Analysis of a Five-Phase Fault-Tolerant Consequent-Pole Permanent-Magnet Vernier Machine

The five-phase fault-tolerant consequent-pole permanent-magnet Vernier machine (FTCP-PMVM) has attracted extensive research attention owing to its excellent permanent-magnet utilization while maintaining competitive electromagnetic performance. However, the double-salient structure poses considerable challenges for analysis. The torque generation and power factor characteristics of the FTCP-PMVM are analyzed from a magnetic field modulation perspective in this work. Initially, based on the air gap field modulation effect, the modulation processes of both the permanent-magnet field and the armature field are analyzed. Subsequently, the torque generation mechanism is explained through harmonic matching resulting from the field modulation process, the results demonstrate that the 23rd air gap harmonic dominates the generation of average electromagnetic torque and accounts for the majority of output torque. Furthermore, the power factor is examined in depth by analyzing the reactive power contributed by the machine inductive components (e.g., self-inductance, mutual inductance and leakage inductance) and the active power generated by the permanent-magnet portion, all from the standpoint of field modulation. Finally, a prototype is fabricated to test the machine’s torque, power factor and efficiency. Experimental data confirms the reliability of the theoretical analysis.