计及线路随机故障的机会约束最优风电消纳模型

Chance-constrained Optimal Wind Power Accommodation Point Considering Transmission Line Contingencies

在大规模风电并网的背景下,为提升电网运行的经济性与安全性,基于最优风电消纳比的概念提出一种计及输电线路随机故障的两阶段机会约束机组组合模型。一方面,采用机会约束量化风电出力的不确定性,确定最优的机组组合方式与风电消纳比;另一方面,综合考虑电网基态与故障态的运行方式,在故障发生后引入弃风、切负荷等控制措施,保证电网的稳定运行。为应对机会约束模型带来的求解难题,采用采样平均近似算法处理机会约束,并通过双线性Benders分解法将原问题分解为预测风电出力下的预测主问题和风电出力波动条件下的场景子问题,主子问题迭代求解,得到系统优化运行策略。6节点系统与IEEE RTS-79测试系统算例验证了所提模型与算法的有效性。

With high proportion of wind power penetration, to enhance economy and security of power grids, based on the concept of optimal wind accommodation point, a chance-constrained two-stage unit commitment(UC) model considering transmission line contingencies is proposed. On one hand, uncertainty of wind power is described with chance constraint to determine optimal UC scheduling and wind accommodation point. On the other hand, normal states and the states after contingencies are also considered at the same time. By introducing load and wind power curtailment into contingency control, the stability of power grids is guaranteed. To achieve computational efficiency, the chance constraint is dealt with sample average approximation(SAA) method, and the primal proposed model is converted into main problem and subproblems with bilinear Benders decomposition method. The decomposed main problem optimizes operational cost of power grids based on prediction of wind power generation, while the subproblems focus on re-dispatching cost under fluctuation of wind power. Validity and effectiveness of the proposed model are illustrated with simulation on 6-bus system and modified IEEE RTS-79 system.