Software Patches

July 21, 2016

Features and Improvements

  • Case Information Displays: Modified how Simulator determines the tap integer position for transformers. Previously Simulator would treat the 0 position as the tap in the middle of the TapMax/TapMin range. This has been changes so that the 0 position is always represented by 1.0000 on the TRANSFORMER BASE. Positive tap positions then move upwards from there and negative tap positions move downwards from there.
  • Case Information Displays: Added the ability to edit the variable transformer tap ratio (or phase) by editing the Integer Tap Position directly instead of by editing the TapRatio or Phase.
  • Case Information Displays: Added new fields for Branch objects to show the Maximum Integer Tap Position and Minimum Integer Tap Position. These are calculated from the the TapMax and TapMin values (just as the TapMaxxfbase and TapMinxfbase are calculated). Also added the ability to edit these fields which will modify the TapMax and TapMin field as appropriate.
  • Case Information Displays: Added 2 new user-entered fields to a transformer for use in translating Simulator's integer tap position into an integer that uses the EMS convention. One field is TapPosEMSNom which specifies the integer considered to be at the nominal tap (1.0000 on transformer base or 0 degrees for a phase shifter). The second field is the TapPosEMSStepSign which is either +1 or -1.
    TapPosEMSStepSign = +1 indicates that a positive TapPosEMS means an increasing tap ratio going up to TapMax.
    TapPosEMSStepSign = -1 indicates that a positive TapPosEMS means a decreasing tap ratio going down to TapMin.
    The translation is as follows: TapPosEMS=TapPosEMSNom+(TapPosEMSNom*TapPosEMSStepSign)
  • Case Information Displays: Added a new field to show the integer tap position using the EMS convention. The tap or phase can then be edited using this field as well. The EMS convention uses the following conversion: TapPosEMS=TapPosEMSNom+(TapPos*TapPosEMSStepSign).
    When editing this field the Tap or Phase of the transformer will be edited as appropriate.
  • Case Information Displays: Added a new field to show the integer max tap position using the EMS convention.
    If TapPosEMSStepSign = +1, then TapPosEMSMin = TapPosEMSNom + TapPosMin.
    If TapPosEMSStepSign = -1, then TapPosEMSMin = TapPosEMSNom - TapPosMax.
    Notice that when TapPosEMSStepSign = -1 then TapPosEMSMin is related to TapPosMax.
    When editing this field the respective TapMin or TapMax are edited as appropriate.
  • Case Information Displays: Added a new field to show the integer min tap position using the EMS convention.
    If TapPosEMSStepSign = +1, then TapPosEMSMax = TapPosEMSNom + TapPosMax.
    If TapPosEMSStepSign = -1, then TapPosEMSMax = TapPosEMSNom - TapPosMin.
    Notice that when TapPosEMSStepSign = -1 then TapPosEMSMax is related to TapPosMin.
    When editing this field the respective TapMin or TapMax are edited as appropriate.
  • Bug Fixes

    • File Formats: Fixed how the maximum and minimum tap (ratio or phase) are read from the hdbexport CSV files. Note that the actual tap positions for phase/tap ratio were being read correctly and this only impacted the minimum and maximum tap ratios. See the explanations of the many new fields added as part of this patch for more information. Previously if the integer tap positions NOM_TAPTY was exactly in the middle of the MX_TAPTY and MN_TAPTY tap positions read from the CSV file, then the TapMax and TapMin were read correctly (this was true the vast majority of time).
    • File Formats: Fixed error when loading Generator Reactive Capability Curve data (*.gcp) files exported from PSS/E. Any quote characters were not being properly handled in this format.
    • Power Flow Solution: Modified how SVC control of fixed switched shunts is handled when the terminal voltage is extremely low (below 0.7)
    • Transient Stability: modified to read the BASEGEN PTI helper file for dynamics data from WECC. A newer version of this file supports entering the "baseload flag" as either 0, 1, or 2 in the same manner as it is listed int he EPC file. (0 = normal, 1 = Down Only, 2 = Fixed).