Optimal Control of Battery Energy Storage System Based on Variable Smoothing Time Constant

Integrating a battery energy storage system(BESS) with a wind farm helps smooth the fluctuant output of wind power.To smooth wind power output and prolong the life of BESS,an optimal control method of the grid-connected inverter for BESS is designed.An optimal control method based on variable smoothing time constant and power limit is proposed to protect BESS by adjusting the smoothing time constant and the limiting power of BESS in real-time.For the sublayer implementation of the inverter,the improved double-loop control algorithm is adopted which is able to switch mode to avoid over-voltage or under-voltage of BESS.The experimental results show that the proposed method is feasible and effective,and over-charge,over-discharge and over-load of BESS can be averted.