Software Patches

October 21, 2015

Features and Improvements

  • Transient Stability: Modified loading of DYR files to look for particular user-written models commonly used in ERCOT and MMWG cases which represent wind turbine models.
    * USRMDLs W4G2U and SWTGU1 are both converted to WT4G1.
    * USRMDL VTGTPA is converted to VTGTPAT
    * USRMDL VTGDCA is converted to VTGDCAT
    * USRMDL FRQTPA is converted to FRQTPAT
    * USRMDL FRQDCA is converted to FRQDCAT
    * USRMDL which are part of the GEWTG1/GEWTE1/GEWTT/WGUSTC/GEWTA/GEWTP/GEWTPT suite of user-written models are automatically converted to WT3G2/WT3E1/WT3T1/WT3P1. (This suite of models is seen in ERCOT cases.)
    * USRMDL which are part of the GEWTG2/GEWTE2/GEWTT1/GEWTP2/GEWGD1/GEWTA2/GEWPLT2 suite of user-written models are automatically converted to WT3G2/WT3E1/WT3T1/WT3P1. (This suite of models is seen in MMWG cases.)
  • Transient Stability: Many renewable energy machine models feed a commanded Ip and Iq through a small time delay with the output then feeding into the network boundary equations as the real and reactive current injections. We have added parameter checking to ensure that these time delays are no larger than 0.20 seconds. If the time delay is larger than 0.2 seconds then it will be treated as 0.2 seconds. In the 1000s of models like these we have seen, these time delay values are on the order of 0.02 seconds, but we were seeing a case with a value of 1.0 second which creates an unstable model. This effects the following models presently: WT3G, WT3G1, WT3G2, WT4G, WT4G1, REGC_A, PVD1.
  • Transient Stability: Improved messages written to the log when encountering user-written model in the DYR file.
  • Transient Stability: When reading DYR files, added support for reading a USRMDL/GENROA model. This is a user-written model commonly used in NY-ISO in North America which simply copies the input parameters for GENROU from another GENROU model.
  • Bug Fixes

    • Auxiliary Files (SCRIPT and DATA Sections): In the TapTransmissionLine script command the first bus entered is now the nearbus and this will be used as the reference for the PosAlongLine. Previously, we were always using the frombus of the line as the reference.
    • Contingency Analysis: Fixed error with loading in variable name references when Model Expressions refer to another model expression when using the WECC RAS format