High Efficiency Balancing Converter with Battery Impedance Measurement Function

In the context of renewable energy consumption and functions such as grid peak and frequency regulation, the field of battery energy storage systems has emerged as a prominent area of research. The presence of voltage differences between multiple parallel battery clusters in these configurations can give rise to phenomena such as circulating currents, with the potential to influence system capacity utilization and efficiency. The utilization of a balancing transformer is often essential to ensure state balancing. Existing balanced converters generally rely on full power conversion of battery clusters, leading to substantial losses. This paper proposes a novel energy storage system architecture and the corresponding balancing converter, which can achieve efficient balancing of battery cluster energy. Additionally, during battery state balancing, the converter can measure the electrochemical impedance of the battery, further correcting the battery state and achieving fault warning.