Electrolytic Capacitor Deterioration Detection Method Using Equalization Current for an LC Series Circuit Type Cell Voltage Equalizer

An LC series circuit type cell voltage equalizer requires a large capacitance capacitor, e.g., electrolytic capacitors, to transiently store the electric charge of batteries. The lifespans of electrolytic capacitors are shorter than those of other electrical and electronic components. Therefore, the lifespans of equalizers are limited by those of electrolytic capacitors. Thus, determination of capacitor deterioration is essential for the long-term stable operation of equalizers. This study proposed an electrolytic capacitor deterioration detection method for the LC series circuit type cell voltage equalizer. In addition, the usefulness of the proposed method was verified based on theoretical analysis, simulations, and experiments. It was confirmed that the proposed method could be used to determine the deterioration of an equalizer.