Software Patches

August 20, 2021

Features and Improvements

  • File Formats: Added ability to read "vs converter data" from EPC files and then parse the records to create 2-terminal VSC DC Line objects. Also added the ability write the "vs converter data", "dc bus data", "dc line data" to an EPC file.
  • Oneline Diagrams: Added a new feature called a Spatial View which can be used for temporarily laying out a part of the system using geography if available. Intent is for this feature to work like a temporary Bus View, though you will also be able to save the spatial view as a stand-alone oneline after building it.
  • Power Flow Solution: Added 2 new options to modify the algebraic equations used to model line-commutated DC converters. Both options are not recommended, but when reading an EPC file PowerWorld will set these 2 options to YES so that the DC converter solutions will match the equations used by PSLF.

    Use Approximate DC Converter Power Factor Equations:
    Sim_Solution_Options VariableName = UsePSLFConverterApproximatePowerFactor
    Set to YES to use an approximate calculation (to match what PSLF does) for DC converter power factor of
    cos(Phi) = 1/2*(cos(FiringAngle) + cos(FiringAngle + mu))
    instead of the more accurate equation
    tan(Phi) = (2*mu + sin(2*FiringAngle) - sin(2*(mu + FiringAngle)))
    /(cos(2*FiringAngle) - cos(2*(mu + FiringAngle)))

    Use PSLF treatment of Fixed Tap in DC Converters:
    Sim_Solution_Options VariableName = UsePSLFConverterIncorrectFixedTap
    This only impacts DC converter transformer equations.
    NO - Uses the correct equation of TotalTap = VariableTap + FixedTap - 1
    YES- Uses the incorrect equation of TotalTap = VariableTap*FixedTap (implemented by PSLF).
  • Transient Stability: Added ability to read from a DYD file VHVDC1 models for 2-terminal VSCDCLine records.
  • Bug Fixes

    • Transient Stability: Bug fix for generating plots of fields only if they are stored in Hard Drive (storing to RAM is okay). Users might have observed that incorrect values were being plotting fields of certain devices. For example, plotting the "OEL Other 1" field for a Generator which does not actually have an OEL Active. The correct behavior is to not show any plot series on the generated plot, because the field itself does not exist for that generator. This issue is now fixed.