低速大转矩永磁电机的转子散热问题

对一台低速大转矩永磁电机进行有限元温升计算,并在保证电机性能参数基本不变的情况下对电机进行改进设计,缩短了铁心长度,提高了转矩密度,节省了材料。但改进后电机的转子和永磁体温度过高,易使永磁体退磁。结合fluent流固耦合计算方法,首先理论分析影响对流换热强弱的因素,然后研究加装散热风刺的不同尺寸对永磁体散热效果的影响规律,以及开设转子轴向、径向通风道对永磁体散热效果和温升分布的影响。最后进行样机试验,与理论分析结果进行对比,验证了所提转子散热方法的有效性及计算的准确性。该方法对低速大扭矩永磁电机的设计有借鉴意义。

The Rotor Heat Dissipation Problem of Low Speed and High Torque Permanent Magnet Motor

In this paper,the temperature rise was calculated by finite element method with a low speed and high torque permanent magnet motor,and the accuracy of the calculation method was verified by the experiment.The temperature rise of the motor was low,so the design was improved,the length of the iron core was shortened,the torque density was increased,and the material was saved.But in the improved motor,the high temperature of the rotor and permanent magnet(PM)can lead to PM demagnetization.Therefore,this paper has carried out the researching on this problem,the theoretical analysis and the calculation of fluid solid coupling method were used to solve the problem that the heating of the rotor of the improved motor.Firstly,the factors that affect the intensity of convective heat transfer were analyzed,and then the heating problem was solved by the installation of cooling wind thorn and rotor axial/radial ventilation duct.The heat dissipation effect of PM with different size of wind thorn was studied.The heat dissipation effect and temperature rise distribution of PM with the rotor axial/radial ventilation duct was studied.The accuracy of the research and the validity of the method were verified by the experiment.The research on the heat dissipation problem of the rotor has a certain guiding role for the design of the low speed and high torque permanent magnet motor