Software Patches

July 30, 2012

Features and Improvements

  • Transient Stability: Modified transient initialization so that MTDC converter voltage setpoints are initialized the initial DC voltage of the MTDC bus. This was done so that the converter always initializes to a flat start even when no dynamic model is given.
  • Transient Stability: Added parameter checks on the Tdr time constant for Ac7B and AC8B so that if it is zero it treats Kdr as zero as well.
  • Transient Stability: When using a LDFR model, we now apply the frequency dependence to the transient stability default load model instead of the underlying power flow ZIP model. Using the underlying model commonly results in a constant power flow load model which is a problem.
  • Transient Stability: Modified validation of T1 for the URST5T and ST5B exciter.
  • Transient Stability: Added more error checking on Xdpp and Xqpp to enforce values that values must be greater than 0.05.
  • Transient Stability: Limited how much bigger Xqpp can be than Xdpp in GENTPF and GENTPJ. If Xqpp > 1.1*Xdpp then Xqpp := 1.1*Xdpp
  • Transient Stability: Modified ESAC8B_GE exciter validation so that Vfemax must be greater than 3.0
  • Transient Stability: Modified GGOV1 validation so that Kturb must be greater than 0.1
  • Transient Stability: Modified GGOV1 validation so that Vmax <= 1.0 and Vmin >= 0.0
  • Transient Stability: Modified GPWSCC validation so that R >= 0.1
  • Transient Stability: Modified G2WSCC validation so that Velopen and Velclose must surround zero.
  • Transient Stability: Modified URGS3T and GAST_GE validation so that B >= 0.1
  • Transient Stability: Modified validation of WT1G and WT2G to ensure proper relationship between Ls > Lp >= Lpp > Ll
  • Transient Stability: Modified validation of WT1G and WT2G to ensure Tpo > 0 and Tpoo >= 0 and also multiple of the time step
  • Transient Stability: Added validation check for GGOV1 on Kpgov/Kigov to prevent numerical instability. If it results in too small a time constant, then Kpgov is set to zero.
  • Transient Stability: Modified use of subinterval integration with induction machine based models (WT1G, WT2G, WT1G1, WTG2, GENWRI, CIMTR?, etc...) to use it more liberally if Tpo or Xp are too small.
  • Transient Stability: Modified ST5B, ESST5B, and URST5T validation of the T1 time constants
  • Bug Fixes

    • Contingency Analysis: When clicking on one of the fixed columns in the contingency analysis list, the violation list and contingency definition list was not updated immediately. This has been fixed.
    • Oneline Diagrams: Right-clicking on a background line and choosing to convert the background line to a multi-section line would not function if the oneline presently had no buses on it. This has been fixed.
    • Transient Stability: Fixed access violation that could occur when looking at the transient limit violation table while the simulation was running.
    • Transient Stability: The options to specify when to start transient limit monitoring was not be automatically saved to the AUX when storing the transient options. This has been fixed.
    • Transient Stability: Removed error check on enforcing that T10 > 0 from PSS2B. This is not necessary.
    • Transient Stability: Fixed error in limit enforcement of VfeMax for ESAC3A