An Active Equalization Method Based on an Inductor and a Capacitor for Series Battery Pack

Abstract

Combining the characteristics of the high precision of inductive energy storage equalization and the fast speed of capacitive energy storage equalization, an active equalization method is proposed for a series battery pack based on an inductor and capacitor. The energy storage devices responsible for energy transfer have only one inductor and one capacitor. First, we propose the topology, analyze the working principle, and elaborate on its parameter design process. Second, an adaptive equalization control strategy matching the topology is designed. Third, based on the simulation models, the speed and efficiency characteristics of the new equalization method are verified, and the significant cost and volume advantages and the simple control characteristics are analyzed in detail. Finally, an experimental platform was built for a four-cell series battery pack to verify the effectiveness of the new equalization method for the battery pack charging and discharging process. The voltage difference is less than 80 mV.