Temperature Field Analysis of Line-Start Asynchronous Permanent Magnet Motor Based on Fluent

As the wide application of line-start permanent magnet motors in oil pumping units, the motor 3D model is presented, and the simplified methods of rotor core, stator base, slot insulation, cover and shaft as well as the reasonable block split size are given. According to the mathematical model of temperature calculation, the basic assumptions and boundary conditions are specified. The equivalent thermal conductivity coefficient of air gap and heat transfer coefficient of casing surface are caculated with the semi-empirical formula method. At the same time, the influence of fit-up gap between stator and case, magnet and rotor core, rotor core and shaft, case and cover, cover and bearing, cover and shaft to the motor highest temperature is also taken into consideration. The heat value is caculated with measured loss value and distributed in proportion to the motor. Finally, the temperature caculated by finite volume method (FVM) and the temperature of experimental value is contrast to verify the feasibility of this method.