基于准零相位滤波器的电池储能系统平滑风电波动控制方法

利用电池储能系统(BESS)平滑风电功率波动可以提高风电场输出稳定性,但基于一阶低通滤波器的控制方法易将风电功率趋势分量引入BESS充放电指令,增加BESS容量需求。针对该问题,提出一种基于准零相位滤波器的BESS控制方法。首先,分析滑动平均滤波器时频特性及滞后相位特性对BESS充放电控制的影响。然后,以中心滑动平均滤波算法为基础,融合风电功率趋势预测信息来构建一种相位延时近似为零的准零相位滤波器。最后,该滤波器提取风电功率波动分量,显著降低滤波延时,减小BESS充放电指令中的趋势分量。对典型风电功率波动情景的仿真结果表明:在获得与传统低通滤波方法近似平滑效果时,所提策略能够明显减小BESS最大能量波动和累积能量交换,进而降低容量配置要求,延长使用寿命。

Control Method of Wind Power Fluctuation Smoothing for Battery Energy Storage System Based on Quasi-Zero Phase Filter

The output stability of the wind farm can be improved by using the battery energy storage system (BESS) to smooth the wind power fluctuation, but the control method based on the first-order low-pass filter is prone to the introduction of the trend component of wind power into the charging/discharging order of the BESS, which increases the demand of energy storage capacity. Aiming at the problem, a control method of BESS based on the quasi-zero phase filter is proposed. Firstly, the impact of time-frequency domain and phase lag characteristics for the moving average filter (MAF) on the charging/discharging control of BESS is analyzed. Then, based on the central MAF algorithm, a quasi-zero phase filter with the approximate zero phase delay is established by integrating the prediction information of wind power trend. Finally, the fluctuation component of wind power is extracted by the proposed filter to significantly reduce the filter delay, and the trend component in the charging/discharging order of the BESS is decreased. The simulation results of typical wind power fluctuation scenarios show that when the obtained smoothing effect is similar to that of traditional low-pass filtering method, the proposed method can significantly reduce the maximum energy fluctuation and cumulative energy exchange of BESS, thus the capacity requirements is reduced and the service life of BESS is extended.