基于脉冲压缩的锂电池宽频阻抗快速测量方法

Fast Measurement Method of Broadband Impedance of Lithium Battery Based on Pulse Compression

锂电池广泛应用于电动汽车及储能等领域,快速准确地评估锂电池健康状态对电池管理系统十分重要。通过电化学阻抗谱(EIS)可以分析锂电池内部电化学反应机理从而估计其健康状态。针对现有锂电池阻抗谱测量技术需要连续交流信号扫频,测量过程耗时长的问题,此处提出一种基于脉冲压缩理论的锂电池宽频阻抗快速测量方法。首先,向锂电池注入线性调频扰动信号,在小时宽下产生宽频带激励;然后,采用匹配滤波算法结合快速傅里叶变换获取锂电池宽频阻抗谱。最后,通过仿真和18650锂电池实验验证了所提方法可以在低信噪比条件下快速准确地测量锂电池宽频阻抗,为锂电池健康管理提供技术支撑。

Lithium batteries are widely used in electric vehicles and energy storage.It is very important to evaluate the health status of lithium batteries quickly and accurately for battery management system.Electrochemical impedance spectroscopy(EIS)can be used to analyze the electrochemical reaction mechanism in lithium batteries and estimate their health status.In order to solve the problem of AC signal sweep and time consuming in the current measurement technology of lithium battery impedance spectrum,a fast measurement method of broadband impedance of lithium battery based on pulse compression theory is proposed.Firstly,a linear frequency modulation disturbance signal is injected into the lithium battery to generate a broadband excitation at an hour width.Then,the broadband impedance spectrum of lithium battery is calculated by matching filter and fast Fourier transform.Finally,simulation and 18650 lithium battery experiment verify that the proposed method can quickly and accurately measure the broadband impedance of lithium battery under the condition of low signal noise ratio,and provide technical support for the health status management of lithium battery.