Bidirectional Converter-based Broadband Lithium-Ion Batteries Impedance Measurement Approach with Model Predictive Current Control

Measuring electrochemical impedance spectroscopy (EIS) is a crucial path to increase the operational safety of lithium-ion batteries (LIBs). However, conventional EIS is time-consuming and depends on professional equipment. To address this issue, this paper proposed a broadband EIS measurement scheme using a bidirectional DC-DC converter. First, a discrete-interval binary sequence (DIBS) signal is designed to improve the measurement accuracy at the specified harmonics. Then, the model predictive current control scheme is proposed to track the DIBS-based reference current precisely and rapidly. In addition, without increasing the signal amplitude, the measurable frequency band is expanded by setting different generation frequencies for the DIBS signal. Finally, experiment results show the effectiveness of the proposed approach by measuring two types of LIBs.