Software Patches

October 27, 2022

Features and Improvements

  • Available Transfer Capability (ATC) Tool: Added new field with TransferLimiter objects called RemedialActionApplied. This field will indicate if at least one remedial action element was applied for the contingency. This field is only valid for IterativelyFound results of YES, NO, or blank.
  • File Formats: Added log warning messages for invalid Terminal Equipment Data when reading substation topology
  • File Formats: Added 'Load Contingencies Complete' and 'Load RAS Complete' messages at the end of the hdbexport contingency and RAS import routines.
  • QV Curves: Added new field with QVCurve objects called RemedialActionApplied. This field will indicate if at least one remedial action element was applied for the contingency.
  • Transient Stability: Modified PSS2C, PSS3C, PSS6C, and PSS7C stabilizers to include Tpgfilt parameter as a time constant for measuring Pgen for use in the PSS Output logic decisions. Added reading and writing this parameter from the DYD format.
  • Transient Stability: Modified PSS2C, PSS6C, and PSS7C stabilizers to include Xcomp and Tcomp parameter for use in the compensated frequency calculation. Added reading and writing these parameters from the DYR file.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Under certain conditions loading an AUX file could result in a star bus being shared between 3 winding transformers. This should never be allowed. The code has been updated to detect this and create a new star bus when this situation is encountered.
    • Power Flow Solution: Note that unless a user entered something into PowerWorld's special "Slack Bus Priority" field the following change makes no difference. When using a slack bus priority to determine the slack for an island, we were not checking the conditions that determine if an island is viable like having load, being connected to a dc line, or having more than one bus. This could result in islands that have only a single generator and nothing else in them, which doesn't make much sense. Now these checks are done. If a bus should be a slack regardless of the rest of the island viability checks the Slack field for the bus should be set to YES.
    • Transient Stability: Default value of Trate for the H6E governor was 163. The default is now 0.0 and means to use the generator MVABase which is what all other governors default to.
    • Transient Stability: Features were added in the May 26, 2022 patch modifying how the automatically determined Min and Max vertical axis scales were determined. These worked correctly when the plot was first opened, but were not properly recalculating the min/max scale while an already opened plot was updated. For example, using the legend to hide/show plot series would not automatically updated the scale. Nor would a plot updating with additional new time-series be updated correctly. This has been fixed.
    • Transient Stability: Modified script command TSDisableMachineModelNonZeroDerivative(MaxAbsDerivative) to use a default value of 0.001 if not specified instead of a value of 0.