采用电池储能系统(battery energy storage system,BESS)平滑风电功率波动可以优化风电场出力特性,提高风电场输出功率的稳定性。为了延长BESS的使用寿命,需最大限度控制BESS的荷电状态(state of charge,SOC)在限定区间内,以便拥有足够的容量进行下一时刻的充放电动作,从而带来更好的平滑效果。为此,提出了一种运行策略,该策略由2种控制算法组成,系统运行时,根据风电功率波动量的大小决定采用何种算法,2种算法依据风电场实际运行状况相互切换。仿真结果表明,该策略与传统低通滤波相比,不仅拥有较好的平抑效果,还能让BESS的SOC在合理的区间内,从而延长了BESS的使用寿命,节约了储能投资成本。
Using battery energy storage system( BESS) to smooth wind power fluctuation can optimize wind power output characteristics and improve the stability of output power in wind farm. In order to extend the service life of BESS,it needs to control the state of charge( SOC) of BESS in a defined interval furthest,which can have enough capacity to charge and discharge at next moment and bring a better smoothing effect. Therefore,this paper proposes a new control strategy which consists of two control algorithms. The selection between these two algorithms is determined according to the value of wind power fluctuation during the operation of system. Two algorithms are switched with each other based on the actual operating conditions of wind farms. Simulation results show that,compared with the traditional low pass filtering,the new strategy not only has a good stabilizing effect but also can make the SOC of BESS in a reasonable range which can largely extend the service life of BESS and save the cost of energy storage investment.