Research And Design Of Electric Vehicle Drive System Based On SRM

Abstract:Switched reluctance motor (SRM for short) becomes an attractive alternative in electric vehicle drive motors due to its simplicity in motor construction, low starting current, large pull-in torque, efficient operation in a wide range of speed and torque, high reliability. However, the high cost of the controller and the big output torque ripple make the application of switch reluctance motor in electric vehicle restricted.This paper takes the electric vehicle drive system based on SRM as the research object, analyzed the advantages of switched reluctance motor in the application of electric vehicle and the key technologies that need to be overcome. In this paper, the working mechanism of switched reluctance motor and various control strategy is researched, and the advantages and disadvantages of various topological structure of power conversion circuit are compared. A55kw switched reluctance motor which is used in the electric vehicle is designed with Ansoft Rmxprt software module. The SRM performance simulation based on Maxwell2D (two dimensional finite element analysis software) has been done. And a three-phase full-bridge power circuit control strategy based on two-phase excitation is proposed. The switched reluctance motor drive system starting torque and running efficiency are improved, and the cost of hardware are reduced.Based on the above basis, in this paper, the hardware and software implementation for the electric car with switched reluctance motor drive system is done.The hardware of the system includes two parts:power circuit and controller circuit. Three-phase full-bridge power circuit is to be the power circuit topology in this paper. The controller circuit with microcontroller XC2765X is chosen as the core.The overall structure of the system software in which the average torque control strategy is used is proposed. System program is written by Infineon Corporation integrated development environment TASKING. Some of the implementation method of several important program modules is analyzed in experimentation. The result of the experimentation demonstrates the practicability of two-phase conduction three-phase star connected circuit which is proposed in this paper.