Prediction of starting performance of PM motors by DC decay testing method

This paper presents a method to predict the direct- and quadrature-axes ope rational impedances and starting performance of permanent-magnet CPM) motor s by a simple standstill response testing method using a small-capacity de power supply unit. In this method, not only the starting performance but al so the direct- and quadrature-axes synchronous machine constants (synchrono us, transient, and subtransient reactances) and equivalent circuit constant s are calculated, This proposed strategy, tentatively named the de decay te sting method, is carried out on a 3.7-kW 200-V 22-A 100-Hz four-pole interi or PM motor with damper winding. The results measured by on-load tests and those predicted by the proposed method on starting performance demonstrate the validity and usefulness of the proposed method.