西部地区高比例风电场景下的电力系统暂态电压稳定性分析及概率评估

At present, power system voltage stability is a research focus for high proportion of renewable energy. However, mechanism of dynamic coupling including wind cluster, wind farm groups and the connected power grid, the transient voltage instable mechanism and the probability assessment method should be investigated further in this scene. This project will take the high proportion of renewable energy in Jiuquan of Gansu as study object, study on cluster and group of wind turbines and wind farms based on dynamic reactive power and dynamic voltage characteristics and establish a dynamic equivalent model of power system with high proportion of wind power scene. Through the analysis of the dynamic coupling characteristics of the wind turbines, wind farms/groups and the influence factors of transient voltage stability, a theoretical method is proposed for transient voltage stability analysis of high proportion wind power multi machine dynamic strong coupling scene, and the dynamic coupling mechanism of the wind farm and the transient voltage instable mechanism of the power system under high proportion wind power scene are revealed. By exploring the influence and the coupling laws of the wind power output、the system fault、 the dynamic voltage and the reactive power under the high proportion of wind power scene, put forward a high proportion of wind power machine dynamic coupling scene the probability assessment method of transient voltage stability probability is proposed under the multi-machine dynamic coupling scene. The research has great significance to improve the stability of the power system with high proportion of renewable energy.

高比例新能源场景下的电力系统电压稳定性是目前研究热点，然而在高比例新能源场景下的风机群、风电场群与所接入电网的动态耦合机理及系统暂态电压的失稳机理、暂态电压稳定的概率评估方法有待深入研究。本项目拟以甘肃酒泉地区高比例新能源发电系统为研究对象，基于动态无功和动态电压特性的风机群、风电场群的聚类分群法研究，建立高比例风电场景下的电力系统的动态等值模型。通过对风机群、风电场群与所接入系统动态耦合特性以及影响暂态电压稳定性的影响因素的分析，提出高比例风电多机动态强耦合场景下系统暂态电压稳定分析的理论方法，揭示风电场群与所接入电网的动态耦合机理及高比例风电场景下电力系统暂态电压失稳机理；通过探索高比例风电接入系统时风电出力、系统故障、动态电压和动态无功等各种随机因素的影响和耦合规律，提出高比例风电多机动态强耦合场景下暂态电压稳定概率评估方法。该研究对提高含高比例风电的电力系统稳定性具有重要意义。

随着电力系统双高特性的凸显，新型电力系统的暂态电压稳定性问题日趋严重，因此进行高比例风电场景下暂态电压稳定性分析与概率评估具有理论研究价值和工程应用意义。本项目基于高比例新能源场景下的风机群、风电场群与所接入电网的动态耦合特性，从风电场多机动态等值建模方法、风电功率概率模型建立、风电并网系统概率潮流计算、关键支路与节点的选择、暂态电压稳定分析与评估等方面展开研究，取得如下进展：（1）提出了基于模糊C均值的混沌粒子群算法(CPSO-FCM)的风电场动态等值研究，选取风速、发电机角速度、转子电流、实时有功和无功功率等运行参数作为聚类指标，将风电场分成若干机群，通过等效参数聚合将同一机群中的风力发电机聚集为一个等值风力发电机。（2）提出采用考虑边界校正的非参数核密度估计建立概率潮流计算中的风电功率概率模型，并引用机器学习中带交叉验证的网格搜索法优化核密度估计的带宽参数。（3）根据潮流计算结果筛选出系统中的各交流支路构成的薄弱断面，准确判断出薄弱断面中的关键支路与节点。（4）提出基于最大李雅普诺夫指数（LLE）的风电并网系统暂态电压稳定分析方法，揭示高比例风电场景下电力系统暂态电压失稳机理。（5）提出了基于CPSO-BP神经网络的风电并网系统的暂态电压稳定性评估方法。基于时域仿真结果运用多二元表判据分别对系统中枢母线及风电并网母线进行了暂态电压稳定评估。项目研究成果对提高含高比例风电的电力系统稳定性具有重要意义。