Scaling

The following section describes how units and scaling are used and configured in TwinCAT Power Plant Control.

All power values in Target and Demand as well as parameters associated with power control are expected by the controller as a percentage of the nominal value. The nominal value is defined by the parameter ActiveNominal (in watts) and corresponds to P_{b inst} according to VDE standards or P_Max according to EN standards. User-specific scaling can be configured for Target and Demand power values using the ActiveScale parameter (default=100.0) for active power values and ReactiveScale (default=100.0) for reactive power values. If Scale = 1.0, per-unit scaling is set. The default setting is Scale = 100, which corresponds to the percentage scaling.

Incoming grid data is received in SI units (such as V, A, W) and scaled internally to per-unit with corresponding parameters such as VoltageNominal . The parameters assigned to the voltage are given as a percentage, as in the VDE and EN standards.

The frequency is not standardized and is expected by the controller in Hertz.