Abstract: A wind power plant which supplies power to a utility grid in accordance with an active power reference, where the wind power plant comprises a plurality of wind turbine generators and a power plant controller arranged to send an active power set point to the wind turbine controller of each of the plurality of wind turbine generators.

Abstract: A receptor arrangement for a wind turbine blade, the arrangement comprising a receptor component connectable to a down conductor of a lightning protection system wherein the receptor component is encapsulated by an insulating member. The invention extends to apparatus for lightning protection in a wind turbine blade including such a receptor arrangement connected to a down conductor, and also to a method of assembling lightning protection apparatus for a wind turbine blade.

Abstract: The present disclosure relates to a control system for a wind turbine comprising more controllers and where at least some of the controllers operate at different sample frequencies. The control system comprises at least two controller units, a first controller (10) for determining an operational value (OV) of a sub-system and a second controller (20) for the sub-system. The second controller operates at a higher sample frequency than the first controller. It is disclosed that a faster reaction to a received demand value (V1), received for controlling the sub-system, can be obtained by setting the operational value (OV) of the sub-system as the sum of an internal operational value (V5) and a difference value (V4).

Abstract: The present invention relates to a method for controlling a wind turbine, the wind turbine comprises a rotor connected to a generator, and a rotational speed controller configured to control a speed of the rotor in response to a generator speed reference, and a power controller to control an electric power production, the method comprises the step for receiving a boost command to request a power boost event, so to increase the electrical power production, and imposing a dead band with a dead zone value limit to the rotational speed controller, and wherein the dead band imposes a zero signal to be send to the rotational speed controller, when a speed error is within the dead zone value limit and wherein the dead band imposes an error signal to be send to the rotational speed controller, when a speed error is greater than the dead zone value limit, the error signal being a function of the speed error and the dead zone value limit.

Abstract: A contaminant sensor (1) for detecting magnetizable contaminants (7) present in a lubricant flow is disclosed. A permanent magnet (3) is arranged movably inside a sensor housing (2). A sensor element (6, 11, 13), e.g. in the form of a distance sensor (6) or a pressure sensor (11), is arranged to detect a displacement of the permanent magnet (3) inside the sensor housing (2), and an indicator is arranged to generate an alert signal when a displacement and/or a rate of change of displacement of the permanent magnet (3) inside the sensor housing (2) exceeds a predefined threshold value. The permanent magnet (3) is arranged to move inside the sensor housing (2) in response to magnetizable contaminants (7) collected on an outer surface of the sensor housing (2).

Abstract: When performing interleaved switching, a power generation system may include chokes for filtering out a high-frequency ripple. However, because the chokes are interconnected, a common mode current can flow between the different parallel converters. Instead of connecting all the outputs of a parallel converter to the same choke, the same phase of each of the parallel converters is sent to one of the chokes. For example, the first phase signals are sent to a first choke, the second phase signals are sent to a second choke, and so forth. By doing so, air gaps in the chokes can be manipulated in order to provide a different inductance for the common mode current than a grid current. For example, the air gaps may be arranged such that the inductance corresponding to the common mode current is greater than the inductance corresponding to the grid current.

Abstract: A wind turbine generator includes a gearbox, wherein the gearbox includes a planetary gear system, wherein the planetary gear system includes a carrier assembly, wherein the carrier assembly includes a carrier supporting at least one planetary gear that is rotatably mounted through a bearing on a shaft, wherein the shaft is fixed in a bore defined by the carrier. The carrier assembly includes interlocking means to prevent angular movement of the shaft relative to the bore. This improves the robustness of the coupling between the shaft and the bore of the carrier.

Abstract: A fast-converging and reliable method for estimating a wind speed at, for example, a wind turbine comprising a rotor carrying a set of variable pitch angle wind turbine blades. The estimated wind speed is iteratively derived using a wind turbine rotor rotational speed, a turbine blade pitch angle, and a derived initial estimated wind speed. The initial estimated wind speed is based on the rotational speed and an initial tip speed ratio. The initial tip speed ratio is selected to be a value greater than a minimum tip speed ratio, wherein the minimum tip speed ratio defines a control region stability limit as a function of the pitch angle. Thus, for a given pitch angle, a minimum tip speed ratio is derived as a limit or boundary point between a stable control region and an unstable control region.

Abstract: A method of determining torsional deformation in a drivetrain e.g. of a wind turbine. To provide a reliable and simple deformation assessment, the method comprises the step of generating a first signal representing first rotational speed of a low speed shaft, generating a second signal representing the second rotational speed of a high speed shaft, and determining torsional deformation based on changes in the ratio between the first and second signals.

Abstract: A method is disclosed for controlling a wind turbine generator to provide power above a rated level based upon operational constraints. The wind turbine includes an over-rating controller that calculates an over-rating power demand in response to the values of one or more operating parameters, and communicates this demand to the generator. An over-rating command value is calculated according to set points of the operating parameter(s), the calculation taking into account the extent to which the operating parameter differs from these set points. The over-rating command value may vary proportionately with the difference between the operating parameter and the associated set point. If multiple operating parameters are used then the over-rating power demand may correspond to the minimum over-rating command value. Furthermore, the power demand maybe communicated to wind turbine generators individually, or may be calculated for a wind turbine park.

Abstract: The present invention relates to a wind turbine system comprising a plurality of wind turbines mounted to a common support structure (4) by a support arm arrangement (10) comprising a mount portion (12) and at least one arm (13) extending from said mount portion and carrying a respective wind turbine (6). Said support arm arrangement (10) is capable of yawing around said support structure (4); and said wind turbine system comprises an improved arrangement for cable guiding in this connection.

Abstract: A method of making a wind turbine blade incorporating a lightning protection system includes providing a blade mold; arranging a protruding element in the mold; arranging an electrically conductive layer over the protruding element; arranging one or more structural layers and/or structural components over the conductive layer; consolidating the layers under vacuum to form a blade shell having the conductive layer proximate an outer surface of the shell; separating the protruding element from the blade shell to define a recess with the conductive layer extending into the recess; providing an electrical component adjacent an inner surface of the shell; and electrically connecting the conductive layer to the component. An end portion of the connecting member is housed in the recess such that a surface of the connecting member abuts the conductive layer inside the recess.

Abstract: A method of making an elongate wind turbine blade is described. The wind turbine blade extends longitudinally between a root end and a tip end in a spanwise direction, and the method comprises: (a) providing an elongate mould tool (20) extending longitudinally in a spanwise direction; (b) arranging an elongate spar structure (40) in the mould tool, the spar structure (40) N extending longitudinally in the spanwise direction; (c) arranging core material (24) adjacent to the spar structure (40); (d) providing resin-permeable material (114) between the spar structure (40) and the core material (24); and (e) administering resin into the mould during a resin infusion process. The resin-permeable material (114) restricts the flow of resin between the spar structure (40) and the core material (24) in the spanwise direction and thereby substantially prevents lock-offs from forming during the infusion process.

Abstract: The present invention relates to a heating installation arrangement and a method of forming the heating installation arrangement for a wind turbine blade. The heating installation arrangement (100) for a wind turbine blade comprises a sleigh (101), wherein the sleigh (101) forms a platform of the heating installation arrangement (100), the sleigh further includes a recess (109), wherein the recess (109) includes one or more connection points (110, 112) for a corresponding one or more heating apparatus.

Abstract: A method of replacing an anchor bolt used to support a wind turbine to a foundation. The method includes providing the wind turbine and the foundation supporting the wind turbine. The foundation includes a lower base flange, at least one anchor bolt extending between the lower base flange and a lower tower flange of the wind turbine, and a rigid body at least partially formed around the at least one anchor bolt. The method further includes drilling a core in the lower tower flange and the rigid body circumferentially around the anchor bolt and removing the anchor bolt and the core to create a cavity. The method further includes inserting a replacement anchor bolt into the cavity and coupling the replacement anchor bolt to the lower base flange. The replacement anchor bolt may then be tensioned.

Abstract: A method of controlling a wind turbine is provided. The method comprises determining a target fatigue life consumption for each of one or more components of the wind turbine; comparing the target fatigue life consumption with a measure of fatigue life consumption for each of the one or more turbine components; and controlling the turbine power output based upon the comparison. The target fatigue life consumption is determined by combining data indicative of a target rate of accumulation of fatigue damage over at least a portion of the operating life of the wind turbine and data indicative of an expected rate of accumulation of fatigue damage caused by seasonal variations in turbine operating conditions. A corresponding wind turbine controller and wind power plant controller is also provided.

Abstract: The invention relates to a method for determining dynamic parameters associated with damping properties of a wind turbine. The method involves active excitation of tower oscillations by adjusting the pitch or rotor torque. After the active excitation, the parameters can be determined from the passive decay of the excited oscillations. Alternatively, the oscillations can be actively damped, so that the parameters can be determined from the active decay of the excited oscillations. The method for promoting oscillations may be triggered in response to different events or in response to predetermined times for determining the actual dynamic parameters.

Abstract: A variable speed wind turbine is arranged to provide additional electrical power to counteract non-periodic disturbances in an electrical grid. A controller monitors events indicating a need to increase the electrical output power from the wind turbine to the electrical grid. The controller is arranged to control the wind turbine as follows: after an indicating event has been detected, the wind turbine enters an overproduction period in which the electrical output power is increased, wherein the additional electrical output power is taken from kinetic energy stored in the rotor and without changing the operation of the wind turbine to a more efficient working point. When the rotational speed of the rotor reaches a minimum value, the wind turbine enters a recovery period to re-accelerate the rotor to the nominal rotational speed while further contributing to the stability of the electrical grid by outputting at least a predetermined minimum electrical power.

Abstract: The present invention relates to a method for operating a wind power plant in a wake situation, said wind power plant being connected to a power grid, the method comprising the steps of operating the wind power plant in a predetermined power mode of operation, terminating said predetermined power mode of operation, and increasing power generation of the wind power plant to a power level that exceeds an optimized wake power level of the wind power plant, and injecting the increased amount of power into the power grid as a power boost. Thus, the present invention is capable of generating a power boost to an associated power grid, said power boost exceeding the power level normally being available in a wake situation. The present invention further relates to a system for carrying out the method.

Abstract: The present invention relates a method of controlling a wind power plant connected to an electrical grid, the wind power plant comprises a power plant controller (350), a plurality of wind turbine generators (1) and a STATCOM (230), with a STATCOM controller, comprises: controlling the plurality of wind turbine generators in a first control mode, with the power plant controller controlling a reactive power production from each of the plurality of wind turbine generators according to a closed loop control scheme, and controlling in a first control mode with a closed loop control scheme a reactive power production from the STATCOM according to a first setpoint dispatched from the power plant controller, and controlling the reactive power production from the STATCOM in a second control mode from the STATCOM controller according to an electrical measurement in the grid, and controlling the plurality of wind turbine generators in a second control mode, with the power plant controller controlling a reactive power p