Design And Research On The Control Method Of The Novel Permanent Magnet Synchronous Machine For Electric Vehicle Application

With the energy issues have become increasingly prominent and environment pollution is becoming more and more serious, the whole society are in the promotion of green environmental protection and clean energy. The concept of development of the automotive industry is moving in the energy saving and environmental protection, especially pure electric vehicles as the most clean energy vehicles is the main direction of the development of new energy vehicles in China. Drive motor and its control strategy is the core part of the pure electric vehicle, and to meet the high efficiency of electric vehicles, wide speed range and high overload capacity requirements. Therefore, this paper designed a new type of drive motor and the corresponding control methods to achieve these high performance of pure electric vehicles.Through the comparison and analysis of the performance of various types of electric vehicles, the high performance of the interior permanent magnet synchronous motor is selected, and the structure characteristics and working principle are introduced. The waveform of the air gap magnetic density for traditional interior permanent magnet synchronous motor is worse than the waveform of the surface mount type, because the waveform of the air gap flux density is similar to sine wave, and traditional interior air gap magnetic density waveform is to square wave. Therefore, in this paper, the design of the novel interior permanent magnet synchronous motor(IPMSM), using the method of ladder shaped magnetic flux density waves is close to sine wave, both to ensure motor with magnetic paste density sine waveform, and the motor having built-in flux weakening performance. By using the finite element analysis method and electromagnetic simulation software Ansoft Maxwell, the performance of the novel interior permanent magnet synchronous motor(IPMSM) is compared with surface mounted and traditional interior permanent magnet synchronous motor. The results show that the interior permanent magnet synchronous motor has the advantage of good air gap flux density, small torque wave dynamic, the high efficiency and a higher flux weakening capability.In order to meet the pure electric vehicle in the constant power region with a wide speed range, the paper used the field weakening control strategy based on the feedback voltage, and PI regulation loop, current loop decoupling and weak magnetic for the weak magnetic control strategy were designed. Finally, Matlab/simulink is simulated, and the results verify the correctness of the control method.Using TI’s TMS320F2812 chip to build a digital motor control experiment platform, design software and the corresponding flow chart. Complete motor prototype test results show that the motor meets the design requirements.