Transient Motor Starting
PowerFactory’s Transient Motor Starting functionality analyses motor starting scenarios where the effect of a motor starting on the grid frequency is negligible. In such situations, the typical questions to be answered are:
- What is the maximum voltage sag? (This is typically not the initial voltage sag at t=0)
- Will the motor be able to be started against the load torque?
- What is the time required to reach nominal speed?
- How will the supply grid be loaded and which starting options should be considered?
The Transient Motor Starting function makes use of the PowerFactory stability module by providing a pre-configured shortcut for easy-to-use motor starting analysis. The motor starting is initiated by selecting the respective motors within the single line diagram and initiating the motor starting calculation.
- A complete symmetrical or asymmetrical AC/DC load flow will be computed prior to the motor starting event; pre-selected and pre-configured VIs are automatically created and scaled with full flexibility for user-configuration.
- Consideration of high-precision, complex motor models with built-in parameter estimation. A comprehensive library of low voltage, medium voltage and high voltage motors is provided.
- Typical motors supported are: single- and double cage asynchronous machines, squirrel and slip-ring motors, double-fed induction machine, synchronous motors.
- Access to the model library for built-in motor driven machine characteristics (torque-speed characteristics) with flexible user-modelling support.
- Support of various starting methods such as direct start, star-delta starting, variable rotor resistor, thyristor softstarter, transformer softstarter, variable speed drives, etc.; start from any rotational speed.
- Full flexibility in considering starting sequences.
Full representation of generators with exciter/AVR model support on the basis of built-in models (e.g. IEEE models) as well as user-defined models utilising the DSL approach; consideration of protection devices such as under-voltage protection, over-current protection, automatic restarting relays (EMR) or transformer OLTC.
