基于阶梯波的锂离子电池电化学阻抗谱低频段在线辨识方法  

Study on Online Identification Method of Low Frequency Electrochemical Impedance Spectroscopy for Lithium-Ion Battery Based on Step Wave

作　　者：孙丙香[1] 王家驹 苏晓佳 张维戈[1] 赵鑫泽 Sun Bingxiang;Wang Jiaju;Su Xiaojia;Zhang Weige;Zhao Xinze(National Active Distribution Network Technology Research Center Beijing Jiaotong University,Beijing 100044 China;Yinchuan Power Supply Company State Grid Ningxia Power Co.Ltd,Yinchuan 750011 China)

机构地区：[1]北京交通大学国家能源主动配电网技术研发中心,北京100044 [2]国网宁夏电力有限公司银川供电公司,银川750011

出　　处：《电工技术学报》2023年第11期3064-3072,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52177206,51907005)。

摘　　要：电化学阻抗谱(EIS)是锂离子内部特性参数的外在表征,如何摆脱对专有设备的依赖,通过在线辨识得到EIS,尤其是低频段EIS对于准确地估计电池状态具有重要意义。该文以三元锂离子电池为研究对象,在电池管理系统和双向充放电机的协议框架下,设计了工况实验,利用阶梯信号和正弦信号的变换关系,提出了一种基于阶梯波的锂离子电池EIS低频段在线辨识方法。分析了不同荷电状态(SOC)和不同数据采集间隔对于阻抗谱辨识结果的影响,对比了该方法相对于方波傅里叶分解法的优势,给出了满足辨识精度的最低采样要求。该方法通过现有配备的电池外围系统即可实现,有效地解决了工程应用中无法实现锂离子电池EIS低频段在线辨识的难题。Electrochemical impedance spectroscopy(EIS)is an external characterization of the internal performance parameters of lithium-ion battery.How to get rid of the dependence on proprietary equipment for online identification of EIS,especially low-frequency EIS identification is of great significance for accurately estimating battery status.At present,the existing methods of online identification of EIS in engineering mainly obtain the corresponding sine wave by Fourier decomposition of the square wave.However,there are differences between the harmonic amplitudes obtained after decomposition and the fundamental amplitudes,and the identification results have relatively large errors in the low frequency band of EIS.Therefore,in order to further improve the identification accuracy of the EIS low frequency band,this paper takes NCM lithium-ion battery as the research object in the framework of the communication protocols between battery management system(BMS)and bi-directional charging-discharging device.Further,an online identification method for lithium-ion batteries low-frequency EIS based on step waves is proposed via the transformation relationship of step signals and sine signals,the frequency range is selected to be below 2 Hz.In order to better analyze the EIS low-frequency identification method based on step wave proposed in this paper,three groups of experiments are mainly designed.The feasibility of the step wave EIS(STEIS)identification method,the accuracy of the STEIS low-frequency identification results with different sampling frequencies,and the advantages of the EIS test method compared with the square wave Fourier decomposition are mainly analyzed.The test frequency is 10 mHz~2 Hz,and the temperature is all carried out at 25℃.The equipment and components used in the experiment include Bio-Logic VMP-300 electrochemical workstation for electrochemical impedance spectroscopy,high and low temperature test chamber for controlling ambient temperature,power battery under test,and computer for control and data

关 键 词：锂离子电池 电化学阻抗谱 低频段 阶梯波 在线辨识 

分 类 号：TM911[电气工程—电力电子与电力传动]