Software Patches

April 28, 2016

Features and Improvements

  • Auxiliary Files (SCRIPT and DATA Sections): Added optional parameter, Delimiter, to specify the file delimiter for both the Renumber3WFormerStarBuses("filename", Delimiter) and RenumberMSLineDummyBuses("filename", Delimiter) script commands. Options are COMMA,SPACE, or BOTH. If not specified then BOTH is assumed. The file delimiter can now be specified on the dialog that allows you to renumber multi-section line dummy buses or three-winding transformer star buses.
  • Case Information Displays: Added the ability to turn on hints on Case Info Displays that display column metrics for selected cells. Settings for these hints are on the Case Information Display tab of the Simulator Options dialog.
  • Difference Case Tool: Added ability to see which PartPoint objects are added/removed when using the present topological differences from base case tool.
    Also added ability to see changes in the PartPoint parameters between cases.
  • Transient Stability: Modified the PIDGOV governor model to return an initial limit violation of the final point on the non-linear Gate versus Power lookup function (P3) was a power that was less than the initial mechanical power.
  • Transient Stability: Modified the PIDGOV, WPIDHY, IEEEG1, IEEEG3_GE, TGov3, WSIEG1, URGS3T, WSHYDD, WSHYGP, G2WSCC, GPWSCC, GAST_GE governor models so that when setting the option of "Handling of Initial Limit Violations" to "Modify Limits and Run", Simulator will modify the final value of the nonlinear gain input curve if the initial output of the block is larger than the final value of the nonlinear gain.
  • Transient Stability: When reading the PIDGOV model from a DYD file, modified to ignore the MWCap value in the DYD file if it is different than the generator MVABase. The MWCap value is not used by PSLF or PSSE for this model and a value of MVABase is always assumed in those software tools. To be consistent with how the DYD format expresses the PIDGOV parameters, when reading a PIDGOV model Simulator will now always set the TRate value equal to the generator MVABase.
  • User Interface Dialogs: Fixed a bug on the Transformer Control Options dialog which was causing the regulated Max and Min values to be flipped.
  • Bug Fixes

    • Contingency Analysis: On the Contingency Specific Solutions Options dialog, two check boxes where not allowing you to click on them to revert them back to the "Use Default" options. These check boxes were the "Disable SVC Control" and the "Disable Treating Continuous SSs as PV Buses". This has been fixed.
    • Distributed Computation: Fixing some small memory leaks and also a problem where Simulator hangs when closing after certain large distributed runs.
    • File Formats: Fixed an access violation that could result when saving a PWB file with transformers that had been loaded from an EPC file.
    • Oneline Diagrams: Fixed a bug in specifying the the output of the Area record's slack generator MW using a Generic Model Field on a oneline.
    • Power Flow Solution: Made some corrections to how line drop compensation is implemented during contingency analysis.
    • Power Flow Solution: Corrected the logic when switched shunts are moved as part of the voltage control loop with the power flow solution. This shouldn't have caused any issues other than maybe causing additional voltage control loop iterations when Voltage Control Groups exist and the shunts in them are being changed.
    • Power Flow Solution: Fixed a very obscure bug that would only occur when two Continuous SwitchedShunt objects has different regulated buses AND those regulated buses were connected by very low impedance branches. In this situation the switched shunt control might result in one shunt moving slow upward and the other moving slowing downward until either the solution ran out of Voltage Control Loop iterations or one of the shunts hit a maximum or minimum Mvar limit. Simulator has been modified so that in situations like this the the switched shunts' control algorithms do not fight against one another. This was first seen in a WECC case (26HW1ae.epc) with switched shunts at bus number 56485 and 54159.
    • Simulator Automation Server (SimAuto): Return error messages in SimAuto if using ProcessAuxFile or LoadAux with RunScriptCommand.
    • Transient Stability: The option to Abort the simulation if any initial limit violations exist was not working properly. This has been fixed.