Wind turbines are increasingly connected to the bulk power grid through electronic devices. Compared with the dynamic characteristics of traditional power system, transient characteristics are dramatically changed. Recognizing the transient characteristics of large-scale wind power connected to the bulk power grid and proposing practical and feasible transient control strategies for wind turbines are important to the safe and stable operation of current power grid. This paper focuses on the interactive characteristics of doublefed induction generator (DFIG) coupled to the power grid of receivingend. A DFIG-based wind farm can be reduced to a single DFIG wind turbine by simplifying it, transient dynamics of the wind turbine, such as output fault current characteristics, under different fault levels of power grid are analyzed. Moreover, according to the fault ride through (FRT) standard of wind farms, FRT control strategies of DFIG wind turbines under different fault levels of power grid are presented to form a coordinated fault ride-through control scheme. Finally, a case study was conducted with MATLAB/Simulink. The simulation results verified the effectiveness and feasibility of the interactive characteristics analysis and the proposed FRT control scheme of DIFG-based wind farms connected to the receiving power grid.

receiving-end power grid; doubly-fed induction generator; fault ride-through; transient interaction