Investigation of multiphase modular stator SPM with fault tolerance

Multiphase modular stator permanent magnet machine (MSPM) features fractional slot concentrated windings, negligible mutual phase inductance and thus the high fault tolerance. This paper intends to investigate the fault tolerance of a five phase 20-slot 22-pole MSPM with shaped permanent magnets. The faulty modes include one phase open-circuited, two non-adjacent phases open-circuited, two adjacent phases open-circuited, and one phase short-circuited. Optimal current control strategy is studied and applied to achieve maximum average torque without regard to torque ripple. Finite element analysis is performed to simulate the MSPM with all of the mentioned faulty conditions. Torque characteristics of the MSPM under healthy and faulty modes show that, the MSPM still possesses satisfactory electromagnetic performances in case of the faulty modes.