Software Patches

September 8, 2020

Features and Improvements

  • Transient Stability: Added a parameter conversion when writing out a CHVDC2 model to a DYD file. The DYD record does not include the Vrate and Irate input parameters that are used in both PowerWorld and also in DYR files. Instead the DYD record always assumes that the Vrate and Irate are calculated in a hard-coded manner from the DC converter records from the power flow data using
    VrateDYD = dcc.vdc_base * dcc.nbridge
    IrateDYD = dcc.i_rate
    In order to make a model that responds the same writing out the DYD record, a conversion is done for several input parameters as follows.
    1. Per unit voltage input parameters V1 and V2 are multiplied Vrate_PowerWorld/Vrate_DYD
    2. Per unit current input parameters Idc_margin_r, Idc_margin_i, Imax1, and Imax2 are multiplied by Irate_PowerWorld/Irate_DYD.
    3. Current gain parameters Kir, Kpr, Kii, Kpi, Kcos, Kref, and Kmax are multiplied by Irate_DYD/Irate_PowerWorld.
    This converts the input parameters to be consistent with the voltage and current bases used in the DYD file.
  • Transient Stability: On the machine model GENQEC, modified the Limit on the multiplication of Kw*Id to +/-0.4 instead of +/-0.25. Also added appropriate limit violation reporting if the initial value is outside of this range.
  • Bug Fixes

    • Transient Stability: DUTT logic for DistRelay and DistRelayITR is updated to correctly allow for transfer trip from its companion relay