Study On The Voltage Stability Of Distributed Wind Power Access To Distribution Network And Reactive Power And Voltage Control

With increasing the installed capacity of wind farms, that impact on the grid are also increasinglysignificant. In order to better develop and utilize wind resources, must in-depth study and analysis of theimpact of wind farms in the network access to its stable operation of the power system generated, Dispersedwind power is different from the large-scale wind power and distributed small wind wind energydevelopment new way, access to the distribution network, Recently, its targeted research has become windpower integration hot research. Among them, the voltage stability is an important research. Due to the windfarm active power, reactive power fluctuations and randomness, making the wind farm voltage stabilityproblems become more complex. Voltage stability issues about wind power access to distribution networkintegration are investigated in this paper,and the main contents are as follows:1、 For the impact of integration of DFIG based wind farm on the static voltage stability of powersystems。Use of static voltage stability based on short-circuit capacity, Analysis of the changes in each nodevoltages and voltage stability indicators before and after the distribution grid connection of wind farm. In thispaper, use of the standard35KV radiation distribution network with12nodes, Analyzes the influence ofdifferent Wind Power Penetration and location of access with grid voltage, Gives a load node voltage windpower penetration curve changes; Given by short-circuit capacity of load bus and calculate minimumshort-circuit capacity for keeping voltage stability to estimate voltage stability degree of load bus.2、 Dynamic model of variable speed wind turbine equipped with doubly fed induetion generator(DFIG) are studied. Wind speed model，Wind turbine model，Shaft Model，Pitch eontroller model，Dynamicload models, DFIG model are analyzed. The overall models of wind turbine for the dynamic simulation. aregiven.3、 In consideration of the Impact of the actual system load random fluctuations, wind powerpenetration and line failure for the distribution network and wind field of transient voltage stabilitysimulation, Analysis of the occurrence of non-permanent fault, the impact of different fault location and faultdistance voltage transient stability, And the analysis of the occurrence of a permanent fault, the systemtransient voltage stability problems in case of a wind farm islands. 4、 Proposed distribution network power-voltage control method that the send line of wind farminstallation UPFC device, Used constant voltage control strategy, And Simulation results show that themethord can greatly improve the distribution network power-voltage level of wind farms.5、 the small-signal model doubly-fed wind farms are given to analysis the distribution networkcontaining doubly-fed wind power generation system, under different wind power penetration and access topositions of different wind farms, characteristic root system state matrix changes, Dynamic voltage stabilityof small perturbations.