Software Patches

August 11, 2016

Bug Fixes

  • Auxiliary Files (SCRIPT and DATA Sections): When using the CTGSaveViolationMatrices script command, contingency names containing commas were not enclosed in double quotes so that they could be properly loaded in Excel. This has been fixed.
  • Difference Case Tool: Fixed comparison of the MTDCConverter Firing Angle in the Difference Case Tool.
  • File Formats: When loading in an EPC DC Converter record, the DC-side transformer taps were not being used appropriately. We now read the DC side tap and adjust the transformer ratio appropriately to model that effect. Also, when writing out the EPC file the DC-side taps are written back out as they were input and the DCBase is written appropriately.
  • File Formats: DC converters can have 2 sources of losses:
    1. Losses in the transformer, valves and auxiliaries that are proportional to the DC current (modeled as a commutating resistance Rc)
    2. Losses due to the voltage drop across the diode (modeled as a voltage drop)
    The RAW format supports the commutating resistance but not the Vdiode drop.
    The EPC format supports the Vdiode drop but not the commutating resistance.
    Simulator now supports both of these phenomena. When writing out to a RAW file, if the Vdiode term is non-zero then the Rc term is written increased by Vdiode/(2*DCCurrent) to represent the losses at the present operating point. When writing out to an EPC file, if the Rc term is non-zero then the Vdiode term is written increased by 2*Rc*DCCurrent.
  • Power Flow Solution: Augmented the modeling of DC Converter losses to allow the use of a Vdiode drop term as part of the converter model. This effects both the calculation of the DC voltage as well as adds an additional MW loss to each converter equal to the NumBridges * Vdiode * DCCurrent.
  • Power Flow Solution: Fixed the modeling of the DC Converter losses using the Commutating Resistance term. This was being properly modeled for the effect on the DC voltage, but the resulting MW losses were not being includied in the Power injection at each converter. This has been changed so that an additional MW loss is added to each converter equal to the NumBridges * 2 * Rcomm * sqr(DCCurrent).
  • Transient Stability: Corrected torque curve calculations for type 2 motors.
  • User Interface Dialogs: Modified dialogs and hints regarding the generator field "Enforce MW Limits" to make it clear that this only applies when the generator is being automatically controlled by the software. This limit is not immediately enforced and may not be enforced at all if the generator does not participate in control.