Abstract: A ventilation system for a wind turbine generator system having a ventilation duct for conducting a cooling air that has been heated by waste heat from an air intake section of the ventilation duct to an air outlet section of the ventilation duct, along a flow path bounded by a duct wall which extends between the air intake section and the air outlet section, wherein in a sectional plane, preferably in every sectional plane that extends perpendicular to the flow path, the inside span of the ventilation duct can be adjusted by applying pressure to an outer boundary surface of the duct wall.

Abstract: According to embodiments of the invention, a method is provided for the feeding of a multiphase electric network by means of an electric generator of a regenerative energy source that is connected to the network through an inverter. In the event of the occurrence of a non-symmetrical network fault, the feed to the phases that are not affected by the fault is interrupted and a current effecting voltage back-up voltage is fed to the affected phases.

Abstract: In a method for supplying a multiphase electric network (17) by means of an electric generator (1) of a regenerative power source, the generator being connected to the network (17) via a converter (4 to 12), by which the amplitude of the fed current and the phase angle thereof relative to the voltage can be controlled, according to the invention the controls for the individual phases are carried out independently of one another.

Abstract: The invention relates to a wind energy system comprising a tower, a nacelle attached to the tower, the interior of which can be entered, a rotor that is rotatable relative to the nacelle, with a hub, the interior of which adjoins the nacelle interior and is accessible from this via a connecting passage, and comprising a rotor stop mechanism, with which rotor rotation can be enabled in a released position and blocked in a locked position, wherein a warning device, which is controlled on the basis of the position of the rotor stop mechanism, and which can emit a warning signal against accessing the hub interior when the rotor stop mechanism is in the released position [sic—Translator].