Fuzzy logic based fault detection of PMSM stator winding short under load fluctuation using negative sequence analysis

A negative sequence analysis coupled with a fuzzy logic based approach is applied to fault detection of permanent magnet synchronous motors (PMSM). First, the fundamental components of the motor terminal currents and voltages are separated effectively, based on which the negative sequence components are calculated. A fuzzy logic based approach is implemented to generate a robust detection using the adjusted negative sequence current and negative sequence impedance. The adjusted negative sequence current is obtained by separating the high frequency components caused by the load fluctuation from the total negative sequence current. The adjusted negative sequence current provides a qualitative evaluation on severity of the stator fault. Validation of the method is performed online using a PMSM experimental setup with dSPACE^reg and Matlab^reg/Simulink^reg environment. The use of fuzzy logic improves the sensitivity of fault detection while reducing false alarm rate under load fluctuations.