考虑光伏预测误差兼顾平抑波动的双层储能运行策略

Double-layer energy storage operation strategy that takes into account PV output error and smooths out fluctuations

为满足新能源发电并网要求、保证电力系统稳定运行,针对间歇性新能源发电的不确定性及波动性给电网设备稳定运行带来的安全问题,文中提出一种以补偿预测误差和平抑并网功率波动为目标的双层规划模型。首先,构建容量与误差满足率特性曲线得出最优储能容量,提高储能系统的经济性。其次,上层规划模型以预测误差最小为目标,建立储能系统充放电功率分配策略,并考虑储能电池循环寿命,设置非必要补偿值以避免其过充过放;下层规划模型以并网波动率最小为目标函数,采用模型预测控制算法对补偿后的光伏出力进行超前滚动优化控制,实现对光伏出力波动的平滑。最后,以上述模型为基础建立模型评估指标函数,以新疆某21 MW光伏电站为例进行算例分析,验证了策略的可行性。

In order to meet the grid connection requirements of new energy power generation and ensure the stable operation of the power system,in view of the security problems brought by the uncertainty and volatility of intermittent new energy power generation to the stable operation of power grid equipment,a bilevel programming model aimed at compensating the output error and stabilizing the grid connection power fluctuation is proposed.First of all,the capacity and error satisfaction rate characteristic curve is constructed to obtain the optimal energy storage capacity to improve the economy of the energy storage system.Then,the upper planning model takes the minimum output error as the goal.The charging and discharging power distribution strategy of the energy storage system is established,the cycle life of the energy storage battery is considered and unnecessary compensation values is set to avoid its overcharge and overdischarge.The lower planning model takes the minimum grid connection fluctuation rate as the objective function,and the model predictive control algorithm is adopted to carry out the advanced rolling optimization control for the compensated photovoltaic output,so as to achieve the smooth fluctuation of photovoltaic output.Finally,based on the above model,the model evaluation index function is established,and a 21 MW photovoltaic power station in Xinjiang is taken as an example to verify the feasibility of the strategy.