Optimal control of film growth in dual lithium-ion battery energy storage system

Abstract

This paper examines a charging/discharging scheme for Li-ion battery energy storage system used in renewable generation systems, with the view to minimize the growth of the solid-electrolyte interphase film and to prolong the battery life. A suitable reduced-order equivalent circuit model of the lithium-ion battery is developed based on electrochemistry. The model is used in the design of the battery power flow control scheme. By solving an optimization problem using dynamic programming algorithm, a computationally-efficient heuristic control strategy is further developed in accordance with the result of the optimization. The proposed new strategy is then compared with conventional dual-battery charging method to demonstrate the use of the proposed scheme can indeed extend the battery lifetime.