Research On Modeling And Stability Simulation Of DFIG Connected Into Network

The paper presents the principle and structure of variable speed constant frequency(VSCF) double-fed induction generator(DFIG). It compares the variant speed constant frequency and the constant speed constant frequency. Also it builds the mathematic model of all section of VSCF double-fed wind power generation system on two-phase synchronous rotation coordinate by the coordinate commutation technology, and builds the simulink model all section of DFIG by Matlab. The dynamic process simulations have been studied in condition of variable velocity wind and grid fault. The comparison with const velocity wind generator group has been given.The simulation results show that DFIG has the maxim wind power capture operation and the capability of active&reactive power decoupled control which can improve the stability. It also has low voltage ride through capabilities (LVRT) under grid fault by simulation results.For this reason,it can become a available source when the grid occur faults.The conclusions provide that VSCF double-fed wind generator possesses good dynamic characteristics and has theoretical foundation for ulteriorly studying on wind power system.