Pulling in dynamic cables for floating wind turbines

Abstract

1. A system for remote cable pulling of a dynamic cable 3 from a vessel 5 to a floating wind turbine 2, comprising: a floating wind turbine 2 having a pulling wire 10 attachable to the dynamic cable 3 connected to the floating wind turbine 2; and a vessel 5 for performing a dynamic cable pulling operation to connect the dynamic cable 3 to the floating wind turbine 2, the pulling wire being attachable to the dynamic cable 3 and the vessel 5 adapted to pull the pulling wire and the dynamic cable 3 attached to the floating wind turbine, the system being adapted to compensate for relative motion between the vessel 5 and the floating wind turbine 2 during the pulling operation.

Description

Technical Field

[0001] The present invention relates to a system for remotely cable pulling of a dynamic cable from a ship to a floating wind turbine (FWT), a floating wind turbine (FWT), a ship for performing the cable pulling operation of the dynamic cable on the FWT, and a method for pulling a dynamic cable onto a floating wind turbine (FWT).

Background Art

[0002] An FWT organized in a floating wind turbine park as shown in FIG. 1, or an individual FWT, is generally connected to a submarine power cable for transferring the electrical energy produced by the wind turbine to its destination, which can be, for example, on land, at sea, or for export. The submarine export cable is connected to an offshore converter or substation (OSS), and can further be connected to a power distribution network. The wind turbines in a floating wind turbine park can be connected together by inter-array power cables. To export the produced electrical energy, the inter-array cables can be connected together to an offshore converter or substation. The offshore substation generally plays a role of raising the voltage from the distribution voltage of the site to a higher voltage. For a project located far from the grid connection point, the electrical energy can be converted from AC to DC.

[0003] The capacity of inter-array power cables is typically 36kV or 66kV. High-capacity cables or export cables can have up to 220kV. Inter-array dynamic power cables for wind turbines are typically connected to submarine power cables within transition joints. For larger wind turbine parks, the turbines may be connected to several "strings" leading to the converter / substation before the power travels through the export cable. Inter-array cables may include specific cross-sections in the dynamic portion of the cable with transition joints, compared to reduced cross-sections in the static portion of the cable. The static portion may be pre-installed and connected to the dynamic portion which connects to the dynamic cable installation. Alternatively, it is possible to have only one dynamically dimensioned cross-section along the entire length of the inter-array cable between turbine a and turbine b, but this presents cost issues regarding manufacturing and installation.

[0004] FWTs require dynamic, high-capacity underwater cable systems to collect and export the generated power. FWTs are generally moored to the seabed to keep them in a more or less stable position. In contrast to fixed-bottom wind turbines such as monopile wind turbines that stand on the seabed in a fixed position, FWTs float and are therefore exposed to external forces such as wind, currents, and waves that cause movement. During the installation process for the cables, not only may the installation vessel move, but the FWT may also move relative to the vessel. Therefore, the installation procedure for FWTs is generally more difficult in terms of the technical and safety issues that need to be addressed compared to fixed-installation WTs that stand on the seabed. The movement and displacement of the FWT, in addition to waves and currents, subject the inter-array dynamic power cables to significant dynamic stress. Thus, these inter-array dynamic cables must withstand all the motion and loads from the ocean related to the floating wind turbines, as well as the weight of the dynamic cables themselves. Inter-array dynamic cables are sensitive to voltage and bending, and the possibility of damage is high while they are being installed on a floating water turbine (FWT). The process of installing and connecting inter-array dynamic cables to a floating water turbine can be complex and time-consuming. Because FWTs are exposed to and react to external forces such as waves, wind, and currents, the installation process is generally more complex and sensitive compared to the installation process on a fixed-bottom wind turbine. Current solutions for dynamic cable installation require access by personnel on board a cable installation vessel and, likewise, personnel on board the floating water turbine for winch control. To install inter-array dynamic cables to a floating water turbine, a pull-in winch for pulling in the inter-array dynamic cables can be pre-installed on the floating water turbine (FWT) along with other necessary infrastructure and equipment. The pull-in winch can be either a permanent system left on the floating water turbine or a temporary system that is dismantled after use. A support vessel with a motion-compensating passage (gangway) may be used to provide the pull-in crew with access to the FWT.When a retractable winch system is temporarily installed on a floating waterwheel (FWT), a vessel with a 3D crane may be used to lift / lower the retractable winch system. Motion-compensated passages and 3D cranes can allow for operations under higher weather conditions (higher waves, stronger winds, etc.) and also provide for the safe installation of inter-array dynamic cables by floating wind turbines. [Overview of the project] [Problems that the invention aims to solve]

[0005] As floating wind turbines transition from demonstration and experimental projects to large-scale development, there is an industry need to develop novel and improved methods for installing and connecting inter-array dynamic cables to floating wind turbines. Conventional methods for attaching cables to offshore equipment, such as those described in the brochure of European Patent Application Publication No. 2696123, do not address the aforementioned industry needs. [Means for solving the problem]

[0006] This invention provides a system for remote cable routing of dynamic cables from a ship to a floating wind turbine. The system is: - A floating wind turbine having a pull-in n that can be attached to a dynamic cable connected to the floating wind turbine, - A vessel for performing a dynamic cable pull operation to connect a dynamic cable to a floating wind turbine, wherein the pull wire is attachable to the dynamic cable, and the vessel is adapted to pull the pull wire and the dynamic cable attached to the floating wind turbine, - The system is adapted to compensate for the relative motion between the vessel and the floating wind turbine during the retraction operation.

[0007] The system can be adapted to compensate for the motion of the draw wires relative to the floating wind turbine, which may result from the fluctuating distance between the vessel and the floating wind turbine, caused by the vertical and / or horizontal movement of either the vessel or the floating wind turbine. The motion may be axial.

[0008] The system may further include a first sensor for measuring the distance between the floating wind turbine and the vessel. The first sensor may be a distance sensor, preferably an optical sensor. The relative motion between the vessel and the floating wind turbine may be indirectly estimated by using data from at least two sensors, where at least one sensor is located on the vessel and at least one second sensor is located on the floating wind platform. The at least two sensors may be absolute position sensors.

[0009] A vessel may be equipped with a dynamic positioning system adapted to control the vessel based on at least one first input parameter. The dynamic positioning system controls the vessel's position and orientation by using the vessel's own propellers / thrusters. A winch control system may be adapted to control a winch on the vessel based on at least one second input parameter. The winch control system may be installed on the vessel.

[0010] At least one first input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the winch control system, It may have at least one of the following.

[0011] At least one second input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the DP system, It may have at least one of the following.

[0012] Compensating for the relative motion between the vessel and the floating wind turbine during the retraction operation can be done by a winch, or by a winch and a dynamic positioning system.

[0013] The system may further include at least one inertial navigation system (INS). The system may further include at least one of a satellite navigation system or an inertial measuring device. The inertial measuring device may be at least one of a motion reference unit (MRU) and a motion gyro compass (MGC). At least one second sensor may be provided for monitoring the hang-off area on the floating wind turbine relative to dynamic cables. The second sensor may preferably be an optical sensor. The system may further include a first communication system adapted to transmit at least one sensor signal from the floating wind platform to the vessel, and a second communication system on the vessel for receiving at least one sensor signal. The first and second communication systems may be marine broadband radio (MBR).

[0014] A system is provided for remote cable pulling of dynamic cables from a vessel to a floating wind turbine. The system comprises a floating wind turbine having a pull-in wire that can be attached to the dynamic cables connected to the floating wind turbine. The system further comprises a vessel having a winch for performing a dynamic cable pulling operation to connect the dynamic cables to the floating wind turbine. The pull-in wire is attachable to the dynamic cables. The vessel is adapted to pull the pull-in wire and the dynamic cables attached to the floating wind turbine by a winch controlled by a winch control system. The system for remote cable pulling is adapted to compensate for relative motion between the vessel and the floating wind turbine during the pulling operation via the winch and winch control system, and the winch control system is adapted to compensate for and control the motion of the pull-in wire resulting from the relative motion between the vessel and the floating wind turbine during the pulling operation.

[0015] The winch control system controls the winch based on at least one of the relative position between the ship and the floating wind turbine, the speed of the floating wind turbine relative to the ship, and the orientation between the floating wind turbine and the ship. A instrumentation system provided on the floating wind turbine determines the relative position, speed, and orientation between the ship and the floating wind turbine and provides output data to the winch control system on the ship.

[0016] The system may further include a dynamic positioning system adapted to compensate for the tension of the winch. The tension of the winch is applied by an external force. The dynamic positioning system may be further adapted to compensate for environmental influencing forces such as wind, waves, and currents.

[0017] The present invention provides a floating wind turbine having a retractable wire attachable to a dynamic cable connected to the floating wind turbine, the retractable wire being attachable to a ship for performing the retracting operation of the dynamic cable to the floating wind turbine, and the ship being adapted to compensate for the relative movement between the floating wind turbine and the ship during the retracting operation. The cable may be compensated to allow for relative movement between the ship and the floating wind turbine. The ship may be adapted to compensate for the movement of the retractable wire relative to the floating wind turbine, which may be caused by the varying distance between the ship and the floating wind turbine resulting from vertical and / or horizontal movement of either the ship and / or the floating wind turbine. The movement may be axial movement.

[0018] The floating wind turbine may further be provided with a sensor for measuring the distance between the floating wind turbine and the ship. The sensor may be a distance sensor. The floating wind turbine may further have at least one inertial navigation system (INS).

[0019] A floating wind turbine may further include at least one of a satellite navigation system and an inertial measuring device, preferably a motion reference unit (MRU) or a motion gyro-compass (MGC). The floating wind turbine may further include at least one sensor for monitoring the hang-off region relative to the dynamic cable. The sensor for monitoring the hang-off region may be an optical sensor. At least one sensor may be adapted to provide a signal when the dynamic cable is in its final hang-off position. The floating wind turbine may further include a hang-off device adapted for the hang-off of the dynamic cable that is retracted and connected to the floating wind turbine. The hang-off device may be adapted for the hang-off of the dynamic cable that is retracted and connected to the floating wind turbine without manual intervention. The hang-off device may be adapted for automatic hang-off. The hang-off device may be a mechanical hang-off device. The hang-off device may be a hang-off clamp arrangement. The hang-off device may include a weak link system to release the cables in the event of mooring line failure and large floating wind turbine drift-off. The floating wind turbine may further include a communications system, preferably marine broadband radio (MBR), adapted to transmit at least one signal from the floating wind turbine to the vessel.

[0020] The present invention provides a vessel for performing a dynamic cable pull-in operation to connect a dynamic cable to a floating wind turbine equipped with a pull-in wire, wherein the pull-in wire is attachable to the dynamic cable, and the vessel has a winch adapted to pull the pull-in wire to pull the dynamic cable into the floating wind turbine, and the vessel is adapted to compensate for relative motion between the floating wind turbine and the vessel during the pull-in operation. The cable may be compensated to allow relative motion between the vessel and the floating wind turbine.

[0021] The vessel may be adapted to compensate for the motion of the lead wires to the floating wind turbine, which may result from the vertical and / or horizontal motion of either the vessel or the floating wind turbine, and from the fluctuating distance between the vessel and the floating wind turbine.

[0022] The motion may be axial motion. The vessel may further include sensors for measuring the distance between the floating wind turbine and the vessel.

[0023] The vessel may further be provided with a dynamic positioning system adapted to control the vessel based on at least one first input parameter. The winch control system may be adapted to control the winch based on at least one second input parameter.

[0024] At least one first input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the winch control system, It may further have at least one of the following.

[0025] At least one second input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the DP system, It may further have at least one of the following.

[0026] Compensating for the relative motion between the vessel and the floating wind turbine during the retraction operation can be done by a winch, or by a winch and a dynamic positioning system.

[0027] The vessel may be equipped with a communication system, preferably marine broadband radio (MBR), to receive at least one sensor signal from a floating wind turbine.

[0028] The present invention also provides a method for performing cable pulling of a dynamic cable to a floating wind turbine according to the system described above. The method includes the steps of: attaching the dynamic cable to a pull wire on the floating wind turbine; pulling the pull wire by a vessel until the dynamic cable is installed in a hang-off device on the floating wind turbine; and compensating for the relative motion between the floating wind turbine and the vessel during the pulling operation. The cable may be compensated to allow for relative motion between the vessel and the floating wind turbine. Pulling by the vessel may be performed by a winch on the vessel.

[0029] The system can be adapted to compensate for the motion of the draw wires to the floating wind turbine, which may result from the fluctuating distance between the vessel and the floating wind turbine, caused by the vertical and / or horizontal motion of either the vessel or the floating wind turbine.

[0030] The motion may be axial motion. The method may further include the step of measuring the distance between the floating wind turbine and the vessel. The distance may be measured between the exit point for the take-in wire on the floating wind turbine and the inlet point for the take-in wire on the vessel.

[0031] The method may further include the step of controlling a vessel by a dynamic positioning system based on at least one first input parameter. The method may further include the step of controlling a winch by a winch control system based on at least one second input parameter. At least one first input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the winch control system, It has at least one of the following.

[0032] At least one second input parameter is, - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the DP system, It has at least one of the following.

[0033] Compensating for the relative motion between the vessel and the floating wind turbine during the retraction operation is performed by a winch, or by a winch and a dynamic positioning system.

[0034] The idea behind this concept is to create a dynamic cable pull-in system, which can be installed and operated from a vessel that installs or performs inter-array dynamic cable pull-in, on a floating and therefore moving installation such as a FWT. The vessel in the concept of the present invention is floating and maintains a substantially fixed position by dynamic positioning. However, the vessel can also perform the pull-in operation by using an active winch that does not have the DP system described above. Industrial challenges are addressed by eliminating the need for pull-in winches installed on each FWT, and by reducing the need to move personnel and equipment to and from the FWT during the construction phase. For wind parks of a certain size, particularly large wind parks, the system of the present invention having its outlined methodology is 1. Reduce the total cost of installing dynamic cables between arrays. 2. Avoid moving personnel and heavy equipment to and from the FWT during cable entry and hang-off, thereby enhancing safety. 3. Improve flexibility in the marine schedule by reducing the need for coordinating support vessels and personnel. 4. Reduce travel time for future cable cutting / connecting by enabling easy equipment installation (retrofit) on the FWT and on board the vessel.

[0035] The remote dynamic cable pulling system according to the present invention addresses industrial challenges in the installation and connection processes of dynamic cables. The new solution provides a faster, more standardized installation process compared to current solutions, reduces the need for equipment and personnel on floating vehicles, and reduces the need for ROVs in the process.

[0036] The new solution provides enhanced safety in the process, offering feasibility for synchronized DP and winch control systems. The DP control system can also provide a system for improved process overview during retraction operations. The DP control system can be integrated with the winch control system for semi-automatic fault handling. Integration between the winch control system and the DP control system on a ship can allow these systems to monitor each other. This provides improved operator awareness and the ability to automatically trigger compensatory actions in the event of a ship's DP or winch failure, which improves process safety and prevents damage to power cables. For enhanced safety, the DP system and winch control system can be jointly installed on the ship's bridge.

[0037] A dynamic positioning (DP) system with specially enhanced task execution capabilities controls the position and orientation on the vessel. The DP system may have an interface for a dynamic positioning operator. This DP system also provides payout / retract commands, setpoints from the dynamic positioning (DP) / dynamic positioning operator (DPO) system, and the system status of the DP / DPO system to the winch control system. The winch control system may provide data to the DP / DPO system regarding wire length, wire tension, and the system status of the winch control system. The winch control system may also provide a local human-machine interface (HMI). The winch control system may receive speed and setpoints from the winch. The winch control system controls the winch based on commands and data received from the DP / DPO system, the local HMI, and the winch.

[0038] The advantages of the new remote dynamic cable entry solution include: Dynamic cable pulling and hang-off procedures can be performed faster and in higher wave conditions compared to known solutions, without compromising safety. • The amount of pre-deployed equipment required on the FWT is significantly reduced, and a retraction winch on the FWT is unnecessary. Since dynamic cable pulling and temporary hanging off of dynamic cables can be performed remotely from the cable installation / pulling vessel without personnel on the FWT, the need for a second vessel to support the process is significantly reduced. The need for ROVs is reduced by using pre-installed messenger wires that can be picked up at the water's surface.

[0039] A reference study implementing the DP remote dynamic cable pull-in solution of the present invention demonstrates significant cost reduction. • Uncompromising process safety, improved operability and productivity • Integrated DP and winch control for automated, consistent vessels and winch operation with reduced human interaction.

[0040] Next, exemplary embodiments will be described with reference to the following drawings. [Brief explanation of the drawing]

[0041] [Figure 1] The image shows three floating wind turbines 2 in an offshore wind turbine park, which are interconnected using inter-array power cables 3. The floating wind turbines are moored to the seabed by mooring lines and anchors 4. [Figure 2] This example demonstrates a remote dynamic cable pull-in concept for installing inter-array dynamic power cables on a floating wind turbine. [Figure 3] This exhibits exemplary equipment on a floating wind turbine to enable the installation of inter-array dynamic cables to a floating wind turbine using a remote dynamic cable pull-in concept. [Figure 4] This shows an example of a retractable winch system on a ship used for installation. [Figure 5] This example demonstrates an enhanced DP control system for a stationary vessel, including a dynamic working area for safe operation. [Figure 6] This shows a combined DP and winch control system that can also be operated manually by personnel on board the installation vessel. [Figure 7] This illustrates an exemplary remote hang-off connection for dynamic cables installed on a floating wind turbine. [Figure 8] This demonstrates the conceptual integration of equipment on a floating wind turbine, a retractable winch, and a dynamic positioning system on an installation vessel. [Figure 9] Steps (1) to (4) of the “direct cross-hole” of the first inter-array dynamic cable end in the first floating wind turbine are shown. [Figure 10]Steps (5) to (7) in the “direct cross-hole” of the first inter-array dynamic cable end in the first floating wind turbine are shown. [Figure 11] Steps (8) to (10) of the “direct cross-hole” of the first inter-array dynamic cable end in the first floating wind turbine are shown. [Figure 12] This example demonstrates the installation of inter-array dynamic cables between a first floating wind turbine and a second floating wind turbine. [Figure 13] This paper presents an example of a ship-based technique for dynamic cable pull-in and hang-off between arrays in a second floating wind turbine. [Figure 14] This illustrates the steps for the inter-array dynamic cable cross-hauling process in a second floating wind turbine, in which an installation vessel is first positioned near the second floating wind turbine to perform inter-array cable cross-hauling using pre-installed messenger wires connected to the floating wind turbine. [Figure 15] This example illustrates the steps for the retraction and hang-off process of the second inter-array dynamic cable end in a second floating wind turbine, in which the inter-array dynamic cable is retracted via guide tubes and cable hang-offs on the floating wind turbine. [Figure 16] This example illustrates the final step of the draw-in and hang-off process for the second inter-array dynamic cable end in a second floating wind turbine, where the messenger wire is cut from the draw-in system and released from the installation vessel. [Figure 17] This example illustrates the steps involved in the retrieval and pull-in operation of an inter-array dynamic cable being recovered from a wet store on the seabed. [Modes for carrying out the invention]

[0042] Exemplary embodiments are described with reference to the drawings. These examples should not be considered limiting to the invention. The same reference numerals are used for the same or similar features throughout the drawings and throughout this description.

[0043] Figure 1 shows three floating wind turbines 2 within the offshore wind turbine park. The floating wind turbines are interconnected using inter-array power cables 3. The floating wind turbines are moored to the seabed by mooring lines and anchors 4.

[0044] Figure 2 shows an example of a remote dynamic cable pull-in concept for installing inter-array dynamic power cables on a floating wind turbine.

[0045] Figure 2 shows a system for remote cable pulling of a dynamic cable 3 from a vessel 5 to a FWT 2. The floating wind turbine 2 may be provided with a pull-in wire 10 that can be attached to the dynamic cable 3 connected to the floating wind turbine 2. The FWT may also be provided with a hang-off device for the dynamic cable 3 that can be attached to the floating wind turbine 2. The hang-off device will be described in detail later. The system may also include a vessel 5 for performing a dynamic cable pulling operation to connect the dynamic cable 3 to the floating wind turbine 2, the pull-in wire being attachable to the dynamic cable 3. The vessel 5 may be provided with a winch 6 adapted to pull the pull-in wire and the dynamic cable 3 attached to the floating wind turbine. The system may be adapted to compensate for relative motion between the vessel 5 and the floating wind turbine 2 during the pulling operation. Relative motion may be, for example, waves or currents induced and / or generated when the vessel decides to move.

[0046] The system can be adapted to compensate for the motion on the lead wire due to the relative distance between the FWT2 and the vessel 5, and the longitudinal and / or transverse motion of the FWT2 and the vessel 5. This makes it possible to synchronize the motion of the lead wire with the motion of the floating wind turbine 2.

[0047] A first sensor for measuring the distance between the floating wind turbine and the vessel may be installed on the FWT and / or the vessel. The first sensor may generally be a distance sensor. The distance sensor may be an optical sensor. The optical sensor may be a laser or IR sensor. Other distance sensors, such as radar or ultrasonic sensors, may also be used depending on the system and system requirements.

[0048] The relative motion between the vessel 5 and the floating wind turbine 2 can, alternatively, be estimated indirectly by using data from at least two sensors, where at least one sensor is located on the vessel 5 and at least one sensor is located on the floating wind platform 2. The at least two sensors may be absolute position sensors.

[0049] The vessel 5 may be equipped with a dynamic positioning system 51. Dynamic positioning (DP) involves automatically or semi-automatically controlling the position and orientation of the vessel by using its own propellers and thrusters with respect to one or more position references. The dynamic positioning (DP) system can maintain the position of the vessel fixed within given parameters, or can steer the vessel in a manner in which the dynamic positioning system is indispensable to the vessel. The dynamic positioning (DP) system can steer the vessel based on several input parameters. These input parameters are, for example, - Sensors for location, direction, and speed; - Sensors for external factors such as wind, waves, and currents; and - This may result from user input to perform tasks such as maintaining position or moving in a specific pattern. The control algorithm of the dynamic positioning (DP) system takes in sensor and user input parameters and performs the steering of the vessel by controlling the onboard propellers and thrusters, even when there are changes in external forces.

[0050] The DP system may be adapted to control the vessel 5 based on at least one first input parameter, the parameter being: - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the winch control system, It may have at least one of the following.

[0051] The winch control system 61 is adapted to control a winch 6 on a ship based on at least one second input parameter, the parameter being: - Location of floating wind turbines, - Ship's position, - Motion of a floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw. - The motion of a ship including at least one of heave, sway, surge, roll, pitch, and yaw. - The location of the pull-in wires and dynamic cables, and, - Tension in a dynamic cable, - Tension within the pull-in wire, - Position of the pull-in wire relative to the FWT, - Motion of the pull-in wire relative to the FWT, - Dynamic cable position relative to FWT, - Dynamic cable motion relative to FWT, - Output from the DP system, It may have at least one of the following.

[0052] The system may be provided with at least one inertial navigation system (INS) 13, which may be a satellite navigation system or an inertial measuring device. The inertial measuring device may be at least one of a motion reference unit (MRU) and a motion gyrocompass (MGC).

[0053] The vessel may or may not be equipped with a dynamic positioning system.

[0054] If a vessel cannot be equipped with a DP system, an exemplary concept system includes a winch on the vessel and equipment on a floating wind turbine. By communicating with the equipment on the floating wind turbine, the winch compensates for the motion of the floating wind turbine and the vessel. This allows for control of the motion of the pull-in wire relative to the guide tube for the dynamic cable on the floating wind turbine. The winch is an active winch capable of compensating for motion on both the vessel and the floating wind turbine (FWT). The active winch is controlled by a winch control system. The vessel's position can be controlled manually, for example, in "joystick" mode. The instrumentation system determines the relative position, speed, and heading between the vessel and the floating wind turbine and provides output data to the winch control system on the vessel. The winch control system is adapted to precisely compensate for and control the motion of the cable resulting from the relative motion between the vessel and the floating wind turbine during the pull-in operation, using sensor data from the vessel and the floating wind turbine. Decisions may be provided in real time, and data may be provided to the winch control system as a continuous output. Decisions may be provided quasi-real time or periodically, and data may be provided to the winch control system as a nearly continuous or intermittent output, depending on the requirements of the process. Part of the system (ship processing equipment) is installed on the ship, and another part (remote motion system) is installed on a floating wind turbine. The two parts of the system may communicate via a marine broadband radio (MBR) data link.

[0055] Where a vessel is equipped with a DP system, an exemplary concept includes a winch on the vessel and a DP control system and equipment on a floating wind turbine. The winch is controlled by a winch control system. The DP control system and winch control system are adapted to optimally compensate for the relative motion between the vessel and the FWT during cable retrieval. The instrumentation system determines the relative position, speed, and heading between the vessel and the floating wind turbine and provides output data to the DP system and winch control system on the vessel. The determination is provided in real time, and the data may provide continuous output to the DP system and winch control system. The determination is provided in real time, and the data may provide continuous output to the winch control system. The determination is provided in near real time or periodically, and the data may provide nearly continuous or intermittent output to the winch control system, depending on the requirements of the process. The vessel DP system compensates for winch tension (external force) in addition to environmental influences. A shipboard processing unit can receive real-time position data from a floating wind turbine, calculate relative position, velocity, and bearing, and output this data to the DP and winch control systems. A remote motion system is installed on the floating wind turbine. The remote motion system may include an inertial measuring device, a processing unit, and a battery. The remote motion system and the shipboard processing unit can communicate via a marine broadband radio (MBR) data link. Further details of these systems will be described later.

[0056] When a vessel is equipped with a dynamic positioning (DP) system, measuring and compensating for 2 x 6 degrees-of-freedom (DOF) motion is achieved by synchronizing the DP control system and the winch control system. The DP control system and the winch control system are synchronized to maintain a safety margin during the process of connecting the vessel and the floating wind turbine together. The DP control system and the winch control system are adapted to optimally compensate for the relative motion between the vessel and the FWT during cable retraction. The synchronization of the DP control system and the winch control system may involve at least one of the following: the position of the floating wind turbine (e.g., measured using sensors on the floating wind turbine), the position of the vessel provided by the dynamic positioning system, the position of the retracted cable provided by the winch / winch control system, and the operating status of the DP system and the winch / winch control system. The DP control system and the winch control system operate together and know each other's operation based on the input parameters described and listed above. Each of the DP control system and the winch control system is aware of the status of the other system. The status may take the form of a fault / error condition or whether the system is operating normally. This can be used to improve the security of the system in the event of a fault / error. If one of the DP control system or the winch control system fails in operation, i.e., if it can no longer maintain the precise position of the vessel and the retraction wire, the remaining motion control system (DP or winch control system) will move the vessel and wire to a position with an increased safety margin. The retraction wire (with attached dynamic cable) may be guided to a safe position, for example, and the motion may be reversed or interrupted.

[0057] Some examples of winch or DP system failures: Example a): The winch is locked and cannot be compensated -> The vessel then moves closer to the FWT to lower the dynamic power cable and hold it away from the critical point near the FWT. Example b): The DP fails and the vessel does not maintain its position -> The winch pays out the pull wire to lower the dynamic cable to the seabed in preparation for emergency cutting.

[0058] As described above, Figure 2 shows an exemplary remote dynamic cable pull-in concept 1 for a floating wind turbine (FWT) 2. The cable to be pulled in is an inter-array dynamic cable 3 connected to the floating wind turbine 2. The floating wind turbine may be part of an offshore wind turbine plant. As previously described, the inter-array dynamic cable is sensitive to voltage and bending, and the possibility of damage is high during installation. In the example of Figure 2, the floating wind turbine 2 is provided with a guide tube 20 for the inter-array dynamic cable 3. As will be described in detail below, a floating instrumentation kit 7 is provided to monitor the messenger wire 10.

[0059] The installation vessel 5 may be equipped with a dynamic positioning system (DP) and a retractable winch 6. The winch 6 may be equipped with a winch control system. The winch control system is located on the vessel 5. The winch control system is connected to the DP control system to provide winch parameters to the DP control system and to control the winch 6 by the DP control system. The DP system may be integrated with the winch control system. System integration may provide an improved process overview to the operator of the integrated DP and winch control system.

[0060] The retraction winch 6 retracts the messenger wire / retraction wire 10, which is connected to the inter-array dynamic cable 3 via a guide tube 20. The messenger wire / retraction wire 10 moves over rollers or pulleys on the floating wind turbine deck that support and guide the messenger wire / retraction wire 10. Rollers and pulleys are also provided on the installation vessel 5 to support and guide the messenger wire / retraction wire 10 when it comes onto the vessel and then onto the deck of the vessel before reaching the retraction winch 6. The installation vessel 5 and the floating wind turbine 2 are provided with wireless communication to transmit signals from the equipment on the floating wind turbine 2 to the installation vessel 5.

[0061] An example of equipment typically installed on a floating wind turbine 2 is shown in Figure 3. A first pulley / guide 11 is positioned within a guide tube 20 on the floating wind turbine to gather the messenger / pull-in wire 10 around it. The pulley / guide 11 is positioned above a guide tube hang-off 16. A second pulley / guide 12 is positioned to support and deflect the messenger wire 10 from the floating wind turbine 2 before it leaves the floating wind platform and travels over the installation vessel 5. An upper guide tube hang-off device 16 for remote cable hang-off is provided at the top of the guide tube 20. This is where the messenger wire and inter-array dynamic cables 3 exit the guide tube 20. One or more sensors may be provided to monitor the hang-off area for the dynamic cables 3. The sensors may be, for example, distance sensors in the form of laser or IR sensors or radar. The sensors may be optical sensors, such as cameras or video cameras. A first camera 14 may be positioned to monitor the dynamic cable hang-off area. A second camera 17 may be positioned to monitor the messenger wire 10 in a further pulley / guide 12. The second camera 17 may also monitor the exit of the messenger wire from the further pulley / guide 12. The first and second cameras may be, for example, video cameras. The FWT may be provided with at least one sensor adapted to provide a signal when the dynamic cable is in its final hang-off position.

[0062] A floating wind turbine may be equipped with an inertial navigation system (INS) 13. The inertial navigation system 13 may include at least one of a satellite navigation system (e.g., Global Navigation Satellite System (GNSS) or GPS) and an inertial measuring instrument (MRU or MGC) to measure the position and motion of the floating wind turbine 2. The satellite navigation system may be, for example, GNSS, GPS, GLOANASS, BeiDou, Galileo, QZSS, IRNASS, or NavIC. The inertial navigation system (INS) may be mounted near a second pulley / guide 12 on which a messenger wire exits the floating wind turbine. This allows monitoring of the motion of the floating wind turbine, i.e., heave, sway, surge, roll, pitch, and yaw. The floating wind turbine 2 may also be equipped with a communication system (transceiver) 15 to transmit signals from floating equipment mounted on the floating wind turbine, such as signals from an inertial navigation system (INS), sensors, and cameras, to the installation vessel. The communication system may be, for example, marine broadband radio (MBR), but other wireless communication systems may also be used. Equipment on the floating body may be pre-installed. Installations on the floating body may be removable. Similarly, messenger wires / pull-in wires 10 may be pre-installed on the floating wind turbine 2. The floating wind turbine may be equipped with distance sensors for measuring the relative distance between the floating wind turbine 2 and the vessel 5. The distance sensors may be, for example, lasers, IR sensors, ultrasonic sensors, or radar.

[0063] The retraction winch system on the installation vessel 5 can be adapted using various pulley configurations at various locations to route and support the retraction wire (see, for example, Figure 4). This enables the concept to be implemented in various vessel laying spreads, such as horizontal laying spreads (HLS) using dynamic cables installed above the stern or sides, and vertical laying spreads (VLS) using dynamic cables installed through the moonpool or above the sides.

[0064] Messenger wires on floating wind turbines can be pre-installed in various configurations for opening and connecting to dynamic cables and retraction winches. Hang-off devices can also be incorporated into the messenger wire configuration to allow the retraction winch wire to be released when the dynamic cable is temporarily hung off and dumped.

[0065] The remote cable hang-off mechanism mounted on the floating wind turbine 2 may be a mechanical arrangement, a mechanism incorporated into the hang-off clamp design, a mechanism incorporated into the hang-off flange, or a mechanism combining the clamp and the hang-off flange. The combined hang-off flange mechanism may be a remotely operated connector design similar to a diverless bend-reinforced connector. The hang-off of the dynamic cable 3, which is drawn into and connected to the floating wind turbine 2, may be performed without manual intervention. Automatic hang-off allows the hang-off operation to be performed without personnel on the floating structure. An example may be the use of a system having three latch dogs that rotate and grip in a groove or support within the cable termination head. The three latch dogs are mounted on top of the guide tube. The latch dogs may include a weak link that releases the cable from the floating wind turbine if the large floating wind turbine drifts, for example due to a mooring line failure.

[0066] The pull-in winch 6 on the installation vessel 5 is shown in more detail in Figure 4. The pull-in winch (PIW) may be equipped with a PIW control system 61. The control system 61 may also have backup in the form of personnel 62 (local HMI of the PIW) on board the installation vessel 5 who can manually control the pull-in winch. The control system is connected to a communication system 18 to communicate with a transceiver 15 on the floating wind turbine. The communication system may be marine broadband radio (MBR). Equipment on the installation vessel may also include a pulley / guide arrangement 63 to support and deflect the messenger / pull-in wire 10. The pulley / guide arrangement may allow the vessel to optimize its position and orientation. A dynamic positioning system (DP) 51 (Figure 6) on the installation vessel 5 may also be equipped with specially enhanced task functions to control the installation vessel 5 during dynamic cable pull-in operations, based on input from a sensor system on the floating wind turbine 2. The dynamic positioning system 51 on the installation vessel 5 may have a communication module to enable communication with and control the retraction winch control system 61. As a security system in case of system failure, the DP system and the retraction winch control system may be equipped with manual controls 52, 64 for control by personnel on board the installation vessel 5.

[0067] Figure 5 illustrates an example of how the DP control system on the installation vessel 5 may include determining a safe working area for positioning the installation vessel in the current operating step. When the installation vessel is directly connected to the dynamic cable, the working area is defined by limits to avoid damage to the dynamic cable, for example, by bending or dragging. After the dynamic cable is connected to the messenger / pull-in wire, the limits of the installation vessel's position and orientation are defined by the operating angle and length of the pull-in winch. The defined limits may be used by the DP control system to prevent the operator from moving or orienting the installation vessel outside the safe working area. Alarms and warnings may also be issued to the operator if the installation vessel approaches these limits.

[0068] The floating wind turbine 2 (FWT) equipment, the ship's pull-in winch (PIW) system 6, and the installation ship 5's dynamic positioning (DP) system 51 work together to accomplish the task of pulling in the array-to-array dynamic cables mounted on the floating wind turbine 2. Figure 8 illustrates this concept of integration between the floating wind turbine 2 equipment kit 7, the pull-in winch 6, and the dynamic positioning system 51. The equipment on the floating wind turbine 2 measures the position and motion (heave, sway, surge, roll, pitch, yaw) of the floating wind turbine 2. These position and motion parameters are transmitted to the installation ship 5. The pull-in winch 6 control system 61 and the dynamic positioning system 51 receive the position and motion parameters from the equipment 7 on the floating wind turbine. The dynamic positioning system 51 controls the installation vessel 5 based on several parameters, including the position of the installation vessel and position and motion parameters from the equipment 7 on the floating wind turbine, and compensates for relative motion between the floating wind turbine 2 and the installation vessel to enable controlled cable retraction and hang-off operations. The dynamic positioning system 51 also provides input parameters to the winch control system 61 that controls the retraction winch 6, as shown in Figure 8.

[0069] The integration of the winch control system 61 with the ship DP system 51 enables coordinated ship positioning and winch unwinding / retraction operations, and also improves overall safety in the event of a ship DP incident or winch failure. To perform dynamic cable retraction operations without onboard personnel, the floating wind turbine 2 further has pre-installed messenger wires 10 routed through guide tubes 20 and pulley arrangements 11, 12 as described above. To perform dynamic cable hang-off operations without onboard personnel, the floating wind turbine 2 is provided with an automatic hang-off clamp arrangement 31. The automatic hang-off clamp arrangement is placed on the upper surface of the floating body and may generally be placed on the upper surface of the end of the guide tube 16, as illustrated in Figure 7.

[0070] Figure 7 shows an example of an automatic hang-off device on an FWT. The guide tube 20 is provided with an upper hang-off flange arrangement / interface 16 for remote cable hang-off. The inter-array dynamic cable 3 may be provided with a hang-off clamp having a spring-loaded latch arrangement 31. When the inter-array dynamic cable 3 is pulled up through the guide tube 20 and exits the upper surface of the guide tube 16, the spring-loaded latch arrangement 31 inflates, fixing the inter-array dynamic cable 3 in the upper position of the hang-off plate and preventing the inter-array dynamic cable from slipping back into the guide tube 20. Further functions of the guide tube when guiding the cable during the retraction operation are described.

[0071] Figure 8 illustrates the conceptual integration between the equipment kit 7 on the floating wind turbine 2, the retraction winch 6, and the dynamic positioning (DP) system 51 on the installation vessel. The equipment on the floating wind turbine distributes information about the floating wind turbine's position and motion to the winch control system 61 and the dynamic positioning system. The retraction winch can send information about the messenger wire / retraction wire length and messenger wire / retraction wire tension to the DP system 51. The retraction winch control system 61 can receive the setpoint for the messenger wire / retraction wire length from the dynamic positioning (DP) system 51. The winch control system receives separate signals for the vessel's motion, the floating wind turbine's motion, and relative motion from the remote motion system on the floating wind turbine.

[0072] A method for performing cable pull-in of a dynamic cable to a floating wind turbine for the system described above is disclosed. The dynamic cable is attached to a pull-in wire on the floating wind turbine. Pulling the pull-in wire by the vessel is performed until the dynamic cable is positioned on the hang-off device on the floating wind turbine. Pulling the pull-in wire can be performed by moving the vessel, pulling the pull-in wire, and / or pulling it in. Pulling in can be performed by using a winch or by using a pulley (for example, as in a heave compensation system). The pulley performs dynamic compensation. The winch can be dynamically controlled. Relative motion between the floating wind turbine and the vessel is compensated during the pull-in operation.

[0073] The system is adapted to compensate for the relative distance between the floating wind turbine 2 and the vessel 5, and for the motion on the pull-in wire due to the longitudinal motion of the floating wind turbine 2 and the vessel 5. To control the pull-in operation, the distance between the floating wind turbine and the vessel may be measured. The distance may be measured between the exit point for the pull-in wire on the floating wind turbine and the inlet point for the pull-in wire on the vessel. The exit / inlet points may be the starting / starting points, or vice versa, depending on the surrounding conditions. The vessel may be controlled by a dynamic positioning system based on at least one first input parameter. The winch may be controlled by a winch control system based on at least one second input parameter. At least one first input parameter has at least one of the following: position of the floating wind turbine; position of the vessel; motion of the floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw; position of the pull-in wire and dynamic cable; motion of the vessel including at least one of heave, sway, surge, roll, pitch, and yaw; and tension in the dynamic cable; tension in the pull-in wire; position of the pull-in wire relative to the FWT; motion of the pull-in wire relative to the FWT; position of the dynamic cable relative to the FWT; motion of the dynamic cable relative to the FWT; and output from the winch control system. At least one second input parameter has at least one of the following: position of the floating wind turbine; position of the vessel; motion of the floating wind turbine including at least one of heave, sway, surge, roll, pitch, and yaw; motion of the vessel including at least one of heave, sway, surge, roll, pitch, and yaw; position of the draw wire and dynamic cable; and tension in the dynamic cable; tension in the draw wire; position of the draw wire relative to the FWT; motion of the draw wire relative to the FWT; position of the dynamic cable relative to the FWT; motion of the dynamic cable relative to the FWT; and at least one output from the DP system.

[0074] Cable pulling operation As mentioned above, cables are sensitive to voltage and bending, and the cable pull-in procedure must be carried out carefully. Cable pull-in performed on a floating wind turbine limits tension monitoring against heave / deviation on the floating wind turbine. Pull-in from a vessel is known from a fixed-bottom turbine, and tension monitoring is limited to the vessel's heave / deviation (when operated on a DP). Pull-in from a vessel to a floating wind turbine may involve monitoring and compensating for the relative distance / motion of both the vessel and the floating wind turbine. As previously explained, in contrast to fixed-bottom wind turbines, floating wind turbines (FWTs) are suspended and therefore exposed to external forces such as wind, currents, and waves generated by motion. During the cable installation process, not only is the installation vessel moving, but the FWT is also moving relative to the vessel. Cables are vulnerable to small-radius bending, as well as tension, which imposes stringent requirements on the operation and the equipment involved in the operation. Therefore, the installation procedures for FWTs are generally more complex in terms of the technical and safety issues that need to be addressed compared to fixed-installation wind turbines standing on the seabed. The described retraction solutions include an automated system for coordinating the motion of the floating body, the retraction winch, and (if the vessel is a DP vessel) the DP setpoint during normal operation and in unforeseen scenarios.

[0075] Direct cross-hole of the first inter-array dynamic cable end in the first floating wind turbine Figure 9 shows the different steps (1) to (4), indicated in parentheses in Figure 9, which are used by the installation vessel 5 to prepare the first floating wind turbine 2 for direct cross-hauling of the first inter-array dynamic cable ends. The floating wind turbine has mooring lines 4 for tethering to the seabed.

[0076] At the start of operation, the installation vessel may be positioned near the floating wind turbine. Operation tasks in steps (1) to (4) of Figure 9: 1. The installation vessel 5 may pick up the messenger wire 10 that has been pre-installed on the floating wind turbine on the sea surface, or the messenger wire 10 may be picked up below the sea surface by the ROV. 2. The ends of the messenger wires routed underwater are picked up by the installation vessel or ROV and connected on the upper surface of the inter-array dynamic cable 3 mounted on the installation vessel 5. 3. The messenger wire ends routed to the upper surface of the floating wind turbine are connected to the ship's retraction winch 6. 4. The position and orientation of the vessel are optimized within the limits of the procedure to cross the array dynamic cable 3 to the floating wind turbine 2.

[0077] The installation vessel is now ready to perform the cross-haul of the first array-to-array dynamic cable to the first floating wind platform. Operation steps (5)-(7) in Figure 10: 5. The first end of the inter-array dynamic cable is deployed from the installation vessel to the cross-hole depth. The cable is sensitive to bending, and the cross-hole depth is determined to provide an acceptable bending of the cable that does not damage the cable. 6. Continue paying out the cable from the installation vessel 5 and begin pulling in the first end of the cable with the pull-in winch 6. This task may have a laying schedule for each dynamic cable. The laying schedule is a detailed description of the position and movement of the installation vessel, the payout / retraction of the dynamic cable, and the payout / retraction of the winch based on the analysis of the task. The laying schedule is to be followed by the operator of the installation vessel and / or programmed within the dynamic positioning system. Underwater operations are generally monitored by an ROV. 7. The cable is pulled in using the retraction winch, and the upper end is monitored by camera 14 as the cable enters the bottom of the guide tube 20. The position of the installation vessel is adjusted, and the cable is paid out to ensure that the cable enters the guide tube 20 correctly.

[0078] The pulling in and hanging off of the inter-array dynamic cables on the floating wind turbine may be performed next. Figure 11a shows different steps (8) to (10), indicated in parentheses, for pulling in and hanging off the first inter-array dynamic cable end on the first floating wind turbine 2 by the installation vessel 5. Figure 11b also shows the cable 3 with a hang-off clamp as it is attached to the pull-in wire 10 and enters the guide tube 20 in step (8), and the cable 3 after the hang-off clamp 31 has been pulled up through the guide tube and is placed on the upper surface of the hang-off flange / interface 16 (in steps (9) to (10)). Operation steps (8) to (10): 8. The installation vessel continues to pull the upper end of the cable into the guide tube, carefully monitoring the cable as it enters the bottom of the guide tube. The bottom of the guide tube may be provided with a bell mouth or an alternative bending reinforcement connector (not shown). For dynamic cables, a single bending reinforcement arrangement may be appropriate for FWT. 9. While being monitored by the top camera, continue pulling the cable through the guide tube and up onto the top hang-off flange / interface until the cable is pulled up, then stop pulling it. 10. Lower the hang-off clamp with the extracted latch onto the hang-off flange / interface.

[0079] As shown in Figure 12, after the first inter-array dynamic cable has been retracted and hung off, the installation vessel cuts the retraction winch wire at the first floating wind turbine and continues to install the inter-array cable toward the second FWT. The retraction operation may be reversed until the hang-off clamp is pulled and passes the guide tube hang-off flange / interface. After this point, the installation vessel continues to install the inter-array cable.

[0080] A method for retracting and hanging off inter-array dynamic cables in a second floating wind turbine is shown in Figure 13. The installation vessel 5 is positioned near the floating wind turbine 2 to perform inter-array dynamic cable retraction and hang-off in the second floating wind turbine. Upon approaching the second floating wind turbine 2, the installation vessel 5 rotates until its bow faces outward from the floating wind turbine and its stern faces the floating wind turbine. The installation vessel then reverses toward the floating wind turbine with its stern facing forward. The method in Figure 13 is shown for a horizontal laying system with a chute above the stern of the vessel. This suggests that, as described above, the vessel must rotate and reverse toward the floating structure with its stern facing forward. The method shown in Figure 13 is an alternative, and other methods may be possible depending on the floating structure and vessel.

[0081] Figure 14 shows the cross-haul of the inter-array dynamic cable 3 end in the second floating wind turbine 2. In Figure 14, the installation vessel is positioned near the floating wind turbine to perform the inter-array dynamic cable cross-haul operation task. The installation vessel deployed the inter-array cable 3 from the first floating wind turbine to the second floating wind turbine. The underwater routed end and the top-route end of the pre-installed messenger wire are picked up and connected in the first floating wind turbine 2 in the same manner as in the steps of Figure 9. 1. The installation vessel 5 lowers the dynamic cable on its A&R wire (discard and retrieve wire) to the transfer depth. At the transfer depth, the pull-in winch is pulled to remove slack in the messenger wire. 2. The installation vessel 5 continues to pay out the A&R (discard and retrieve) wire and begins to pull in the second end of the inter-array dynamic cable 3 using the pull-in winch 6 according to the laying schedule for the operation. The underwater operation is generally monitored by an ROV. 3. When the suspension load of the inter-array dynamic cable is transmitted to the pull-in winch 6, the A&R (discard and retrieve) wire is ready to be cut. 4. Installation vessels will continue cable pulling even after the A&R (discard and recovery) wire has been cut. ROVs are commonly used to cut A&R wires.

[0082] Figure 15 shows the pulling in and hanging off of the end of the inter-array dynamic cable 3 in the second floating wind turbine 2. In step 1, the inter-array dynamic cable is pulled in onto the floating wind turbine 2 through the guide tube 20. In step 2, the inter-array dynamic cable is hung off onto the floating wind turbine.

[0083] In Figure 16, the messenger wire / pull-in wire is cut from the installation vessel 5. On the floating wind turbine, the pull-in and hang-off operation of the second inter-array dynamic cable end is similar to that of the first inter-array dynamic cable end. The process may be reversed until the hang-off clamp is pulled and passes the guide tube hang-off flange / interface.

[0084] Recovery and extraction from wet storage Figures 17A–17C show the retrieval and retraction of inter-array dynamic cables from the wet storage facility. The wet storage facility is located on the seabed.

[0085] Stage 1: 1. Position the installation vessel 5 above the upper end of the wet-stored inter-array dynamic cable. 2. Deploy the retrieval wire and connect it to the inter-array dynamic cable.

[0086] Stage 2: 3. Begin retrieving the inter-array dynamic cables, and monitor the configuration and touch-down point (TDP) of the inter-array dynamic cables, typically using an ROV. 4. The installation vessel is moved to a position near the floating wind turbine for operation.

[0087] Stage 3: 5. The pre-installed messenger wire is picked up onto the floating wind turbine. 6. Connect the underwater routed messenger wire ends to the inter-array dynamic cables. 7. Retract the messenger wire end routed to the top surface and connect it to the winch. The cross-hauling, pulling, and hang-off operations are continued in the same manner as described above for the cross-haul of the second inter-array dynamic cable end.

[0088] The steps shown in Figures 9 to 17 are merely examples, and the remote access concept may also be implemented in other steps according to the dynamic cable installation plan. Alternative methods may be conceived depending on the vessel and installation spread, the dynamic cable configuration, and the interface on the floating installation. The remote access concept can be adapted to various variants and scenarios.

[0089] While the examples are shown and described for floating wind turbines, the dynamic cable pull-in concept may also be used for other floating structures where dynamic cables are provided, and the examples and the present invention are not limited to floating wind turbines. The concept may be used on other floating structures on which the equipment and fixtures described above can be pre-installed and integrated with the FWT on the floating structure.

[0090] In practice, inter-array dynamic cables connect floating wind turbines, but this is just an example; dynamic cables can generally be installed using the remote retraction concept described above. The remote retraction winch concept can also be used to install dynamic cables on floating structures and / or between floating structures, especially when there are many floating structures connected together by dynamic cables. The retraction winch concept for performing retraction operations can also be used on floating structures where it is difficult or dangerous to obtain personnel and equipment on or off the floating structure. On some floating structures, space for larger essential equipment, such as a winch to perform retraction operations, is limited or unavailable. Space on floating structures can also be limited or too small for the personnel required during retraction operations.

[0091] The cable installation process can be carried out by the method described above, by controlling the relative position between the FWT and the vessel via dynamic positioning on board the vessel, combined with winch control and position signals from the FWT. Thus, cable installation can be controlled by monitoring the distance between the vessel and the FWT. The motion of the retraction wire and cable can, alternatively, be monitored relative to a reference point on the FWT and compensated by the retraction system.

[0092] While preferred embodiments of the present invention have been described, it will be apparent to those skilled in the art that other embodiments incorporating this concept may be used. These and other examples of the present invention shown above are intended for illustrative purposes only, and the actual scope of the invention should be determined by the following claims. [Explanation of Symbols]

[0093] 1. Cable installation system 2. Floating wind turbine 3 Dynamic Cables 4 Anchors 5 Ships 6. Winch 7. Floating Object Instrumentation Kit 8 steps 9 steps 10 Messenger wire / Pull-in wire 11. First pulley / guide 12. Second pulley / guide 13. Inertial Navigation System 14. First camera 15. Communication Systems (Transceivers) 16 Guide Tube Hang-Off, Guide Tube Hang-Off Device / Interface 17. Second Camera 18 Communication Systems 20 Guide Tubes 31 Automatic hang-off clamp placement 32 Unknown (Symbols in Figures 11 and 15) 51 Dynamic positioning system 52 Manual control 61 Winch control 62 personnel 63 Pulley / Guide Arrangement 64 Manual control

Claims

1. A system for remote cable pulling of a dynamic cable (3) from a ship (5) to a floating wind turbine (2), A floating wind turbine (2) having a pull-in wire (10) that can be attached to a dynamic cable (3) connected to the floating wind turbine (2), A vessel (5) for performing a dynamic cable pulling operation to connect the dynamic cable (3) to the floating wind turbine (2), wherein the pulling wire is attachable to the dynamic cable (3), the vessel (5) has a winch (6) and is adapted to pull the pulling wire by the winch (6), thereby pulling the dynamic cable (3) attached to the pulling wire to the floating wind turbine, and A winch control system (61) adapted to control the winch (6) to compensate for the relative movement between the vessel (5) and the floating wind turbine (2) during the retraction operation, and It has, The relative movement between the vessel (5) and the floating wind turbine (2) is indirectly estimated, and therefore the winch control system uses data from at least two sensors, the at least two sensors comprising at least one first sensor located on the vessel (5) and at least one second sensor located on the floating wind turbine (2), wherein the system is configured such that the relative movement between the vessel (5) and the floating wind turbine (2) is indirectly estimated, and the winch control system uses data from at least two sensors, the at least two sensors comprising at least one first sensor located on the vessel (5) and at least one second sensor located on the floating wind turbine (2).

2. The system according to claim 1, wherein the winch control system (61) is adapted to compensate for movement of the pull-in wire relative to the floating wind turbine (2) that may result from the fluctuating distance between the vessel (5) and the floating wind turbine (2) caused by the vertical and / or horizontal motion of either the vessel (5) or the floating wind turbine (2).

3. The system according to claim 1, further comprising a sensor for measuring the distance between the floating wind turbine and the vessel.

4. The system according to claim 1, wherein the vessel (5) comprises a dynamic positioning system (51) adapted to control the vessel (5) based on at least one first input parameter.

5. The system according to claim 4, wherein compensation for the relative movement between the vessel (5) and the floating wind turbine (2) during the retraction operation is performed by the winch control system (61) and the dynamic positioning system (51).

6. The system according to claim 1 or 2, wherein the winch control system (61) is adapted to control the winch (6) of the vessel based on at least one second input parameter.

7. The at least one first input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the aforementioned pull-in wire and the aforementioned dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the aforementioned winch control system, The system according to claim 5, having at least one of the following.

8. The at least one second input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the pull-in wire and the dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the DP system, The system according to claim 6, having at least one of the following.

9. The system according to claim 1 or 2, further comprising at least one inertial navigation system (INS) (13).

10. The system according to claim 1 or 2, further comprising at least one of a satellite navigation system or an inertial measuring device.

11. The system according to claim 10, wherein the inertial measuring device is at least one of a motion reference unit (MRU) and a motion gyrocompass (MGC).

12. The system according to claim 1 or 2, further comprising at least one second sensor for monitoring the hang-off region on the floating wind turbine for the dynamic cable (3).

13. A first communication system (15) adapted to transmit at least one sensor signal from the floating wind platform to the vessel (5), A second communication system (18) on the ship for receiving the at least one sensor signal and The system according to claim 1 or 2, further comprising the above.

14. The system according to claim 13, wherein the first communication system (15) and the second communication system (18) are marine broadband radio (MBR).

15. A floating wind turbine (2), The floating wind turbine (2) has a pull-in wire (10) that can be attached to a dynamic cable (3) connected to it, The pull-in wire is attachable to a vessel (5) to perform the operation of pulling in the dynamic cable (3) to the floating wind turbine, and the vessel (5) has a winch (6) for pulling the pull-in wire and a winch control system (61) adapted to control the winch (6) to compensate for the relative movement between the floating wind turbine (2) and the vessel (5) during the pull-in operation. The relative movement between the vessel (5) and the floating wind turbine (2) is indirectly estimated, and therefore the winch control system uses data from at least two sensors, the at least two sensors comprising at least one first sensor located on the vessel (5) and at least one second sensor located on the floating wind turbine (2), wherein the floating wind turbine (2).

16. The floating wind turbine (2) according to claim 15, wherein the winch control system (61) is adapted to compensate for movement of the pull wire relative to the floating wind turbine (2) that may result from the fluctuating distance between the vessel (5) and the floating wind turbine (2) caused by the vertical and / or horizontal motion of either the vessel (5) or the floating wind turbine (2).

17. The floating wind turbine (2) according to claim 15 or 16, further comprising a sensor for measuring the distance between the floating wind turbine and the vessel.

18. A floating wind turbine (2) according to claim 15 or 16, further comprising at least one inertial navigation system (INS) (13).

19. The floating wind turbine (2) according to claim 15 or 16, further comprising at least one of a satellite navigation system and an inertial measuring device (13).

20. The floating wind turbine (2) according to claim 15 or 16, further comprising at least one sensor for monitoring the hang-off region for the dynamic cable (3).

21. The floating wind turbine (2) according to claim 20, wherein at least one sensor is adapted to provide a signal when the dynamic cable is in its final hang-off position.

22. The floating wind turbine (2) according to claim 15 or 16, further comprising a hang-off device adapted for hanging off the dynamic cable (3) that is drawn in and connected to the floating wind turbine.

23. The floating wind turbine (2) according to claim 15 or 16, further comprising a communication system (15) adapted to transmit at least one signal from the floating wind turbine to the vessel (5).

24. A vessel (5) for performing a dynamic cable pull operation to connect a dynamic cable (3) to a floating wind turbine (2) equipped with a pull wire, wherein the pull wire is attachable to the dynamic cable (3), the vessel (5) has a winch (6) adapted to pull the pull wire to pull the dynamic cable (3) into the floating wind turbine, and the vessel (5) has a winch control system (61) adapted to control the winch (6) to compensate for relative movement between the floating wind turbine (2) and the vessel (5) during the pull operation. The relative movement between the vessel (5) and the floating wind turbine (2) is indirectly estimated, and therefore the winch control system uses data from at least two sensors, the vessel (5) having at least one first sensor located on the vessel (5) and at least one second sensor located on the floating wind turbine (2).

25. The vessel (5) according to claim 24, wherein the winch control system (61) is adapted to compensate for movement of the pull-in wire relative to the floating wind turbine (2) that may result from the fluctuating distance between the vessel (5) and the floating wind turbine (2) caused by the vertical and / or horizontal motion of either the vessel (5) or the floating wind turbine (2).

26. The vessel (5) according to claim 24 or 25, further comprising a sensor for measuring the distance between the floating wind turbine and the vessel.

27. The vessel (5) according to claim 24 or 25, further comprising a dynamic positioning system (51) adapted to control the vessel (5) based on at least one first input parameter.

28. The vessel (5) according to claim 24 or 25, wherein the winch control (61) system is adapted to control the winch based on at least one second input parameter.

29. The at least one first input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the pull-in wire and the dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the aforementioned winch control system, The vessel according to claim 27, further comprising at least one of the following.

30. The at least one second input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the pull-in wire and the dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the DP system, The vessel according to claim 28, further having at least one of the following.

31. The vessel according to claim 27, wherein compensation for the relative movement between the vessel (5) and the floating wind turbine (2) during the retraction operation is performed by the winch control system (61) and the dynamic positioning system (51).

32. The vessel (5) according to claim 24 or 25, further comprising a communication system (18) for receiving at least one sensor signal from the floating wind turbine (2).

33. A method for performing cable routing of a dynamic cable to a floating wind turbine using the system described in claim 1, The steps include attaching the dynamic cable to the draw wire on the floating wind turbine, The steps include: pulling the pull-in wire by the vessel until the dynamic cable is positioned on the hang-off device on the floating wind turbine; A method comprising the step of compensating for the relative movement between the floating wind turbine and the vessel during the aforementioned retraction operation.

34. The method according to claim 33, wherein the winch control system (61) is adapted to compensate for movement of the pull-in wire relative to the floating wind turbine (2) that may result from the fluctuating distance between the vessel (5) and the floating wind turbine (2) caused by the vertical and / or horizontal motion of either the vessel (5) or the floating wind turbine (2).

35. The method according to claim 33 or 34, further comprising the step of measuring the distance between the floating wind turbine and the vessel.

36. The method according to claim 33 or 34, further comprising the step of measuring the distance between an outlet for the lead wire on the floating wind turbine and an inlet for the lead wire on the vessel.

37. The method according to claim 33 or 34, further comprising the step of controlling the vessel by a dynamic positioning system based on at least one first input parameter.

38. The method according to claim 33 or 34, further comprising the step of controlling the winch by the winch control system based on at least one second input parameter.

39. The at least one first input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the pull-in wire and the dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the aforementioned winch control system, The method according to claim 37, further comprising at least one of the following.

40. The at least one second input parameter is, The position of the floating wind turbine, Confirmation of the aforementioned vessel, The motion of the floating wind turbine, including at least one of heave, sway, surge, roll, pitch, and yaw. The motion of the vessel, including at least one of heave, sway, surge, roll, pitch, and yaw, The positions of the pull-in wire and the dynamic cable, The tension within the dynamic cable, The tension within the aforementioned pull-in wire, The position of the pull-in wire relative to the FWT, Movement of the pull-in wire relative to the FWT, The position of the dynamic cable relative to the FWT, Movement of the dynamic cable relative to the FWT, Output from the DP system, The method according to claim 38, comprising at least one of the following.

41. The method according to claim 37, wherein compensation for the relative movement between the vessel (5) and the floating wind turbine (2) during the retraction operation is performed by the winch control system (61) and the dynamic positioning system (51).

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