基于模型预测控制平抑光伏输出功率波动的储能充放电策略

Strategy of Energy Storage for PV Power Smoothing Based on Model Predictive Control

随着光伏发电在电力系统中的渗透率不断上升与储能技术的成熟,利用储能降低光伏输出功率波动对系统造成的影响将是重要的技术手段之一。由于光伏出力的预测精度会随时间尺度的增加而下降,将会增加储能损耗成本;若只考虑当前时刻光伏输出功率波动可能会导致储能对下一时刻的光伏波动难以控制。因此,提出了一种基于模型预测控制平抑光伏输出功率波动的储能充放电策略,建立了综合考虑光伏输出功率波动满足率和储能寿命损耗的目标函数;同时,进一步考虑实际光伏输出功率与预测值之间的偏差,对光储逆变器输出功率进行反馈校正,确保下一时刻光伏输出功率波动计算准确,提高储能动作的正确。最后结合仿真算例验证了该策略的有效性和优越性。

With the increasing penetration of photovoltaic(PV)generation in power system and maturity of energy storage(ES) technologies,the use of ES to reduce the impact of PV fluctuations will be one of the important means in the future. Because the prediction accuracy of PV output will decrease with the increase of time scale,the loss cost of energy storage will be increased. If only considering the current PV fluctuation,it is difficult to control the PV fluctuation in the next moment. Therefore, a strategy of energy storage based on model predictive control is proposed for PV power smoothing. The satisfaction rate of PV fluctuation and the life loss of ES are treated as objective function. Meanwhile,considering the deviation between the actual PV output and the predicted output, feedback correction is introduced as so to improve the computational accuracy of PV fluctuation and to ensure proper operation of ES in the next time. The simulation verifies the effectiveness and superiority of the proposed model.