A stator turn-fault detection method for inverter-fed IPMSM with high-frequency current injection

This paper presents a turn-fault detection method for inverter-fed Interior Permanent Magnet Synchronous Machines(IPMSMs) using high-frequency current injection when the motor is at standstill. When the motor is stopped, the fault current which flows in the faulty turns and the phase currents can be expressed with the injected phase current and the mutual inductance between each phase winding and the faulty turns. Because of the turn-fault, the injected high frequency currents cause different losses according to the direction of the injection. The proposed detection method exploits the difference of the losses of each case to diagnose the turn-fault. Experimental results are provided to verify the proposed detection method. The resultant loss pattern agrees well with that of the electrical model and shows reasonable sensitivity to the turn-fault. Two-turn fault among 27 turns of a phase winding of the motor under test has been detected easily with existing hardware of the drive system.