Inter-Turn Fault Diagnosis and Control for Five-Phase PMSMs by Disturbance Observer

This article proposes a new method, simultaneously considering inter-turn short-circuit (ITSC) fault diagnosis and fault-tolerant control of a five-phase permanent magnet synchronous motor (FPMSM), to realize an online diagnosis and fault-tolerant operation. This article is focused on linking the signals required for fault-tolerant control with diagnostic algorithms. The method uses a disturbance observer to obtain the disturbance signal from the ITSC and directly utilizes the fault characteristics in the disturbance signal for fault-tolerant control. No additional fault parameters (short-circuit current and short-circuit turn ratio) and no additional hardware equipment are required in this process while reducing the complexity of the fault-tolerant control method of FPMSM. In addition, since fault-tolerant reference current and injected current are both ac signals, the deadbeat current prediction control is constructed for fault conditions to track the signals accurately. The effectiveness and feasibility of the method are verified by simulation and experiment.