Finite element analysis for field currents and reactances of doubly fed induction generators for wind turbines

Accurate determination of field currents and reactances is important for design of doubly fed induction generators for wind turbines. An analysis method using finite elements for the saturated reactances and field currents at any balanced steady-state conditions of the generators has been developed, dq-axis equations with cross magnetization are shown and all the reactances in them are calculated. A finite element mesh model of the machines has also been proposed. The proposed method and model are applied to a 1 MW machine for a wind turbine. The calculated field currents, voltages and power factors agree well with the measured values. Variation of the reactances due to saturation is also shown