The Applied Research Of Electric Vehicle CAN Bus And Electric Signal Measurement

With the increasing of energy crises and environmental issues by fuel vehicles, it has become an inevitable trend that the electric vehicle (EV) replaces the traditional fuel vehicle. Pure EV with many advantages,such as zero emissions, low noise etc., is highly valued by the international community. As one of the essential technologies for developing EV, CAN bus and electric signal measurement which in order to promote the safety and controllability, is one of the key technologies to achieve commercialization and practicability of EV. Using CAN bus and electric signal measurement is benefit drivers to manipulate car and understand battery status and electric insulation status, and benefit EV developers to understand EV's situation and provide reliable basis for further development and improvement of EV.This dissertation specified content of EV general electric signal measurement, detailed analysed implementation method of measurement of several electric signal. On the base of consulting and referencing relevant research from home and abroad, and combining the purely electric car, the insulation monitoring device of high-voltage drive power, battery management system (BMS) of EV, gear controller and vehicle status display instrument were designed, and linked up these devices by CAN network using SAE J1939 protocol, to realize the monitoring different information, including insulation of high-voltage drive power, drive battery voltage, drive battery temperature, drive battery current and drive battery remain energy.This dissertation deeply analysed SAE J1939 protocol, designed the EV CAN network based-on SAE J1939 protocol and realized in each device of electric signal measurement. After studied and compared the current insulation monitoring devices, the EV drive power insulation on-line monitoring device was developed. This dissertation analysed and discussed the principle of Li-ion drive battery, factor of influence battery remain energy, and difficult question of battery management system. The SOC predicts method was deeply discussed and BMS based on using battery management chip were designed.The research of this dissertation will facilitate improving EV performance, safety and controllability. The solution of this dissertation is valuable for engineering application and reference for research in the future.