A Study On Voltage Stability Of Multi-node Wind Power Access In Regional Power Grid

With the increasingly demand for load and power point's more and more far away from the load center,the power system in our country is transmit to the long-distance,high-capacity,ultra-high voltage form.And because of the economy and possibly appeared environmental introduction of the electricity market,the power system is forced to approaching its limit state.And the stability of the power grid problem becomes increasingly prominent.At the same time,because the intermittent and random characteristics of wind power,when a large number of wind power access into the grid,the power system voltage will be in an unstable situation.At present,the wind power as the most large-scale and commercial development prospects of new energy technologies attracts more and more attention from many countries.At present,the installed capacity of wind power in Northeast China has exceeded 10 million kilowatts,however in Tong Liao area the wind power installed capacity will reach 2.9 million kilowatts by the end of 2010,and the load capacity of Tong Liao area are only 1 million kilowatts.Such a large-scale wind power capacity has brought unprecedented challenges to the regional grid voltage stability.Based on the domestic and foreign research results of the system voltage stability and the characteristics of the wind power itself,Such a large-scale wind power capacity has brought unprecedented challenges to the regional grid voltage stability,the voltage stability of the wind power access system's work are as follow: Firstly,we make instructions to the simple single node network structure,load parameters and the engine parameters,and according to the dynamic and non-linear characteristics of the power system,expounded several representative mathematical models,then obtain the algebraic equations which conform to this paper.And the stability of the power grid problem becomes increasingly prominent.At the same time,because the intermittent and random characteristics of wind power,when a large number of wind power access into the grid,the power system voltage will be in an unstable situation.Secondly,we focus on the bifurcation theory and the stability of the power system elaborated the saddle-node bifurcation and Hopf bifurcation,at the same time,use the second-order differential equation an example to introduce the program of AUTO 07 Specific functions and software operation flow.Finally,based on the IEEE14 nodes wind power model,we made the function of AVR and SVC devices into the research field,and selected dynamic load model to reflect the running state of the wind farm,then emphasis on the positive andnegative utility of AVR,SVC magnification and voltage value on the voltage stability.