A Fault-Tolerant Field Oriented Control for Five-Phase Surface-Mounted Permanent-Magnet Synchronous Motor With Non-sinusoidal Back EMF

A fault-tolerant field-oriented control (FOC) is proposed for five-phase surface-mounted permanent magnet synchronous motor (SPMSM) with non-sinusoidal back electromotive force under single-phase open-circuit fault. On the basis of the concept of preserving the circular rotation of fundamental magnetic motive force and PM flux linkage, the decoupled model of five-phase SPMSM under single-phase open-circuit fault is derived. To suppress the torque ripples caused by third-harmonic content of PM flux linkage, the closed-form solution of current references with zero-torque pulsation in the synchronous coordinate is presented. Then, the presented solution is used for obtaining optimum current references to achieve minimum stator winding losses and maximum available torque while satisfying the zero-torque-pulsation constraint. The optimal current references generation method is simple and is suitable for real-time implementation. The experimental results confirm that the proposed method can effectively suppress the torque ripples and produce lower stator winding losses as well as wider-torque operation range compared with traditional fault-tolerant FOC method.