Current Sensor Fault Diagnosis Based on Sliding Mode Observer for Permanent Magnet Synchronous Traction Motor

This paper presented a current sensor fault detection method based on sliding mode observer (SMO) for closed-loop torque control system of permanent magnet synchronous motor (PMSM). A current SMO is constructed in dq coordinate to generate fault residuals of alpha beta axis current sensors, then online diagnosis of abc phase current sensor fault is realized based on relationship between the residuals and the phase current sensors faults, and fault diagnosis rules. Structure of the designed observer is concise, the theoretical derivation and the process of stability proof are all simple. Simulation and experimental results demonstrate the feasibility and effectiveness of the method.