Wind turbine having a hts generator with a plurality of phases

Abstract

The present invention relates to a wind turbine having a wind turbine tower with a nacelle provided on the top to which a rotor hub with one or more wind turbine blades is rotatably mounted by a rotor shaft. A generator is arranged in the nacelle, wherein the superconducting rotor coils induce a current in the stator coils when the rotor is rotated, and wherein the stator coils are arranged in at least four phases. One or more converter modules convert the power output from the generator so that it matches the power of a power grid. The generator side of the converter modules comprises a number of rectifying circuits equal to the phases in the generator, while the power grid side comprises a number of inverting circuits equal to the phases of the power grid. This allows the transient of the electromagnetic brake torque relative to the nominal electromagnetic torque of the generator to be reduced. The ripples of the electromagnetic torque are also reduced since the switching frequency of the converter is increased. This in turn reduces the mechanical stresses occurring in the drive train in the event of a failure or error occurring in one of the converter modules. The present invention also relates to a method of operation of such a wind turbine where the defective converter module is selectively switched off and the wind turbine is put into operation again at a lower operation level.