Calculation of fault current contribution of Type I wind turbine-generators

Increasing fault current contribution from wind farms into the utility network presents new engineering challenges for utility protection engineers. Traditionally, sequence component networks are used to calculate fault currents for relay settings, but there is at present uncertainty on the appropriate sequence component models of the various wind generator types for inclusion into protection calculation software. This paper develops a sequence component model for Type I (cage rotor induction generators) wind generators. Time-domain transient simulations of wind turbine-generator fault currents are run using several popular power system simulation packages, including PSCAD/EMTDC, EMTP-RV, and SimPowerSystems; these results are compared with the calculations based on the sequence network circuits, and found to have good agreement.