The Drive System For And CAN Bus Network Control System

EV (electric vehicle) becomes the new hot point in vehicle for its advantages such as cleaning, pollution-free, high efficiency and diversified power sources. It is also one kind of the most promising green vehicle in future. As the driving core and key technology of EV, motor and its control system is the first problem to solve in developing EV. The SRM (Switched Reluctance Motor) drive system with low voltage and low power designed in this thesis can be used to drive both golf cart and sightseeing trolley.Firstly, this thesis introduces each part of the speed control system of SRM and the current common control method. Besides, it analyzes the advantages and disadvantages of each kind of control methods. Based on this, this thesis accomplishes the software and hardware system design combining with the three-phased SRM (3kW/48V and 12/8 poles). The hardware design of the SRM drive and control system mainly includes the design of power inverter in the main circuit of SRM and the parameters selection, drive circuit and the driving power design, estimation of power loss in the power circuit and the heat sink design, all kinds of signals detection and protection circuit design and the improved design of control circuit, etc.At the same time, this thesis designs the motor data acquisition and display system based on CAN bus. Advanced network communication technology is applied in vehicles. The acquisition and transmission of all motor data is realized through local area network CAN bus and the transmission wiring harness is simplified greatly. The communication with the liquid crystal display (LCD) system is realized and real time monitoring of motor status information is realized. In the software design of the control system, modular programming is adopted to strengthen the readability and popularity of the program.Finally, the motor operation and the testing experiment of CAN bus communication is conducted. The thesis also analyzes the data and wave form obtained from all kinds of experiments and verifies the rationality of this system design. Finally, this thesis summarizes the operating performance of the whole system which has certain reference value for the following development of EV.