基于分岔理论的含双馈风电机组的电力系统电压稳定性分析

Analysis on Voltage Stability of Power System with Doubly Fed Induction Generator Wind Turbine Based on Bifurcation Theory

为了研究含双馈风力发电机组的电力系统电压失稳的机理,本文以3节点电力系统为例,建立了含双馈风电机组电力系统的简化数学模型,采用局部参数延拓法追踪系统的平衡解流形,在此基础上基于分岔理论并结合时域仿真分析了系统电压失稳乃至崩溃的发生发展过程,揭示了系统随参数变化而引起的电压稳定性和解的结构变化的非线性动力学本质,确定了在几种不同风速情况下系统的分岔点和电压崩溃临界点,并且分析了风速变化对系统电压崩溃临界点的影响。分析结果表明,该系统中存在着Hopf分岔、同宿分岔、普通静分岔和鞍结分岔现象;这些分岔现象是导致系统电压失稳及崩溃的动力学本质;并且风速的变化会对系统的电压稳定裕度产生影响。

In order to study the mechanism of the voltage instability of the power system including doubly fed induction generator wind turbine （DFIG WT）, the simplified model of a three-node power system with doubly fed induction generator wind turbine was developed, and the equilibrium manifold was tracked using the locally parameterized continuation method. Based on the bifurcation theory and the simulation, the processes of going from stability to voltage instability and voltage collapse were analyzed. From the nonlinear dynamics point of view, the nature of the voltage instability and the solution structure variation caused by varying the system parameters were illustrated The critical points of the bifurcation and voltage collapse at different wind speeds were identified and the impact of the wind speed on the voltage collapse point was presented. The results show that Hopf, homoclinic, static and saddle-node bifurcations have been observed and they essentially induce the voltage instability even the voltage collapse of the studied system. Moreover, the wind speed can have influence on the voltage stability margin of the system.