多能流不确定耦合下输配网交互特性分析及协同决策

Under energy internet, it is essential to achieve the high accommodation of renewable energy resource and the efficient utilization of multiple energy through interaction between transmission and distribution network. Traditionally, transmission and distribution network are analyzed separately, and coupling of multiple energy flow has not been taken into consideration. Based on system of systems concept, this project proposes a novel methodology of analysis on the interactive features of transmission and distribution network and collaborative decision-making under uncertain coupling of multiple energy flow. The multiple energy coupling feature of energy hub with wind power generation and combined cooling, heat and power unit is revealed, and the random fuzzy and spatio-temporal correlative model is built. As for the normal and N-1 states of system, regarding the transmission-distribution coupling bus voltage and branch power as the shared variables, models which respectively are power flow, continuation power flow and optimal power flow are established considering interaction between transmission network and active distribution network under uncertain coupling of multiple energy flow. Models are solved by incorporating random fuzzy simulation, transmission and distribution network corresponding power flow method and multiple energy flow method. The shared variables and Jacobian matrix of power flow are used to reveal the characteristic of power interactive features of transmission and distribution network. Based on continuation power flow, the steady-state voltage stability region of space of interactive power between transmission and distribution network is obtained. Mechanism of impact which interaction between transmission and distribution network has on steady-state voltage stability is clarified through the security distance. Considering the random fuzzy chance constraint of security distance, collaborative decision-making method of transmission and distribution network is proposed based on hierarchical multi-objective optimal power flow. Pareto optimal solution sets and the corresponding risk indices are obtained. This work can provide some theoretical basis for analysis and optimization of energy internet which centers on electricity network.

能源互联网中可再生能源高比例消纳和综合能源高效利用依赖输配网交互协同实现。传统输配网分离分析且不考虑多能流耦合，借鉴体系工程思想，提出多能流不确定耦合下输配网交互特性分析及协同决策新理论。揭示含风电和冷热电联供机组能源枢纽的多能流耦合特征，建立随机模糊及时空相关不确定模型；针对系统正常及N-1状态，以输配网耦合节点电压和支路功率为共享变量，建立多能流不确定耦合下输电网和主动配电网交互协同潮流、连续潮流及最优潮流模型，结合随机模糊模拟、输配网相关潮流、多能流潮流等对其求解。通过共享变量及潮流雅可比矩阵信息揭示潮流交互特征；基于连续潮流模型获取输配网交互功率空间的静态电压稳定安全域，通过安全距离阐明输配网潮流交互影响静态安全机理；考虑安全距离随机模糊机会约束，提出基于分层多目标最优潮流的输配网协同决策方法，获得帕累托解集及其风险特征。该研究可为以电网为核心的能源互联网分析和优化提供理论基础。

构建清洁能源高比例消纳和综合能源多能互补高效利用的能源互联网依赖输配网交互协同实现。随着风电、光伏等分布式电源（distributed generation resource，DER）和能量枢纽（Energy Hub）广泛接入，主动配电网（active distribution network，ADN）不确定性和多能耦合日益明显；及规模化随机模糊性风电和大量ADN接入输电网 (Transmission Network, TN)，输配网交互特性日趋复杂，协同决策难度日益加大。本项目对此开展研究，相关研究与成果如下：.多能流不确定耦合特征提取与建模。考虑风电出力随机模糊模型，提取优先利用风电的EH多能流耦合特征并建模，进而获取EH与ADN随机模糊交互功率。.多能流不确定耦合下输配网潮流计算及其交互特征分析。在考虑EH与ADN交互基础上，进一步三相不平衡因素，采用SoS（System of System）描述ADN与TN交互关系，提出多能耦合三相不平衡ADN与TN交互随机模糊潮流模型，并提出结合三相解耦法、随机模糊模拟、牛顿-拉夫逊和前推回代结合的算法，从而为多能流不确定耦合下输配网交互潮流分析提供新方法。.多能流不确定耦合下输配网静态安全分析。提出了一种三相不平衡主动配电网随机模糊安全距离及其多目标优化提升方法；研究提出了考虑天然气系统动态特性的电-气综合能源系统连续潮流方法，进而建立电力系统和天然气系统气压安全域模型；提出了一种考虑天然气系统N-1的多能流系统静态安全分析方法，上述工作为多能流不确定耦合下输配网静态安全分析提供了新思路。.安全约束下多能流不确定耦合的输配网协同决策方法。考虑输配网随机模糊静态电压稳定安全裕度、交互功率和边界电压安全约束，基于SoS，建立兼顾发电费用最小、随机模糊安全裕度最大、网损最小等多目标优化的输配网分层多目标动态最优潮流模型，并提出相应算法，从而可实现多能耦合ADN和TN协同决策。.综上，项目相关模型和算法算例验证正确有效，上述多能流不确定耦合下输配网交互特性分析及协同决策模型和方法，为能源互联网分析及决策提供一定理论支持。