A Consequent-Pole Five-Phase Fault-Tolerant Permanent-Magnet Synchronous Machine for Electric Vehicles

Abstract

This paper investigates a consequent-pole five-phase fault-tolerant permanent-magnet synchronous machine (PMSM) for electric vehicles (EVs). In order to limit the phase short-circuit current, a consequent-pole rotor structure which features homopolar radially magnetized permanent magnets (PMs) is proposed for the five-phase PMSM. Topology and principle of the proposed machine are studied. The influences of the consequent-pole rotor on the machine characteristics like cogging torque and radial force distributions are investigated by finite-element analysis (FEA). The effects of the span ratio of PMs on the machine performances, such as cogging torque, electromagnetic torque, and phase short-circuit current, are further studied. A consequent-pole five-phase outer-rotor PMSM is designed and compared with the five-phase surface-mounted PM machine, and the comparison results show that the proposed machine features advantages of lower PM use, lower phase short-circuit current, and larger constant power speed range (CPSR).