Software Patches

May 17, 2017

Features and Improvements

  • Sensitivity Calculations: Modified how various methods of calculating LODF and LCDF values handle the degenerate situations when opening a branch splits the system into islands or closing a branch merges two islands. The LODF or LCDF values will now consistently report values of 100,000,000% to help users using automated scripts recognize that this is occurring. Previously the values would remain as zero when using some methods of calculations. We had changed the LODF matrix in January 2017 to report the large number, but this patch now makes other methods like a single LODF/LCDF calculation also report a large number to indicate that a value can not be calculated.
  • Bug Fixes

    • Bus View and Substation View Onelines: Fixed error with bus view object sizes that could occur.
    • Case Information Displays: The pre-weight flow for an interface element was being returned as zero if the weighting was set at 0. The pre-weight flow was correct for all weightings except for 0. This has been fixed.
    • Transient Stability: A result reporting error existed when using the CMPLDW model and entering 0.0 fractions for the fMa, fMb, fMc, or fMd, the result reporting of the electronic and static load components of the CMPLDW were not functioning correctly. The Electronic and Static loads would always return zeros in the results reporting even though values were properly being simulated.
    • Transient Stability:
      When storing load CMPLDW fields to hard drive for the Electronic Load and Static Load, the values were not actually being stored. This has been fixed
    • Transient Stability: Fixed bug on error checking on SEXS_GE. Kc must be > 0 only if Tc > 0.
    • Transient Stability: Addressed issue of PSSE machine models not storing Ra values. When reading various transient stability models from a DYR file, we now automatically populate the Ra value of the stability model from the value stored with the generator. In addition when writing out a RAW file, we now automatically obtain the Ra value from any presently defined transient stability synchronous machine model.
    • Transient Stability: Fixed more features with OEL1 runback.