磷酸铁锂电池表征内阻特性的研究  

Study on characterization impedance characteristics of LiFePO4 batteries

作　　者：林文衡 严晓[1] 王影 黄碧雄 刘中财 LIN Wen-heng;YAN Xiao;WANG Ying;HUANG Bi-xiong;LIU Zhong-cai(College of Automotive Engineering, Shanghai University of Enigccring Science, Shanghai 201620, China)

机构地区：[1]上海工程技术大学汽车工程学院

出　　处：《电源技术》2019年第7期1116-1118,1124,共4页Chinese Journal of Power Sources

基　　金：上海市科委项目(15110501100);上海工程技术大学新能源汽车协同创新建设试点项目(2016xt02)

摘　　要：以6并13串的50 Ah磷酸铁锂电池模组为实验对象,从能量损耗角度出发,定义了一个参量表征内阻,在45℃下,参考Freedom CAR功率辅助型混合动力车电池测试手册中混合脉冲功率测试方法(HPPC)测试不同脉冲电流大小,不同脉冲时间长度下的表征内阻,得出表征内阻的变化规律。实验结果表明,在相同荷电状态(SOC)下,随着脉冲时间的增加,表征内阻增加,增加的幅度基本不变并略微减小。随着脉冲时间的增加,表征内阻随SOC的变化在总体趋势上保持一致,前期稳定并在SOC=0.3时出现最小值,在SOC=0.8以后开始大幅减小。在同一电流倍率下,随着SOC的增加,表征内阻呈现减小趋势,且脉冲电流倍率越大,这种减小越呈现出强烈的线性,当脉冲电流达到1.5 C时,这种减小已基本呈线性;当SOC为0.1~0.6时,表征内阻随电流倍率的增加接近线性增加,变化趋势一致,且增加幅度减小。With the battery module which consists of 6 parallel and 13 serial 50 Ah LiFePO4 battery as the experimental object, refering to the HPPC test method in Freedom CAR power-assisted hybrid car battery test manual, different pulse current and characterization impedance with different pulse time length were tested at 45 ℃,and the law of characterization resistance was obtained. The experimental results show that under the same state of charge(SOC), the characterization resistance increases with the increase of pulse time, and the increase speed is stable and slightly decreases. The resistance shows the same variation trend with the increase of pulse time, the variation trend is stable at the beginning of the test, the minimum value appears at SOC=0.3, and the maximum value appears at SOC=0.8. The resistance decreases with the increase of SOC when the pulse rate is certain. The decrease trend shows strong linearity when the pulse rate reaches 1.5 C. The resistance tends to linear increase with the increase of pulse rate when the SOC is from 0.1 to 0.6.

关 键 词：磷酸铁锂 表征内阻 混合脉冲功率性能测试 脉冲电流 脉冲时间长度 电池荷电状态 

分 类 号：TM912.9[电气工程—电力电子与电力传动]