Study on the PWM Ripple Current based Turn Fault Detection for Interior PM Machine

Turn fault detection technique is of key importance for the system safety which can protect the machine and enable the appropriate mitigation strategies. In this paper, an advanced turn fault detection method is investigated for an interior permanent magnet machine (IPM) using the ripple current induced by the inherent PWM voltage harmonics. The resultant current harmonics under high frequency voltage harmonic are analyzed for both healthy and turn fault conditions. The feasibility of the detection method is validated by both simulation studies and prototype tests. It is confirmed that the PWM ripple current based diagnosis technique can be employed to detect the turn fault in IPM without introducing undesirable noises and vibrations. And it is capable to detect early turn fault.