Analysis and calculation of short circuit current of doubly fed induction generator

Abstract

With continual installation of wind power generators, proportion of wind energy increases dramatically in electric power system, and influence of wind power must be considered in power system analysis or design. Calculation of short circuit current is an important task for wind farm and power system. Doubly fed induction generators (DFIG) are widely equipped for wind turbines, and this type of wind power generator is studied in detail in this paper. Transient of DFIG is analyzed under short circuit condition, and the theorem of constant flux linkage is applied to determine short circuit currents in the synchronously rotating reference frame dqO. In succession, formulas for calculation of the short circuit currents are deduced. Comparison of the calculation results with simulation results shows validity of the proposed formulas.