由于虚拟电厂(virtual power plant VPP)中存在波动电源,使得火电机组更加频繁地调节,甚至启停,需要系统具有更强的备用来匹配,为电力系统调度灵活性带来了极大挑战。为了研究VPP接入配电网的调度灵活性问题,分别建立火电、储能系统(energy storage system, ESS)的灵活性数学模型,针对VPP的弃风和甩负荷风险,建立VPP接入配电网的经济调度模型,提出了系统综合调度灵活性指标,用以反应系统中灵活性资源间的互补性。基于6节点系统研究加入ESS和不同置信区间下的风力发电对系统灵活性的影响,探讨系统调度过程中经济性和灵活性的平衡关系,对所提指标进行量化分析,验证所提指标的有效性。
英文摘要:
Due to the presence of fluctuating power in the virtual power plant (VPP), the thermal power units are regulated more frequently, even starting and stopping, requiring the system to have a stronger backup to match, which brings great challenges to the power system scheduling flexibility. In order to study the scheduling flexibility of VPP access distribution network, the mathematical model of the flexibility of thermal power storage system (ESS) is established. Aiming at the risk of wind and load shedding of VPP, the economic dispatching model of VPP access distribution network is established, and the comprehensive scheduling flexibility index is proposed to reflect the complementarity between flexible resources in the system. Based on the 6-node system, the influence of wind power generation under ESS and different confidence intervals on system flexibility is studied. The balance between economy and flexibility in the system scheduling process is discussed. Quantitative analysis of the proposed indicators to verify the validity of the proposed indicators.