21-09-2008, 11:24 PM
A variable-speed controller, for an existing 225 kW fixed-speed wind power generator, is presented in this paper. A sensorless direct torque control algorithm-based controller is proposed for the squirrel-cage induction generator. Generator torque reference is derived based on sensorless maximum power tracking mode algorithm, up to the base speed of the generator. A three-phase front-end converter is used here to deliver the generated power to the grid with unity-power-factor operation at all wind speeds. This algorithm is based on direct active and reactive power control. The experimental waveforms from the actual installation site are presented in this paper with a comparison of the existing fixed-speed system. An interpretation of the results is also presented here..
