Fault Diagnosis for PMSM Drive System in Electric Vehicle

Electric and hybrid electric vehicles (EV/HEVs) have attracted considerable interest among automobile manufactures worldwide due to their advantages of better fuel economy. To guarantee safe, clean and reliable operation of electric drive systems, it is imperative to develop reliable and robust diagnostic schemes so that appropriate corrective actions can be taken in case a component or subsystem fail to operate normally. This paper proposes a diagnostic scheme for permanent magnet synchronous motor (PMSM) drives in EV/HEV applications. The proposed strategy uses two generalized observers to detect and isolate current, speed, and rotor position sensor faults in a PMSM drive. Since in real driving cases, the load torque is usually unknown due to unexpected road disturbance, the proposed diagnostic scheme uses an Unknown Input Observer (UIO) to estimate the load torque. The diagnostic algorithm is validated in Matlab/Simulink using the Ohio State University EcoCAR as testbed. The simulation results show that the proposed scheme is effective in detecting and isolating various sensor faults under road disturbance.