Research On Permanent Magnet Synchronous Motor High Performance Flux-weakening Control

The permanent magnet synchronous motor(PMSM) has the advantages of high efficiency, high power density, small volume and good speed performance, so it has very high application value in rail transportation and other industrial fields, and the research on this aspect of the domestic and foreign scholars have made a lot of achievements. At the same time, along with the continuous development of permanent magnet materials, power electronic devices and the AC drive technology,theoretical research and practical application of control of permanent magnet synchronous motor also will continue to improve and enhancing the permanent magnet synchronous motor drive system will use in a more broad application prospects.This paper first introduces the development of permanent magnet synchronous motor and the structure characteristics, then analyzes the development of control theory of permanent magnet synchronous motor and the domestic and foreign study for flux-weakening control. Starting from the theory of coordinate transformation, the paper establishes the mathematical model of permanent magnet synchronous motor in the d-q rotating coordinate, and introduces the Space Vector Pulse Width(SVPWM) Modulation technology, which lays the theoretical foundation for the full research.On this basis, vector control theories of several control strategy of permanent magnet synchronous motor are analyzed, thus id=0 control,Maximum Torque Per Ampere control(MTPA), unit power factor control,flux-weakening control, Maximum Output Power control and Maximum Torque Per Voltage control(MTPV). And the whole process of step motor permanent magnet with flux-weakening control principle and the flux-weakening region are analyzed. Then, the id negative current compensation and Maximum Torque Per Voltage two kinds of permanent magnet synchronous motor based on flux-weakening control scheme are proposed. And the smooth transition strategy based on fuzzy control is put forward to, which, realizes the smooth transition of motor running from region 1(the constant torque region) to 2(the constant powerregion), region 2 to region 3(depth of flux-weakening region). At the same time, this paper also takes into account the influence of motor parameters on flux weakening capability, and puts forward to a kind of parameter identification of permanent magnet synchronous motor based on the load test method.Based on the above theoretical analysis, the use of MATLAB/SIMULINK simulation is carried out to verify the proposed method; Then, the d SPACE semi physical simulation experimental platform for the hardware design and software design is used, and the semi physical simulation experiment is carried out; Finally, though simulation laboratory system of subway permanent magnet platform for confirmatory test. The results show the accuracy and effectiveness of the proposed scheme.