锂离子电池内阻测量系统设计

Design of Measurement System for Lithium⁃ion Battery Internal Resistance

电池内阻的精确测量是锂离子电池智能管理的基础,利用交流注入法结合开尔文四线检测法、交直分离技术及微弱信号检测技术,设计了锂离子电池内阻测量系统。该系统通过向锂离子电池施加交流恒流激励信号,利用信号调理电路获取锂离子电池输出的电压和电流响应信号,采用模数转换和数字信号处理获得锂离子电池的交流阻抗信息,并初步研究了锂离子电池内阻与其SOC之间的关系。实验结果表明,系统对锂离子电池内阻的测量结果与商用高精度内阻测量仪的测量误差小于1 mΩ。

Accurate measurement of internal resistance is the basis of intelligent management of lithium⁃ion battery.The alter⁃nating current injection method is combined with Kelvin four⁃line detection method,alternating signals separation technology and weak signal detection technology to study and design the lithium ion battery internal resistance measurement system.The system applies an alternating current excitation signal to the lithium ion battery,and obtain the voltage and current response signals out⁃put from the lithium ion battery by using signal conditioning circuits,and obtains the internal resistance of lithium ion battery with analog⁃to⁃digital conversion and digital signal processing.Furthermore,the relationship between the internal resistance and SOC of lithium⁃ion battery is researched preliminary.The experiment results show that the measurement error between the internal resist⁃ance of lithium ion battery and the commercial high precision internal resistance measuring instrument is less than 1 mΩ.