Influence Of DFIG Wind Farms Integration On Transmission Line Protection

In the global energy crisis and vigorously support the development of new energybackground, wind energy as a sustainable development can play in the energyindustry to reduce environmental pollution, adjusting energy structure, easing the roleof the energy crisis, more and more countries attention. Because wind power capacityincreasing in the power system is also increasing proportion of the impact of windturbines operating characteristics during the fault on the grid increasingly significant.During external faults, double-fed wind turbine with traditional synchronous motor isnot bound to configure the same characteristics have an impact on traditionalprotection. Therefore, this study when the grid fails, the transient characteristics ofwind turbines Line Protection sent its impact.This paper analyzes the basic structures doubly-fed wind turbines, on this basis, adetailed explanation of the double-fed wind turbine can be achieved VSCF windpower principles expounded back to back converter in which the role. Then,depending on the wind speed on the operating mode of the doubly-fed wind turbinesare analyzed in the wind speed is small, the work in the sub-synchronous generatorstatus, and in the case of large wind, in super-synchronous generating state.Mathematical model of the doubly-fed wind turbine has been studied, obtained underthe three-phase stationary coordinate system and mathematical equations synchronousrotating coordinate system.Introduces the theory associated with DFIG wind turbine, analyzes the wind powerwind turbine-speed characteristics, based on this interpretation of the principle ofmaximum wind tracking strategy and implementation. Then double-fed wind turbinecontrol strategies under different wind speeds are described. On the back to backconverter works were analyzed for the stator flux vector control methods wereintroduced, and then analyzes the rotor-side converter control strategy for the rotor–side converter how to achieve active and reactive power decoupling control conducteda detailed study. Then, the network-side converter, such as how to control the busvoltage control strategies were studied. Finally, based on PSCAD/EMTDCsimulation of the proposed control strategy was validated.Finally, the different slip under the changes in the positive and negative sequence impedance sequence impedance of the double-fed wind generator, the impedancecharacteristics of doubly-fed wind turbines to the positive and negative sequencecurrent distribution factor had an impact, thereby affecting the judgment conventionalcurrent differential mutation rate on the fault phase simulation sends the case of windfarms line failure, the impedance characteristics of doubly-fed wind turbines do causefalse fault phase selection element...