Online Inverter Open-circuit Fault Diagnosis for Fault Tolerant Permanent Magnet Synchronous Motor System under multi-fault condition

The on-line inverter open-circuit fault diagnosis method of the six-phase fault tolerant permanent magnet synchronous motor (FTPMSM) system is investigated in this paper. The fault characteristic model of the FTPMSM system is first established, in which the optimal torque control is used to guarantee the ripple-free electromagnetic torque operation of the system under the fault condition. Then the fault characteristic extraction approach based on the Lissajous figure of the non-fault phase current is proposed. Finally, the inverter open-circuit fault diagnosis is proposed based on the Park's vector transformation, which can detect the power switch fault the inverter even in fault tolerance operation condition for the FTPMSM system.