Inter-turn fault detection in five-phase pmsms. Effects of the fault severity

This paper deals with the effects of inter-turn short circuit faults in five-phase permanent magnet synchronous motors (PMSMs). For this purpose a finite-elements model (FEM) of a faulty machine with 1, 2 and 4 inter-turns in short circuit is analyzed. From the results of this model the effects of these fault severities in the stator currents and zero-sequence voltage components (ZSVC) harmonics is analyzed and the possibility of developing a fault diagnosis scheme based on the changes in their spectral content is exposed. Moreover, the effect of the fault severity on the total power losses in the machine is presented. Inter-turn faults generate large circulating currents which may lead to catastrophic failures. Therefore it is very important to know the increase in power losses in the machine due to the occurrence of such faults for applying corrective actions at the precise time once the fault has been diagnosed.