Inductor-Based Active Balancing Topology with Wide Voltage Range Capability

With the increasing number of batteries integrated into the grid, the electrification of transportation, and the importance of reusing secondary batteries to preserve natural resources, active balancing techniques are becoming critical for optimizing battery performance, ensuring safety, and extending their lifespan. There is a demand for battery management solutions that can efficiently manage the balancing of battery cells across a wide range of voltage levels. This paper proposes a new inductor-based active balancing topology that achieves balancing by transferring energy from battery cells to the battery pack. One of its main advantages over existing designs is that it can operate over a wide battery cell voltage range. Moreover, multicell balancing with a balancing current independent of the imbalance level can be achieved by adjusting the width and interval of pulses. The proposed topology can be implemented using traditional low-side gate driving integrated circuits, avoiding the need for expensive isolated power modules and high-side gate drivers. Sample balancer designs for low-voltage battery cells as well as higher-voltage cells are provided. The presented experimental results verify the operation of the proposed balancer on a lithium-ion battery pack.