Active balancing control for distributed battery systems based on cooperative game theory

For the smooth integration of renewable and volatile energy sources in the electricity grid, there is a need for scalable and efficient storage systems. Stationary battery systems provide the required efficiency but lack the scalability to meet varying requirements. In this article, we present a novel distributed control approach for active balancing of battery cells facilitating a scalable and flexible battery system design. For the proposed algorithm, the topology of the underlying battery system is assumed to be not predefined and can change at runtime. In such a system, each battery cell may has its own power electronics and processing unit which are used to manage the control actions for active balancing on cell level. Thus, the battery system is objected as a multi agent system (MAS) with battery cells as agents. Each agent locally computes and optimises its own control actions in a leaderless MAS setup based on cooperative bargaining games and the Nash solution. Each cell is required to find a single partner or multiple partners to form coalitions and exchange energy for active balancing. The working principle and capability of the distributed control algorithm is evaluated by simulations and compared to a passive balancing approach and a central optimal control algorithm. •Distributed control is applied to active balancing of flexible battery systems.•The battery system and its cells are modelled as a multi agent system (MAS).•Cooperative bargaining and the Nash solution are applied for optimal energy exchange.•The proposed control algorithm handles battery structure changes at runtime.