A High-Precision Method of Online Battery Impedance Identification

This paper provides a high-precision method for online battery impedance identification. The proposed method can be performed without interrupting the normal operation of the battery system, which can meet the demands for realtime and dynamic applications. In this paper, the power converter and sampling circuit are specially designed for the features of the signal to be measured, which improves the accuracy of signal measurement and impedance identification. Firstly, this paper elaborates on the theoretical basis of the proposed high-precision method for online battery impedance identification. By controlling the excitation signal, the battery system can meet the electrochemical impedance spectrum (EIS) measurement conditions. By improving the power converter and sampling circuit, the excitation signal resolution and sampling accuracy can be improved. Then, the proof-of-concept experimental results are obtained.