A Novel V-shape Interior Permanent Magnet Synchronous Machine with Asymmetric Spoke-type Flux Barrier

This paper proposes an asymmetric interior permanent magnet (AIPM) synchronous machine with symmetrical V-shape PMs and asymmetric spoke-type flux barriers. This asymmetric rotor structure is featured by unequal distances between the flux barrier and its adjacent PMs, which can utilize the magnetic-field-shifting (MFS) effect by reducing the current angle difference between the maximum PM and reluctance torque components. Consequently, compared with the conventional V-shape IPM design with the same PMs, the novel topology can achieve resultant torque enhancement while no extra cost is required. Influences of position and dimensions of asymmetric flux barriers and pole arc of V-shape cavity on the maximum average torque and open-circuit air-gap flux densities are investigated. The proposed AIPM and the conventional V-shape IPM benchmark are designed by global parametric optimization with the same stator, rotor diameters and PMs. The comparison between electromagnetic performances confirms that the torque enhancement of the proposed AIPM is achieved by the MFS effect.