Permanent magnet synchronous motors (PMSMs) are used in many applications including the control systems due to their high efficiency, high power density, good dynamic behavior, high precision and excellent controllability. One of the PMSM problems is the cogging torque which is made by interaction between PMs and stator teeth. This leads to some noise and vibration of the motor that in control applications leads to fluctuation of the motor from its trajectory when tracking the target point. Hence, the motor should be designed in such a way to have very low cogging torque. In this research to reach this purpose, at first a suitable combination of slot/pole has been selected for the motor. Then, the optimum shape of the magnet has been obtained by using 2D finite element method. For the magnet shape, two important parameters of the magnet are optimized simultaneously. The designed motor has been fabricated and tested. The experimental results validate the simulation results and show that by the presented design the motor has very low cogging torque. 

Keywords: Permanent Magnet Synchronous Motor (PMSM), Cogging Torque, Magnet Offset, Magnet Embrace.

Full-Text [PDF 1044 kb]   (10269 Downloads)