Abstract: A first aspect of the invention provides a wind turbine blade having a blade shell that defines a suction side, pressure side, leading edge, and a trailing edge of the blade. The blade further comprises a blade heating system comprising one or more heating elements configured to heat the blade in first and second heating areas, wherein the first heating area is closer to the leading edge than the second heating area is, and the heating system is configured to generate heat fluxes in the first and second heating areas such that the heat flux generated in the first heating area is lower than the heat flux generated in the second heating area.

Abstract: A wind turbine blade includes a first blade portion and a second blade portion coupled together by a connection joint. A first spar cap is associated with an upper shell half and a second spar cap is associated with the lower shell half of each of the first and second blade portions. A shear web extends between the first spar cap and the second spar cap of each of the first and second blade portions. The shear web is terminated away from a joint interface at which the first and second blade portions meet, and there is no shear web extending in a longitudinal direction across the joint interface. The shear web extending between the first spar cap and the second spar cap is branched in the longitudinal direction toward the first and second blade interfaces of the first and second blade portions respectively.

Abstract: A method of estimating a temperature of a component of a wind turbine is provided, comprising, during a calibration period, receiving measurements of the temperature of the component and of one or more corresponding operational parameter; and calculating, using the measurements coefficients of a model of the temperature of the component. The model relates temperature at a current time to a temperature a preceding time, Tn?1. The model is segregated into separate bins based on wind speed or power generated by the wind turbine. The method further comprises using the model to estimate a temperature of the wind turbine.

Abstract: A wind turbine comprising: a tower; a first arm extending from the tower; a first rotor-nacelle assembly disposed on the first arm; a first movement sensor disposed on the first arm or on the first rotor-nacelle assembly and arranged to generate first movement data based on movement of the first arm or of the first rotor-nacelle assembly; a second arm extending from the tower; a second rotor-nacelle assembly disposed on the second arm; a second movement sensor disposed on the second arm or on the second rotor-nacelle assembly and arranged to generate second movement data based on movement of the second arm or of the second rotor-nacelle assembly; and a control system coupled to the first and the second movement sensors and arranged to receive and to process the first and second movement data; wherein the control system is arranged to determine an oscillation characteristic of the wind turbine from the first and the second movement data.

Abstract: A plurality of wind turbine blades or blade portions have substantially the same size and outer geometrical shape, and corresponding plies of the blades or blade portions having the same position within the respective wind turbine blades or blade portions have different fibre orientation angles relative to a pitch axis of the respective wind turbine blade or blade portion. By changing the fibre orientation angles of the corresponding plies a bend-to-twist coupling of the blade or blade portions may be varied amongst the plurality of blades or blade portions. The blades may then be tailored according to their siting within or on a wind turbine park. A common mould shape may be used across the plurality of wind turbine blades or blade portions, together with a more streamlined blade design process.

Abstract: Embodiments provide for the control of a power plant including several generators by setting a reference frame for the generators with a first and a second axis; measuring a grid demand voltage at the shared connection point; determining active and reactive currents required at the shared connection point based on the grid demand voltage and grid codes; transforming the active and reactive currents required at the shared connection point to the reference frame where the first axis defines a first current set point and the second axis defines a second current set point; and dispatching the first and second current set points to generator controllers associated with each generator. Current set points may be generated for positive/negative frames, direct quadrature frames, real/imaginary frames and may be set evenly for all generators or adjusted per generator.

Abstract: The present invention relates to a method and controller for heating a wind turbine blade that comprises a plurality of heating zones. An icing factor is determined based on environmental conditions and one or more heating zones are determined based on the determined icing factor, wherein each heating zone comprises one or more Electro-Thermal Heating Elements. The one or more Electro-Thermal Heating Elements corresponding to the determined heating zones are activated to generate heat.

Abstract: Systems, methods, and computer program products for monitoring a wind turbine (10). The system receives a signal (426) indicative of a pitch force being applied to a blade (20) of a wind turbine (10). The signal (426) is sampled to generate a discrete time-domain signal (426) including a plurality of pitch force samples. Samples are selected for analysis using a sampling window (326) that excludes samples obtained under operating conditions determined to be detrimental to obtaining good data. The selected samples are processed to generate a spectral density (150) of the signal (426), and the frequency content of the spectral density (150) analysed to determine the condition of one or more components of the wind turbine (10). If the analysis indicates that a component of the wind turbine (10) needs attention, the system generates an alarm.

Abstract: A method for handling a load (2) including a wind turbine component (202). The method includes, while a crane (1) is supported by a supporting element (G), arranging a control arrangement (501, 502), which is at least partly elongated and flexible, so as to extend, while the load (2) is lifted in a suspended manner with the crane (1), from the load (2) to an actuator (511, 512), located on the supporting element (G), at a distance from the crane (1). The actuator (511, 512) controls the orientation of the load (2) by the control arrangement (501, 502), and the control arrangement (501, 502) is extended, during the load orientation control, via a redirection device (531, 532) which is connected to the supporting element (G).

Abstract: A grid side inverter system includes a grid side inverter, a phase locked loop controller arranged to determine a phase of a dq-frame dependent on a monitored grid voltage vector in the dq-frame and a reference grid voltage vector in the dq-frame, a current reference decision unit arranged to generate a reduction of at least one of an active and a reactive current reference, wherein a decision to generate the reduction is based on an electrical parameter relating to the phase difference of the monitored grid voltage vector and the PLL vector, a current controller arranged to determine control signals for the grid side inverter for controlling generation of active and reactive power to the grid dependent on the active and reactive current references and monitored active and a reactive grid currents in the dq-frame.

Abstract: A wind turbine comprising a plurality of wind turbine blades, a blade anti-ice system including a blade heating arrangement associated, wherein the anti-ice system includes a control system and a power supply configured to provide power to the blade heating arrangement, characterised in that the power supply comprises a power converter. A benefit of using a power converter to supply electrical power to the heating devices is that power can be applied in a stepless manner. A much finer degree of control is therefore achieved over the thermal energy applied to the blade since the power can be ramped up gradually as the system controller determines that the icing conditions are becoming more severe. As a result of the use of the power converter, the magnitude of thermal energy that is applied to the blade can be increased gradually and smoothly.

Abstract: According to embodiments described herein a Modular Multilevel Converter (MMC) is pre-charged by: driving a bypass current from an auxiliary power source through a plurality of bypass switches included in a corresponding plurality of cells; in response to a summed voltage across a plurality of cell capacitors included in the plurality of cells satisfying a drive threshold, driving an insert current through a plurality of insert switches included in the plurality of cells; and in response to a voltage across a Direct Current (DC) link capacitor satisfying a pre-charge threshold when driving the insert current, opening a circuit breaker connecting the auxiliary power source with the plurality of cells and connecting a generator with external power line rails between which the DC link capacitor is connected.

Abstract: A wind turbine comprising one or more wind turbine blades arranged to perform pivot movements between a minimum pivot angle and a maximum pivot angle, each wind turbine blade extending between an outer tip and an inner tip, wherein each wind turbine blade has an outer portion extending between the hinge and the outer tip and having a first length, and inner portion extending between the hinge and the inner tip and having a second length, wherein a coning angle of the blade carrying structure is larger than zero and/or a tilt angle of the rotor axis is larger than zero, and wherein a horizontal distance from the tower at a vertical position defined by a position of the hinge at tower passage to a point of connection between the blade carrying structure and the hub is equal to or less than the second length.

Abstract: A system for a wind turbine that includes a protection system interfaced to a circuit breaker system and a sensing system. The protection system is configured to determine an operational mode of the wind turbine by monitoring at least two parameters determine a parameter set comprising a plurality of operational parameters based on a determined operational mode, and an associated set of expected values corresponding to the parameter set, determine actual values corresponding to the determined parameter set, identify a fault condition in the event that the determined set of actual values of the operational parameters do not correspond to the determined set of expected values of the operational parameters, and implement a protection action based on the identified fault condition.

Abstract: The invention relates to a method for controlling a wind turbine system, more particular for a method for determining shadow flicker at a location and identifying a wind turbine in a wind park with a plurality of wind turbines causing the shadow flicker. A remote detector located at or near the location is determining the presence of shadow flicker and generating flicker data representative of the shadow flicker. A target wind turbine potentially causing a shadow at the location is identified based on the turbine position and the position of the sun. Operational data from the target wind turbine is obtained and it is verified whether the target wind turbine generates the shadow flicker by comparing the flicker data and the operational data.

Abstract: A wind turbine cooling system comprising a cooling circuit arranged to convey a cooling fluid to and from a heat source, a cooling device arranged to cool the cooling fluid, a 5 pump arranged to circulate the cooling fluid in the cooling circuit, and a cooling fluid tank arranged in fluid connection with the cooling circuit and having a first fluid port adjacent a top of the tank and a second fluid port adjacent a bottom of the tank, wherein the second fluid port is arranged to communicate with the cooling circuit, wherein the pump has an outlet arranged in fluid connection with the cooling circuit and in fluid 10 connection with the tank, and wherein a fluid path between the pump outlet and the tank includes a flow restriction device.

Abstract: A method of operating a wind turbine generator comprising a plurality of blades, the method comprising iterating the following steps: comparing an indicated rotor speed with a rotor speed target to determine a rotor speed error; generating a modified rotor speed error by applying a control factor to the rotor speed error; controlling the pitch angle of the blades via a pitch control system in accordance with the modified speed error; and altering the control factor in dependence on a size of the indicated rotor speed.

Abstract: A wind turbine drive train component (22) comprising a rotating shaft (61) with a radial seal (50) is provided. The radial seal (50) comprises a stationary part and a rotating part. The stationary part comprises a ring (51) with an inner edge and an outer edge, the inner edge being configured for contactlessly surrounding the shaft (61). The rotary part comprising a disc (52), coaxially connected to the shaft (61) for rotation therewith and comprising a flange (53) that wraps around the outer edge of the ring (51). The radial seal (50) further comprises an annular air lock gap (55) for containing an amount of lubrication fluid (64) and thereby closing off the air lock gap (55) when the rotary part rotates at a rotational speed above a predetermined threshold speed, the annular air lock gap (55) being formed by an inner surface of the flange (53), an outer part of the opposing parallel surface of the disc (52) and the outer edge of the ring (51).

Abstract: There is provided a method (40) of correcting blade pitch in a wind turbine (10) having a tower (12) and a plurality of rotor blades (18). The method (40) comprises: receiving (410) sensor output data from one or more wind turbine sensors (141), the sensor output data including data indicative of excitation of the tower (12) for a plurality of different pitch angles of a particular one of the blades (18); determining (420) a corrected pitch reference of the particular blade (18), the corrected pitch reference corresponding to a minimum tower excitation based on the received sensor output data; and, sending (430) the corrected pitch reference to a pitch actuator system (24) of the particular blade (18).

Abstract: A connection system for joining two wind turbine components together includes one or more bearing surfaces and one or more support surfaces extending away from the one or more bearing surfaces on a first wind turbine component, and one or more bearing surfaces and one or more support surfaces extending away from the one or more bearing surfaces on a second wind turbine component. One or more bores are formed in the one or more support surfaces of the first and second wind turbine components. One or more pins are configured to be engaged with respective one or more bores of the first and second wind turbine components to thereby join the two components together. A method for joining two wind turbine components together is also disclosed.