基于电池内阻特性的电动汽车放电模式研究

Study on discharging modes of electric vehicle based on lithium-ion battery resistance performance

电流、温度大小会影响电动汽车锂离子动力电池组放电的效率及电池组一致性,其本质是电池内阻本身固有特性所致。通过研究锂离子动力电池组在不同温度、不同放电电流下的内阻变化,建立电池内阻变化图谱,分析不同温度、电流对电池输出能量的影响。根据电池内阻特性,结合整车动力性及经济性,将电动汽车放电策略分为可供选择的三种模式:动力模式、经济模式及限制模式。通过电动汽车续驶里程及放电能量的对比测试,比较所提出的各种模式的优缺点。实验证明,根据不同路况及使用需求,采用不同的放电模式,可以保证整车动力性,延长电池寿命,提高整车续驶里程。

The discharging efficiency and consistency of electric vehicle lithium-ion battery can be affected by the current and temperature,and the reason for the phenomenon is that the resistance of battery is affected by the current and temperature.The changing of resistance at different current and temperature was studied,and the battery resistance map was established,and the battery output energy at different current and temperature was analyzed.According to the dynamic characteristic and economy,the discharging strategies of electric vehicle were divided into three modes： dynamic mode,economic mode and limit mode.The electric vehicle driving tests were carried out and the different modes were compared in the experiments.The results show that the proposed method can improve the dynamic characteristic,energy efficiency and extend the battery life.