Rotor fault diagnosis in permanent magnet synchronous machine using the midpoint voltage of windings

Abstract

A new strategy is proposed here for the diagnosis of asymmetric demagnetisation in permanent magnet synchronous machines. The strategy is based on the measuring of the voltage at the midpoint of the windings within a phase. Unlike the phase voltage, for a fault situation, the midpoint voltage shows sidebands around the fundamental component, which allows detecting and quantifying the demagnetisation phenomenon. A low-cost implementation for the automatic detection of faults is also proposed in the present study and experimental results are presented to validate the strategy.