Investigation of a Novel Hybrid Less-Rare-Earth Consequent-Pole Interior Permanent Magnet Machine with Asymmetric Rotor

This paper investigates two V-shaped hybrid less-rare-earth asymmetric interior permanent magnet machines (HLRE-AIPMs), in which one machine adopts the conventional rotor and the other adopts the consequent-pole rotor. The PM poles of both machines are featured by three PMs with different sizes and asymmetric spatial positions, where the large-size PM contains rare-earth element and the two small-size PMs are ferrite type. The geometric parameters of the two machines are optimized globally. Then, the open-circuit air-gap flux densities of the conventional IPM machine and the consequent-pole IPM machine are calculated by the magnetic circuit method to qualitatively address them. The electromagnetic performances of the optimized machines are compared in detail. It shows that the HLRE-AIPM with the consequent pole rotor has comparable maximum average torque and efficiency as the one with the conventional rotor, while the former one has much lower torque ripple and consumes much less PM material.