The present invention relates to a method of controlling an electro-thermal heating system in a wind turbine blade, comprising measuring a supply voltage to the electro-thermal heating system, determining a duration of a variable time based enforced off period based on the measured supply voltage, and inserting the variable time based enforced off period between subsequent switching duty cycles that controls the electro-thermal heating system. The present invention also relates to a wind turbine that comprises one or more wind turbine blades wherein each wind turbine blade comprises an electro-thermal heating system and a processor adapted to perform the method.

The present invention relates to a method of controlling an electro-thermal heating system in a wind turbine blade, comprising measuring a supply voltage to the electro-thermal heating system, determining a duration of a variable time based enforced off period based on the measured supply voltage, and inserting the variable time based enforced off period between subsequent switching duty cycles that controls the electro-thermal heating system. The present invention also relates to a wind turbine that comprises one or more wind turbine blades wherein each wind turbine blade comprises an electro-thermal heating system and a processor adapted to perform the method.

A rotor for an electric machine, especially a generator of a direct drive wind turbine, includes a cylindrical rotor housing with several magnet means arranged at the inner housing surface, wherein each magnet means includes several magnet elements arranged in a row parallel to an axis of rotation, wherein the inner housing surface is provided with at least one groove-like recesses extending parallel to the axis of rotation, wherein each recess is covered by the magnet elements of a row, and wherein at least two magnet elements in at least some of the rows are arranged with at least one gap extending in the circumferential direction, which gap communicates with the respective recess.

A wind turbine and a method for locating an event corresponding to a failure of a heating element at a wind turbine blade, the heating element comprising an electric resistive material configured to generate heat using electrical power, the method comprising: providing a location of an event corresponding to a failure of a heating element, wherein the heating element is in an Ohmic contact with a reference potential; applying a voltage impulse to the heating element relative to the reference potential at a first point in time; measuring a voltage at the reference potential at a second point in time; determine the location based at least on the first point in time and the second point in time.

A wind turbine, including a main gear box, which is lubricated and/or cooled by oil, and a thermosiphon cooling system for cooling the oil is provided. The thermosiphon cooling system solves the main challenges facing the oil cooling systems in wind turbines. The high efficiency of the evaporation heat transfer mechanism gives the capacity to transfer the required heat load in relatively smaller size system. In this way, installation space is reduced. The thermosiphon cooling system has no service requirements over the lifetime of the wind turbine since the thermosiphon cooling system has no moving parts. Costs are saved since the simplicity of the thermosiphon cooling system adds a big value to the system business case.

A wind turbine, including a main gear box, which is lubricated and/or cooled by oil, and a thermosiphon cooling system for cooling the oil is provided. The thermosiphon cooling system solves the main challenges facing the oil cooling systems in wind turbines. The high efficiency of the evaporation heat transfer mechanism gives the capacity to transfer the required heat load in relatively smaller size system. In this way, installation space is reduced. The thermosiphon cooling system has no service requirements over the lifetime of the wind turbine since the thermosiphon cooling system has no moving parts. Costs are saved since the simplicity of the thermosiphon cooling system adds a big value to the system business case.

A vertical wind turbine that includes a plurality of vertical vanes which can be rotated independently of one another about a respective vane rotational axis by a motor and which are mounted on a common circular path in a rotatable manner about a vertical rotor rotational axis. A method for operating a vertical wind turbine. Angular positions are specified for vertical wind turbine vanes which are mounted in a rotatable manner about a respective vertical rotor rotational axis and which can be rotated about a respective vane rotational axis by a motor. The vertical wind turbine is operated in a particularly efficient and material-preserving manner in that the angular positions of the vanes are specified by at least one respective pitch motor which at least partly supports the respective vane.

A vertical wind turbine that includes a plurality of vertical vanes which can be rotated independently of one another about a respective vane rotational axis by a motor and which are mounted on a common circular path in a rotatable manner about a vertical rotor rotational axis. A method for operating a vertical wind turbine. Angular positions are specified for vertical wind turbine vanes which are mounted in a rotatable manner about a respective vertical rotor rotational axis and which can be rotated about a respective vane rotational axis by a motor. The vertical wind turbine is operated in a particularly efficient and material-preserving manner in that the angular positions of the vanes are specified by at least one respective pitch motor which at least partly supports the respective vane.

An assembly includes a transformer tank that is arranged in a nacelle of a wind turbine, wherein the transformer tank is configured to be filled with a gas or a liquid to cool the active part of the transformer and the active part is enclosed by the transformer tank in a liquid-tight or gas-tight manner, such that use of the transformer tank as a reinforcement or a bracing of the steel construction of the nacelle with as little additional material expenditure as possible for the transformer is facilitated by integrating the transformer tank into the mechanical support structure of the nacelle such that the transformer tank forms a part of the mechanical support structure of the nacelle and by providing at least one bracing in the interior of the transformer tank, where bracing connects mutually opposing wall regions of the transformer tank.

An assembly includes a transformer tank that is arranged in a nacelle of a wind turbine, wherein the transformer tank is configured to be filled with a gas or a liquid to cool the active part of the transformer and the active part is enclosed by the transformer tank in a liquid-tight or gas-tight manner, such that use of the transformer tank as a reinforcement or a bracing of the steel construction of the nacelle with as little additional material expenditure as possible for the transformer is facilitated by integrating the transformer tank into the mechanical support structure of the nacelle such that the transformer tank forms a part of the mechanical support structure of the nacelle and by providing at least one bracing in the interior of the transformer tank, where bracing connects mutually opposing wall regions of the transformer tank.