An Online Battery Electrochemical Impedance Spectroscopy Measuring Method

The safety of battery energy storage systems is becoming increasingly important in the context of the rapid development of renewable energy. In order to address that issue, the identification of battery state is crucial. At present, methods for estimating battery states using electrochemical impedance spectroscopy (EIS) are widely studied, and existing research results indicate that EIS can estimate battery state of charge (SOC), state of health (SOH) and even state of safety (SOS). Therefore, achieving online measurement of EIS has become a hotspot. At present, the vast majority of EIS online measurement methods focus mainly on measuring the full frequency band and require injecting current disturbances of different frequencies, resulting in low testing efficiency and insufficient utilization of the current during system operation. This article analyzes the most valuable EIS frequency range for achieving state estimation, and proposes an EIS online measurement system and corresponding measurement method. Relevant verification has been completed using a publicly available dataset. The proposed method exhibits good performance for measuring within the specified frequency range.