考虑高渗透率风电虚拟惯性控制的大电网失步解列策略研究

The virtual inertia control of the variable speed wind turbines can make the proper lightening operation in the case of high wind power permeability. It also participates in the system frequency adjustment, which helps the maintenance inertia of entire network. However, this new control strategy is challenged when it is applied in the clustering of generators and oscillatory behavior analysis after the system suffered from large disturbances. Therefore, this project studies a novel islanding strategy when large power system is out of step considering the effects of the virtual inertia control of the variable speed wind turbines from some aspects like islanding criterion, clustering mechanism, parameter identification and islanding boundaries search. This project also proposes a new locating method and verified criterion of oscillation center based on the bus voltage frequency, which overcomes the inadaptability caused by the oscillation center migration. The migration happens due to the change of some islanding criterion like, which is heavily influenced by virtual inertia control. An improved slow coherency clustering method considering virtual inertia control of the variable speed wind turbines is put forward in this project. When it is combined with modified tabu search algorithm that searches for the optimal islanding boundaries, the feasible islanding boundaries can be acquired in a fast speed. Furthermore, the project also proposed the virtual inertia parameter identification method of variable speed wind turbines based on WAMS data, which can get online virtual inertia parameters in the situation of wind power fluctuations. The research will enrich and develop the out of step theory of power system islanding issues, not only expanding the connotation and extension of the third line of defense, but also providing theoretical basis and practical support for power system islanding problems in high wind power permeability circumstance.

在高渗透率风电接入情形下，变速风机的虚拟惯性控制能使风机适当减载运行，参与系统频率调整，有助于全网惯性维持。但是这种新的控制策略却对电力系统遭受大扰动的分群和振荡行为上带来新的挑战。为此，本项目从解列判据、分群机理、参数辨识和断面搜索等方面系统研究考虑变速风机虚拟惯性控制的大电网失步解列策略，提出一种基于母线电压频率的振荡中心定位方法和改进新判据，能克服了传统失步解列判据因虚拟惯性控制引起振荡中心迁移而导致的不适应性；提出一种计及风电虚拟惯性控制的改进慢同调分群方法，结合改进的禁忌搜索解列断面快速求解方法，快速获得可行的大电网失步解列断面；提出一种基于WAMS数据的变速风机虚拟惯性参数辨识获取方法，能在风电波动情形下在线获得风电虚拟惯性参数。上述研究丰富和发展了电力系统失步解列理论，拓展了第三道防线的内涵和外延，为高渗透率风电接入情形下的大电网失步解列提供理论基础和方法支撑。

本项目构建了含高比例风光新能源接入的电力系统失步振荡模型，研究风光接入及其不同控制环节对振荡中心迁移的影响机理。采用解析法实现风电场虚拟惯性参数辨识，构建了含传统风电机组与含虚拟惯性控制风电机组的电力系统同调分群模型，提出基于特征向量映射的含风电电力系统在线分群算法，运用发电机之间的“弱连接”关系修正功角轨迹信息，该分群算法能兼顾电力系统的拓扑结构和潮流水平等多元信息。进一步研究不同惯性参数对系统同调性的灵敏度，将传统慢同调理论扩展到含高比例新能源电力系统。最后提出一种考虑虚拟惯性控制的大电网失步解列策略，将风电虚拟惯性控制用于抑制振荡中心迁移与系统振荡模式更迭。所提策略能大幅提高第三道防线的有效性，为新一代高比例新能源电力系统的稳定运行提供坚强保障。