Analysis of Short-circuit Characteristics and Calculation ofSteady-state Short-circuit Current for DFIG Wind Turbine

Large-scale doubly-fed induction generator（DFIG）wind turbines are connected to the grid and required toremain grid-connection during faults，the short-circuit current contributed by the generation has become a significantissue.However，the traditional calculation methods aiming at synchronous generators cannot be directly applied tothe DFIG wind turbines.A new method is needed to calculate the short-circuit current required by the planning， protection and control of the power grid.The short-circuit transition of DFIG under symmetrical and asymmetricshort-circuit conditions are mathematically deduced，and the short-circuit characteristics of DFIG are analyzed.Anew method is proposed to calculate the steady-state short-circuit current of DFIG based on the derived expressions. The time-domain simulations are conducted to verify the accuracy of the proposed method