无刷直流电机的理想与非理想定位力矩及其综合抑制方法

可以采用多种有效的方法来抑制无刷直流电动机的定位力矩,但电机各部件制造或材料偏差的存在,使得按照上述方法实际生产出的电机出现较明显的定位力矩.文中从理论上分析了理想与非理想定位力矩的产生机理和规律;以4极9槽和4极12槽径向磁路无刷直流电机为例,采用数值计算和试验的方法定量分析了理想与非理想定位力矩,给出了定位力矩产生的一般规律.采用极槽配合法、磁极优化法、闭口槽法及定子齿冠开槽法抑制理想定位力矩,并分别给出了Z次和2P次非理想定位力矩的抑制措施.计算和试验结果验证了理论分析结论的正确性.

THE IDEAL AND NON-IDEAL COGGING TORQUE IN BRUSHLESS DC MOTOR AND ITS COMPREHENSIVE REDUCING METHODS

Many techniques can be adopted to reduce the cogging torque in brushless DC motors. But the unavoidable manufacturing tolerance and material nonhomogeneity make attribute to evident cogging torque in the practical brushless DC motors produced according to those techniques. The mechanism of generation and general rules of ideal and non-ideal cogging torques were theoretically analyzed, and the ideal and non-ideal cogging torque of two radial field brushless DC motors with 4 poles 9 slots and 4 poles and 12 slots respectively was quantificationally analyzed by using finite element computation and experiments. The slot/pole combination, magnet shape optimization, closed slot, and notching in tooth face methods were adopted to reduce the ideal cogging torque. The respective methods for reducing the Zth and 2Pth non-ideal cogging toque were presented. The calculated and experimental results verify the validity of the theoretical analysis.