含海上风电的交直流电力系统线性潮流模型与高效调度方法研究

Fast, high-efficient, secure and economic dispatch is an important guarantee to enhance the ability of AC/DC systems to integrate off-shore wind power. This project makes full use of the flexible and fast control ability of multi-terminal VSC-HVDC and the reactive power supporting ability of energy storage system, and proposes the fast and high-efficient dispatch methods for the large-scale AC/DC systems with off-shore wind farms. First, this project starts with linearizing power flow equations and proposes the linear power flow model of large-scale AC/DC systems considering the effects of the reactive power, the features of off-shore wind farms and the operational characteristics of multi-terminal VSC-HVDC. On this basis, this project reveals the coordinated operation mechanism of the conventional generators such as thermal generators, the off-shore wind farms and the multi-terminal VSC-HVDC and proposes fast algorithms for large-scale AC/DC systems real time dispatch, which can make full use of the flexible and fast control ability of multi-terminal VSC-HVDC. In the end, this project reveals the integrated influencing mechanism of the reactive power control of energy storage system and the flexible and fast control of multi-terminal VSC-HVDC on the operation and dispatch of AC/DC systems, and proposes convex-optimization based high-efficient algorithms for day-ahead dispatch of large-scale AC/DC systems, which can realize the secure and economic dispatch of large-scale AC/DC systems with consideration of the effects of the uncertain off-shore wind power. This project is of important scientific significance for the economic and reliable operation of large-scale AC/DC systems with off-shore wind power.

快速高效的安全经济调度是提升交直流电力系统消纳海上风电能力的重要保障。本项目充分发挥多端VSC-HVDC的灵活快速控制能力和储能系统的无功支撑能力，提出含海上风电场的大规模交直流电力系统快速高效调度方法。首先，从线性化潮流方程出发，提出计及无功影响、海上风电特性、多端VSC-HVDC运行控制特征的大规模交直流系统线性潮流模型；在此基础上，揭示火电等传统机组、海上风电场、多端VSC-HVDC的协同运行机理，提出可充分发挥多端VSC-HVDC灵活快速控制能力的大规模交直流电力系统实时调度快速算法；最后，揭示储能系统无功控制和多端VSC-HVDC灵活快速控制综合影响交直流系统运行调度的机理，提出基于凸优化理论的大规模交直流电力系统日前调度高效算法，实现计及海上风电出力不确定性影响的大规模交直流电力系统安全经济调度。本项目对于含海上风电的大规模交直流电力系统的经济可靠运行具有重要的科学意义。

实现快速而高效的潮流分析与安全经济调度，是保障含海上风电的交直流电力系统可靠、高效运行的重要手段。基于此，本项目面向含海上风电的交直流电力系统线性潮流模型与优化调度方法展开了深入研究。在线性潮流模型方面，本项目提出了物理模型与数据混合驱动的交流大电网潮流线性化方法、考虑VSC下垂控制的含海上风电交直流电力系统线性潮流模型；在优化调度方法方面，本项目提出了基于机会约束规划理论的交直流电力系统优化调度方法、基于区间优化的交直流电力系统调度方法、考虑VSC快速控制和拓扑优化的交直流电力系统调度方法、考虑VSC和储能快速控制能力的交直流电力系统日前机组组合方法等。本项目研究成果对于提升含海上风电的交直流混联系统安全高效水平具有重要的科学意义。