Optimization of dovetail magnetic isolation device for permanent magnet torque motor based on finite element method

Abstract

To further improve the torque performance of permanent magnet torque motors and enhance the magnetic stability of surface-mounted permanent magnets, a new dovetail magnetic isolation device (DMID) is discussed. First, the initial model of the motor is constructed and the structure of the DMID is parametrically designed. Second, a mathematical model of the average torque and torque ripple considering the DMID is developed based on the equivalent magnetic circuit model of the motor and the principle of electromagnetic torque generation. Then, with the help of the ANSYS Maxwell finite element simulation tool, the average torque is used as the optimization target, and the variation pattern of the slot width, inner circle radius, and position of the DMID are simulated and discussed. Finally, the average torque and torque ripple of the optimized motor are compared with those of the initial motor, and the results show that the average torque is increased by 37.2 Nꞏm and the torque ripple is weakened by 0.04% when the optimal parameters of the DMID are selected.