Turn fault detection for surface-mounted permanent magnet synchronous machine based on current residual

The mathematical models of the surface-mounted permanent magnet synchronous machine (SPMSM) in both healthy and turn fault conditions are utilized to generate the current residual with the same voltage input. The features in the current residual are analyzed with the consideration of model accuracy. The 2 nd harmonic in the positive rotating dq reference or the dc component in the negative rotating dq reference can be extracted as the fault indicator. To estimate the dc component in the negative rotating reference that is more accurate and robust to transient states, a periodical integral is used in favor of conventional filtering or fast Fourier transform (FFT). It can be shown that the proposed fault detection scheme can distinguish the effect of speed or torque transient from the fault, thus giving a more reliable detecting result. The proposed technique is verified by simulation on a 12-slot, 14-pole SPMSM under various operating conditions.