低速电动汽车电池管理系统研究

Research of battery management system for low-speed electric vehicles

针对低速电动汽车使用过程中出现的剩余电量估计不准及电池组寿命短的问题,提出了一种基于改进的安时法和耗散式均衡电路的电池管理系统策略。通过电动势和剩余电量的对应关系确定安时计算的初始值;利用继电保护测试仪校正霍尔电流传感器的精度,减小安时法积累误差;引入耗散式均衡电路降低单体电池电压的差异。实验证明,该管理系统对低速电动汽车剩余电量的估计有较高的准确性,且原理简单,易于硬件实现;均衡电路效果良好,能降低电池管理系统成本,延长蓄电池组的使用寿命。

To solve the problems of poor accurate SOC estimation and short life of the battery strings for low-speed electric vehicles,a BMS strategy based on an improved ampere-hour method and dissipative balanced circuit was proposed.The initial value of ampere-hour computation could be obtained through relationship between electromotive and SOC;the precision of Hall current sensor was calibrated to reduce the accumulated error;the introduction of dissipative balanced circuit could reduce the monomer battery voltage difference.The experiment results show that the proposed BMS strategy for low-speed electric vehicles can make high accurate SOC estimation and the principle is easy to implement;the balanced circuit is effective with low-cost which can extend the service life of battery strings.