Research On CAN Communication And Test System Of Electric Vehicle Motors

In recent years, electric vehicles became the trends in the automotive indu stry due to its features like little impact on the environment, low noise, and lo w cost energy while traditional internal combustion engine vehicles faced the problems of energy shortage and environmental pollution. The performance of motor drive system, as drive system of electric vehicles, directly determines the dynamic performance and safety of electric vehicles. Currently, the industry sta ndard for electric vehicle motors has not been fully established, and there are different kinds of motors in different car manufacturers. Therefore, the high-power motor test system for evaluating the performance of electric vehicle mot ors has some practical effect. Meanwhile, development of communication softw are of electric vehicles motor system based on CAN bus and PC monitoring software is necessary in order to solve different communication messages and transmission rate between electric vehicle motor drive and vehicle system.First of all, this article describes J1939protocol as mainstream high level protocol of the electric vehicle CAN bus communication protocol, and describ es the data link layer, the application layer, troubleshooting and network mana gement of J1939protocol. Then, on the basis of this protocol, motor drive CAN communication software based on TMS28035is designed. The design re alizes communicate between electric motor drive and automobile platform. Me anwhile, the accuracy of the motor controller CAN communication is tested by CAN communication monitoring experiments.Secondly, in order to realizing the communication of different motor drive and electric vehicle control system, a design of CAN communication relay station based on Renesas SH72A2integrated controller is presented. Relay station hardware design includes CAN interface design and external circuit design. Relay station software realizes dual-channel CAN communication, message conversion, parking control and other functions. Finally, design of power motor test platform for electric vehicles is proposed. Power capacity of test system is selected based on the analysis of mainstream electric vehicle motors, and design the cabinet of drive and feedback energy system according to drive motor’s and load motor’s capacity. Meanwhile, this paper describes the data acquisition performance of the motor test system, including the functions of power analyzers, torque sensors, temperature capture card, and data acquisition card. Automatic test of temperature rise test, load test and load test of electric vehicles’ high-power motor are completed with using PC test software.