Optimal Power Dispatch Strategy for Multiple Battery Containers in a Grid-scale BESS Station

Abstract

A grid-scale BESS station usually contains multiple battery containers and corresponding electric paths. Each path and container could become a dispatchable unit when receiving network operators’ orders. Battery containers will perform differently after long-term use, especially considering a mixed utilization of new and recycled battery. Currently the storage import/export power is distributed equally among containers. The dispatch and control strategy for containers mainly focus on their capacity constraint, rather than their performance, temperature, and ageing conditions. This paper proposed a novel optimal power dispatch strategy for multiple battery containers in a BESS station. This method established the mathematical relationship between battery ageing with SOC, DOD, operating temperature and charging state transition times. The minimum total battery ageing is used as the optimization objective to achieve the optimal power dispatch among containers. The simulation results showed this strategy helps to balance the ageing, temperature and SOC between containers, leading to a more reliable and secure operation of BESS station.