Study On The Efficiency Optimization Strategy Of Permanent Magnet Synchronous Motor

The increasing seriousness of China’s energy and environmental pollution problems,coupled with the growing support efforts of our country on the development of new energy vehicles makes China’s current electric vehicles develop in a blowout pace.Excelling in its high power-mass ratio,wide high-efficiency interval and fine operation characteristics etc.,together with the absolute unique advantage that China’s rare earth resource occupancy ranks first in the world,Permanent Magnet Synchronous Motor(PMSM)should by no means become the second to none choice of China’s electric vehicle motor.Therefore,it is of remarkable significance to study the driving system of Permanent Magnet Synchronous Motor,in the development of electric vehicle industry and the implementation of energy saving and emission reduction policy.This paper mainly attempts to study on the control of electric vehicle Permanent Magnet Synchronous Motor as well as its efficiency optimization strategies.In the first part,the research status of PMSM at home and abroad,and the research status of PMSM efficiency optimization strategy are analyzed.Based on the current high-speed development trend of electric vehicles and the short battery life of a single charge,the study on the efficiency optimization of permanent magnet synchronous motor has certain application value.Secondly,the basic structure of PMSM and the theory of coordinate transformation are introduced briefly firstly.Then comes the mathematical equations of PMSM in three-phase and two-phase rotating coordinate systems.And the latter’s basic electromagnetic relation and power transfer process are highlighted in this part.Thirdly,the basic working principle of the voltage-type inverter is analyzed,and the principle of the space vector modulation algorithm and the digital realization method are studied.Based on the above research,the vector control simulation model of PMSM has been established and studied by using MATLAB/Simulink.Fourthly,two main optimization methods----the control strategy of torque current ratio maximum and the optimization strategy based on the motor loss model----of PMSM are analyzed in details.So do the advantages and disadvantages as well as the problems in practical use of these two methods.Then MATLAB/Simulink are adopted to build the simulation model of the above two efficiency optimization strategies for the further research and analysis.Finally,this paper proposes an efficient and fast response control strategy for PMSM based on EKF.With a brief introduction of the Kalman filter model and its application,in this part,the author describes thoroughly the EKF model of PMSM in α-β coordinates and d-q rotating coordinate system.And substitution method is applied for the simplified analysis of the EKF and MATLAB/Simulink for the model establishment,research and analysis of the above optimization strategies.Simulation results validate the effectiveness and rationality of the EKF algorithm in the efficiency optimization control of PMSM.