Torque Ripple Suppression Of Permanent Magnet Brushless DC Frameless Torque Machine

Abstract

This paper analyzes the effects of different slot-pole combinations, unequal-magnet height poles, motor structural parameters, and permanent magnet parameters on torque ripple by finite element simulation. In order to cope with the working condition of a permanent magnet brushless DC frameless torque motor (PMFTM) sensitive to speed fluctuations in a robot drive system, the 39-slot/12-pole frameless motor is taken as an example. Two eccentric pole structures were selected for the analysis of air gap magnetism and radial electromagnetism, as well as their impact on vibration noise. Furthermore, a multi-objective genetic algorithm based on sensitivity analysis method is introduced to obtain the optimal torque and torque ripple. The simulation results demonstrate that the designed motor exhibits excellent performance in terms of cogging torque and suppression of ripple torque.