含分布式电源及灵活负荷的配电网电量合约市场

针对含有分布式电源和灵活负荷的配电网电量合约市场,首先介绍了市场结构、交易流程和合约内容,并对市场中各组成部分进行了建模。利用Copula理论,对分布式电源出力的随机特性及相关性进行计算,从而在已知预测出力情况下得到分布式电源实际出力的条件概率密度。在此基础上,以最小化总购电成本为目标,考虑本地电量平衡概率约束,建立了电量合约市场集中出清优化模型。基于Shapley值衡量负荷灵活性对降低购电总成本的贡献,进而提出了购电成本分摊方法。通过算例分析了分布式电源自身预测精度、与其他电源互补性以及负荷灵活性对最终合约电价的影响。验证了所提出的模型能够将电源和负荷的特性反应在最终的电价上,利用市场的手段来匹配分布式电源的不确定性和灵活负荷的灵活性,从而减少配电网给输电网带来的电量平衡方面的压力,促进分布式电源的就地消纳。

Electricity Contract Market for Distribution Network With Distributed Generations and Flexible Loads

This paper firstly analyzes the structure, transaction process and contract content of distribution electricity contract market. Then various components comprising the market are modeled. Based on historical data, Copula theory is used to calculate the stochastic characteristics and correlation of distributed generations. Conditional probability density of the distributed generations is obtained under the case of known predicted output of each distributed generation. On this basis, a centralized market clearing optimization model is proposed to minimize the total cost of purchasing electricity considering local power balance probability constraint. The contribution of each flexible load to total purchase cost is measured based on Shapley value, and a purchase cost allocation mechanism is proposed. Through case studies, the influence of the distributed generation prediction accuracy, complementarity with other distributed generations and load flexibility on contract price is analyzed. It is verified that the proposed model can reflect the characteristics of distributed generations and flexible loads in electricity contract price. Therefore, the proposed model can match the uncertainty of the distributed generations and the flexibility of the load through market measures, thus promoting local accommodation of distributed generations and reducing the power balance pressure of transmission network.