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Simulator Version 11.0 Patch Description


What's in the Simulator 11.0 Patch?

PowerWorld Simulator 11.0 Patch addresses problems found in Simulator 11.0 following its official release in April 2005.  New features are also added via the patch as appropriate. You can view patch descriptions by date or view summary descriptions of New Features/Minor Improvements or Bug Fixes by selecting the appropriate links.

SimAuto 11.0 Users

If you have not already done so, please download and run the following program:  UnRegSimAuto.exe Running this will clean up your Windows registry settings allowing SimAuto to work properly.

This patch was first introduced on May 10, 2005.

The patch was last modified July 18, 2006.

Click here to go to the patch download page.

Select one of the following links to view descriptions of the changes incorporated via the PowerWorld Simulator Patch files

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 Descriptions by Date:

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May 10, 2005

New Features/Minor Improvements

  • Auxilliary Files - When using the LoadScript(filename, ScriptName) and LoadData(filename, DataName) script commands to load a particular SCRIPT or DATA section, previously we would read all the sections that had the ScriptName or DataName specified. This has been left that way for the LoadData() command. For the LoadScript command however, if multiple SCRIPT sections with the same ScriptName exist, only the first one is read.
  • Auxilliary Files - Added new script command: ZeroOutMismatches;
  • Auxilliary Files - Added new script command: CalculateVoltSelfSense(filter);
  • Auxilliary Files - Added new script command: CalculateVoltToTransferSense([transactor seller],[transactor buyer],TransferType,TurnOffAVR)
  • Case Information Displays - When pasting in data from the clipboard into a case information display, the column headers are now trimmed of leading and trailing spaces. Previously we did not do this, so " Num " would not be interpreted as "Num" thus preventing a paste from occurring.
  • Sensitivity Calculations - Under Tools, Other Sensitivities, previously all the sensitivities were used to calculate the sensitivity at a single metered point to multiple transfers (transfer from each bus to the slack bus). New tabs have been added for calculating the voltage sensitivity at all the buses for transfer of real or reactive power, and a tab the self sensitivity of voltage with respect to P and Q injection at each individual bus.
  • Oneline Diagrams -  Modified how the underlying drawing on oneline diagrams occurs so that the memory footprint of PowerWorld will remain consistent while you are resizing and moving around a set of open onelines. While this results in a larger memory footprint on average it will not change over time and result in memory fragmentation.
  • Oneline Diagrams -  Modified so that when setting the Undo Memory Limit Per Oneline to zero MB, this has the same effect as disabling the undo feature.
  • Oneline Diagrams -  Modified the oneline link so that it can also be used to open an Auxiliary File from the oneline diagram.
  • Oneline Diagrams - Added support for reading comments from a PTI Draw (*.drw) file.
  • Contingency Analysis Tool - Added ability to report contingency analysis violations based on the relative change in the dV/dQ self-sensitivity at a bus. The user specifies a list of buses to look at dV/dQ and will then report a violation if the dV/dQ changes by a specified multiple.
  • Contingency Analysis Tool - Add the ability to "merge contingencies". This is done by selecting a set of contingencies on the Contingency Dialog and then creating all possible combinations of two of the selected contingencies.
  • PVQV Tool - Added the ability to monitor the dV/dP sensitivity while running the PV Curve tool. This will calculate the sensitivity of the bus voltage with respect to a change in the transfer amount.

Bug Fixes

  • File Formats - Simulator 11.0 no longer supports the old load variation schedules. These may now be implemented using the time step simulation. However, when reading in an old PWB or AUX file which had the load variation schedule, Simulator 11.0 was including these. The user had no way to see them or remove them however. This has been fixed now so that load variation schedules are now longer kept when read from an old case.
  • File Formats - Simulator 11.0 sped up the reading of 3-winding transformer data form all file formats. Previously it was very slow because of a slow search routine. In the original release of 11, however, when reading in a PWB file which contained a 3-winding transformer that had one terminal connected to a DC transmission line, this would result in an error and a failed file read. This occurred with some cases in ERCOT. This has been fixed.
  • File Formats - When saving a oneline diagram in an older PWD file format, all display objects were showing up with a color of black. This has been fixed so that Version 11 will now properly save older PWD version files.
  • Auxiliary Files - The deletion of MW transactions was not possible using the Delete SCRIPT command. This has now been enabled.
  • User Interface Dialogs - When creating or viewing a Model Filter via the Model Filter dialog, access violation bugs could occur. These have been fixed.
  • User Interface Dialogs - When clicking the box "Use Another Filter" on the Advanced Filter dialog, Simulator was not properly registering that you had chosen a value for the field. This has been fixed.
  • Oneline Diagrams - The saving/loading of Keyboard Shortcuts to an auxiliary file format was not working correctly. This has been fixed.
  • Oneline Diagrams - Fixed bug with contouring the percent flow on an interface. It was showing the MVA percent instead of the MW percent.
  • Oneline Diagrams - When dragging line vertices or moving a bus to which a line was anchored, the movement of circuit breakers, line fields, or pie charts could occur incorrectly for lines. This was caused by the CB, field, or pie thinking it was anchored to the wrong segment of the line. This has been fixed.
  • Oneline Diagrams - When specify the pie chart color and scalar options by percentage, values above 100% were not allowed. This has been fixed so that values above 100% are now allowed.
  • Oneline Diagrams - When zooming out on a diagram with pie charts shown, in some situations, it was possible for a divide by zero error to occur for pie charts showing text. This has been fixed.
  • Oneline Diagrams - Printing oneline diagrams and copying them to the windows clipboard was limited by the resolution of the monitor on the computer from which printing was done. This has been fixed so that the resolution is not limited in this way for either printing or copying.
  • Oneline Diagrams - When deleting a display object that had been added to the oneline since that oneline had been opened, an access violation would occur. This has been fixed.
  • Oneline Diagrams - When right-clicking on a bus and choosing Insert Connected Buses, the new buses are inserted in a radius around the bus. This radius was a function of the size of the bus which for horizontal buses was only checking the height. This made is so that the normal action for this feature would be to put the buses right on top of one another. This has been fixed so that the radius is now based on the maximum of the height and width.
  • Oneline Diagrams - Fixed bug when right-clicking on a line and choosing the Open action. Previously it would update the display to show zero flow on the line, but would not cause Simulator to resolve the power flow. This has been fixed.
  • Bus View and Substation View Onelines - Normally, bus view onelines will not prompt the user to save them as a oneline diagram. Under some situations this was still occurring which could cause some confusion. This has been removed so that you will never be prompted to save a bus view.
  • Bus View and Substation View Onelines - For the bus view onelines, the other end bus link objects height was not being properly set. This has been fixed.
  • Power Flow Solution - When using the merit-order dispatch for injection groups in the PVQV or Contingency analysis tools, if the enforcement of generator MW limits was turned off for the case, then all the change in dispatch would come from the generator with the highest merit. This has been fixed so that generator limits are always enforced for merit-order dispatch.
  • Power Flow Solution - Simulator was not properly handling the outage of a multi-terminal line DC converter outage which was caused by the loss of the AC system at the converter. This has been fixed.
  • Power Flow Solution - Simulator will now handle the status of a DC converter separately from the loss of the AC system bus. Previously, the DC converter status was not used.
  • Contingency Analysis Tool - Fixed writing out the contingency analysis AUX file so that it does not write out the label name of the contingency twice.
  • OPF and SCOPF Tool - Removed limitation of modeling 500 line constraints as simultaneously binding in the linear program solution. No limitation is now enforced.
  • Memory - Fixed memory leak when deleting a Model Condition
  • Memory - Fixed memory leak when reading an auxiliary file with MW Transactions in it
  • Memory - Fixed memory leak associated with copying data to the windows clipboard.
  • Memory - Fixed memory leak when deleting an Advanced Filter 
  • Memory - Fixed memory leak in creation of Select by Criteria settings.

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May 13, 2005

New Features/Minor Improvements

  • PVQV Tool - Added the ability to track voltage-control devices hitting limits during the PV and QV curve tool.

Bug Fixes

  • File Formats - Added support for reading/writing various PSS/E sequence data file formats from Version 24-30.
  • Case Information Displays - The column for interfaces labeled # of Monitored elements was showing the number of contingent elements instead. This has been fixed.
  • User Interface Dialogs - Fixed bug created by May 10 patch which removed old load variation schedules. This bug removed the ability to use a multiplier in the area/zone records to increase all loads in the area/zone by the multiplier.
  • User Interface Dialogs - When choosing to bring up the on-line help documentation if the help file location was set wrong then nothing would happen. It will now bring up a dialog asking you to locate the help file.
  • Oneline Diagrams - When auto-inserting a list of bus display objects from a text file list of locations, consecutive buses with the same x/y coordinate are places in a circle around the location. The radius of this circle was previous being set to the height of the bus. It is now being set to the larger of either the height or width.
  • PVQV Tool - Modified the plotting tools in the PV and QV curve plots so that enough significant digits are always available on the plots.

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May 17, 2005

New Features/Minor Improvements

  • Case Information Displays - Modified the "Send to Excel" commands so that the cell format is changed to "Text" for all string fields sent out from PowerWorld. This will correct problems related to Excel automatically converting strings into some other format, such as a date string. An example: "MAR 2551" might become "March 2551".
  • PVQV Tool - Added the ability in the devices hitting limits lists so that you can filter out all devices that never change. For example: a generator which is always at its maximum VAR output will not be listed.

Bug Fixes

  •  File Formats -In the installation files for Simulator 11.0, the file type registration with Windows for PWB and PWP files was not correctly configured to open a file when it was double-clicked upon. This patch will automatically correct this problem if it exists.
  • File Formats - Fixed bug which could sometimes result in buses not being written out as part of the RAW file format. This occurred because Simulator was incorrectly treating a bus as the star bus of a three-winding transformer when it was not. These buses were then not written to some RAW file formats.
  • Oneline Diagrams - Add check to ensure that right-click options work correctly when right-clicking on a vertex handle. Previously some of the options line split background line were not working correctly.
  • PVQV Tool - Modified previous bug fix regarding increasing the number of significant digits on PVQV plots so that too many digits were not used.

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May 26, 2005

New Features/Minor Improvements

  • Case Information Displays - Modified so that case info displays that they can be released after they are embedded on a oneline.
  • Case Information Displays - Added a right-click option to create an interface from a selection of lines/transformers in a case info display.
  • Case Information Displays - Added a right-click option to create an injection group from a selection of generator or loads in a case info display.
  • User Interface Dialogs - Added a button on the Interface dialog to allow you to copy elements from one interface into another interface.
  • Contingency Analysis Tool - Modified the display of the percent column for bus voltage contingency violations so that it is only displayed when the violation represents a "change violation" relative to the reference case.
  • Contingency Analysis Tool - Added the ability to "clone" a contingency. This will make a contingency that is an identical copy of another with the work "copy" appended to the name.
  • ATC Tool - Added a new option on how the ATC Solution Method "(IL) the Full CTG Solution" is processed called "Force all transfer ramping to occur in pre-contingency states and repeat full CTG Solutions". Prior to this new option, the Full CTG solution would only occur once and extra ramping would occur after that.
  • ATC Tool - Added a new option to specify whether to include phase-shifters in the determination of the post-contingency sensitivity values when performing ATC calculations.

Bug Fixes

  • File Formats - When reading Multi-Section lines from a PTI RAW file adjustments were being made to the area/zone assignments of the dummy buses similar to those made when reading a GE EPC file. These adjustments are needed when reading GE because the multi-section line itself maintains where the meter is. This is not done in PTI, but we were still adjusting area/zone definitions incorrectly.
  • Case Information Displays - Modified so that case info displays can not be embedded once they have already been embedded in a oneline.
  • Oneline Diagrams - Modified transformer display objects so that their symbol size can be edited using the size value on the generic format dialog.
  • Oneline Diagrams - Fixed an error with reading in line flow arrow objects. Previously the angle-orientation of the arrow was not being read in correctly and was defaulting to zero always.
  • Contingency Analysis Tool - Fixed an error when performing a comparison of two lists of contingency results which could sometimes result in an access violation.
  • OPF and SCOPF Tool - When using the script command SolveFullSCOPF(OPF, success.aux, failure.aux), if the SCOPF ran out of LP iterations it was incorrectly executing the success.aux Auxiliary file anyway.  This has been fixed.

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June 6, 2005

New Features/Minor Improvements

  • User Interface Dialogs - Modified to allow series capacitor objects to be tapped the same as a transmission branch.
  • Oneline Diagrams -  Add a right-click option on a selection of display objects that allows you to "snap selection to grid".  This will align the objects you have selected to the drawing grid.
  • Oneline Diagrams -  Added a new option so that the font color of a Pie Chart can be specified on the oneline display options dialog.
  • Oneline Diagrams -  Generally cleaned up some of the local menu (right-click drop-downs) that appear on a oneline diagram so that options related to all objects appear in a consistent manner.
  • Oneline Diagrams -  Fixed font name alignment on substation display objects.  Previously the fonts were shifted downwards a small amount.
  • ATC Tool - Added a script command which would perform the same action as done on the ATC multi-scenario results tab for Write to Excel.

Bug Fixes

  • File Formats - Modified the read/write routines for GE EPC file so that they utilize only a period (.) as the decimal place separator.  The read/write routines for PTI files had previously been changed to behave this way.
  • Auxiliary Files - When using regional settings in Windows, which set the comma as the decimal place separator, you could not read in numeric values correctly in the auxiliary files.  PowerWorld was incorrectly treating the text entered as though it were not the right format.  This has been fixed.
  • Case Information Displays - When using regional settings in Windows, which set the comma as the decimal place separator, you could not edit numeric values correctly in the case information display.  PowerWorld was incorrectly treating the text entered as though it were not the right format.  This has been fixed.
  • Contingency Analysis Tool - Fixed bug that would occur when the first contingency the list did not contain any elements, or the elements did nothing (such as opening a line that was already open).  In these situations when using the DC approximation for the power flow, or when using one of the linearized contingency calculation methods, the contingency results could be calculated wrong.  The results would be very strange (100,000% overloads and such).
  • Memory - When deleting a bus that was also an island slack bus and then trying to save the case, an access violation error would occur this has been fixed.
  • Memory - When deleting a bus that was a terminal or the star bus of a three winding transformer, you would get errors because the three winding transformer was not getting properly deleted along with the bus.  Now if one of the terminals or the star bus is deleted, the entire three winding transformer record and all three equivalent transformers are removed as well.
  • Memory - Fixed memory leak in clearing of the time step simulation results

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June 8, 2005

New Features/Minor Improvements

  • No new features added. 

Bug Fixes

  • Memory - When defining more than one label, it was possible that an infinite loop would occur if none of the labels were assigned as primary labels.  This has been fixed.
  • Memory - For older Pentium III processors, the emphasis filtering on a oneline diagram or the OPF algorithm may fail giving an "External Exception C0000001D".  This was related to some speed enhancements done in Version 11 which were improperly calling some assembly code instructions.  The error has been fixed.

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June 14, 2005

New Features/Minor Improvements

  • Power Flow Solution - At the end of a power flow solution, Simulator looks at the voltage angles in each island and if the angles are outside of the +/- 160 degrees, then Simulator automatically rotates all the angles by an equal amount to center the range around zero.  This is done to prevent angles from spanning across +180/-180 degrees.  This isn't really a problem generally and rotating the angles has no effect on the system solution, but PowerWorld considered the situation very strange.  If you would like to disable this feature, a new option has been added to the solution options called "Disable Angle Rotation Processing".
  • Power Flow Solution - Added ability to specify that a discrete switched shunt be available for switching during the inner power flow loop.  This option is specified with each switched shunt record by changing the "Inner PF Loop Switching" field to YES.  By default these are all NO.  This is accomplished by setting any discrete shunts allowed to switch in the inner power flow loop to continuous shunts, solving the inner power flow loop, setting the selected shunts back to discrete and rounding the nominal Mvar up to the nearest block, and then solving the inner power flow loop again.
  • Oneline Diagrams - Added options to specify whether to show flow arrows on branches, generator, shunts, or loads separately.  This allows you to disable flows on specific types of objects while keeping the flow on other types.
  • Oneline Diagrams - Added options on whether to show circuit breakers for particular types of objects.

Bug Fixes

  • Oneline Diagrams - When auto-inserting buses and substations, if a bus/substation does not exist in the case, under some situations an error could occur.  This has been fixed.
  • Oneline Diagrams - Fixed some errors with using the Dynamic Formatting dialog to specify formatting for different kinds of Case Information Fields.
  • File Formats - When reading in PWB files containing the old "Scheduled MW Transactions" Simulator will now convert these into the newer MW Transaction records.
  • Memory - Added checks throughout to ensure that users are not able to add more buses than the maximum number allowed.  Previously when performing actions like "tap transmission line" or "split bus", Simulator would attempt to add the extra bus needed but this would result in access violations because too many buses were being created.

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June 15, 2005

New Features/Minor Improvements

  • File Formats - Modified the reading of PTI *.sub files so that when a PARTICIPATE block is encountered inside a SUBSYSTEM without any previous definition of subsystem buses, then PowerWorld will assume that all buses listed in the PARTICIPATE block should be used.  Previously we would not create the injection group which is represented by the subsystem.
  • File Formats - Added better error messaging to alert if the incorrect number of ENDs are encountered in a *.sub file.

Bug Fixes

  • Oneline Diagrams - An access violation error could occur when merging buses together or when auto-inserting generators on a oneline.  This has been fixed.
  • Oneline Diagrams - When pressing the A and B keys, the oneline diagram would toggle between 2D and 3D mode.  This has been removed and switching between 2D and 3D mode can now be done only through the main menu.
  • ATC Tool - When using injection groups in conjunction with the iterated ATC solution methods, the method for ramping the transfer could sometimes result in not achieving the correct amount of transfer.  This was related to the slack bus picking up part of the losses when Simulator is designed to assign all losses to the buyer injection group. 

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June 28, 2005

New Features/Minor Improvements

  • Auxiliary Files - Added script action “SetCurrentDirectory” which sets the present directory path.
  • Auxiliary Files - Modified calls the all script actions which might change the current directory path so that they do not do so. All current directory changes must now be handled using the script command SetCurrentDirectory. This included the actions RenameFile, CopyFile, DeleteFile, LoadAux, LoadScript, LoadData, SaveData, OpenCase, SaveCase, LogSave, and others.
  • Oneline Diagrams - Modified the dynamic formatting for transmission lines so that setting the fill color dynamically will change the color of the flow arrows.
  • Contingency Analysis - Add options for specifying post-contingency high and low voltage limits which are different than the normal voltage limits. Note that Version 11 patch, these options are not stored with the PWB file because these would change the file format. These options can only be saved/loaded with the AUX file format. In Version 12, these will be added to the PWB file format.
  • ATC Tool - For multiple ATC scenarios, now have the option of changing line rating A and B.
  • Power Flow Solution - For switched shunts which are controlling the Mvar output of generation, a modification was made to the power flow which allows the generation to ignore its Var limits during the direct inner power flow loop solution. This switched shunt will then bring it back into limits, otherwise a subsequent run through the inner loop will bring it back.

Bug Fixes

  • Auxiliary Files - Modified writing out auxiliary files so that when a numeric field contains a text which includes the field delimiter (spaces) it will always uses quotes.
  • Auxiliary Files - Writing out the LPVariable information to an auxiliary file or passing it out via SimAuto was not working correctly. This has been fixed.
  • Case Information Displays - Fixed the super area fields for showing the total production cost and profit for the super area. These were only showing the values of the last area in the super area instead of the sum.
  • Oneline Diagrams - Modified the area fields which show transaction-related values to work properly. Simulator now allows multiple transactions between two areas which was not properly supported by these area fields.
  • Oneline Diagrams - When editing a text box memo on a oneline diagram, keyboard shortcuts such as the arrow keys were being passed through to the oneline. As a result you couldn’t use the arrow keys on the memo because this would pan the oneline. This has been fixed.
  • Oneline Diagrams - The scalar size for normal pie charts was being applied in Edit Mode. Pie chart scaling is only supposed to be applied in Run Mode so this has been modified to behave correctly.
  • Oneline Diagrams - Mvar flow arrows were appearing in Edit Mode. This has been removed.
  • Oneline Diagrams - When using the toolbar buttons to zoom on a oneline diagram, under some situations an access violation could occur. These have been fixed.
  • PV and QV Tool - On the PV analysis dialog, the option for how reactive power load should change as real power load is ramped did not behave consistently. This has been fixed to not allow a specified power factor entry when the option to keep the ratio constant is checked.
  • PV and QV Tool - When performing the PV tool runs, Simulator modifies the unspecified MW transactions for areas to keep area transfer in balance. This doesn’t affect the PV tool results at all, but is convenient if you perform studies on cases generated by the PV tool. A bug was found in the accounting for these transfers which has now been fixed.
  • Contingency Analysis - When loading two contingencies files for comparison, errors could occur when refreshing the contingency result displays. This has been fixed.

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July 5, 2005

New Features/Minor Improvements

  • User Interface Dialogs - Added memo tabs to the Line Dialogs, Super Area Dialog, Load Dialog, and Zone Dialog.
  • User Interface Dialogs - Added an option to automatically set the case as a base case after the case is loaded.
  • Oneline Diagrams - Added option to local menu for background rectangles and ellipses to convert them to buses or substations.

Bug Fixes

  • File Formats - Removed the memo field from the DC Line and Multi-Terminal DC Line records. These were available for entry, but the values were not included in the Version 11 PWB format, so for now they have been removed. Starting with Version 12 these will be included again.
  • File Formats - When reading a PWB file, Simulator was not correctly setting which end of a multi-section line was metered. This has been fixed.
  • Auxiliary Files - Fix so that unlinked elements of interfaces are saved to an auxiliary file when the user chooses this option.
  • Auxiliary Files - When calling the SaveData() script action using SubData sections, Simulator was not properly recognizing the subdata section names. This has been fixed.
  • Oneline Diagrams - Pie Charts were modified to show a different graphic when the line was out-of-service. This was not working correctly when using the difference flows feature to show the base case system. It has been fixed to properly show the out-of-service graphic when displaying the base case.

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July 10, 2005

New Features/Minor Improvements

  • Contingency Analysis - Added a right-click option to the contingency-violation case info displays to create contingent-interfaces from the selected violations.
  • User Interface Dialogs - Completely overhauled the transformer impedance correction dialog to allow showing more information regarding the transformers that use the table

Bug Fixes

  • Oneline Diagrams - When auto-inserting buses and substations from the latitude/longitude information in the case, the substations and buses were not being inserted at exactly correct point. They were being inserted within a radius of the point specified by the width of the object. This has been fixed.
  • User Interface Dialogs - Errors could occur when trying to insert new Transformer Impedance Correction tables.  These have been fixed.
  • Auxiliary Files - When reading a DATA record, if not enough fields are found on the first line of text, Simulator will read and append fields on the next line of text. This was leading to errors if the next line of text was the start of a SUBDATA section or the termination character "{" of the data section. This would only occur if there was a problem in the AUX file format, but Simulator now detects this problem and just appends some blanks to the last data record.
  • Auxiliary Files - The auxiliary script command LoadAux() was resetting the submode to PowerFlow or Edit after it was called. This has been fixed.
  • Memory - When deleting an object which had a label assigned to it, Simulator was not properly removing the invalid label. This was leading to memory access violations. This has been fixed.
  • Memory - Fixed potential access violations that could occur when saving a case that employs labels for some types of objects but not for others.
  • Memory - Very old Simulator cases (Version 8 and earlier) allowed interfaces with the same name. This is no longer allowed, but old PWB cases still exist. Error checking was added to assign a unique name to these.

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July 17, 2005

New Features/Minor Improvements

  • Oneline Diagrams - Added ability to export a oneline diagram to a set of Shapefile files (shp/shx/dbf set).  This is available in the Tools, GIS Tools menu.
  • Oneline Diagrams - When saving out a list of dynamic formatting or select by criteria descriptions to an auxiliary file, Simulator will now automatically include a data section describing the advanced filters used.
  • Case Information - When sending data from a case information to Excel, a dialog may now appear prompting the user to select which instance of Excel and to which sheet name to send the data.
  • User Interface Dialogs - Added an option to include a timestamp on every message sent to the message log.

Bug Fixes

  • Oneline Diagrams - When zooming in on very large filled lines, the fill color would sometime flip. This has been fixed.
  • Oneline Diagrams - A degradation of display performance was introduced between version 10 and 11 so that drawing in Version 11 was about half as fast as in Version 10. The degradation has been corrected.
  • Oneline Diagrams - Fixed error in the drawing of transmission lines connected between substations that could result in the flow arrows appearing in the wrong direction.
  • OPF Tool - When performing the intial power flow solution to initialize the DC OPF, Simulator would sometimes return an "excessive angle separation higher than 360 degrees" error. This would cause the OPF to abort. Simulator has been changed to ignore this error during the initial power flow solution because the error is normally only a notification that the gen/load balance in the case is wrong and too much power is coming from the slack bus. Because the LP OPF is solved immediately after this initialization, this will be fixed by the LP.
  • PV and QV Curve Tool - When writing out the PV Curve options, the tracking settings for Transmission Lines was not being properly saved to the auxiliary file. This has been fixed.
  • Memory - When deleting an advanced filter which was used as part of a Dynamic Formatting description, the link from the dynamic formatting was not properly cleaned up in memory. This was causing bugs which have now been fixed.

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July 22, 2005

New Features/Minor Improvements

  • Oneline Diagrams - Added new measurement lines which can be added to determine the length of a particular parts of the oneline.
  • Oneline Diagrams - Modified the up/down arrows associated with the transformer tap position so that they are always available if the transformer is on manual control.
  • Oneline Diagrams - Modified the keyboard shortcut which performs the "Bring to Front" on a oneline so that it will not open a second oneline if the oneline is already open. Previously it would only bring forward a oneline which had been created as a result of a keyboard shortcut.
  • Case Information - Modified the Interface Case Information display so that there are now subtabs that show a list of only a specific type of object in the interface. For example, a list of branches can now be brought up which then allows the user to customize the list with all the fields available for a branch.
  • Case Information - Modified the Injection Group Information display so that there are now subtabs that show a list of only a specific type of object in the injection group. For example, a list of generators can now be brought up which then allows the user to customize the list with all the fields available for a generator.
  • Power Flow - Simulator has handled for a few years the situation when all transmission lines connected to a slack bus are opened by choosing a new slack bus. Simulator did not however handle the situation when generators at the slack bus were opened. This would cause a dialog to appear which said that the slack bus must have generation. Simulator has now been changed so that a new slack bus will automatically be selected with appropriate messages sent to the message log.

Bug Fixes

  • Oneline Diagrams - ATC Tool - Modified the generator scenarios so that negative generator values are allowed. 
  • Auxiliary File - The auxiliary script command Move() was improperly causing the script to abort. The first Move() command would occur, but then the script would immediately abort. This has been fixed.
  • Sensitivity Calculations - When calculated the TLR sensitivity for interfaces that contained elements marked to "meter the far end" of the line, Simulator was calculated the sensitivity incorrectly. The PTDF calculation has always been correct, but a sign error was occuring in the TLR calculation. This has been fixed.
  • Contingency Analysis - A bug has been fixed that occurred when reducing the generation in an Injection group using merit order dispatch. This was resulting in not enough generation being dropped.

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July 29, 2005

New Features/Minor Improvements

  • Oneline Diagrams -  Modified auto insertion for buses and substations so that the user has the option to not insert buses or substations that are already shown on the diagram
  • Oneline Diagrams - Added the ability to change the shape of substation, bus, area, zone and injection group objects using the Format Selected objects dialog.
  • Oneline Diagrams - Added an Apply button the oneline display options dialog so that the options can be applied without closing the dialog.
  • Oneline Diagrams - Added the ability to select objects touched by the selection window instead of only objects fully contained by the selection window.
  • Oneline Diagrams - Modified the writing out of shapefiles to use longitude/latitude coordinates if the user has chosen to "show coordinates in lon/lat"on Oneline Display Options dialog.
  • File Formats - Modified the reading of EPC files so that we read in the interface element multipliers and utilize these fields in the calculation of interface flows.
  • File Formats - Modified the reading of RAW files when encountering loads that are assigned to a different area than their terminal bus. Most RAW files have been solved so loads like this are not treated as tie-lines. (AREA INT CODE = 1 FOR LINES ONLY). Simulator requires that loads be treated as they are modeled (i.e. as tie-lines) (AREA INT CODE = 2 FOR LINES AND LOADS). To make the area interchange consistent, Simulator now creates new transactions to represent these loads. If the RAW file was solved assuming that loads like this are treated as tie-lines, then you will need to open the MW Transactions table and remove the transactions with ID "RAW_LOAD".
  • PVQV Tool - Added the ability to control whether constant power, current, or impedances load is used as part of the transfer of a PV curve.
  • Contingency Analysis - Modified the interaction contingency elements that modify individual generators and the post-contingency max/min generator response. Now generators that are modified by individual contingency elements will ignore the max/min generator response option.

Bug Fixes

  • Oneline Diagrams - The option on the Oneline Display Options Dialog for Show longitude,latitude coordinates when showing x,y coordinates was not being saved as part of the PWD file. This is now saved with the PWD file. 
  • Oneline Diagrams - Modified the Bus View and Substation View oneline so that they no longer inherited any oneline display options from the oneline that invokes them. Previously when you right-clicked on a oneline object and choose Bus View it would inherited the settings from that oneline such as the pie chart sizes, colors, animation settings, etc...
  • Power Flow Solution - If the user has specified that all generator Mvar limits should be ignored, Simulator now forces all generators with an AVR status of YES to force their setpoint to be enforced. Previously if a generator was stuck at its min or max limit, it would stay there after checking the ignore limits options.
  • Auxiliary Files - When loading in an AUX file that uses labels as the identifier, it was possible to change the primary keys of the objects, thus allowing you for instance to set all the buses in the case to have the same bus number. While obviously a bad thing to attempt, Simulator allowed this. Simulator will no longer allow key fields to be modified via auxiliary files or via copy/paste to/from Excel.
  • Auxiliary Files - When loading in default drawing values via an auxilary file, the default fields positions were sometimes being set incorrectly. This has been fixed.
  • Contingency Analysis - When bypassing a series capacitor as part of a contingency action, Simulator was sometimes having difficulty solving the power flow due to an error in resetting the system state. This only affected Series Capacitor bypassing and has now been fixed.

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August 1, 2005

Bug Fix

  • SimAuto - Modified the commands WriteAuxFile(*), SendToExcel(*), and variations of ListOfDevices(*) so that they will not return error messages of the form "No objects returned for type *** and filter***". Having commands such as ListOfDevices(*) return no objects because none exist in the case should not be considered an error.

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August 2, 2005

Bug Fix

  • File Formats - After loading in an AUX file that contains injection group descriptions, Simulator will maintain records for “unlinked” injection group elements representing gens or loads described in the AUX file that do not exist in the case. After loading such an AUX file and then saving the case as a PWB file, Simulator is supposed to ignore these unlinked elements and not save them. There was, however, a bug that was causing these to be saved resulting in a corrupted PWB file that could not be reopened. This has been fixed.

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August 3, 2005

New Features

  • Contingency Analysis - Modified the clone contingency tool to insert the contingency right next to the cloned contingency.
  • Oneline Diagrams - Added the ability to renumber the areas, zones, and substations on a oneline diagram.  This new feature works in the same manner as the "renumber bus" feature.
  • PVQV Curve Tool - Added the ability to scale the Load Mvar as part of a PVQV transfer by a multiple relative to the amount that it would change if the load maintained constant power factor. For example: Assume an initial load of 100 MW and 50 Mvar. If you wanted to increase the load by 50 additional MW and maintain constant power factor, you would increase the Mvar by 25 and end up with 150 MW and 75 Mvar. If instead you said increase it by 0.8 of what it would increase for constant power factor, then you increase by 20 Mvar and end up at 150 MW and 70 Mvar.

Bug Fix

  • Optimal Power Flow (OPF) - Simulator previously contained both Cost of Energy and Cost of Losses Reference fields.  There should only be one reference that applies to Energy, Losses and Congestion. The feature has been changed so that only one reference is specified as the "Cost of Energy, Losses, and Congestion Reference." Backward Compatibility:  When reading PWB and AUX files containing the now obsolete Cost of Energy and Cost of Losses references, the Cost of Energy Reference value will be used. The Cost of Losses Reference will be ignored.

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August 8, 2005

New Features

  • User Interface Dialogs - Added diagrams and equations to the transformer dialog to better explain how transformer base values are converted to system base values.
  • User Interface Dialogs - Added support to Model Filters for showing columns that represent the number of Model Conditions and the number of unlinked Model Conditions.

Bug Fixes

  • One-Line Diagrams - In run mode, the user can toggle the AGC status of an area by placing an Area AGC Status field on the one-line.  Fixed a problem where toggling the AGC status would not immediately update the one-line field.
  • One-Line Diagrams - An object with the dashed line format option set would not always be drawn with a dashed line as expected. This has been fixed.
  • One-Line Diagrams - Fixed bug with graphical Interface objects not correctly linking to Interface data.
  • Case Information Displays - Fixed bug when displaying Advanced Filters in Case Information Display.  Only those filters that are associated with a power system element will be displayed.
  • Auxilary Files - Fixed bug with reading in transformer records from auxiliary files when the transformer type is something other than fixed.

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August 19, 2005

New Features

  • Oneline Diagrams: Modified the showing of MW and MVar arrows simultaneously so that the initial locations for the arrows were offset from each other. This makes the initial locations so that the MVar arrows are not hidden by the MW arrows.
  • Oneline Diagrams: Modified the oneline link dialog so that when you click browse you can choose an auxiliary file to link to as well.

Bug Fixes

  • Oneline Diagrams: When using Select by Criteria to find substations, if a substation was empty it was not being selected. This has been fixed.
  • Oneline Diagrams: When marking a line field or pie chart as immobile, the object would then no longer follow its anchor when a bus was moved that was connect to its line. This has been fixed.
  • Oneline Diagrams: Unselecting objects using a Shift-Click on a presently selected object was not properly working. This has been fixed.
  • Oneline Diagrams: When unselecteding a single text object, the handle squares were not properly erased making it appear that the object was unselected. This has been fixed.
  • Oneline Diagrams: When checking the box "Use the default font size for new text fields (Ignore object-specific sizes)", all new text and fields were being inserted with a negative font size making it so that you could not see them. This has been fixed.
  • AUX Case Info: Modified so that secondary key fields can be editted using an auxiliary file. Simulator does not require their uniqueness so this is not a problem.
  • Power Flow: Setting the status of a multi-terminal DC transmission line to OPEN was not being properly handled by Simulator. Simulator now properly handles this and treats it the same as setting the mode to BLOCKED.
  • Contingency Analysis: Fixed bug which resulted in the contingency records not properly linking to the model criteria when read from a PWB file. This worked fine when read from an AUX file however.
  • OPF: When committing and decommitting generation in the OPF it was possible for an infinite loop to occur under some circumstances. This has been fixed.
  • PVQV: When plotting our the points in the PV Curve plots, the order of the points near the nose would sometimes be switched. This was caused by the plotting program sorting the points by the x-axis dimension. This sorting has been removed.
  • PVQV: Fixed the coordination of the default step size and max/min voltage and the values specified with each bus. Previously they were not properly coordinated.
  • PVQV: Fixed bug that occurred when the temporary directory name was specified without a path. Simulator will now use the current directory. Without the path, users coudl not save the QV results or plot them.
  • PVQV: Fixed bug when using the QV curve script command. The output filename was not being correctly set and thus the results not properly saved.
  • PVQV: When running a QV curve at a bus that is remotely regulated by other generators, Simulator will now set the AVR status of the remotely regulating generators to NO while running the QV Curve. This was a mistake which was causing two different generators to be controlling the same bus to different voltages.
  • PVQV: When reading an AUX file which contained tracking information for MVar values of switched shunts, the tracking of MW and MVar values for switched shunts were conflicting. This resulted in the MVar value never being set for tracking. This has been fixed.

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August 31, 2005

New Features

  • Oneline Diagrams: Added the ability for formatting of color, font color, etc... of substation fields to be determined by the dynamic formatting specified with buses that make up the substation. For instance, this allows the "min kv of max nom kv" substation field to be formatting based on dynamic formatting related to a bus voltage.
  • Oneline Diagrams: Cleaned up interaction with the Dynamic Formatting dialog.
  • Case Information Displays: Modified the Search for Text... right-click feature of the case information displays so that it can optionally "Search Ignoring Filtering". When searching with "Search Ignore Filters" chosen, then the search will look through all possible records regardless of what the filtering is. If text is found which is not presently displayed due to filtering, then all filtering will be removed for the case information display and the text shown.
  • Case Information Displays: Modified the Search for Text... right-click feature of the case information displays so that it can optionally "Search All Fields". When searching with "Search All Fields" chosen, then the search will look through all possible columns regardless of how the present Display/Column options are set. If text is found in a column that is not presently displayed, then this column will be added to the end of the case information display and the text shown.
  • OPF: Added new script command InitializePrimalLP;

Bug Fixes

  • Bus View Onelines: When right-click on a bus link object to bring up the bus dialog, the delete button was available on the dialog. It should not have been and has been removed. Deleting a bus in this manner would cause access violations.
  • OPF: The LP OPF, OPF Transactions case information display showed each transaction twice. This has been fixed.
  • PVQV: The user had to press "ok" twice after changing the name of the output file, but that has been corrected so that the user has to confirm his choice only once.
  • Oneline Diagrams: Circuit Breaker and Pie Chart objects had their stack level changed to top regardless of what had been saved in the PWD file. This made it so that the user could not change their stack level.
  • Oneline Diagrams: Fixed bug which was causing the flow arrows for DC transmission lines to flow backwards in some instances.
  • Case Information Displays: Modified the manner in which labels are defined and the interaction with primary labels. The column "primary label" is no longer available and only the "Labels (All)" column may be used to define labels. The primary label is only significant in that it is the first label listed when there are multiple labels.
  • Case Information Displays: The columns showing Bus CTG voltage per unit limits were erroneously added in a patch of Simulator. There are only 4 high and 4 low per unit limits specified with each bus. The contingency limit is specified by choose which rating set A, B, C or D to use during the contingency.

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September 11, 2005

New Features

  • User Interface Dialogs - Added messages to the log when bus load is reduced because the bus voltages are dropping below the minimum voltage for constant power load. Also changed the default value for the minimum voltage for constant power load from 0.8 to 0.7.
  • Oneline Diagram - Added an Simulator Environment option that allows the user to specify not to show the dialog asking the user if they would like to create a new oneline after opening a case.

Bug Fixes

  • Oneline Diagrams - Made changes to the Select by Criteria so that unlinked objects can be selected as long as selecting by all areas, zones, and voltages.
  • Oneline Diagrams - Fixed bug occurring when objects that were set to a fixed screen locations were displayed along with the Thumb Nail View. This was resulting in erratic movement of the objects.
  • Oneline Diagrams - Fixed the storage of Dynamic Formatting Definitions to an AUX file. Previously we were not writing out all the necessary fields for the file.
  • OPF - When using the DC approximations and choosing the DC Solution Option "Use bus MW loss sensitivities in OPF and ED dispatch algorithms, if the ...", Simulator was correctly utilize the loss sensitivities in calculating the MW Marginal Cost at each bus. However, when performing the post-processing to split the Marginal Cost into a cost of Energy, Losses and Congestion, Simulator was not using the sensitivities correctly resulting in an incorrect allocation.
  • File Format - Fixed a problem when reading in a Promod file that would terminate prematurely if it was trying to read a contingency element that was not found in the case
  • File Format - Modified the storage of the jumper threshold and Minimum Voltage for Constant Current Load in the GE EPC file.
  • Format - Corrected bug when writing out he branch records to a GE EPC file. .

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September 13, 2005

New Features

  • PV and QV Curve: Modified the layout of the PV Curve tool to make the new features regarding scaling components of constant power, current, and impedance load more easily understood.
  • Power Flow Solution: Modified so that the generator setpoint voltage can not be set to zero. Now, when the user tries to change the voltage to zero Simulator will not change the voltage.

Bug Fixes

  • Oneline Diagram: Fixed an error with the pie-chart option for "Min Pie Chart Font Size for Warning/Limit" setting. This was not working properly when zooming out on a large display. This has been fixed.
  • Power Flow Solution: Fixed a bug which might occur when a very low impedance branch connects a generator's terminal bus to a bus that it remotely regulated. This bug would cause the generator to not control its voltage and report a warning to the log saying the generator could not regulate because "there is no path between them that doesn't go over another regulated bus". This has been fixed.
  • Power Flow Solution: After reading in a generator which had it's minimum and maximum VAR output equal Simulator disables VAR control at the generator internally. A bug existed however that would not allow the generator to regulate even after changing the min or max VAR output. This has been fixed.

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September 15, 2005

New Features

  • PVQV Curve: Modified the QV Curve tool so that when viewing the results of the QV Curve runs, you may right-click and choose Display/Columns Options and add all field related buses.
  • Oneline Diagrams: Added a feature to convert the selected AC tranmsission lines into background lines. To use this feature, the user must customize the toolbars and added the new command available under the Insert category called "Convert AC Line to BackgroundLine"
  • Available Transfer Capability: Added a better indication of when the "(IL) then full CTG" solution method encounters an unsolvable power flow when ramping out the pre-contingent state. A new gray-highlighted transfer limitation will appear showing the final state at which a successful contingency solution was achieved. Additional fuchsia-highlight transfer limitations then show the pre-contingent state at which the power flow solution failed.

Bug Fixes

  • Available Transfer Capability: When using "(IL) then Full CTG" solution method and forcing all ramping to o