Software Patches

September 12, 2022

Features and Improvements

  • Transient Stability: Added support to read and write from a PSLF dyd file for Transient Stability models
    ESAC10C (AC10C in PowerWorld)
    ESST2C (ST2C in PowerWorld)
    ESST3C (ST3C in PowerWorld)
    ESST7C (ST7C in PowerWorld)
    ESST8C (ST8C in PowerWorld)
    ESST9C (ST9C in PowerWorld)
  • Transient Stability: Added support to read and write from a PSSE dyr file for Transient Stability models
    ST7C (ST7C in PowerWorld)
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): Fixed bug with saving Model Conditions to auxiliary files from a case information display. By default they should be saved using separate data sections for ModelConditions and ModelConditionConditions but they were being saved using SubData. When using the Save to Auxiliary with Options and choosing to save with SubData would not save anyting in the SubData section. This has all been fixed.
    • General: Fixed bug merging buses across the terminals of selected lines. An error could be encountered if one of the terminals was connected to a dc line, but this should be fixed.
    • Oneline Diagrams: Fixed bug when drawing phase shifter symbols if the terminal buses are directly on top of each other. There could be a line drawn from the phase shifter symbol to infinity at the top left of the oneline. This will no longer appear.
    • Sensitivity Calculations: Modified the bus fields shown by default of the Self-Sensitivity tab of the Sensitivities\Flows and Voltage dialog.
      Negative Reactance Lines: this will now return NO if a neighbor branch has a negative X but this branch connects to the internal star bus of the equivalent of a three-winding transformer. The Star bus itself will still say YES, but the terminals of the three-winding transformer will return NO.
      Likely Alternative Solution Fields: These fields will now return YES if a terminal of a three-winding transformer has a negative dV/dQ even if the connection to the star bus has a negative X.
    • Sensitivity Calculations: When attempting to calculating shift factors on a branch that was not online, an error message would be presented saying that the transactor and study device "do not share any common viable electric island". While this is true (since the open branch is not in ANY island), it was confusing. The error will now simply say that the "study device is not online" instead.
    • Transient Stability: Transient Stability stores various statistical information about all generators in the case (This is called Minimum/Maximum Values in the Results from RAM). There were entries in this table for internal fictitious generators with an ID of "<0". These were not harming or breaking anything in the software, however showing these results as generators is confusing. This has been removed to avoid confusion.
    • Transient Stability: Modified the initialization of the H6E governor models to ensure they initialize to a flat start. Limitation in the gate position prevent the Pmech from being achieved are now handled by modifying the Hdam value instead for H6E. In addition, the initialization for the gate position was improved.
    • Transient Stability: For truly bad input data on synchronous machine models, checks on (Xqpp > Xqp) could conflict with checks on the ratio of (Xqpp/Xdpp). Modified the auto-correction routines in these situations to just leave the Xqpp value alone and return an error to force the user to go correct these models.