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 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 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: Wind turbine pitch actuator mounting structure A mounting structure is described for attaching a pitch actuator to a hub of a wind turbine. The mounting structure has one or more legs each having a proximal end and a distal end, and a flexible intermediate portion between the proximal and distal ends. The mounting structure further comprises an actuator attachment portion for attaching to a wind turbine blade pitch actuator. The actuator attachment portion is arranged at the distal end(s) of the one or more legs. The proximal end(s) of the one or more legs are configured for attachment to a wind turbine hub. The flexible intermediate portion(s) of the one or more legs are configured to flex in use to absorb loads acting on the pitch actuator. The mounting structure therefore allows the pitch actuator to pivot in a first plane by virtue of the flexible legs.

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 multirotor wind turbine (1) comprising a tower structure (2) and at least one load carrying structure (3), each load carrying structure (3) being arranged to carry two or more energy generating units (5), is disclosed. The wind turbine (1) further comprises a yawing arrangement (6) comprising a first part (9) being fixedly connected to the tower structure (2) and a second part (10) being fixedly connected to at least one of the load carrying structure(s) (3). The first part (9) and the second part (10) are configured to perform rotating movements relative to each other, thereby allowing the load carrying structure (3) to perform yawing movements relative to the tower structure (2). At least one guy wire (7) is connected between an anchoring point (8) at the ground and the first part (9) of the yawing arrangement (6). The invention further provides a yawing arrangement (6) for such a multirotor wind turbine (1).

Abstract: A multirotor wind turbine (1) comprising a tower (2), a yaw arrangement (6) and at least two energy generating units (4) is disclosed. The yaw arrangement (6) is carried by the tower (2) and comprises an outer wall (7) being rotationally suspended about the tower (2). Each energy generating unit (4) is carried by an arm (3) extending from the outer wall (7). The multirotor wind turbine (1) further comprises a load management system (14, 30, 31, 32, 33, 34, 36) for hoisting articles (15, 26) from the tower bottom to each energy generating unit (4) via the yaw arrangement (6).

Abstract: A multirotor wind turbine (1) comprising a tower structure (2) and at least one load carrying structure (3), each load carrying structure (3) being arranged to carry two or more energy generating units (5), is disclosed. The wind turbine (1) further comprises a yawing arrangement (6) comprising a first part (9) being fixedly connected to the tower structure (2) and a second part (10) being fixedly connected to at least one of the load carrying structure(s) (3). The first part (9) and the second part (10) are configured to perform rotating movements relative to each other, thereby allowing the load carrying structure (3) to perform yawing movements relative to the tower structure (2). At least one guy wire (7) is connected between an anchoring point (8) at the ground and the first part (9) of the yawing arrangement (6). The invention further provides a yawing arrangement (6) for such a multirotor wind turbine (1).

Abstract: A multirotor wind turbine (1) with a tower (2) and at least two energy generating units, the units held by a load carrying structure (9, 10) extending transverse to the vertical direction of the tower. To enable improved access to the wind turbine, a platform (12) forming an upwards facing plane working surface (17) is provided.

Abstract: Wind turbine pitch actuator mounting structure A mounting structure is described for attaching a pitch actuator to a hub of a wind turbine. The mounting structure has one or more legs each having a proximal end and a distal end, and a flexible intermediate portion between the proximal and distal ends. The mounting structure further comprises an actuator attachment portion for attaching to a wind turbine blade pitch actuator. The actuator attachment portion is arranged at the distal end(s) of the one or more legs. The proximal end(s) of the one or more legs are configured for attachment to a wind turbine hub. The flexible intermediate portion(s) of the one or more legs are configured to flex in use to absorb loads acting on the pitch actuator. The mounting structure therefore allows the pitch actuator to pivot in a first plane by virtue of the flexible legs.

Abstract: The invention provides a wind turbine comprising a load carrying structure and an energy generating unit. The load carrying structure is connected to the energy generating unit and holds the energy generating unit above ground. The energy generating unit houses a facility which requires a particular orientation relative to gravity for being operational. Furthermore, the energy generating unit comprises an adaptation structure e.g. arranged between the load carrying structure and the facility. The adaptation structure facilitates a first configuration with a first position of the facility relative to the load carrying structure, and a second configuration with a second position of the facility relative to the load carrying structure.

Abstract: A method of handling a wind turbine component (112) in a wind turbine (101) comprising a tower (102) extending in an upwards direction, a load carrying structure (103, 103?, 103?) fixed to the tower and extending in an outwards direction transverse to the upwards direction. According to the method, a crane (21) with a fixation structure (22) is provided and raised to the level of the load carrying structure by use of a hoisting rope. Once in position, the crane is used for handling the wind turbine component.

Abstract: There is provided a method for controlling a hydraulic pitch force system (220) so as to reduce or eliminate a decrease in hydraulic oil pressure (241) if a hydraulic system parameter value is outside a hydraulic system parameter range, the method comprising: Obtaining (690) the hydraulic system parameter value, and operating the hydraulic pitch force system (220) according to a reduced mode (692) if the hydraulic system parameter value is outside the hydraulic system parameter range, wherein in the reduced mode one or more pitch based activities are reduced (694) or suspended. An advantage thereof may be that it enables keeping the wind turbine in production in certain instances rather than shutting down the wind turbine. In aspects, there is furthermore presented a computer program product, a pitch control system (250) and a wind turbine (100).

Abstract: Pitch cylinders for adjusting a pitch angle of a blade, methods of assembling pitch cylinders, and the use of pitch cylinders in wind turbines are disclosed. The pitch cylinder includes a cylinder barrel having a first thread with a first pitch, a piston arranged in and extending out of the cylinder barrel for coupling to a blade or hub, and a trunnion to couple the cylinder barrel to the other of the blade or hub. The cylinder barrel extends through the trunnion. The trunnion has a first thread with a second pitch different from the first pitch, and a sleeve arranged between the trunnion and the cylinder barrel that extends through the sleeve. The sleeve has an inner sleeve thread with the first pitch engaged with the first cylinder barrel thread and an outer sleeve thread with the second pitch engaged with the first trunnion thread.

Abstract: A method is provided for controlling the shutdown of a wind turbine of the type having a rotor, the rotor including one or more wind turbine blades. The method includes dynamically determining a rotor speed reference; obtaining a measure of the rotor speed of the rotor; determining an error between the rotor speed reference and the rotor speed of the rotor; and controlling a pitch of one or more of the wind turbine blades based on the determined error. A corresponding wind turbine controller and a wind turbine including such a controller are also provided.

Abstract: The present invention provides a segmented pitch ring for use in a blade pitch system of a wind turbine. The segmented pitch ring is formed of a plurality of segments manufactured by different processes. In particular, one or more of the segments are formed by a rolling process, and one or more of the segments are formed by a casting process. The segments are arc-shaped or include arc-shaped sections that in combination define a substantially circular circumference of the pitch ring.

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 wind power plant includes a plurality of wind turbine systems arranged in rows and columns and includes a cable support system with at least one cable. The cable is coupled to the support structure above the first wind turbine and below the second wind turbine. The cable couples directly adjacent wind turbine system together. The cable may extend the entire length of at least one row or at least one column. A wind turbine system includes a plurality of wind turbines and a support structure including a tower and support arms. The cable support system that is coupled to the wind turbine system and that is configured to transfer loads on the wind turbine system to other wind turbine systems in the wind power plant.

Abstract: The present disclosure relates to wind turbines, pitch adjustment cylinders for adjusting a pitch angle of a blade of a wind turbine, to methods of assembling pitch adjustment cylinders, and to use of pitch adjustment cylinders in wind turbine, wherein the pitch adjustment cylinder comprises a cylinder barrel having an first cylinder barrel thread with a first thread pitch, a piston arranged movably in the cylinder barrel and extending out of the cylinder barrel for coupling to one of the blade and a hub of the wind turbine, a trunnion adapted to couple the cylinder barrel to the other one of the blade and the hub of the wind turbine, wherein the cylinder barrel extends through the trunnion, the trunnion has an first trunnion thread with a second thread pitch being different from the first thread pitch; and a sleeve arranged at least partially between the trunnion and the cylinder barrel, wherein the cylinder barrel extends through the sleeve, the sleeve has an inner sleeve thread with the first thread pitch

Abstract: A load carrying structure (3) for a multirotor wind turbine (1) is disclosed. The load carrying structure (3) comprises a first load carrying arrangement (4) and a second load carrying arrangement (4), and each load carrying arrangement (4) comprises a primary structure (9) and at least two secondary structures (10), the secondary structures (10) extending on opposing sides of the primary structure (9) between an energy generating unit (5) carried by the load carrying arrangement (4) and an attachment point at a tower structure (2). Gravity acting on the energy generating units (5) causes push in the primary structures (9) and pull in the secondary structures (10), thereby causing preload of the secondary structures (10). The load carrying structure (3) is capable of handling thrust loads.