Modeling And Analysis Of Interior Permanent Magnet Synchronous Motor Based On Equivalent Magnetic Network

The new energy industry led by electric vehicles has been booming in various countries.The interior permanent magnet synchronous motor(IPMSM)is the heart of electric vehicles,and its fast and high-precision analysis methods play a pivotal role in the development of more efficient and more powerful electric vehicles.Finite element analysis(FEA)is widely used due to its high calculation accuracy and high interaction.However,its calculation is time-consuming and cannot meet the early design requirements of motors.Although analytical method can quickly predict the performance of the motor,it often ignores the saturation of the iron,so the calculation error is large,and the accurate electromagnetic characteristics of the motors cannot be obtained.The equivalent magnetic network(EMN)method is favored by more and more scholars because of its high accuracy and short calculation time,and is widely used in the analysis of electromagnetic characteristics of IPMSM.However,the existing EMN model for IPMSM has problems such as low calculation accuracy,unclear theory of relative motion analysis and poor portability.This paper takes an shifted asymmetrical IPMSM as an example to illustrate the method of establishing a new EMN model for IPMSM,which effectively solves the problems of the existing EMN model.Additionally,the effectiveness of the proposed IPMSM modeling method is verified through FEA and experimental tests,and the method for analyzing the electromagnetic characteristics of IPMSM based on the EMN method is clarified.The specific research results are as follows:1.Based on the equivalent theory of reluctance and magnetic source,three commonly used EMN modeling methods are reviewed,and the mesh theory is introduced,which provides method selection for modeling IPMSM.2.The method of establishing the EMN model for IPMSM is proposed.Firstly,the IPMSM is divided into three regions,and hybrid modeling is carried out according to the magnetic field distribution of those regions,so that the calculation efficiency and accuracy is balanced.Secondly,based on the equivalent theory of mixed materials mesh,an ideal air gap model is proposed,which greatly simplifies the analysis of relative motion.Finally,the rules for dividing the sub-region model of the rotor unit are proposed,which enhances the versatility of the EMN model for IPMSM.3.The process of calculating the EMN model for IPMSM is analyzed,and linear interpolation method is replaced by cubic spline interpolation method,which improves the calculation efficiency of EMN model.4.The test platform of prototype is built,and the FEA model of shifted asymmetrical IPMSM is constructed.By comparing the results of FEA,EMN models and experimental tests,the effectiveness of the proposed IPMSM modeling method is verified.Meanwhile,the calculation method of reluctance torque and eddy current loss of permanent magnets is explained.