Comprehensive Study of a Novel Six‐Phase Rotor‐Permanent Magnet Axial Field Modular Fault Tolerant Flux‐Switching Machine for Electric Vehicle/Hybrid Electric Vehicle Application

ABSTRACT In this paper, a novel six‐phase rotor‐permanent magnet axial field modular fault‐tolerant flux‐switching machine (RPM‐AFMFTFSM) is proposed. The separated stator core and rotor cells provide effective electromagnetic isolation for the armature windings, and this leads to enhanced fault‐tolerant operating capability. The segmented permanent magnet (PM) is integrated in the rotor, by which the magnetic saturation of the stator iron core is alleviated and the PM eddy current loss is reduced. The stator‐slots and rotor pole‐pairs (Ps/Pr) combination of the proposed machine is optimised, and the cogging torque is reduced. A comparative study between the RPM‐AFMFTFSM and conventional stator permanent magnet axial field flux‐switching machine (SPM‐AFFSM) is carried out by 3‐D finite element analysis (FEA) method. The advantage of the proposed machine with respect to the overload capability, flux‐weakening capacity and antidemagnetisation ability are revealed. The fault‐tolerant performance under single‐phase and two‐phase open‐circuited conditions is analysed. The full‐bridge inverters are employed on the six‐phase armature windings to achieve the reduced amplitude of the fault‐tolerant current and copper loss by adopting the round rotating magnetomotive force reconfiguration control strategy. Finally, a prototype of the RPM‐AFMFTFSM is manufactured and the FEA predicted results are validated by experimental measurements.