Abstract:To reduce the noneffective harmonic content in the armature reaction magnetic field(ARMF)of a permanent magnet vernier motor(PMVM)and realize the high efficiency operation of the motor, a dual-winding low-harmonic permanent magnet verier(DWLH-PMWM)was proposed based on the air-gap magnetic field modulation theory. Firstly, the DWLH-PMVM structure was introduced and the harmonic cancellation principle was illustrated. Subsequently, considering the influence of temperature rise on the performance of conductor windings and permanent magnets, a bidirectionally coupled computation based on the finite element method was adopted to calculate and compare the performances of the conventional PMVM and the DWLH-PMVM, including the air-gap magnetic density, the torque, and the temperature rise. The results reveal that the torque and the efficiency of the proposed motor are improved due to the low-harmonic design. Compared with the conventional PMVM, the average torque and the efficiency of the proposed DWLH-PMWM can be improved by 2.62% and 0.55%, respectively, as well as the torque ripple can be decreased by 50.15% at 20 ℃. In addition, the torque and the efficiency can be improved by 2.66% and 0.57%, respectively, and the torque ripple can be decreased by 50.16% when the temperature converges to a steady state. Thus the effectiveness of the low-harmonic design scheme is verified.