Embedded Electrochemical Impedance Spectroscopy into Battery Management System
Desmon Simatupang, Abdulraouf Benshatti, Sung-Yeul Park
Abstract
This paper presents the integration of electrochemical impedance spectroscopy (EIS) in the battery management system (BMS) with reduced number of components. The functions of BMS in this paper are to equalize the batteries’ state-of-charge (S0C) and to internally heat the batteries through the internal resistance of the batteries during the winter condition. The EIS method is to inject the periodically current signal and measure the output voltage in the terminal of the battery. Then, the battery impedance can be obtained by calculating the comparison of voltage and current in the battery. The impedance data processing will be used to estimate the condition of the battery-related to the state of health (SoH) or lifetime. The internally heating mechanism will be used during the winter or sub-zero temperature conditions to heat up the battery. The equalizer is needed to balance the SOC in each battery and to prevent over-charging and over-discharging which can lead to thermal runaway. Batteries 18650 will be used in the proposed method for PSIM simulation.