新能源电力系统灵活性供需量化及分布鲁棒优化调度

Quantification of Flexibility Supply and Demand and Distributionally Robust Optimal Dispatch of Renewable Energy Dominated Power Systems

电网中新能源渗透率的提升导致电力系统在局部时段灵活性严重不足。针对现有处理电力系统灵活性和供需不确定性过于保守或冒险的问题,提出一种数据驱动的分布鲁棒优化调度模型。首先,考虑风光出力的时空相关性,基于Copula理论构建出力集合。结合场景法与区间法对电力系统灵活性需求进行量化,引入灵活调节因子表征各类资源参与灵活性调节的能力,建立灵活性供需平衡约束。其次,考虑电动汽车等需求侧资源的灵活性供给能力,以灵活性资源运行成本与电网灵活性缺额惩罚成本最优作为目标函数,建立数据驱动的两阶段分布鲁棒模型。为降低保守性,采用综合范数对其概率分布进行约束,减小了灵活性需求出现极端情况的概率。针对两阶段鲁棒模型求解问题,利用零和博弈思想将模型解耦为主问题和子问题,采用列与约束生成算法进行迭代求解。最后,仿真算例表明,所提模型相比于传统不确定性模型对提高电力系统灵活性裕度与经济性具有积极作用。

The increasing penetration rate of renewable energy in the power grid causes a serious lack of flexibility in the power system.The existing methods for dealing with the uncertainty of supply and demand in power system flexibility have the problem of overly conservative or risky.To address the problem,a data-driven distributionally robust optimal dispatch model is proposed in this paper.Firstly,considering the spatial and temporal correlations of wind and photovoltaic(PV)power,the output power set of wind and PV is constructed based on Copula theory.The flexibility demand of the power system is quantified by combining the scenario method and the interval method.The flexibility regulation factor is introduced to characterize the capability of various resources to participate in flexibility regulation,and the flexibility supply and demand balance constraint is established.Secondly,considering the flexibility supply capability of demand-side resources such as electric vehicles,with the objective of minimizing the operation cost of flexible resources and the penalty cost of grid flexibility deficiency,a data-driven two-stage distributionally robust model is established.To reduce the conservativeness,the comprehensive norms are included to constrain the probability distribution,which can also reduce the appearance probability of extreme cases of flexibility demand.For the solution of the twostage robust model,the theory of zero-sum game is used in the paper to decouple the model into a master problem and a subproblem,which are iteratively solved by using the column-and-constraint generation algorithm.Finally,the case verifies that the proposed model has a positive effect on improving the flexibility adequacy and the economy of the power system compared with the traditional uncertainty model.