Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. The auxiliary unit accommodates a at least one component, e.g. a converter or transformer. To provide efficient transportation, lower costs and easier assembly, the operative component is suspended directly on the main unit.

Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. To increase flexibility and improve assembly and maintenance procedures of the wind turbine, the auxiliary unit comprises at least two sub units each accommodating at least one wind turbine component, e.g. a converter or a transformer. The sub units are attached individually to the main unit or they are joined and attached as one component to the main unit.

Abstract: A wind turbine comprising a tower (2) with a tower wall and having at least one nacelle (3) mounted thereon, and a yaw system (1) interconnecting the tower (2) and at least one nacelle (3) is disclosed. The yaw system (1) comprises a yaw claw (4) comprising an upper radially extending part (5), a lower radially extending part (6) and an axially extending part (7) interconnecting the upper radially extending part (5) and the lower radially extending part (6), thereby defining a space. A sliding bearing connection with at least two axial sliding surfaces (9, 10) and at least one radial sliding surface (11) is arranged between the yaw claw (4) and a flange (8) arranged in the space defined by the yaw claw (4). At least one yaw drive (13) comprising a toothed gear (14) is arranged in meshing connection with a toothed yaw ring (12).

Abstract: A first aspect of the invention provides a method of testing a yaw system (200) of a wind turbine, the wind turbine comprising a rotor; the yaw system (200) comprising a yaw gear (202) coupled to the rotor so that rotation of the yaw gear (202) causes yaw rotation of the rotor, and first and second sub-systems (204a, 204b), the first sub-system (204a) comprising a first pinion gear (206a) and a first drive motor (208a) coupled to the yaw gear (202) by the first pinion gear (206a), the second sub-system (204b) comprising a second pinion gear (206b) and a second drive motor (208b) coupled to the yaw gear (202) by the second pinion gear (206b).

Abstract: A method of yawing a nacelle in a wind turbine having a yawing assembly comprising a drive-ring and a plurality of drives configured to exert a torque during movement along the drive-ring and thereby move the nacelle relative to the tower. The drive-ring is made of drive-ring segments joined in intersections. The method comprises defining a location for each intersection, defining a reference torque exerted by the drives when moving along the drive-ring, defining a reduced torque being lower than the reference torque, determining when a crossing drive moves across the location of an intersection, and to increase the lifetime, exerting the reduced torque by the crossing drive.

Abstract: The invention relates to a method for controlling a wind turbine system, more particular for a controlled sliding strategy to lower loads on the yaw system by controlling mechanical brakes and motor brakes in the yaw drive actuators. When the yaw system being in the non-yawing operational state, and the mechanical brake(s) being in an engaged state, and the yaw controller determines or receives a signal indicative of a yaw moment, and if the signal indicative of a yaw moment is above a signal threshold, then the yaw controller sends a braking signal to the yaw drive actuators to enter the motors into the brake state to apply a braking torque.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. When the yaw drive actuators are applying the same torque to all the motors, this can lead to some motors overspeeding, if the motor is not engaged when the yaw system is activated. Therefore, if the actual motor speed reference of a yaw drive actuator is higher than a specific motor speed reference, then an output signal to reduce the actual motor speed reference is applied to the yaw drive actuators with an actual motor speed reference higher than the specific motor speed reference.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. Based on a requested motor speed reference as an input signal, and a mean motor speed reference as a feedback signal, the method determines a required motor torque reference as an output signal for the plurality of yaw drive actuators. The plurality of yaw drive actuators rotates a nacelle or a structure comprising a plurality of nacelles such that an even load distribution is provided for the plurality of yaw drive actuators.

Abstract: A wind turbine comprising a tower (2) with a tower wall and having at least one nacelle (3) mounted thereon, and a yaw system (1) interconnecting the tower (2) and at least one nacelle (3) is disclosed. The yaw system (1) comprises a yaw claw (4) comprising an upper radially extending part (5), a lower radially extending part (6) and an axially extending part (7) interconnecting the upper radially extending part (5) and the lower radially extending part (6), thereby defining a space. A sliding bearing connection with at least two axial sliding surfaces (9, 10) and at least one radial sliding surface (11) is arranged between the yaw claw (4) and a flange (8) arranged in the space defined by the yaw claw (4). At least one yaw drive (13) comprising a toothed gear (14) is arranged in meshing connection with a toothed yaw ring (12).

Abstract: A first aspect of the invention provides a method of monitoring the condition of a yaw system of a wind turbine, the wind turbine comprising a rotor, the yaw system arranged to control a yaw rotation of the rotor, the method comprising: providing design data 5 representing an expected relationship between yaw moment and yaw rotation speed; measuring a pair of parameters, the pair of parameters comprising a yaw moment parameter indicative of a yaw moment applied to the yaw system, and a yaw rotation speed parameter indicative of a yaw rotation speed caused by the yaw moment; using the design data to evaluate whether the pair of parameters deviates from the expected 10 relationship; and determining a condition of the yaw system on the basis of the evaluation.

Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. To increase flexibility and improve assembly and maintenance procedures of the wind turbine, the auxiliary unit comprises at least two sub units each accommodating at least one wind turbine component, e.g. a converter or a transformer. The sub units are attached individually to the main unit or they are joined and attached as one component to the main unit.

Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least one auxiliary unit. The auxiliary unit accommodates a at least one component, e.g. a converter or transformer. To provide efficient transportation, lower costs and easier assembly, the operative component is suspended directly on the main unit.

Abstract: A wind turbine nacelle configured for mounting on a wind turbine tower and for supporting a rotor-supporting assembly, the nacelle comprising a main unit, and at least two auxiliary units. To increase flexibility and improve assembly and maintenance procedures of the wind turbine, the auxiliary unit comprises at least two auxiliary units each accommodating at least one wind turbine component, e.g. a converter or a transformer. The auxiliary units are attached individually to the same wall of the main unit, e.g. to a side wall or a rear wall.

Abstract: A multirotor wind turbine (1) comprising a yaw arrangement (6) and a tower (2) is disclosed. A load carrying structure comprises first and second arms (3) extending from the yaw arrangement (6) and carrying energy generating units (4). the yaw arrangement (6) comprises an outer wall part (7) arranged coaxially with the tower (2) and forming a closed ring extending circumferentially about an outer surface of the tower (2), thereby forming a space (8) between the tower (2) and the outer wall part (7). The outer wall part (7) and the outer surface of the tower (2) are rotatable relative to each other.

Abstract: A retrofitted wind turbine installation for replacing a prior wind turbine installation includes the foundation of the prior wind turbine installation and a replacement wind turbine supported by the foundation, wherein the tower of the retrofitted wind turbine installation is a cable-stayed tower to reduce the bending loads imposed on the foundation. A method of retrofitting an existing wind turbine installation with a replacement wind turbine includes disassembling at least a portion of the existing wind turbine, assembling a replacement tower to a remaining portion of the existing wind turbine installation, attaching a plurality of stay cables between the tower of the retrofitted wind turbine installation and stay cable foundations, and attaching the replacement energy generating unit to the replacement tower.

Abstract: A method for controlling a multirotor wind turbine is disclosed. A first operational state of each of the energy generating units of the wind turbine is obtained. A difference in thrust acting on at least two of the energy generating units is detected. At least one constraint parameter of the set of operational constraints is adjusted in accordance with prevailing operating conditions and in accordance with the detected difference in thrust, and a new operational state for at least one of the energy generating units is derived, based on the at least one adjusted constraint parameter, the new operational state(s) counteracting the detected difference in thrust. Finally, the wind turbine is controlled in accordance with the new operational states for the energy generating units.

Abstract: A first aspect of the invention provides a method of testing a yaw system (200) of a wind turbine, the wind turbine comprising a rotor; the yaw system (200) comprising a yaw gear (202) coupled to the rotor so that rotation of the yaw gear (202) causes yaw rotation of the rotor, and first and second sub-systems (204a, 204b), the first sub-system (204a) comprising a first pinion gear (206a) and a first drive motor (208a) coupled to the yaw gear (202) by the first pinion gear (206a), the second sub-system (204b) comprising a second pinion gear (206b) and a second drive motor (208b) coupled to the yaw gear (202) by the second pinion gear (206b).

Abstract: A logistics system for a multirotor wind turbine (1) is disclosed. The multirotor wind turbine (1) comprises two or more energy generating units (4), each mounted on an arm (3) extending from a tower (2) of the multirotor wind turbine (1). A transport system (14, 30, 31, 32, 33, 34, 36) interconnects a lower interior part of the tower (2) with each of the energy generating units (4). A plurality of transport containers (15) is connectable to the transport system (14, 30, 31, 32, 33, 34, 36) and configured to hold equipment (26) to be transported. A control unit is configured to receive information regarding contents and position of the transport containers (15), and to plan transport of the transport containers (15) via the transport system (14, 30, 31, 32, 33, 34, 36), based on a service plan for the multirotor wind turbine (1).

Abstract: A multirotor wind turbine (1) comprising a yaw arrangement (6) and a tower (2) is disclosed. A load carrying structure comprises first and second arms (3) extending from the yaw arrangement (6) and carrying energy generating units (4). the yaw arrange-ment (6) comprises an outer wall part (7) arranged coaxially with the tower (2) and forming a closed ring extending circumferentially about an outer surface of the tower (2), thereby forming a space (8) between the tower (2) and the outer wall part (7). The outer wall part (7) and the outer surface of the tower (2) are rotatable relative to each other.

Abstract: A first aspect of the invention provides a method of monitoring the condition of a yaw system of a wind turbine, the wind turbine comprising a rotor, the yaw system arranged to control a yaw rotation of the rotor, the method comprising: providing design data 5 representing an expected relationship between yaw moment and yaw rotation speed; measuring a pair of parameters, the pair of parameters comprising a yaw moment parameter indicative of a yaw moment applied to the yaw system, and a yaw rotation speed parameter indicative of a yaw rotation speed caused by the yaw moment; using the design data to evaluate whether the pair of parameters deviates from the expected 10 relationship; and determining a condition of the yaw system on the basis of the evaluation.