Analysis And Design Of Electric Drive System For Hybrid Electric Vehicles

Combining the advantages of Electric Vehicle (EV) and engine-driven vehicle, Hybrid Electric Vehicle (HEV), which having characteristics of low pollution and low fuel consumption, becomes a good solution to energy saving and environment protection. As a main component of HEV, electric drive system plays an important role in HEV. So, the study of electric drive system has great theoretical and practical significance.This paper focuses on electric drive system of Hybrid Electric Vehicle. Based on the analysis of electric drive system of HEV, the control strategies of electric drive system have been researched. The main task is designing the hardware and software of electric drive system.Firstly, the characteristics and demand of the electric drive system of HEV is analyzed. By comparing the performance and the characteristics of several kinds motor, the 3-phase, 4-pole PMSM (TYBZ-1500-160L-4) is selected as the motor drive. The proper current control strategies of electric drive system are chose. Vector control technology, SVPWM technology and feedback control theory are applied to the control of PMSM. According to this, all digital electric drive control system is designed.Secondly, in order to improve the static and dynamic features of electric drive system, self-adaptive tuning of fuzzy PID is adopted by system. In order to verify the vector control and self-adaptive tuning of fuzzy PID, the whole vector control system is simulated in MatLab/SimuLink. The results show the high efficiency of fuzzy PID control. Fuzzy PID control may meet the demand of electric drive system.According to the design proposal, the electric drive system of HEV is designed based on the dedicated motor control DSP chip-TMS320LF2407A. The hardware circuits is designed, including drive isolation circuit of IPM power module, DSP peripheral circuits, voltage and current detection circuit and protection circuits. At the same time, the software of electric drive system is designed with C language and assembly language. Some subprograms are realized as below, the main subprogram, fuzzy PID control subprogram, and drive interrupt subroutine.Many relevant tests are executed, including SVPWM test, rotor field-oriented control test and motor characteristics test. The results show that the electric drive system runs with constant torque in low speed region. On the contrary, electric drive system runs with constant power in high speed region. The electric drive system designed can meet the demand of Hybrid Electric Vehicle.