Evaluation of Demagnetization Fault in PMSM with partitioned stator windings using Finite Element Method

A permanent magnet synchronous machine (PMSM) model with asymmetric demagnetization in the rotor is proposed in this work. The 2D model implemented using a finite element method reproduces the geometric and electrical characteristics of a prototype PMSM built in the laboratory. In order to analize the effects of asymmetric demagnetization, the PMSM features distributed windings with access to the midpoint of the phase windings. Unlike fault diagnosis methods based on phase voltages, in this work it is proposed to analyze the effects of demagnetization from the voltages measured on the middle of the windings of each phase. Simulation results obteined for the PMSM under normal operating and with demagnetization rotor are presented. It is concluded that asymmetric demagnetization can be diagnosed by monitoring a residual voltages obtained from the midpoint voltages measured in the stator windings.