Simulator 20 Patches

New Features

Bug Fixes

Date

December 4, 2017

Bug Fixes

  • General: Changing the licensing to be more robust in the face of high CPU contention (greatly reducing the propensity for "Pipe read timed out" and thus licensing errors) and also so that the main program terminates more quickly.
  • PV and QV Curve (PVQV) Tool: When using Merit Order dispatch as part of PV ramping, generators pariticipating in the ramping were being set to AGC = NO, which prevented them from moving at the next ramping step if they weren't already at their limits. This was only a problem if using the non-default option with injection group ramping to Allow only AGC units to vary. This has been fixed.

December 1, 2017

Features and Improvements

  • Difference Case Tool: Added a button to remove field customizations for all of the difference grids on the topological differences dialog.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When using the SendToExcel script command and OLE error could result if not specifying the name of the worksheet. This has been fixed by assuming a default name based on the object type of the data being sent to Excel if the user doesn't specify a name.
    • Case Information Displays: When using the Close with Breakers option from a case information display or a oneline, it was assumed that only the chosen device should be closed in. It makes more sense to allow other devices to be closed. This is especially important in situations such as a generator connected to a transformer and the breaker is on the high side of the transformer. If we do not allow the transformer to be closed the generator cannot be closed.
    • Contingency Analysis: Made the local menu options for Contingency case information display consistent whether it is displayed in the Model Explorer or on the contingency analysis dialog.
    • Contingency Analysis: Made corrections to properly retain the AGC method in use during a contingency solution with the reference state if a contingency solution is then manually set as the new contingency reference state.
    • File Formats: When writing to an EPC file, added a space between the from bus nominal voltage and the to bus number for breaker records to prevent long bus numbers from running into the from bus nominal voltage.
    • Oneline Diagrams: The small Color Key dialog for the contouring of a oneline can be made transparent. The option to "Remove Transparency from all Windows" however would not remove the transparency from this particular small window. This has been fixed.
    • Transient Stability: Fixed potential error that could occur after showing a group of plots in transient stability and then choosing to show them again.

November 28, 2017

Bug Fixes

  • Power Flow Solution: During case validation when island numbers are set for buses, a stack overflow error could occur when using the 64 bit version of Simulator. This has been fixed.

November 27, 2017

Features and Improvements

  • Difference Case Tool: Added Case Info Customizations for all case information displays used with the Difference Case tool dialog.
  • Oneline Diagrams: Added color map for showing integer values.
  • Transient Stability: Added substation field for average ROCOF.
  • Bug Fixes

    • Transient Stability: When writing switched shunt dynamic model data to a DYR file, Simulator was writing the ID of the shunt. The RAW/DYR formats do not support multiple switched shunts at a single bus and therefore the DYR format should not include the ID. This has been fixed.
    • Transient Stability: PSS1A stabilizer was not working with T6=0. This has been fixed.

November 21, 2017

Bug Fixes

  • File Formats: Fixed error when saving interfaces with unlinked elements to a PWB file. They were not being correctly counted in the number of elements to save but they were still being saved in the file. This would cause an error when loading the file back in. When loading files that have been saved incorrectly it should be possible to recover them by manually intervening where the errors occur on load.
  • Power Flow Solution: When solving island based AGC, MW limits for the system slack bus were not being enforced correctly and this could cause extra MW loop iterations of the overall power flow solution without actually adjusting the island slack within its limits. This has been fixed.
  • Power Flow Solution: When solving areas or super areas on participation factor control, MW limits for the system slack that is part of the area or super area will be enforced if all appropriate MW enforcement options are selected. If the slack happened to be set to a limit but the amount of change was less than the area or super area tolerance, the change would not be redistributed to the rest of the group. Now this change will be redistributed as long as it is greater than 2 times the MVA convergence tolerance. This might help to prevent extra MW loop iterations.
  • Transient Stability: Added a new parameter to DISTRELAY and DISTRELAYITR (FarRelayEnd). Since now the DistRelay determines how to coordinate with another relay by only using the desired branch and the device id there needs to be a mechanism for specifying the coordination the old way. This new parameter is set to 0 (Default) means it will look for the Far Relay Device to be at a different end from this device location end plus the Device id; 1 means it will look for Far Relay Device and only will look for the Device id (The device end will not matter).

November 17, 2017

Bug Fixes

  • Case Information Displays: Fixed an access violation that could occur when flood filling on a case information display.
  • Oneline Diagrams: An access violation could result when loading Display Auxiliary (AXD) files into a oneline containing grouped objects. This has been fixed.
  • Power Flow Solution: When a switched shunt that is part of a Voltage Control Group is oscillating its Control Mode will now be set to Fixed instead of setting Auto Control to NO. If the Voltage Control Group Status is set to FORCEON, the Auto Control field for a switched shunt in that group is ignored. This will result in the shunt oscillating forever. For a shunt to participate in a Voltage Control Group its Control Mode must be discrete, so setting the Control Mode to Fixed will prevent the oscillations. Any switched shunt that is oscillating and is not part of a Voltage Control Group will have its Auto Control set to No.
  • Transient Stability: Added better comments to know which relay is operating or giving transition events during simulation.
  • Transient Stability: Improved the messaging associated with the DistRelay model.
  • Transient Stability: Corrected how the DistRelay determines how to coordinate with another relay.

November 15, 2017

Features and Improvements

  • File Formats: Can now read version 34 RAW files.
  • Scheduled Actions: Added options to the Scheduled Action grid local menu allowing the user to isolate or energize the target device with breakers.
  • Transient Stability: Added VFE of ESAC8b_PTI into the State Other Fields.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): When reading an AUX file containing a list of script commands, Simulator will now force windows to process any screen, keyboard, or mouse actions after each script command occurs. This ensures that the message log continues to be updated.
    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug where buses with numbers <= 0 could be read and created from an AUX file. Now buses must have a number > 0, or it will be ignored.
    • Case Information Displays: Fixed behavior of navigation using arrow keys so that it is consistent with Excel.
    • Contingency Analysis: An access violation could occur during contingency analysis when injection group actions using the Best Fit Open scaling option are triggered. This has been fixed.
    • Fault Analysis: Fixed bug auto inserting faults where two buses at the same voltage level with the same name EXCEPT for a space in the middle (i.e. MY BUS and MYBUS) would result in one of the two buses not being included in the fault list. These are now treated as two different buses.
    • File Formats: Fixed bug where reading PWB would crash if a Substation was stored in the PWB file that had a bus in its bus list with a number of 0. A 0 bus number shouldn't happen, but somehow it did.
    • File Formats: When reading an EPC file, fixed a bug that was creating Multi-terminal DC lines without a unique record name.
    • Scheduled Actions: When reading Start/End times in the scheduled action tool, the time format "11/20/2017 12:30" in military time was being interpreted an AM time. This only impacted times between 12:00 - 12:59. This has been fixed.
    • Transient Stability: Fixed a bug that was causing an access violation when saving REECA1 model to a DYR file.
    • Transient Stability: Added device ID to DistRelay messages.
    • Transient Stability: Fixed a bug that was preventing the loading of user defined model DLL files.

November 9, 2017

Features and Improvements

  • Case Information Displays: On the Multi-Terminal DC Line and Two-Terminal DC line case information displays, add the ability to right-click on a selection of devices and choose "Remove Device and Converter to Equivalent Loads". This will add in new load objects which replace the MW and Mvar injections coming from these devices and then delete the DC system device.
  • Scheduled Actions: Added ScheduledActionSetReference script action to save the current system state as the reference state for Scheduled Actions.
  • Scheduled Actions: Added Scheduled Actions tab to dialogs for Gens, Loads, Lines, Switched Shunts, and Interfaces containing a case information display listing the Scheduled Actions that target the selected object. The tab is hidden if there are no Scheduled Actions defined in the case.
  • Transient Stability: Added the ability to rename the Device ID from a relay GUI dialog. It will only rename the Device ID if the new Device ID does not exists. If the Device ID already exists then the following message will appear: A Device ID already exists at from/to end (Line Name). Please Modify that particular (Relay Name)relay.
  • Bug Fixes

    • Available Transfer Capability (ATC) Tool: Fixed some inconsistencies in the system state when restoring the initial ATC state when using topology processing and the status of breakers has changed between the current state and the initial state.
    • Available Transfer Capability (ATC) Tool: Fixed a bug when using one of the iterated ATC methods and using the option to close breakers to energize switched shunts or using one of the injection group ramping methods that allow breakers to close to include generators in the dispatch. If a breaker ends up being closed by either of these processes during the ramping and the breaker is part of a contingency, the breaker most likely would have been ignored when calculating the LODFs. The LODFs are calculated once at the beginning of the ATC process for speed. When the LODFs are needed for the contingency including the breaker an access violation would have resulted. This has been fixed.
    • File Formats: Fixed bug that could occur when converting the EMS DC System into a DC model consistent with PowerWorld Simulator. If the DCCNV grouped in a POLE record in the EMS hdbexport file were out-of-service AND those DCCNV were connected to different XF records which were also separated from another by switching devices then it was possible for the DC system to be read incorrectly. This was an unusual situation and has been fixed.
    • Power Flow Solution: Fixed potential error in the power flow solution that could occur when a inverter bus hit a firing angle limit while controlling MW.
    • PV and QV Curve (PVQV) Tool: Fixed some inconsistencies in the system state when restoring the initial PV state when using topology processing and the status of breakers has changed between the current state and the initial state.
    • Scheduled Actions: Restructured internal lists of Scheduled Actions and Scheduled Action Groups to improve performance with large sets of schedules.
    • Scheduled Actions: When reverting scheduled actions to normal status and the object being closed is a Breaker, we also close Disconnects that are in series with the Breaker. There have been some cases where Load Break Disconnects are found to be in series with the Breakers being returned to service and these are normally closed. If we do not also close the Load Break Disconnects we cannot return lines to service. Now when returning Breakers to service we will also close any Load Break Disconnects that are normally closed and they are in series with the Breaker. If we are returning a Load Break Disconnect to service as the element that is part of the schedule we will NOT also close Load Break Disconnects that are in series.
    • Time Step Simulation: Corrected the Starting and Ending Time controls so that these can be specified down to seconds rather than only by hour.
    • Transient Stability: Modified documentation of DER_A to make it clear particular parameters can be equal to zero.
    • User Interface Dialogs: On the branch dialog only show the transformer tap and phase shifter fields if the branch is a transformer or phase shifter or these values have been set to something other than defaults of 1 for tap and 0 for phase shift.

November 6, 2017

Bug Fixes

  • Integrated Topology Processing (ITP): When performing the Equivalencing on a full-topology power system model, some errors could occur in the calculation of the equivalent due to numerical precision problems. This has been fixed.
  • Integrated Topology Processing (ITP): In the integrated topology processing, fixed an error that could cause a power flow mismatch in a very rare situation. A dead bus that was radially connected and had a NomG or NomB value but did NOT have any load, gen, or shunt attached would cause the problem.
  • Transient Stability: Fixed initialization of REPC_A and REPC_B when the Ki or Kig values are entered as exactly zero.

November 3, 2017

Features and Improvements

  • Case Information Displays: Prior to this patch, when dynamic formatting was defined for a bus object's case information displays, it was always inherited by the area, zone, and substation objects. These objects would automatically apply the formatting if any bus in the aggregation met the conditions of the dynamic formatting. Previously this inheritance could not be prevented which was reported as a problem by some users. This inheritance has been removed as it is easy enough to define dynamic formatting for area, zone, or substation objects using advanced filtering that applies to a bus object type now.
  • Oneline Diagrams: Fixed an error in patch relase from yesterday related to the new BranchCloseAngleThreshold. It was accidentally preventing the closing of any breaker on a oneline.

November 2, 2017

Features and Improvements

  • Case Information Displays: In Version 20 we added the Quick Filter drop-down directly on the Filter toolbar. As part of doing this we changed the caption of the button for opening the quick filter dialog to "Dialog". This also changed the caption of the button under the Filter drop-down the the Case Information Toolbar to "Dialog" which caused confusion. We have changed the caption under the Filter drop-down back to "Quick Filter..." to be consistent with previous versions.
  • Case Information Displays: The list of secondary filter classes available for objects has continued to grow to provide flexibility. However this has made the Filter drop-down menu on the case information toolbar extremely long as a result. We have organized this drop down menu so that object types are grouped by type such as "Network", "Aggregations", etc... Secondary filter classes that are in the same grouping will continue to appear directly under the filter submenu, but those in a different grouping have been moved inside an additional sub menu.
  • Oneline Diagrams: Added a new field to a Branch object called the "BranchCloseAngleThreshold". Specifying a non-zero value for this field will impact how oneline diagrams behave for this branch. When clicking on the circuit breaker objects on a oneline diagram that represent the status of a particular branch, if the branch is presently OPEN and the angle difference across the branch is greater than the threshold specified, then the oneline diagram will not permit you to close in this branch. This was added to help users perform operating training simulations.
  • Oneline Diagrams: Added ability to include arrows on the generator cost multiplier field.
  • Transient Stability: modified the Transient Stability tab on Load dialog to always show the "Terminal and State Values" tab so that the user knows it's available. Previously this tab would be hidden on the load dialog if the transient stability simulation had not been initialized. Now it will always appear, but if the simulation is not initialized then it will show all empty values.
  • Bug Fixes

    • Distributed Computation: Added a message to the log when all remote SimAuto sessions have finished when running distributed contingency analysis.
    • Sensitivity Calculations: Corrected the warning message that is shown when doing a PTDF calculation from the PTDF dialog with a seller and buyer of injection groups. If either of the injection groups does not have any nonzero participation factors, the error message indicated that both of them did not have any nonzero participation factors. This message has been fixed to show the correct injection group that does not have nonzero participation factors.

October 31, 2017

Bug Fixes

  • Difference Case Tool: Fixed error in ownership filtering of base case objects in the difference case tool.
  • Power Flow Solution: When choosing the Power Flow Solution Advanced Option to "Evaluated Power Flow Solution for Each Island", if the island ends up being short of controllable generation or load hit MW limits, then a dialog will appear indicating "Some islands did not have enough controllable generation or load and are hitting RESERVE LIMITS. Click OK to open the islands case information display in the Model Explorer". This will then open the island case information display which now has the Solved column as a default column which will say "RESERVE LIMITS" for islands that don't have enough control.
  • Simulator Automation Server (SimAuto): Updating RegSimAuto so that it notifies the user that 32-bit RegSimAuto doesn't affect 64 bit registration and vice versa. Also gives more visual feedback that a version of Simulator *is* registered, but not the one that is currently registered by the running RegSimAuto.

October 30, 2017

Features and Improvements

  • Optimal Power Flow (OPF): Added check boxes to the OPF tab of the Area dialog for specify whether to Enforce Branch Limits, Enforce Bus Angles, Enforce Interface Limits, Allow DC Line Control, or Include Marginal Losses.
  • Bug Fixes

    • Contingency Analysis: Fixed 3 bugs related to the Max Loading Field for branches that provides the maximum % contingency loading for a branch over all contingencies.
      (1) When used in the AC solution method it was not correctly calculating the loading based on the contingency rating.
      (2) It is now calculated when using linear contingency methods or solving while in dc power flow mode.
      (3) It will be updated if solving a single contingency and the single contingency loading is greater than any previously stored loading.
    • Contingency Analysis: Fixed an access violation that would occur in the 64 bit version of PowerWorld Simulator when performing the Auto-Insert contingency procedure.
    • Oneline Diagrams: Fixed a very rare bug that could occur when display a Background Rectangle on a oneline diagram and also simultaneously showing the contouring color key. This would cause the background rectangle to be drawn in the incorrect place immediately after contouring a oneline. Subsequent refreshes of the oneline drew correctly however. All of this has been fixed.

October 27, 2017

Features and Improvements

  • Oneline Diagrams: When performing an action by clicking on a oneline link, now automatically invalidate the NWin to force a redraw after doing this.
  • Transient Stability: Modified the interpretation of Direct parameter of the LOCTI, TIOCR1, and TIOCRS over-current models. Previously it only had options 0 and 1 below. Option 2 has been added.
    0 - means no directional element
    1 - means directional element AND Direction will be based upon current leaving the FROM end of the branch
    2 - means directional element AND Direction will be based upon current leaving the TO end of the branch
  • Bug Fixes

    • Transient Stability: Fixed a bug when reading some particular svsmo2 fields from an AUX file or when copy/pasting from a spreadsheet. The fields effected were Tdbd, PLLdelay, Tout, and dbe.
    • Transient Stability: Fixed a bug where setting a fault to single line to ground, and checking the box for the impedance to be created from the sequence data, resulted in an access violation when the transient was run.

October 25, 2017

Features and Improvements

  • User Interface Dialogs: Separating "Save" and "Save To Aux" button on the bus, branch, load, gen, shunt, and lineshunt dialogs. Clicking the Save to AUX will now store the fields specified as part of the built-in "Network Model" Auxiliary File Export Format Description.
  • Bug Fixes

    • Optimal Power Flow (OPF): When running the OPF with a full topology case and using topology processing it was possible to get an out of memory error at the end of the OPF solution. This has been fixed.

October 24, 2017

Bug Fixes

  • Power Flow Solution: When determining how switched shunts should switch when they are part of a control group regulating the same bus, the Var Regulation Sharing parameter determines the order in which shunts should switch. For discrete shunts we switch them in the order of highest to lowest Var Regulation Sharing parameter. We had been NOT been switching any shunts away from zero if they did not have a Var Regulation Sharing parameter greater than 0. Cases loaded from hdbexport files can end up having this parameter set to 0, which was causing shunts that presumably are supposed to move not to move. Because this parameter is defined as an order, the restriction on the Var Regulation Sharing parameter being greater than 0 has been removed when switching discrete shunts. For continuous shunts, we will still not move any shunts unless this parameter is greater than 0.
  • Power Flow Solution: Better handle situation in which the initial base case power flow does not solve for PV analysis. The error messages should be clear now that this is a problem.

October 23, 2017

Features and Improvements

  • General: Optimized the closing of a power system case for cases that included a very large number of of model conditions, model filters, model expression, and/or contingencies. The case will now close much more quickly.
  • Integrated Topology Processing (ITP): Added storage in the Window Registry for the user interface options on the Limit Monitoring Dialog. Previously the following was maintained during a session of PowerWorld Simulator, but after you closed Simulator and reopened it, it was not retained. The options include
    1. The check box status of “Only show the primary bus for each superbus”
    2. The choice under the “Elements to Show”
    3. Which tab you are on the dialog
  • Transient Stability: Added the ability to filter transient result events table from Object type.
  • User Interface Dialogs: Added two new buttons under the Restore> dropdown on the Tools ribbon tab called "Store User State" and "Restore User State". These provide button access to same functionality as available in the script commands StoreState; and RestoreState(USER);
  • Bug Fixes

    • Case Information Displays: 6 new fields for showing the Percent MVA at both the FROM and TO buses based on the A, B, and C MVA limits were added to branch objects in October 2016. There was an error with the PercentMVAATo value (it showed the FROM side percentage) and the PercentMVACFrom value (it showed the TO side percentage). This has been fixed.
    • Difference Case Tool: A nearly identical fix as made in October 11, 2017 regarding changes in the bus' owner. The behavior was the same for changes in the bus' area, zone, or balancing authority as well. Same changes made.
    • Distributed Computation: Adding the Distributed Computation Configuration tool to the installation.
    • Integrated Topology Processing (ITP): Fixed a bug for PV, QV, ATC, and SCOPF tools when using consolidation along with Remedial Actions that were defined as Open with Breakers (or Close with Breakers). The actions were not properly determining which breakers to open or close.
    • Oneline Diagrams: When loading an AUX file that defines a custom menu hierarchy in the Oneline Viewer multiple times, menu ordering will likely become scrambled. The SortIndex field was added to the CustomMenuNode object in order to keep the menu order stable when loading multiple times.
    • PV and QV Curve (PVQV) Tool: Update the Present Nominal Shift box on the PV curve dialog to show the transfer that is in the current system state. Previously, this would most likely show the highest transfer amount that would solve in the base case, which would most likely not be the actual transfer that is in the current system state. This could cause confusion with the user thinking that this is the amount in the system state.
    • PV and QV Curve (PVQV) Tool: On the PV Curve Dialog, updated the caption with the Restore Last Solved State option to show the transfer amount that is in that state.
    • Scheduled Actions: The Selected field was not toggleable for Scheduled Actions objects but should have been. This has been fixed.

October 17, 2017

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): An interface element will meet the area/zone filter if its interface meets the area/zone filter. Previously, an interface element would meet the area/zone filter if its individual device met the area/zone filter. This could cause situations that could re-define an interface if interface elements are missing when this information was loaded from an aux file. It makes more sense to keep all of the interface elements as long as at least one of the elements meets the area/zone filter. An interface will meet the area/zone filter if at least one of its elements meets the area/zone filter. This is the way that area/zone filtering has always worked for interfaces.
  • Auxiliary Files (SCRIPT and DATA Sections): Added ability for Data Maintainer objects to work as a filter on case information displays in a manner similar to Area/Zone/Owner filters. There is a now a global option that indicates if Data Maintainers should be used as a filter, and if this is set then their is a Filter field on each Data Maintainer.
  • Case Information Displays: Added ability for Data Maintainer objects to work as a filter on case information displays in a manner similar to Area/Zone/Owner filters. There is a now a global option that indicates if Data Maintainers should be used as a filter, and if this is set then their is a Filter field on each Data Maintainer.
  • Case Information Displays: Cleaned up the Owner filtering for objects. When using the find dialog on a table if the object found was not presently visible on the case information display because Area/Zone filters were not met, Simulator would automatically change the area/zone filtering to make the object visible. This has now also been done for Owner filtering and the new Data Maintainer filtering.
  • Contingency Analysis Tool: Modified saving contingency analysis settings using DataMaintainers so that they make use of the new "Filter" field for a DataMaintainer instead of using the Selected Field. This is more consistent anyway.
  • Difference Case Tool: Added ability for the list of Removed Substations in the Present Topological Differences from Base Case tool to properly use the Area/Zone/Owner filters. Previously that table did not use those filters.
  • Difference Case Tool: Modified the Base Case Topological Comparisons dialog so that user may use Data Maintainer filters to specify which objects to write out to a file.
  • Difference Case Tool: Added the Area/Zone/Owner filter menu/case info toolbar option to the Removed object tables in the Topological Differences from Base Case dialog. The functionality to filter these tables by area/zone filters had just recently been added so there had previously been no reason to care about them from these tables.
  • Integrated Topology Processing (ITP): When using the close with breakers algorithm on a branch, breakers will be closed even if the branch is only open at one end. The branch is energized, but the goal should be to have it closed completely. Previously, no breakers would be closed if the branch was considered energized. Now if the branch has Derived Status <> Closed we will search for breakers to close. This is done anywhere that the close with breakers algorithm is used.
  • Oneline Diagrams: Updated kml parser to parse PJM lines. This required fixing some things not handled when parsing the lines for coordinates. The PJM files have x,y,z coordinates instead of just x,y. The files do no contain identifiers that can be linked with the case, but at least unlinked lines are now read in.
  • PV and QV Curve (PVQV) Tool: Changed caption on the PV Quantities to Track tab for injection groups from "Groups" to "Injection Groups".
  • Transient Stability: Modified WT3G, WT4G, REG_A, PVD1 type model that have "reactive current management" that prevent high voltages on voltage source converter machine models. Previously if the initial terminal voltage was above the high voltage limit, we would ignore this limit completely. This has been modified so that instead the high voltage limit is set equal to the initial terminal voltage. Indication that this is occuring will appear in the Validation Warnings.
  • Transient Stability: Added a new plant controller named REPC_B100 which is the same as REPC_B but instead of allowing 50 generators to be referenced, you can have 100 generators.
  • Bug Fixes

    • Difference Case Tool: Support ObjectID field with DataMaintainer object. This is needed for generic functionality with the difference case tool that writes out script commands to remove objects that are missing in the present case when saving out the auxiliary file to implement difference case changes.
    • Oneline Diagrams: Fixed bug parsing bus numbers. Extra whitespace created error converting the text to a number. This has been fixed.
    • PV and QV Curve (PVQV) Tool: When loading an auxiliary file using the Load Auxiliary button on the PV dialog, set the options in the PVCurve_Options object to match what is set on the dialog. If this is not done and the auxiliary file that is being loaded does not contain PVCurve_Options, options on the dialog will change if they are different from what is in the PVCurve_Options. This doesn't make any sense so make sure the options are set correctly.
    • Transient Stability: When using the script command TSGetResults() or the SimAuto command TSGetContingencyResults(), there was bug that could occur in some circumstances. This has been fixed.
    • Transient Stability: The new fields to specify that the field "ROCOF (Hz)" be stored in RAM for a bus in transient stability was added in Version 20. The characters ( and ) where messing up the AUX file format however as these showed up in the variable name in the AUX file. For the variable names these have been removed in the variable names to fix this.
    • Transient Stability: Fixed error with implementation of REPC_B that effected only Verison 20. It was not properly communicating the Vref signals to multiple electrical control models.

October 11, 2017

Features and Improvements

  • Difference Case Tool: In the Present Topological Differences from base case tool, the removed objects did not support the case information display filtering by owner, but only display filtering by Area/Zone. This has been modified to also support Owner filtering.
  • Security Constrained OPF (SCOPF) Tool: Added the contingency name to the 'Bus Marginal Controls' header to allow correlation between the controls and 'LP Basic Variables'
  • Security Constrained OPF (SCOPF) Tool: We have added a column on the LPVariables grid to show the contingency name that corresponds to the variable. Previously it was possible to have variables with the same ID, making it impossible to uniquely identify a variable.
  • Transient Stability: Made more descriptive validation error messages for REPC_A and REPC_B when the model does not have a measurement branch specified. Unless this model is only controlling voltage, then a branch must be specified at which the Qbranch, Pbranch, and/or Ibranch is measured. If the branch is not specified when it is needed an error message will appear indicating why the measurement is needed.
  • Bug Fixes

    • Contingency Analysis: Fixed reading of ViolationCTG objects from an AUX file when reading in custom monitor violations. These were not being read in when multiple of the same custom monitors violations for different violated elements under the same contingencies.
    • Difference Case Tool: In the Present Topological Differences from base case tool, there was an inconsistency when writing out the AUX file that changes one case into another if a device such as a branch, gen, shunt, or lineshunt was
      1. Assigned to the default bus owner in the base case
      2. Assigned to the same owner in the present case
      3. But the default bus's owner was changed
      The problem occurred because when reading an AUX file, Simulator's behavior when a bus owner changes is that any device connected to that bus (gen, load, shunt) that has the same owner as the bus will automatically follow that ownership change. Thus after reading the AUX file you would see the owner of the device (gen, load, shunt) change when you had not expected it to. The fix for this was to modify what is shown for a devices ownership in the Change mode so that if this occurs the device acts as though it's ownership has changed. Thus this would get included in the AUX file and the appropriate behavior would be seen.
    • Difference Case Tool: When saving out the auxiliary file of case changes when using the Difference Case tool, we now include a section that changes the owner of buses in the following situations:
      (1) The owner of the bus has changed between the Present and Base Case
      (2) A new device has been added that is attached to the bus and the owner of the new device is different than the owner of the bus in the Base Case
      (3) A new device has only one owner
      Writing out this additional section will prevent the situation in which a new device is added to a case and the owner matches the owner of the bus to which it is being added. This will mark the device as having the default owner. If the owner of the bus then changes the owner of the device will also change. We want to retain the owner of the device as it was assigned when the device was created. Changing the owner of the bus prior to adding the new device prevents this problem.
    • Oneline Diagrams: Fixed bug parsing bus numbers when read from a KML file. Any extra whitespace created error converting the text to a number. This has been fixed.
    • Transient Stability: Fixed a bug with writing REECB1 from a REEC_B model. It was casuing an access violation when saving a dyr file.
    • Transient Stability: Fixed an access violation that could occur when opening the load dialog for any load. An access violation could occur if a transient stability distribution equivalent had been assigned to the load.

October 6, 2017

Features and Improvements

  • Transient Stability: Modified new DER_A model to add parameter Trf and Vpr
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug in SendToExcel Script Command. The objectname was not being saved into Excel File in the first row.
    • Time Step Simulation: Fixed an access violation that could occur on the Time Step Simulation dialog. This was related to specifying the hour at which the time step simulation could occur which was recently added.
    • User Interface Dialogs: Bug fix in the object chooser -- due to an internal change between v19 and v20, the behavior of the search box changed from matching patterns at the beginning of the target string to matching patterns that occurred anywhere in the target string. The search box is now back to matching from the beginning of the target string (unless explicitly specified otherwise with an asterisk at the start of the search pattern)

October 5, 2017

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Made a commonly used feature much more memory efficient. The feature to Send To Excel by either right-clicking on the case informations display, or when using the related SCRIPT command, could cause Simulator to run out of memory when used on extremely large data sets.
  • Case Information Displays: Made a commonly used feature much more memory efficient. The feature to Send To Excel by either right-clicking on the case informations display, or when using the related SCRIPT command, could cause Simulator to run out of memory when used on extremely large data sets.
  • Scheduled Actions: Added another check when the Use Normal Status option is in use to return disconnects that are in series with the branch that is being returned to service. If a branch is an Open Breaker action, any disconnects that are in series with it and are normally closed will be closed.
  • Transient Stability: Added the requested ability to add the case name into the plot name when in auto save. If the option is checked then the name will have the following format: "ContingencyName_PlotName_CaseName.jpg" Otherwise it will be naming the plot as before.
  • Bug Fixes

    • Contingency Analysis: When doing a comparison of 2 contingency lists in the 64 bit version of Simulator, you coudl see a "stack overflow error". This has been fixed.
    • GIC: Fixed some issues associated with loading and saving *.gic format files.
    • Oneline Diagrams: Fixed a bug with PTDF pie chart displays, which were showing values off by a factor of 100.
    • Oneline Diagrams: Fixed error parsing ERCOT kml files caused by case sensitive text comparison. 'branch' was not matching 'Branch'.

September 28, 2017

Features and Improvements

  • Difference Case Tool: Added the GE Long ID field for loads to the Difference Case tool.
  • Scheduled Actions: When closing disconnects that are in series with breakers when using the Use Normal Status option, also close disconnects that are in series with Load Break Disconnects. This makes sense because we are treating breakers and load break disconnects the same when we are identifying breakers to open or close devices.
  • Bug Fixes

    • Time Step Simulation: When monitoring load results during the time step simulation, access violation could occur. This has been fixed.
    • Time Step Simulation: Added a new TSB version that will save load results. These were previously not being saved. Users will need to make sure that they have the latest version 20 patch or that they save the TSB in the correct version for the version of Simulator that they have.
    • Time Step Simulation: Fixed bug with reading loads for which custom results are monitored. The correct load ID was not being used so not all loads at a given bus were being marked as Time Selected = YES. Duplicate loads could also end up being added to the list of loads to monitor.
    • Time Step Simulation: When loading a TSB file that was saved in a later version than the current version of Simulator can handle, pop a message dialog indicating this.
    • Transient Stability: Fixed bug that would occur when running transient stability on a full-topology model.

September 26, 2017

Features and Improvements

  • Case Information Displays: Added new expression functions for converting floats representing a date time into strings and also converting strings formatted as date/times into floating point numbers. These function all follow similar syntax as used in Excel functions of the same name.
    (1) Text(floatvalue, "formatstring") --> returns a string with the floating point number converted to a data time string using the formatting specified in the format string.
    (2) DateValue("datetimestring") --> returns a floating point number representing only the integer part for the date/time floating point
    (3) TimeValue("datetimestring") --> returns a floating point number representing only the fractional part for the date/time floating point
    (4) DateTimeValue("datetimestring") --> returns a floating point number representing the date/time floating point
    See the PowerWorld help documentation for more information on the format string. Search "Formatting String" in the help.
  • PV and QV Curve (PVQV) Tool: Added a new field to a load for "ScaleMvar". This field defaults to YES. Set to NO to prevent changing the Mvar of this load when shifting power using an injection group (such as in ATC, PVQV, and System Scaling tools)
  • Transient Stability: added support to CHVDC2 to use the parameters which attempt to emulate commutation failure.
  • Bug Fixes

    • File Formats: When load an EPC file, the intermediate buses of multi-section lines have been modified to be assigned to the DataMaintainer of the branch section that connects to this intermediate bus. For example, a multi-section line has 2 sections and connects Bus A to Bus C, then after reading the EPC file Simulator will have branches from A - B and B - C. The intermediate bus B will be assigned the same DataMaintainer as the branch B - C.
    • General: Fixed random access violation that could occur when closing a case if it contains a VSCDCLine or trying to delete a VSCDCLine.
    • GIC: Fixed a bug the could occur when modeling geomagnetic induced currents inside the transient stability simulation. When doing this if a new islands was created during the simulation the simulation would fail. This has been fixed.
    • Oneline Diagrams: When saving a PWD file with many substation, area, or zone objects the saving could be very slow because of saving the swap list that is used when loading the oneline using name_kV linking. This has been fixed.
    • Oneline Diagrams: Renumbering the substations, areas, or zones in a case or oneline that contains many of these objects could be very slow. This has been fixed.
    • Oneline Diagrams: Loading a PWD file containing many substation, area, or zone objects could be very slow when using name_kV linking. This has been fixed.
    • Power Flow Solution: It is possible to end up with a case that has no viable islands. If this happens, the maximum mismatch values for the case are initialized but never set to anything real. An access violation could occur when reporting the maximum mismatch. This has been fixed and the maximum mismatch will be reported as 0 occurring at bus None in a case with no viable islands.
    • Simulator Automation Server (SimAuto): The fix to make Distributed Computation work from September 21, 2017 patch broke the function of SimAuto on a single machine. This fixes this bug.
    • Time Step Simulation: Removed the time step simulation option to enable area interchange. Now always use the Simulator option to enable area interchange. Having two different options was very confusing.
    • Transient Stability: Fixed a bug that was allowing the Auto Insert Transient contingency to enabled the modification of the event duration ONLY when a Gen was selected but only when a Gen was selected is when it should not be enabled.
    • Transient Stability: Fixed some parameter name inconsistencies on the REGC_A, REEC_A, REEC_B, REEC_C, and REPC_A models.
      * REGC_A: Parameter name changed to Tg (was Td); Parameter name changed to Tfltr (was T_LVPL)
      * REEC_A, REEC_B, REEC_C: Parameter name changed to Trv (was Tv)
      * REPC_A: Parameter names changed to fdbd1 and fdbd2 (was dbd1 and dbd2)
      These new parameter names match what the standard model was supposed to be so we have changed it to avoid ongoing confusion. Also, these new names match what was on the block diagrams in PowerWorld's help as well.
      In coordination with this, also modified so that when reading AUX files or copy/pasting from spreadsheet the old parameter names will still be recognized and read in appropriately so that old files can still be used.

September 21, 2017

Bug Fixes

  • Data View: When switching the Type of object on the Data View dialog an access violation would occur. This has been fixed.
  • Distributed Computation: Made distributed computation connections to remote machines more robust and reliable. This fix was required due to changes in remote connections made for Version 20.
  • File Formats: When loading the Areva contingency file include the name of the contingency in the message log when a message is written about not being able to find the object in the contingency elements.
  • File Formats: When loading the Areva contingency file and a contingency with the same name already exists prior to loading the file, clear out all elements in the contingency and only keep the ones that are included in the file currently being read.
  • File Formats: Fixed some bugs when loading the Areva contingency file when contingencies are already defined in the case. This fix will allow all existing contingencies to be kept and the file will simply append contingencies to the list.
  • Oneline Diagrams: When reading a PWD file saved prior to 6/2/2008 in the 64-bit version of PowerWorld Simulator 20, it was possible for the file to fail to load. This bug has been fixed so that the PWD file can be opened.
  • Scheduled Actions: Added a new feature to the Scheduled Actions dialog -- in the Options tab, users can now opt to disable automatic evaluation when changing the View Time, and instead manually evaluate the current time either by a button in the GUI, or with the SetScheduleView script command.
  • Transient Stability: Fixed a the issue that was causing the transient stability simulation to fail when an Island was created during the simulation due to branch status changes.
  • Transient Stability: Fixed some errors in the implementation of the CHVDC2 generic DC Transmission line dynamic model.

September 19, 2017

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): Fixed an intermittent bug that could occur when running the OpenOneline script command. The error would appear as an access violation.
  • Case Information Displays: When loading an advanced filter which were comparing Date/Time fields (such as in Scheduled Actions), it was possible for the Date/Time to be interpreted incorrectly. This has been fixed.
  • Difference Case Tool: In the Difference Case Mode of "Base", Modified the BranchDeviceType for three-winding transformer windings so that it returns "Transformer Winding" instead of the "Transformer". This change had already been made in Present Mode for Version 20 but was not done for Base Mode.
  • File Formats: Fixed error in writing out an EPC file. It was possible for the DC converter of a two-terminal DC line to write out a Psched = 0.0 improperly. When read back into Simulator, a 0.0 value for Psched was automatically replaced by the Pac value so this was not noticed in Simulator, but it should not be written as a 0.0
  • Scheduled Actions: Added checkbox to allow the user to clear any Added or Extra actions before re-running Identify Breakers
  • Scheduled Actions: Fixed a bug with the "Check Conflicts" tool which identifies schedules that perform conflicting actions on the same device at the same time. The bug was related to not properly handling scheduled actions that did not refer to a device (the device field is blank).
  • Transient Stability: Fixed an error in SVSMO1 related the timer which controls controllable fixed shunts. The timer was not properly resetting if the B of the shunt returned to acceptable limits.