Design and Comparative Analysis of a Novel PM Vernier Motor With Trapezoidal Magnets and Flux Barriers for In-wheel Traction Application

In this paper, a novel interior permanent magnet vernier motor with trapezoidal magnets (IPMVM-TM) is proposed and analyzed, which is designed fitting for 16-in wheel. For a clear illustration, the performance comparisons between the interior PMVM with rectangular magnets (IPMVM-RM) and trapezoidal magnets (IPMVM-TM) are carried out under different working conditions. Meanwhile, the flux barriers are introduced aiming at increasing the modulation effect and improving the output torque. With the flux barriers, it is found that the torque increases and the torque ripple is suppressed. Besides, the air-gap permeance, back-EMF and torque expressions are also derived between the IPMVM with and without flux barriers. Finally, the performance optimization is conducted and a quick method is proposed to calculate the flux weakening parameters. Moreover, the results are well validated by the finite-element analysis (FEA).