Inter-turn Short Circuit Fault Detection of a Novel PMSM with Fault Tolerance

Previously, a new type of PMSM with automatic fault tolerance for inter-turn short circuit faults was designed by this research group. When the motor fails, the short circuit current can be effectively suppressed and the output torque can be kept stable. A method for detecting interturn short circuit fault by injecting low frequency signal into existing coil is presented in this paper. Compared with the detection method proposed before, this method makes the structure of the motor simpler, does not need to set additional coils, and can find the fault location and judge the number of short turns more quickly.In this paper, the special structure and fault tolerance principle of motor are introduced, the theory of short circuit current in fault is derived, a low-frequency signal is injected into the existing stator winding and the relevant theoretical derivation about low-frequency short-circuit current is also deduced. Finally, finite element simulation of different short circuit turns is carried out by ANSYS.