Abstract: The present invention relates to a method for feeding an unbalanced, three-phase current into a three-phase AC voltage system, comprising the steps of: producing a positive phase-sequence system for the current to be fed in, producing a negative phase-sequence system for the current to be fed in, superimposing the positive phase-sequence system and the negative phase-sequence system to form the current to be fed in and feeding the current composed in this manner into the three-phase AC voltage system.

Abstract: There is provided a wind power installation foundation having a reinforcement comprising a plurality of steel bars and radial steel bars and a lower pylon segment having a plurality of holes in the wall of the pylon segment for receiving the bars or radial bars. In addition there is provided a concrete body which covers the reinforcement and the lower portion of the pylon segment. The foundation has a plurality of holders for holding the bars or radial bars of the reinforcement. The holder has an upper bracket for fixing to the pylon segment and a lower foot for receiving the bars or radial bars of the reinforcement. The length of the holder is adapted to be variable.

Abstract: There is provided a transport vehicle for transporting wind power installation rotor blades and/or pylon segments. The transport vehicle has a transport support structure having a main frame, a receiving frame fixedly connected to the main frame at a first angle, and a rotary displacement unit which is fixed with one end to the receiving frame and which at its second end has a blade adaptor for receiving a rotor blade or a pylon segment. The main frame spans a main plane. The rotary displacement unit has at least one first rotary mounting, wherein there is provided a second angle between the second rotary plane of the second rotary mounting.

Abstract: The invention relates to a method for operating a wind turbine comprising an aerodynamic rotor that has at least one rotor blade. Said method comprises the steps of operating the wind turbine at an operating point that depends on the wind speed, detecting an operating parameter of the operating point, comparing the detected operating parameter with a predetermined reference quantity, and heating the at least one rotor blade when the detected operating parameter exceeds a predetermined variation from the reference quantity, the operation of the wind turbine being continued.

Abstract: The present invention concerns a rotor blade mold for producing a rotor blade of a wind power installation or a part thereof comprising a heatable mold portion having a shaping surface for shaping the rotor blade surface and wherein the heatable mold portion has at least two heating portions and each heating portion includes at least one electrical resistance heating element arranged at or beneath the shaping surface and a supply unit for supplying the at least one resistance heating element with electrical heating current.

Abstract: There is provided a wind power installation azimuth or pitch drive having a travelling wave drive.

Abstract: The invention concerns a wind power installation rotor blade. The rotor blade has a rotor blade root, a rotor blade tip, a rotor blade leading edge and a rotor blade trailing edge. The rotor blade further has a pressure side and a suction side as well as at least one web at least partially between the suction and pressure sides. The rotor blade has a longitudinal direction between the rotor blade root and the rotor blade tip. The web is of a wave-shaped configuration in the longitudinal direction of the rotor blade.

Abstract: There is provided a lifting unit for lifting a rotor of a wind power installation. The lifting unit has at least one first sling for looping around a region of a rotor blade on a rotor of the wind power installation, which region is near the rotor blade root, at least one transverse strut, at least one first and second strut or sling portion, and at least one first and second hinge unit. The at least one first and second struts or sling portions extend between the at least one first and second hinge units and the transverse strut. The lifting unit further has at least one second sling having first and second sling portions and a strut. The first ends of the first and second sling portions are fixed to the first and second hinge units. The second sling is adapted to be arranged around a rotor blade stub.

Abstract: The present invention concerns a process for the production of a wind power installation rotor blade. To permit more economical manufacture at high quality the following steps are provided: providing at least one mold, placing a layered fiber composite having at least one core in the mold, wherein the core has a top side with first channel portions and an underside with second channel portions, and connecting portions between the first and second channel portions, and feeding resin, in particular through the first and/or second channel portions, until the layered fiber composite is adequately saturated.