Synchronous Machine Modelling by Standstill Frequency Response Tests

The synchronous machine is modelled in terms of operational impedances derived from standstill frequency response measurements. A curve-fitting procedure in the complex plane yields all the parameters including the armature resistance without having to pre-process the data or make other measurements. The validity of the model is demonstrated for a micro-alternator by comparing the sudden short-circuit current predicted by the model with that obtained experimentally. Frequency response data obtained at different current levels are used to show that a useful model can be derived from tests at low per-unit current.