集成静止无功发生装置的直驱风场序阻抗网络模型与稳定性分析

Sequence Impedance Network Model and Stability Analysis for Direct-drive Wind Farm With Static Var Generator

对于大规模风电场的稳定性分析,现有的方法通常忽略风电场中存在的静止无功发生装置(static Var generator,SVG),直接将风电场等效为单台或数台风机接入无穷大系统,但这样的假定条件将会影响风电场稳定性分析的准确性。为此,该文提出一种针对大规模风电场的序阻抗网络建模与稳定性分析方法,构建考虑频率耦合效应、稳态工作点及运行模式影响的风电场功率单元序阻抗模型,提出通用型网络导纳聚合建模方法,将含有大量有源/无源元件阻抗的拓扑网络等效聚合为源–载阻抗互联系统,进而通过稳定判据组合实现系统稳定性的准确判断和稳定裕度的量化评估。最后通过哈密地区的集成SVG直驱风场应用实例分析验证所提方法的有效性,并针对集成SVG直驱风场的振荡机理,以及SVG工作模式和功率外环控制器参数对风电场稳定性的影响展开研究。

The current methods for the stability analysis of large-scale wind farms usually ignore the static Var generator(SVG)equipped in the wind farm,and regard the whole wind farm as a single or several turbines connected to an infinite power system.However,such assumption will affect the accuracy of results in the stability analysis.To solve this problem,a method for sequence impedance network modeling and analysis in large-scale wind farms was proposed.Considering that the effects of frequency coupling effect,steady-state operation point as well as operating mode,this method developed sequence impedance model of power unit in wind farms,and proposed a general method for aggregated network admittance modeling,which aggregates a topological network with large numbers of active/passive component impedances into a source-load impedance interconnection system,to accurately analyze the system stability and achieve the quantitative evaluation by a combined stability criterion.Finally,the effectiveness of the proposed method was verified by an example of a wind farm with direct-drive turbines and SVG in Hami.The oscillation mechanism of the wind farm and the effects of operating mode and parameters in power outer loop controller of SVG on the stability were also studied.