Software Patches

May 19, 2015

Features and Improvements

  • File Formats: Added process to check the voltage magnitude and angle of star buses at the end of the RAW file read, and evaluate the mismatches at the three terminal buses of the three winding transformer. If we determine that our own estimate of what we think the voltage and angle should be at the star bus results in improved mismatches at the three terminal buses, we will apply our estimated voltage values to the star bus, otherwise we will keep the voltage magnitude and angle as read from the RAW file for the star bus.
  • Bug Fixes

    • File Formats: When reading the XF regulation parameters in a UCTE file, a bug existed such that the relevant transformers could not be found. This has been fixed so that the regulation parameters are correctly applied.
    • File Formats: The last line of a UCTE file was not being processed. This has been fixed.
    • PV and QV Curve (PVQV) Tool: Fixed access violation that could occur at the start of a PV run when using the interface ramping option.
    • PV and QV Curve (PVQV) Tool: When using the interface ramping option with the PV tool, do the full OPF solution always rather than trying to speed things up by doing only a single outer loop. This will ensure that the results are within the desired tolerance if a solution is found.
    • Transient Stability: Modified the DC Line calculation when considering mode 3. Mode 3 is the constant Beta mode which is used as a gradual transition between Mode 1 (full current) and Mode 2 (current reduced by the current margin). Mode 3 uses the Beta from the previous network solution which it had in a Mode 1 or 2 solution. Immediately after a network event however, Mode 3 can not use the Beta from the previous solution because the entire network state had a discrete change and the Beta from that solution is not reliably reasonable for the new network state. Doing so could lead to a solution failure. This has been fixed so that Mode 3 operation is not allow in the timestep immediately following a network event.