兼顾补偿预测误差和平抑波动的光伏混合储能协调控制策略

Coordinated Control Strategy of Photovoltaic Hybrid Energy Storage Considering Prediction Error Compensation and Fluctuation Suppression

为了提升光伏输出功率预测精度和平抑功率波动,提出一种兼顾补偿预测误差和平抑波动的光伏混合储能协调控制策略。首先,利用概率统计分布对预测误差和功率波动进行分析,确立补偿预测误差和平抑波动目标域,基于预测允许误差上下限值确定补偿预测误差目标域的充/放电参考功率,以一阶低通滤波平滑曲线确定平抑波动目标域的充/放电参考功率。然后,基于频谱分析将目标域外的功率分解为高频和低频分量,实现功率分配目的,并基于目标域将混合储能电池分为4组,根据充/放电参考功率进行充/放电池组状态切换,实现对不同工况补偿预测误差的初级控制和平抑波动的次级控制,完成混合储能充/放电优先级控制。最后,以中国新疆某光伏电站为例进行算例分析,结果表明了所提策略的有效性。

To improve the prediction accuracy of photovoltaic power output and suppress the power fluctuation,a coordinated control strategy of photovoltaic hybrid energy storage considering prediction error compensation and fluctuation suppression is proposed.Firstly,the target region of compensating prediction error and smoothing fluctuations is established by utilizing the statistical probability distribution to analyze the prediction error and power fluctuation.The charging/discharging reference power of the target domain for compensating prediction error is determined based on the upper and lower limits of the allowable prediction error while the charging/discharge reference power of the target domain for smoothing fluctuations is determined through first-order low-pass smooth filter curve.Then,based on the spectrum analysis,the power outside the target domain is decomposed into highfrequency and low-frequency components,so as to realize the objective of power distribution.The hybrid energy storage batteries are divided into four groups based on the target domain,and the charging/discharging battery group states are switched according to the charging/discharging reference power,so as to realize the primary control of compensating prediction error under different working conditions and the secondary control of smoothing fluctuations,and fulfill the charging/discharging priority control of hybrid energy storage.Finally,the case study is made by taking a photovoltaic power plant in Xinjiang in China as an example.The results show the effectiveness of the proposed strategy.