Abstract: It is described a method for controlling the rotational speed of a rotor of a wind turbine in particular at high wind speeds. The described method comprises (a) determining a rotor acceleration value, wherein the rotor acceleration value is caused by a temporal change of the rotational speed of the rotor, and (b) controlling the rotational speed of the rotor as a function of the rotor acceleration value. It is further described a control system for controlling the rotational speed of a rotor of a wind turbine, a wind turbine being equipped with such a control system and to a computer program, which is adapted for controlling and/or for carrying out the mentioned rotational speed control method.

Abstract: A stator system for an electric machine, in particular a generator of a wind turbine is disclosed. The stator system includes a stator segment, a plate, supply system and a manifold segment. The stator segment includes a cooling channel which includes an opening at an axial front face of the stator segment. The plate is mounted to the axial front face for reinforcing the stator segment. The supply system is adapted for supplying cooling fluid to the cooling channel. The manifold segment is welded to the plate for forming a guide channel for the cooling fluid between the manifold segment and the plate. The plate includes a through-hole for generating a connection between the opening of the cooling channel and the guide channel. The supply system is connected to the guide channel.

Abstract: A wind turbine for power generation is provided. The wind turbine includes a power generating unit and a rotor having a plurality of blades. To control power output of the wind turbine, the blades are capable of being pitched by a blade pitch adjusting device. The wind turbine also includes a pitch control unit for controlling the blade pitch adjusting device. Furthermore, the wind turbine includes a load determining device for determining the blade load from the pitch activity of the blades.

Abstract: An installation for storing thermal energy is provided. The storage is carried out by the compression and relaxation of a working gas, wherein pump and compressor can be driven by, for example, electric motors which temporarily absorb excess power generated in the power grid. The generated thermal energy is temporarily stored in a cold accumulator and a heat accumulator. According to the invention, a vapor circuit is provided to connect to the heat accumulator and the cold accumulator for discharging the installation, by which a turbine for generating electrical energy can be driven by a generator. Said circuit is implemented by means of another conduit system distinct from the circuit for charging the installation. Advantageously, thermal energy generated from overcapacities in the power grid can thus be reconverted with high yield into electrical energy via a vapor circuit.

Abstract: A method for controlling an electric power production unit, in particular a wind turbine, connected to a utility grid, includes obtaining information regarding an event at a point in time, wherein the event relates to at least one of electric power delivered to the utility grid and electric power extracted from the utility grid at the point in time, and automatically adapting, before the point in time, a power transfer between the power production unit and the utility grid based on the information. Further a corresponding controller and a wind park are described.

Abstract: An arrangement to ensure an air gap in an electrical machine is provided. The electrical machine has a stator arrangement and a rotor arrangement, wherein an air gap is defined by a distance between parts of the rotor arrangement and parts of the stator arrangement. A cross section of the air gap changes along the certain length. The stator arrangement includes a stator support structure and a lamination stack, wherein the stator support structure has support elements for a two-sided support of the lamination stack, the support elements being ring-shaped and connected via a single main bearing to the rotor arrangement. Elements of the ring-shaped support element show different diameters in reference to the longitudinal axis. A first diameter of a first element of the ring-shaped support element is greater than a second diameter of a second element of the ring-shaped support-element.

Abstract: A method for manufacturing a rotor for a generator is provided. In accordance with this method, a metal plate is rolled to a circumferentially open circular cylinder having two free ends, the circumferentially open cylinder having an inner diameter smaller than a desired end inner diameter of the rotor. The two free ends of the rolled metal plate are then welded to form a closed cylinder. The closed cylinder is rolled to obtain the desired end diameter of the rotor.

Abstract: A method is provided for the production of tower segments, which are used to assemble a wind turbine tower. The method includes providing a sheet steel, cutting the sheet steel into a plurality of steel plates, cutting at least one opening in the plurality of steel plates, and bending the steel plates into a desired shape. The steps are performed in a continuous process, such that the steel plates move from one step in the production to the next.

Abstract: A generator, a stator segment and a wind turbine are provided. The generator has a rotor and a stator. The stator includes stator segments attached to a circular holding structure. A stator segment has at least one first connection element being in engagement with at least one second connection element of the holding structure. The engagement is detachable in an axial direction and not detachable in a radial and a circumferential direction.

Abstract: A wind turbine is provided comprising a rotatable main shaft having a centre axis and being at least indirectly connected to a wind turbine rotor of the turbine and a main bearing supporting the rotatable main shaft at least indirectly against a first stationary part of the turbine, wherein fastening unit are provided for fastening the rotor to the first or a second stationary part of the turbine during replacement of the main bearing and tappet unit are provided which are able to act on the main bearing and permit a movement of the main bearing relatively to the first stationary part in the direction of the centre axis. A method for replacement of a main bearing is also provided.

Abstract: An arrangement for cooling of an electrical machine is disclosed. The electrical machine includes a stator-arrangement and a rotor-arrangement. The stator-arrangement is mounted on an outer surface of a support-structure. At least one cooling channel is arranged between the stator-arrangement and the support-structure in a way that the cooling-channel is pressed between the stator-arrangement and the support structure.

Abstract: A permanent magnet rotor arrangement includes a rotor and a plurality of nonmagnetic, axially extending profiled tubes defining a closed channel and affixed circumferentially along the outer rim of the rotor. A plurality of permanent magnet pole pieces are arranged in the channels. A single pole piece is arranged in each channel. The cross-sectional profile of the pole piece does not correspond to the cross-sectional profile of the channel.

Abstract: A wind turbine which includes a direct drive generator is disclosed. The direct drive generator includes an inner stator arrangement and an outer rotor arrangement and a stationary shaft with a center axis. The stator arrangement is arranged on the outside of the stationary shaft, the rotor arrangement is substantially arranged around the stator arrangement, on the front side at least indirectly supported or arranged on the stationary shaft by a main bearing and on the rear side at least indirectly supported or arranged on the stationary shaft by a support bearing. The main bearing and/or the support bearing is a four-point bearing.

Abstract: A method is provided for replacing a permanent magnet of a generator of a wind turbine from a first position to a second position. A container is provided having a shell and an opening through the shell. The opening defines an open space for storing the permanent magnet. The open space is surrounded by the shell, and the shell having a thickness that provides that the permanent magnet does not come close enough to other magnetic material to exert significant force on it. The method involves placing the permanent magnet from the first position into the container, transporting the container with the permanent magnet to the second position, removing the permanent magnet from the container, and placing the permanent magnet in the second position.

Abstract: A method, machine and blade of a wind-turbine are disclosed. At least a component of a blade includes at least one layer of a composite structure. The layer is built up by a number of unconnected single roving-bundles, which are aligned unidirectional and which shows a common direction. The roving-bundles are laid down automatically into a forming tool.

Abstract: A base frame for a nacelle of a direct driven wind turbine includes a first interface to connect a rotor arrangement of the wind turbine with the first interface. A second interface is arranged to connect a tower with the second interface. An intermediate part connects the first and the second interface. The second interface has a collar structure. A third interface is arranged to attach a support structure to the base frame. The third interface exclusively has a first connection-area and a second connection-area. The first connection area connects the third interface with the collar structure. The second connection-area connects the third interface via a rib with the intermediate part of the base frame.

Abstract: A permanent magnet rotor arrangement is provided. The arrangement includes a rotor, a plurality of nonmagnetic profiled tubes defining a closed channel and affixed circumferentially along the outer rim of the rotor, and a plurality of permanent magnet pole pieces arranged in the channels. In a preferred embodiment, the tubes are monolithic and one pole piece is arranged in every channel.

Abstract: A method of monitoring quality of a control circuit in a power plant is provided. The quality of the control circuit is continuously assessed by determining characteristic quantities describing the quality by applying a plurality of testing methods suitable for describing dynamic properties of the control circuit to current operating data originating from the instrumentation and control equipment of the power plant, and by evaluating the characteristic quantities.

Abstract: A generator is provided comprising a rotor with a number of magnetic rotor pole shoes, a stator with a number of stator coils wound on the stator, and a generator-utility grid interface comprising a plurality of diode rectifiers, each diode rectifier is connected to a stator coil and the number of stator coils is greater than the number of rotor pole shoes, or the number M of rotor pole shoes is greater than, but not an integer multiple of, the number of stator coils. A wind turbine utilizing the generator of the present invention and a method of assembling such a generator are provided.

Abstract: An arrangement to ensure an air gap in an electrical machine is provided. The electrical machine has a stator arrangement and a rotor arrangement, wherein an air gap is defined by a distance between parts of the rotor arrangement and parts of the stator arrangement. A cross section of the air gap changes along the certain length. The stator arrangement includes a stator support structure and a lamination stack, wherein the stator support structure has support elements for a two-sided support of the lamination stack, the support elements being ring-shaped and connected via a single main bearing to the rotor arrangement. Elements of the ring-shaped support element show different diameters in reference to the longitudinal axis. A first diameter of a first element of the ring-shaped support element is greater than a second diameter of a second element of the ring-shaped support-element.