Research On Li-ion Battery Management System In EV

For the considerations of energy and environmental issues, the electric car has been developed fast under the joint efforts of governments and vehicle manufacturers. In all kinds of electric cars, EV has become one of the most important development directions, due to the realization of the true "zero emission". For its energy density and excellent high voltage performance platform, Li-ion battery has become the ideal power source in EV. However, the anti-abuse capacity of Li-ion battery is poor. The safety and long-life of Li-ion battery, especially Li-ion battery pack has become urgent problems in the management of Li-ion battery use.For the current problems in Li-ion battery management, the paper studied the Li-ion battery management system in EV which was used in bus services for the Peking Olympics.The paper studied the basic working principles of the Li-ion battery at first. From the perspective of the Li-ion internal mechanism, we analyzed the factors which effect Li-ion battery performance and safety. At the same time, we did some tests about the Li-ion battery characteristics. On this basis, to the objectives of safe and effective use, Analyzed the use in vehicle and working environment for Li-ion battery, put forward the management strategies in four areas, as battery SOC estimation, thermal management, insulation detection and charge mode for Li-ion battery pack. Finally, we designed the hardware and software of the Li-ion battery management system, implemented the battery management strategies through the use of software algorithms in the battery management system.During the Peking Olympic Games, a total of 50 electric buses equipped with the BMS have operated and achieved a "zero failure" stable operation.