Software Patches

September 22, 2010

Features and Improvements

  • Case Information Displays: When choosing "Send to Excel", Simulator will now programatically set Excel to NOT "treat consecutive limiters as one". It also ensures that some "Other" character is not being used as a delimiter so that only TAB characters are used.
  • Power Flow Solution: After treating Discrete Switched shunts as continuous shunts in the inner power flow loop, Simulator sets nominal Mvar output to one of the discrete options available. Previously it was biased to set higher Mvar values such that anything at least 5% of the way toward a higher block would switch to the higher block. This has been changed to no longer bias the switching and instead just round to the nearest block.
  • Transient Stability: Improving error messeges when the stability simulation aborts.
  • Bug Fixes

    • Transient Stability: Fixed initialization of the EXWTGE exciter if Kiv = 0.
    • Transient Stability: Decreased tolerances for initialization of the WNDTGE pitch angle/wind speed to reduce initial mismatches
    • Transient Stability: Increased tolerance for what is considered "zero" when initializing the HYGOV, HYGOV4, HYG3, and WEHGOV hydro governor models. These can be problematic for a generator operating at 0.0 MW output because the equation H = sqr(Q/Qss) becomes ill-defined if Q = 0 and Qss = 0 as occurs in initialization of a generator operating at 0.0 MW output.