Power Allocation Strategy for Battery Energy Storage Stations Considering Battery Inconsistency

Energy storage technology is crucial for enhancing renewable energy utilization in power systems. However, operational inconsistency among battery units in storage stations significantly reduces both efficiency and battery lifespan. This paper addresses these challenges by proposing an optimized power allocation strategy considering variations in equivalent internal resistance and state-of-charge (SOC) constraints. Leveraging the Shepherd model, the internal resistance and SOC dynamics of batteries are analyzed, while converter losses are assessed under different operating power levels. The proposed strategy optimizes power allocation across storage units to minimize system losses, incorporating constraints such as power balance, SOC limits, and safe operating ranges. A case study involving four storage units with real-world parameters demonstrates that the strategy reduces cumulative losses by prioritizing units with lower internal resistance. Simulation results indicate that overall system efficiency improves compared to equal power allocation while preventing SOC extremes. The findings validate the strategy’s effectiveness in enhancing operational efficiency and extending battery lifespan, providing practical insights for the management of battery energy storage stations.