Efficiency Evaluation and Optimization for the Combined Application of Reconfigurable Battery Systems and DC-DC Converters

Reconfigurable Battery Systems (RBSs) enable flexible battery connections to improve the operation performance, e.g., enhanced fault tolerance and extended energy storage/delivery. DC-DC converters are commonly used to efficiently convert and regulate voltage levels. This paper explores the application of connecting a DC-DC converter with an RBS to meet power requests. By dynamically adjusting the connection structure of battery cells in the RBS, e.g., the system configuration, it is possible to provide a wide range of input voltages for the DC-DC converter. Given a specific load power, to evaluate the overall efficiency of the RBS and converter for various system configurations, an RBS-converter model is formulated. Then, the overall efficiency can be further maximized by manipulating the system configuration through switch operations. The model-based simulation results show that the optimized overall efficiency of the RBS and DC-DC converter surpasses that of conventional fixed-configuration battery systems with the same converter, especially for low-power requests.