Dynamic Grouping Control of BESS for Remaining Useful Life Extension and Overall Energy Efficiency Improvement in Smoothing Wind Power Fluctuations

Aiming at issues of life loss (LL) and overall energy efficiency (OEE) for battery energy storage system (BESS) in smoothing wind power fluctuations, a dynamic grouping control strategy of BESS for remaining useful life (RUL) extension and OEE improvement is proposed. First, grid-connected power signals are obtained. Second, a model to optimize capacity allocation for three battery groups (BGs) in BESS is established considering LL and OEE, and it is solved by the designed improved beetle swarm antennae search algorithm. Then, a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units (BUs) during operation to keep good sustainable dispatchability. Then, a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE, and also keeps consistency of state of charge for BUs simultaneously. The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined. The lower layer, considering PCS efficiency under different working conditions, finishes power allocation from each BG into BUs inside it. Subsequently, an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time. Finally, the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively, which verifies its correctness and validity.