Abstract:
To restrain the torque fluctuations of five-phase permanent magnet synchronous motor (PMSM) under open-circuit fault condition, a novel direct torque control (DTC) strategy based on novel switching table was proposed in the paper. Firstly, to maintain the same circular trajectory of stator flux vector as that under healthy condition, the stator fluxes were modified under open-circuit fault condition. Secondly, to achieve a switching table being suitable to healthy and fault conditions, a novel switching table was designed according to the characteristics of voltage vectors in the case of fault. The proposed fault-tolerant DTC strategy was not only able to suppress the third harmonic currents under healthy and fault conditions, and avoid reconfiguration of the DTC system after fault, but also can could suppress the torque fluctuations caused by open-circuit fault, and achieve smooth operation. Simulation and experimental results were used to verify the effectiveness of the proposed fault-tolerant DTC strategy.