Calculation of Rotor Currents for Doubly-Fed Induction Generation under Short Circuits in Power Grids

The doubly-fed wind power generator is more sensitive to the voltage of the machine falls, with the increasing of wind power installed capacity, power grid failure of doubly-fed wind power generator rotor current analysis and it is very important to evaluate accurately, relationship with doubly-fed wind power generator through the implementation of the low voltage and the analysis and calculation of fault electric parameters. Starting from the principle of doubly-fed induction generator, mathematical model is established, when grid short-circuit fault of its rotor galvanometer formula is derived, by time domain simulation results verify the validity of the expression and an example. The proposed expression using the voltage of the machine and the grid inverter control parameters can be calculated from short circuit at any time when the rotor current, has clear physical meaning and good practicability.