The Analysis Of Voltage Stability Based On Bifurcation Theory In Wind Power System

Wind power in the process of human new energy exploration is developing, but it broughta series of problems to human beings at the same time of easing the power crisis, whichrestrict its development，especially in the area of voltage stability problem. Based on thisproblem, this paper combines the bifurcation theory to analyze voltage stability problem inthe wind power system. The research includes two points: first one is the effect on windpower system voltage stability of the two typical bifurcation phenomenon--Saddle Nodebifurcation and HOPF bifurcation; Then in view of the adverse effects of bifurcationphenomenon on the system, putting forward the control scheme. The main research contentsand conclusions were as follows:First, using a simple wind power system to do the single parameter and double parameterbifurcation analysis respectively based on the theory of bifurcation and by an improvedcontinuation algorithm, and then studied the relationship between the bifurcation and thesystem voltage stability. Single parameter analysis shows that, with the reactive load andinjected active power of wind power system increasing, bifurcation phenomenon happens,and voltage of the machine been slow down, the stability of the system operation area willshrink; Double parameter analysis shows that the increasing magnification or referencevoltage of SVC are help to enhance the ability to accept active injection of wind farms andimprove system voltage of the machine, and adjust the reference voltage SVC in improvingsystem voltage stability and increase injected active power is more obvious, but the regulationof the reference voltage SVC scope is limited, thereby, to comprehensively consider theparameters of SVC to maintain system stability is necessary.Secondly, based on the the adverse effects for wind power system caused by bifurcationphenomenon put forward a kind of washout filter feedback auxiliary SVC controller tocontrol bifurcation phenomenon of wind power system. Research results show that theproposed control method can delay system bifurcation and eliminate the unstable HOPFbifurcation points in the system, improving the voltage stability of the system to a certainextent, and increase the capability of loading. In this paper the bifurcation control method wasverified effectiveness in the selected wind power system.