计及线路传输能力的新能源电力系统灵活性评估及优化调度方法

新能源大规模接入电网对电力系统灵活调节能力带来巨大挑战，针对目前电力系统灵活性评估及优化调度集中于供需匹配而缺乏对线路传输能力的考虑，提出了计及线路传输能力的新能源电力系统灵活性评估及优化调度方法。首先，分析线路传输能力对灵活性需求实现的影响，并计及新能源及负荷的波动性和不确定性，量化节点灵活性需求及其在线路上的分配。然后，从资源灵活性裕量和线路灵活性传输裕量两个角度提出系统灵活性不足量评估指标，多方面评估系统灵活性。将该评估指标作为机会约束条件，构建考虑资源-线路双重裕量的优化调度模型。采用线性化手段和基于拉丁超立方抽样的机会约束确定性转化方法将优化调度模型化简为混合整数线性规划模型以降低求解难度。最后，采用改进IEEE39节点系统和某实际电网进行仿真验证，结果表明所提方法能够减轻线路阻塞，减少切负荷量，提高新能源消纳。

Flexibility evaluation and optimal dispatching method of a renewable energy power system considering line transmission capacity

The integration of large-scale renewable energy brings great challenges to the flexible regulation ability of the power system. Current research on flexibility evaluation and optimal dispatching focuses on supply-demand matching and lacks consideration of the transmission capacity of the line. In this paper, considering the transmission capacity of the line, a novel flexibility evaluation and optimal dispatching method is proposed. First, the influence of the transmission capacity of the line on meeting the flexibility demand of a power system is analyzed. Considering the fluctuation and uncertainty of renewable energy and load, the bus flexibility demand and its allocation on the line are quantified. Then, an evaluation index of system flexibility deficiency is proposed from the perspective of resource flexibility margin and line flexibility transmission margin. Taking the evaluation index as the chance constraint, an optimal dispatching model considering the double margin of resources and lines is constructed. The optimization dispatching model is reduced to a mixed integer linear programming model by the linearization method and the chance constrained deterministic transformation method based on Latin hypercube sampling to reduce the difficulty of solution. Finally, a modified IEEE39-bus system and an actual power system are used to verify the effectiveness of the proposed method. The results show that the proposed method can reduce line congestion and load shedding, and improve the consumption of renewable energy.