Analysis Of Subdomain Model And Eddy Current Loss For Surface Mount Permanent Magnet Motor

The surface mounted permanent magnet motor has small volume and simple structure,and the permanent magnet is used as a part of the rotor to replace the rotor winding,and the robustness of the permanent magnet motor is strong.The armature reaction magnetic field of the surface mounted permanent magnet motor is calculated,and the eddy current loss model is established.The research objects of this topic are single layer winding motor,distributed double layer winding motor and centralized double layer winding motor.In this paper,based on the subdomain analysis method,the armature reaction magnetic fields of the above three kinds of motors are analyzed.For the single winding of permanent magnet motor,this paper sets up a subdomain superposition model.Only one slot is excited and distinguished from other slots,so the different excitation method is applied to the Maxwell equations.Then the magnetic field generated by single slot can be calculated,and the total magnetic field of all three-phase current excitation is superposed.For distributed concentrated winding surface mounted permanent magnet motor and centralized double winding permanent magnet motor,two currents of each slot are regarded as one current,so that each slot is equivalent to single winding of current.Then subdomain superposition was used and the total magnetic field is superposed.This paper proves the correctness of the equivalent method by analyzing the harmonic of the MMF.Then,the eddy current loss models of single layer winding motor,distributed double layer winding motor and centralized double layer winding motor are built,and eddy current losses are calculated.In this paper,all the results obtained by the models are compared with those of the finite element method,which proves the feasibility and correctness of the proposed method.