考虑电网辅助服务的分布式能源聚合体优化方法

Research on the optimization method of distributed energy polymer considering grid ancillary services

分布式能源个体一般无法直接参与电力市场交易或提供电网辅助服务,这可以通过分布式能源聚合来解决。在多能源类型、多交易市场及多服务基础上,提出一种新的分布式能源聚合体优化方法,该方法分为一级、二级、三级3个阶段的优化。首先,一级优化中使用了线性化技术来克服聚合体跨时空调度问题的非凸性,并将问题转换成混合整数线性规划问题,得出日前机组组合方案;其次,二级优化中基于一级优化给出的机组组合方案并使用最优潮流方程的二阶锥凸松弛求解经济调度问题以获得节点电压和功率流;然后,在三级优化中对偏离二级优化设定点进行惩罚,使三级优化接近系统最佳运行点,同时具有较短的规划范围;最后,在案例研究中将优化方法应用于一个包含电解制氢、风力发电及光伏发电等多能源聚合体模型。测试结果表明:所提出方法在电网辅助服务支持和聚合体灵活性增强方面的优势,并以最大限度增加运营收益,证明所提方法的有效性。

Distributed energy individuals generally cannot directly participate in electricity market transactions or provide grid auxiliary services.This issue can be solved through distributed energy aggregation.This paper proposes a new distributed energy polymer optimization method based on multiple energy types,multiple trading markets,and multiple services.The optimization method can be divided into three stages:high-level,middle-level,and low-level optimization.First,in the high-level optimization,linearization techniques are used to overcome the non-convexity of the cross spatiotemporal scheduling problem of aggregates,and the problem is transformed into a mixed integer linear programming problem to obtain the day-ahead unit combination scheme.Based on the unit combination scheme,the middle-level optimization solves the economic dispatch problem by the second-order cone-convex relaxation of the optimal power flow equation to obtain the node voltage and power flow.Deviations from the middle-level optimization set point are then penalized in the low-level optimization,making the results of the low-level optimization get close to the system optimal operating point while having a shorter planning horizon.Finally,in a case study,the optimization method is applied to a multi-energy polymer model including electrolytic hydrogen production,wind power generation,photovoltaic power generation,etc.The results show the advantages of the proposed method in terms of grid ancillary service and aggregate flexibility enhancement.The operational benefits are maximized,which validate the effectiveness of the proposed method.