基于均衡理论的虚拟电厂市场参与模式及方法

随着化石能源的枯竭与其对环境的污染,分布式发电这种经济、环保、灵活的新型发电方式逐渐得到广泛的应用。但分布式电源大量并入电网将带来电能质量问题,影响电网安全稳定运行。虚拟电厂的出现有效解决了这些问题,它通过对分布式电源进行协调优化,减小了分布式电源并网对电网产生的冲击,提高了电网运行稳定性。然而目前虚拟电厂与主网之间的协调研究仍有待深入,因此提出了虚拟电厂与主网之间交互迭代的市场均衡方法,对虚拟电厂的出力与主网的电价迭代求解从而实现收敛。首先,对虚拟电厂的定义与内部主体进行分析,进而将虚拟电厂与主网之间的协调优化表述为两个层次之间的市场均衡问题,提出虚拟电厂与主网交互的双层模型,分别构建以自身成本最小化为目标,计及分布式能源运行约束与电网安全约束的虚拟电厂与主网数学模型,并采用迭代算法对模型进行求解。算例分析表明提出的市场均衡方法在考虑虚拟电厂对主网影响的同时能够有效降低虚拟电厂与主网协调的复杂程度,同时减小运行总成本,提升经济效益。

Scheme and Method for Market Participation of Virtual Power Plant Based on Equilibrium Theory

With the depletion of fossil energy and its pollution to the environment， the environmentally-friendly distributed generation has been widely adopted. However， large-scale integration of distributed energy resources （DERs） may cause power quality problems and influence the reliable operation of power grids. The emergence of virtual power plant （VPP） effectively solves these challenges. By coordinating and optimizing DERs， a VPP can alleviate the impact of plug-and-play DERs on the bulk power grid； thereby improve the security of power grids. However， research on the coordination between VPPs and power grids still needs further investigation. Therefore， we propose a market equilibrium method in this paper， which enables an iterative coordination between VPPs and the bulk power grid until converged. First， we analyze the definition of VPP and DERs. Then， the optimal coordination between VPPs and the bulk power grid is formulated as a market equilibrium problem. A two-level mathematical model is proposed. The objectives of both VPP-level and power grid-level models are to minimize the operation costs， respecting the constraints for DERs and transmission networks. An iterative solution algorithm is designed to efficiently solve such a problem. Case studies demonstrate that the proposed model and method can effectively reduce the complexity of coordination between VPPs and the bulk power grid while considering the corresponding impacts， thus reducing the total operation costs and improving the economic level of the entire power system.