Dual Cell Links for Battery-Balancing Auxiliary Power Modules: A Cost-Effective Increase of Accessible Pack Capacity

This article focuses on the design of a half-full bridge (HFB) balancing link that can reduce the cost of redistributive battery balancer in electrified vehicle applications by combining the functionalities of a battery balancer and auxiliary power module (APM). The benefits of redistributive balancing are quantified based on existing datasets of commercial battery cells. The power rating for the electric vehicle's APM and balancing capability are discussed. A HFB module prototype is designed to validate the proposed concept. How to reduce the current ripple on the battery cells is presented in order to minimize the degradation of the cells due to highly dynamic current. Nickel-manganese-cobalt cells are installed on the module to investigate the balancing performance in real life. The efficiency map is also given for the prototype. Compared with existing balancing methods, the improvement under the same driving cycle is shown in the long-term simulation.