Coordinated control strategy of the battery energy storage system for lifetime extension and efficiency improvement in wind power applications

The battery energy storage system (BESS) can be controlled to smooth the wind power with the active power regulation. At the same time, the BESS can regulate the grid-side voltage with the reactive power control. In this paper, a coordinated control strategy for active and reactive power control of the BESS based on a variable charge/discharge time (CDT) and an optimal filter time is proposed to extend the BESS lifetime and improve BESS efficiency. First, the relationships between the charge/discharge time (CDT) of the BESS and the lifetime and efficiency of the BESS are studied. To extend the BESS lifetime and improve BESS efficiency, a variable CDT control scheme of the BESS is developed. Then, an optimization algorithm of the variable filter time is developed to satisfy both the wind power smoothing and the grid-side voltage regulation requirements. Finally, the proposed BESS control method is verified by a simulation with the actual data from a wind farm.