information display however would show these fields grayed-out indicating that these fields were not used. This graying-out error has been removed.
    • Optimal Power Flow (OPF): Fixed a tolerance issue that was causing an infinite loop in the OPF solution.
    • Transient Stability: Fixed an error in the SVSMO3 SVC model current calculations.
    • Transient Stability: Modified the result field names for voltage to be consistently: Volt (pu) or Bus Volt (pu).
    • Transient Stability: Fixed reporting of the "Total MW Load Tripped" during a transient stability contingency when using the CMPLDW model.

October 3, 2014

Bug Fixes

  • Retriever: The alias dialog was showing fields associated with the object type of the dialog it was opened from. This can be confusing because opening a generator mw subscription from a substation dialog will clear the subscribed field and populate the list of available fields with the substation fields. If a subscription exists, the dialog is now populate with the existing subscribed object and corresponding field set.

September 19, 2014

Bug Fixes

  • Retriever: Update to respect Data Source Priority when reading in subscriptions in Retriever. When multiple subscriptions are assigned to the same object field, then we did not always obey the data source priority associated with the aliases assigned to them. This has been fixed to ensure Data Source priority is obeyed.

September 3, 2014

Bug Fixes

  • Case Information Displays: On the Bus Case Information Display, the "Bus Neighbor List (in service only)" field was reporting all neighbors regardless of branch status. This has been fixed.
  • Contingency Analysis: When calculating a multi-section line contingency using the linear methods, the results would not properly account for islanded generation or load if the dummy buses contained generation or load. This has been fixed.
  • Power Flow Solution: As part of Robust Solution Process, turn on SVC control if it was originally on.
  • Transient Stability: Modified so that in order for an electrical island to be considered viable it must have at least one machine model which is modeled as a voltage source behind an impedance (such as a synchronous machine). Therefore, islands which are created during a simulation by a switching action that result in an electrical island that contains only Type 3 and 4 wind turbines (and other machines modeled as a constant current injection) are not considered by themselves to be enough to support an island.

August 28, 2014

Features and Improvements

  • Contingency Analysis Tool: Added contingency action that will set the contingency rating of a line.
  • Bug Fixes

    • Transient Stability: Modified to better return error codes.

August 21, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Allow string expressions to be referenced by name in addition to location number.
  • Case Information Displays: Added a new field for BRANCH, GEN, and SHUNT objects called "RegBus by ObjectID". When showing this field, the option that is used to specify which key field to use in SUBDATA sections is used to identify the regulated bus by either primary, secondary, or label identifiers. When reading from an AUX file any of these identifiers can be used to identify the regulated bus.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed access violation that could appear when using the CTGSolve script command to solve a contingency while the case is in DC power flow mode.
    • File Formats: When reading the ABB Spider format correctly read transformer values of regmaxv, regminv, and xftype when they are zero or blank.
    • General: Fixed an access violation that could result when using the MOVE command on a branch, the owner being used before the move is the default owner, and the from bus of the branch following the move is a different owner than the original default owner. Now if the branch has the default owner before the move we will force it to have the default owner after the move as well. The default owner is the owner of the from bus.
    • Transient Stability: Fixed error in reading the ZLIN1 model from a DYD file when nfar value is read as negative. This negative sign in the DYD file indicates the units of the r1ang1 and x1z1 values. Simulator encodes this distinction in the "Imp Type" flag instead. When nfar was read as negative value from DYD we were not properly setting the "Imp Type" flag.

August 19, 2014

Features and Improvements

  • Contingency Analysis Tool: Added options to open the Bus View or Substation View by right-clicking on a contingency violation.
  • GIC: Now have the ability to automatically incorporate scaling factors for geomagnetic latitude and earth resistivity according to the NERC Benchmark Geomagnetic Disturbance Event Description (Draft: April 21, 2014).
  • Sensitivity Calculations: Added calculations for ETLR and WTLR on injection groups.
  • Bug Fixes

    • Integrated Topology Processing (ITP): When using a full-topology case and using the equivalencing tool to delete the external system, an access violation could occur. This has been fixed.
    • Transient Stability: Renamed the GENOF_PW model to GENOF.

August 13, 2014

Features and Improvements

  • File Formats: When reading a RAW file, the options to specify the starting bus number of star buses are now stored in the computer registry.
  • Bug Fixes

    • PV and QV Curve (PVQV) Tool: The ability to access Devices at Limits for saving to a file with script commands was not working. Writing out this information has been fixed but the data cannot be read back into Simulator.
    • Transient Stability: The CLOD load model has extra parameters Vi, Ti, and Tb to specify a load level at which load should be dropped. This feature was not disabled by default but it is now disabled by default.
    • Transient Stability: Fixed a one time step delay in propogation of Eppr and Eppi when using a single cage motor model with the MOTORW (or inside the CMPLDW and CMPLDWNF models) model.

August 7, 2014

Features and Improvements

  • File Formats: Added the ability to choose the default label delimiter when reading in HDB export CSV files.
  • Sensitivity Calculations: Added access to the dV/dControl values for each terminal of a branch for use with the multiple sensitivities to a control change calculations.

August 6, 2014

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added "Simulation: Successful Power Flow Solution (but may have converged to a low-voltage solution)" and "Simulation: Power Flow did no Converge!" to the message log when running a power flow using script commands.
  • Auxiliary Files (SCRIPT and DATA Sections): Added new script command PVWriteInadequateVoltages("filename") that will write the inadequate voltages stored during a PV run to a comma separated file (CSV).
  • Fault Analysis: When defining multiple faults you now have the option to specify the position of the fault along the line. To save computation time, by default a location >= 50 assumes a fault at the To Bus and < 50 assumes a falut at the from bus. A checkbox has been added to instead add a dummy bus at the actual fault location.
  • Transient Stability: Added generator over frequency relay model called GENOF_PW. This allows monitoring of frequency at a specified bus or generator. When monitoring a generator only the generator will be opened when over frequency is detected. If monitoring a bus, generators, loads, and shunts connected at that bus will be opened when over frequency is detected. The relay can also be used for monitoring without actually tripping any devices.
  • Transient Stability: Added EPCDC, CDC4T, CDC6T, and CDC6 DC line models.
  • Transient Stability: Added support for reading/writing the EPCDC, CDC4T, CDC6T, and CDC6 DC line models from DYD and DYR files.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Using the @CASENAME special keyword in the names of saved files was not working correctly. This has been fixed.
    • Case Information Displays: The YBus case information table now allows you to change the number of digits after the decimal point.
    • File Formats: Two-terminal DC lines are given unique names when loading a GE EPC file.
    • General: Access violations could result if creating a bus through an auxiliary file or pasting from Excel without explicitly defining an owner. This has been fixed.
    • Oneline Diagrams: Fixed error when right clicking on a substation display object and choosing Insert Connection, Then Auto-Insert Lines. Lines were not properly inserted after choosing this option.
    • Transient Stability: When writing to an auxiliary file, no longer write repeated records for Line Relay Stability models.
    • Transient Stability: Fixed an error with reading an auxiliary file that contained generator relay, LCFB1, PlayInRef, and under/over excitation.
    • Transient Stability: Modified the auto correction of the GENTPF and GENTPJ models for very low values of Xqpp. If (Xqpp = 0) or (Xqpp < 0.01*Xdpp), then we assume Xqpp is not known so we set Xqpp=Xdpp and thus remove all transient saliency. If Xqpp < 0.5*Xdpp then we set Xqpp=0.5*Xdpp. Xqpp and Xdpp should be very close to each other and values radically different cause numerical problems.
    • Transient Stability: Fixed error with initializing WT3E if WT3T model was omitted.
    • Transient Stability: Modify Vrmax or Vrmin of ESST1A exciter if necessary to initialize without limit violations.
    • Transient Stability: Fixed error with TSGetResults script command and TSGetContingencyResults SimAuto function. If results were requested for an open object, values for other objects would not show up in the results. Now only results for the open object will not be included.
    • Transient Stability: Fixed a bug with the PlayInRef model. At time 0 the value was not being changed from the initial value to the signal value specified at time 0.

July 23, 2014

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): The RenameFile script command will now allow special keywords (@DATETIME, @DATE, @TIME, @BUILDDATE, @VERSION, and @CASENAME) to be included in the new name of the file. The special keywords will be replaced with their actual value.
  • Integrated Topology Processing (ITP): When saving the consolidated case through the SaveConsolidatedCase script command, the contingencies were not being saved for the consolidated state. This has been fixed.

July 2, 2014

Features and Improvements

  • User Interface Dialogs: On the Injection Group Auto Insert dialog added option to specify participation factor by Field or Model Expression. Also, added option to include Bus participation points.
  • Bug Fixes

    • File Formats: Fixed access violation that would result if reading an Areva HDBexport file and the CBTYP records are missing.

July 1, 2014

Bug Fixes

  • File Formats: Memory leaks could result when reading in a large number of Areva HDBexport files in a single Simulator session. This has been fixed.
  • Integrated Topology Processing (ITP): There was a problem renumbering areas and zones when using the Equivalencing tool and Topology Processing. This has been fixed.
  • Integrated Topology Processing (ITP): For some cases, using Topology Processing will result in a "list index out of bounds error". This has been fixed.

June 27, 2014

Bug Fixes

  • Retriever: In certain situations a startup script that begins an automatic retrieval may not complete properly and may cause Retriever to hang. This has been fixed.

June 26, 2014

Features and Improvements

  • Contingency Analysis Tool: Deleting a large number of contingencies (10,000s), but now ALL, was very slow. Delete All contingencies was fast and deleting a few was fast, but deleting a large number and not all was very slow. This is fixed.
  • Sensitivity Calculations: When opening the PTDF dialog, the type is automatically set to Multiple if any directions are defined.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Setting the variable name "EquivLineID" for the object Equiv_Options was not working properly
    • General: A "stack overflow error" could sometimes result when building a power system equivalent. This has been fixed.
    • Oneline Diagrams: Fixed an access violation that occurred when drawing an unlinked switched shunt symbol on a oneline
    • Transient Stability: Continuing to fix the treatment of single phase air conditioner models under extremely low voltages. This impacts CMPLDW, LD1PAC, and CMPLDWNF. Specifically modified so that the "Kcon" curve defined by the parameters Vc1off and Vc2off is used in the algebraic solution of the network boundary equations so that the constant power load does not cause solution failure in the algebraic solution at extremely low voltages.

June 24, 2014

Features and Improvements

  • Contingency Analysis Tool: Added new contingency action with Injection Groups to drop a specified number of elements in the group.
  • Contingency Analysis Tool: Added option with Injection Group contingency action to specify when using Merit Order Open if the total MW dropped is allowed to exceed the desired amount or not. Previously, the default was to never exceed the desired amount.
  • General: Added options with individual Participation Points for Injection Groups to specify the ParFac based on a field of the participant or a Model Expression.
  • Sensitivity Calculations: When calculating PTDF values added a new MWAtZero:1 field for an interface which is similar to MWAtZero, but it assumes each transfer direction containing an injection group is configured to represent an area and as a result the "net injection" of each injection group in the MWAtZero:1 calculation is assumed to be equal to the export of the most common area in the injection group.
  • Bug Fixes

    • General: Fixed bug with storing Base Case values for Branch objects for the Difference Flows tool.
    • Sensitivity Calculations: When opening the PTDF dialog, the type is automatically set to Multiple if any directions are defined.
    • Sensitivity Calculations: Modified so that the Multiple Direction PTDF value fields for Branch and Interface objects are only available as a field/column if the Direction is marked as "Include = YES". This ensures that when using the script command SaveData with the variable "FGPTDFMult:ALL" or "LinePTDFMult:ALL" that fields are not included for directions that are skipped.
    • Sensitivity Calculations: Modified Interface field for showing MWAtZero for PTDF calculations to only include Directions marked as "Include = YES" in the calculation.
    • Transient Stability: Added up to 6 stages for LDST2 model. Previously it only had 3 stages.
    • Transient Stability: Continuing to fix the treatment of single phase air conditioner models under extremely low voltages. This impacts CMPLDW, LD1PAC, and CMPLDWNF.

June 16, 2014

Features and Improvements

  • Case Information Displays: With Branch and Transformer tables can now show the regulated bus for a transformer due to ZBR (very low impedance branches) groupings. The ZBR bus is the bus that is actually regulated.
  • Oneline Diagrams: Added drawing of automatic control symbol when drawing transformer symbol using circles.
  • Bug Fixes

    • Power Flow Solution: Angle smoothing is done when branches are closed to help power flow convergence. Some modifications were made to how this is done to further help convergence.
    • Transient Stability: For WTGT_A model, fKShaft < 0 is treated as a single mass model.
    • Transient Stability: Initial speed Wo can now be specified with WTGT_A model. Previously, this was always assumed to be 1.0.
    • Transient Stability: Fixed initialization of the PRef input to the REEC_A exciter model when (PFlag = 1) is set to model torsional oscillations.
    • Transient Stability: On the User Defined Model GUI, key fields for user defined model machine models were not getting populated correctly and an access violation could result. This has been fixed.
    • Transient Stability: If modifying a transient stability load model through an AUX file or SimAuto, a new model would be created with only the fields specified in the file with the remainder of the fields set to defaults instead of only the fields specified for existing objects being updated. This has been fixed.

June 10, 2014

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added right-click option on the Transfer Limiters display to "Create Contingent Interface for Selection." This will create interfaces with a monitored branch being the Limiting Element in the Transfer Limiter and the contingent element in the interface being the Contingency Element of the Transer Limiter.
  • Case Information Displays: Removed the "-CE" from the end of the column header string for custom expressions that have names.
  • Oneline Diagrams: A line will be drawn through a switched shunt display object if it is on continuous control or an SVC.
  • Transient Stability: Implemented LDELEC load model.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Added new parameter "EstimateVoltages" to AppendCase script when appending either an EPC or RAW file. Set this to YES (this is the default) to estimate voltages for newly created buses and to smooth angles across newly created lines or NO not to do this.
    • File Formats: When appending data from either an EPC or RAW file and using the "with options" file type, an "Estimate voltages at new buses..." option is available to specify if voltages at newly created buses should be estimated and angles should be smoothed across newly created lines. The default is to do this because we assume that you could be appending data from a case with vastly different voltages than the present case. However, in situations where you are appending an entire new island or want to load your own voltage estimates, you do not want Simulator to estimate the voltages that are read in.
    • Power Flow Solution: A single bus system with both a generator and load should solve without giving the blackout message. Previously, a log message would indicate that the power flow solved but the blackout message would still appear.
    • Transient Stability: Added support for properly reading and writing the measured bus and measured branch specification in a DYD file for the REPC_A model.
    • Transient Stability: Fixed a bug with enforcing non-windup limits in the REPC_A model.

June 4, 2014

Features and Improvements

  • Case Information Displays: Modified so that the Selected field can be edited or toggled while iin Difference or Base Case mode for the Difference Flows tool.
  • Contingency Analysis Tool: Added an option to auto-insert contingencies and name them by label.
  • Fault Analysis: Added an option to auto-insert faults and name them by label.
  • Oneline Diagrams: While in Run Mode, left clicking on a bus name or number field will open the Bus View for that bus.
  • Sensitivity Calculations: Added LODF Screening tool to screen single line contingencies by LODF magnitude or loading. Pairs of contingencies can be created from contingencies that are deemed to be significant based on screening thresholds. Purpose is to create a more manageable list of contingencies rather than run all pairs of single contingencies.
  • Transient Stability: Added an option to auto-insert transient contingencies and name them by label.
  • User Interface Dialogs: In Set Selected from Network Cut tool, added option to prompt user asking if they would like to initialize the Selected field.
  • User Interface Dialogs: Added Line length information on Branch Information dialog while in Run mode.
  • Bug Fixes

    • Contingency Analysis: When using one of the linear solution techniques or when solving in dc power flow mode, the impact of contingencies that closed lines was not being correctly calculated. This has been fixed.
    • User Interface Dialogs: When using the equivalencing tool to save out a portion of the system to a PWB file, an error could result when appending the file to another case if transient stability data existed in the original system. Transient stability data is now currently not stored with the portion of the system saved to file.