A Diagnosis for Demagnetization of Permanent Magnetic Synchronous Motor Based on Second Order Generalized Integrator

In this paper, a demagnetization fault diagnosis is proposed for electrical vehicle drive system. A second order generalized integral is applied to calculate the stator flux linkage. The calculated flux linkage is compared with a look-up table value generated by the finite elements analysis to diagnose the fault. In addition, a reference theory is introduced to extract the partial demagnetization characteristic harmonic. The two parts compose the overall diagnosis system. The simulation results are presented to validate the proposed algorithms.