Research On Modeling And Equivalence For The Wind Farm Of Doubly Fed Induction Generator

The paper mainly presents the principle and structure of variable speed constant frequency (VSCF) fan such as double-fed induction generator (DFIG), and builds the mathematic model of all section of VSCF double-fed wind power generation system. On this basis of dynamic model of doubly-fed machine, dynamic model of DFIG wind turbine for intergration analysis is established. The wind farm of double-fed induction generator is equivalenced as one double-fed induction generator using the equivalence method based on the output characteristics of wind farm (EMOC). The energy loss caused by wake effect on wind speed of wind turbine in different location is introduced in detail. It theoretically analyses the influence to equivalent results by EMOC without considering wake effect. Contrasting the equivalent results combined wake effect with EMOC to the one not combined, it proves that EMOC considering wake effect is helpful to the equivalence accuracy, and the simulation time does not increase.With the equivalent model combined EMOC with wake effect, the wind farm of doubly fed induction generator is equivalenced as one equivalent generator. The dynamic process simulations have been studied in condition of variable velocity wind and grid fault, the simulation results showing that DFIG having the maxim wind power capture operation and the capability of active and reactive power decoupled control which can improve the stability. The simulation proves that the equivalent method is reasonable and effective.