大数据驱动的电动汽车动力电池老化状态评价方法  

A Data-driven Battery Aging Estimation Method for Power Batteries in Electric Vehicles

作　　者：王圆圆 华远鹏 王世谦 孙志伟 刘智城 张照生[2] WANG Yuanyuan;HUA Yuanpeng;WANG Shiqian;SUN Zhiwei;LIU Zhicheng;ZHANG Zhaosheng(State Grid Henan Electric Power Company,Zhengzhou 450000,China;School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]国网河南省电力公司经济技术研究院,郑州450000 [2]北京理工大学机械与车辆学院,北京100081

出　　处：《交通信息与安全》2022年第6期157-164,共8页Journal of Transport Information and Safety

基　　金：国家重点研发计划项目(2019YFB1600800)资助。

摘　　要：针对电动汽车动力电池健康状态在线估计困难、老化速率量化缺乏参考指标的问题,研究了实验室数据与实车运行数据相结合的电池老化状态和老化速率量化评价方法。通过实车运行数据与实验室数据的预处理,得到实车停车充电片段和实验室充电片段的电池数据;再基于安时积分法计算电池容量,并提出电池健康状态(SOH)的评估方法。使用最小二乘法拟合实验室电池SOH与循环次数的函数关系,得到实验室电池老化速率模型;利用实车运行数据拟合实车电池SOH与实车充电等价循环次数的函数关系,得到实车电池老化速率模型。最后,结合实车电池SOH与实车动力电池衰退系数β,提出电池老化状态的综合评价方法。为说明方法的有效性,以1辆事故车与2辆正常车为对象,开展电池健康状态与老化状态评估实验,实验结果表明:①已知电池SOH理论使用下限为80%且电池系统衰退系数β阈值通常为1,基于此规律大部分事故车电池的SOH在温度区间的末尾达了理论使用下限,且在大多数温度区间内电池系统衰退系数β接近或超过阈值,表明电池加速老化,符合事故车特征;②对于正常车辆,其SOH在不同温度区间的数值均未达到理论使用下限,且正常运行的2辆车衰退系数β在大多数温度区间内都低于阈值,说明老化速率相对较慢,符合正常车特征。综上,通过结合电池SOH和衰退系数β的评价方法,丰富了电池老化状态的评价手段,使得电池老化状态评价更加全面,为电池老化状态研究提供了新思路。To solve the problem of aging state evaluation of electric vehicle power batteries,a battery aging estimation method combining laboratory experiment data and field experiments data is proposed.First,the battery charging segment data are obtained from the laboratory experiments and field experiments.Secondly,the battery capacity is calculated based on ampere-hour integration,which has been widely used to evaluate the battery state of health(SOH).Thirdly,the relations between the battery SOH and the number of recharge cycles are formulated by using the laboratory data and the field data,which are the battery aging models for laboratory battery and vehicle battery,respectively.Lastly,a comprehensive aging estimation method for electric vehicle batteries is obtained by combining the battery SOH and its decay coefficientβ.The experimental results indicate that:①When the lower limit of battery SOH is 80%and battery decay coefficient threshold is set to 1,the SOH values of the battery from accident vehicles approach the theoretical lower bound at the end of most temperature ranges.It indicates that the degradation of their batteries is obvious,in complying with accident vehicles.②The SOH values of the battery from normal vehicles do not reach the lower bound in various temperature ranges,and the decay coefficient are far below the threshold.It indicates that the degradation of their batteries is relatively slow,in complying with normal vehicles.In conclusion,the proposed estimation method combing the battery SOH and decay coefficientβenriches the choice for battery aging estimation and makes the estimation more comprehensive,which provides a new idea for battery aging research.

关 键 词：电动汽车 动力电池状态评估 健康状态 衰退系数 大数据驱动 

分 类 号：U469.72[机械工程—车辆工程]