Multi-parameter Dynamic Bifurcation Analysis And Control Of Wind Power System Voltage Stability

The wind energy is the important resource that can take the place of the traditionalnonrenewable energy. In recent years, the wind power developed very fast, but along with theexpansion of the scale and capacity of the wind power that integrated into the conventionalpower system, the stability of the entire power system will be under more and moretremendous influence, especially the voltage stability. In order to reveal the principle of thewind power system voltage stability deeply so as to control it, this paper applied thebifurcation theory to analyze the wind power system voltage stability and bifurcationphenomenon based on the model of double-fed wind turbine and walve composite load model,and then used some certain method to control it. The paper’s main research and conclusionsare as follows:1．The wind power system voltage stability and bifurcation phenomenon were studied bythe bifurcation theory based on the wind power system’s dynamic model and bifurcationparameters including active power of wind farm injection system, system’s reactive powerload and the SVC’s parameter.The simulation analysis indicated that: With the increasing ofthe active power that injected to power grid from the wind farm, the system’s voltage willreduce in a certain extend, and will cause dynamic bifurcation phenomenon, which can leadthe wind power system’s voltage to sustained oscillation or instability phenomenon; With theincreasing of the system’s reactive power load, the system had already had the Hopfbifurcation point before achieving limit point, the system’s critical operation point movedahead. Therefore, it will reduce the system’s stability domain and weakened the system’s loadcapacity; Increasing the SVC’s reference voltage and the amplification factor can both delayor even completely eliminate the occurrence of Hopf bifurcation, but compared with the SVCreference voltage, the amplification factor’s effect on the wind power system was quitelimited.2．The washout filter dynamic bifurcation controller was designed to control thebifurcation phenomenon that existed in the system based on the wind power systemmultiparameter bifurcation research results.The simulation analysis indicated that: Byexerting control to the wind farm’s injected power and the system’s reactive load respectively,the system’s load capacity has small drop, but it greatly improved the system’s operationstability domain and voltage quality.