Stator Winding Faults investigation in Permanent Magnet Synchronous Motor using Motor Signatures: Part I

Among various available stator faults in Permanent Magnet Synchronous Motors (PMSMs)., the Stator Winding Faults (SWFs) are more recurrent. The main cause of SWF is the breakdown of insulation between the windings which leads to the heavy flow of inrush currents damaging the stator windings. Depending upon the location of fault in the stator winding, SWFs can be classified viz. Stator Inter-turn Fault (SITF), coil-to-coil fault, phase-to-phase fault and open-circuit winding fault. This paper shall emphasize in detail about Equivalent Electric Circuit (EEC) modeling approach of SWFs. A mathematical model of a PMSM suitable for SWF, is developed and the response of a machine in terms of stator currents, back-EMF, electromagnetic torque and mechanical speed is observed both under healthy and fault conditions. The corresponding changes in the characteristic behavior during faults has been used to classify SWFs of PMSM.