Patent ID: 8853874

Claim:
A wind power turbine with a wind rotor ( 2 ) that is operable at variable speeds, a generator ( 3 ) that has an input shaft and the generator ( 3 ) being operable at a constant speed, and an electric machine ( 4 ) that is operable at variable speeds, the generator and the electric machine are in driving connection with one another by way of a superimposition transmission ( 5 ) such that the electric machine ( 4 ) being operated as a power control device, either as a generator and as a motor, for regulating the speed of the generator ( 3 ), the electric machine ( 4 ) being connected to a power grid ( 14 ), via a frequency converter ( 15 ), for supplying the electric current to the power grid, via the frequency converter ( 15 ), when operating as a generator, and for receiving electric current from the power grid, via the frequency converter ( 15 ), when operating as a motor, a controllable holding brake ( 23 ) being arranged, in a power flow, between the superimposition transmission ( 5 ) and the generator ( 3 ), and the holding brake being actuatable, at low wind speed, to directly couple the driveshaft of the generator to a housing for braking and deactivating the generator ( 3 ) and preventing rotation of the generator ( 3 ), so that all electric current flowing to and from the power grid only flows through the frequency inverter ( 15 ) and the electric machine ( 4 ), and the holding brake ( 23 ) being of an interlocking design.