考虑液化天然气供应风险的气电联合系统运行分析

Operation Analysis for Combined Gas and Electricity System Considering the Risk of LNG Supply

天然气是一种重要的清洁能源,燃气机组在电力系统运行中也具有非常重要的作用。随着国际液化天然气(liquefied natural gas,LNG)贸易的快速增长,LNG接收站作为一种新型气源的比例也将持续增加。尽管有一些研究工作考虑了天然气-电网系统的联合协调优化,但其并未考虑LNG气源在供应上的特殊性。LNG受到船运、LNG储罐等条件的影响形成供应风险,而这种风险也将影响到天然气-电网联合系统在多日(周、甚至月)运行计划上的安排。为此,构建了一个以多日为优化周期的气电联合系统运行模型,考虑了天然气系统与电力系统的协调耦合,对LNG的气源供应风险进行了建模分析,并提出了在不同供应场景下的目标函数构建方法;以比利时20节点天然气系统和IEEE-39节点电力系统为基础构造算例,验证了所提出模型的有效性,并对气电联合系统在不同LNG供应场景下的运行方式与效益进行了全面的分析。

Natural gas is a criticalclean energy, and gas-firedgeneratingunit playssignificant role in powersystem operation. With rapid growth of international trade of liquefied natural gas （LNG）, proportion of LNG terminal as a new gas source in all gas sources increasescontinually. Many researcheson coordinated optimization of combined gas and electricity systemareconducted. However, LNG source characteristicsarenot well taken into account. LNG supplyrisk may be caused by shipping and LNG storage conditions, influencingoperation schedule of combined gas and electricity systemon timescalesof days, weeks and even months. In this paper, an operation model of combined gas and electricity systemis developed for multi-days. It considers coupling of natural gas network and power system. LNG supply risk is analyzed in the model, and modeling approach of objective function under different supply conditions is proposed. The model is verified based on case studiesincombination of Belgian 20-node gas network and IEEE-39 test system. Operation mode and benefit of combined gas and electricity system with different LNG supply are analyzed as well.