Study On Permanent Magnet Synchronous Motor Drive System In Electric Vehicle Application

This dissertation is devoted to the study on permanent magnet synchronous motor (PMSM) drive system for electric vehicle(EV) application.Based on TI company DSP special-designed for motor control on TMS320LF2407A designs and develops a full-digital PMSM vector control system,and both the software and hardware of the system are accomplished.Firstly,the theory of vector control on PMSM has been studied further deeply,the Maximum Torque Per Ampere control strategy in constant torque region and the field weakening control strategy in constant power region are analyzed.This paper presents an algorithm of interior permanent magnet synchronous motor in the field-weakened region. By combining closed-loop control using the output voltage and feed-forward control with the pre-calculated tables,the proposed strategy can achieve fast dynamic control as well as parameter insensitivity in the field-weakening region.Secondly,the Principles structures and the realization of the software and hardware of the control system are introduced.In the hardware of the system,the control circuit and the main circuit design are discussed thoroughly.With assembly language,dual close loop (speed and current) vector control strategy has been realized on the hardware system designed above.The flow charts of main program and PWM interrupt service routines are given.In order to unite all the variables in the program,scaling is used.Thirdly,SVPWM modulation is discussed thoroughly.Voltage using efficiency of accumulator in EV has been improved by the design and realization of software SVPWM, and the harmonic of modulate voltage has been decreased.Finally,the experiment has been done for the driver which design in this paper. Results of the experiment indicate validity of the field-weakening method which introduced in the paper.