VARIABLE SPEED WIND TURBINE WITH DOUBLY-FED INDUCTION GENERATOR COMPENSATED FOR VARYING ROTOR SPEED

摘要

A variable rotational speed wind turbine is disclosed, comprising a doubly-fed induction generator, a rotor current controller for controlling the rotor currents of the generator, compensation means having computation means, and means for pro- viding input to the compensation means, the input being representative of at least the instantaneous angular speed of the rotor of the generator. The computation means is arranged to compute an instantaneous compensation control output in dependency of said instantaneous angular speed of the rotor of the generator and feed the compensation control output to the rotor of the generator, and to compute said compensation control output during operation of the wind turbine to compensate at least partly for dependencies on the rotor angular speed of the locations of poles of a generator transfer function, thus making a resulting generator transfer function substantially independent of variations in the rotor angular speed during operation of the wind turbine.