JP6907715B2 - Attitude control system and attitude control method for underwater floating power generators - Google Patents

Description

The present invention relates to an attitude control system and an attitude control method for an underwater floating power generator.

As an underwater floating power generation device, the devices described in Patent Documents 1 and 2 are known. In the device described in Patent Document 1, two nacelles are connected by a hydrofoil structure. The device is held by a mooring rope perpendicular to the seabed and two mooring ropes arranged at an angle to the seabed. The attitude of the device can be modified by the restoring force of the generator and the vertical mooring to the anchor. In the apparatus described in Patent Document 2, a vehicle having a turbine is rotated in the pitch direction. Thereby, the posture in the pitch direction can be controlled.

On the other hand, the device described in Patent Document 3 is a posture stabilizing device for suspended luggage provided in a helicopter flying in the air. By rotating the propeller attached to the luggage, the behavior of the luggage can be suppressed.

Japanese Patent No. 4920823 Special Table 2009-525427 Japanese Unexamined Patent Publication No. 5-193584

The underwater floating power generator can be inclined in the pitch direction, for example. Conventionally, when the underwater floating power generator is tilted in the pitch direction, it has not been sufficiently studied to correct the posture. Even if an attempt is made to control the attitude in the pitch direction using a conventional method, it is difficult to realize efficient attitude control.

For example, in the apparatus described in Cited Document 1, the depth can be adjusted, but the posture in the pitch direction cannot be controlled. In order to control the attitude in the pitch direction, for example, a mechanism for generating lift using a horizontal stabilizer is required. Further, the device described in Cited Document 2 requires a mechanism for changing the thrust direction of the propeller. If a large amount of power is required for this, the device becomes unsuitable as an energy plant. In addition, a structure having a swivel joint may cause fatigue fracture and water leakage. In the device described in Cited Document 3, the attitude of the luggage in the yaw direction is controlled. Therefore, it is necessary to install a propeller or a power unit at a position deviated from the center of gravity of the luggage. As a result, it is difficult to balance the luggage in a steady state. Moreover, it is difficult to cancel the anti-torque component with a single-shot propeller. As a result, the load with the propeller attached can tilt in the roll direction.

An object of the present invention is to provide an attitude control system and an attitude control method for an underwater floating power generation device that can correct the attitude of the underwater floating power generation device when it is tilted in the pitch direction.

One aspect of the present invention is an attitude control system for an underwater floating power generation device including a power generation turbine including a rotation shaft and a pod arranged along the rotation axis of the rotation shaft and provided with a power generation turbine. The center of gravity of the underwater floating power generation device is located below the rotation axis, and it is a mooring rope for mooring the underwater floating power generation device. One end of the mooring rope is from the rotation axis of the underwater floating power generation device. The mooring rope connected to one or more mooring points provided below and below the center of gravity of the underwater floating power generator, and at least the pitch angle of the underwater floating power generator. The detection unit for detecting, the rotation speed adjusting means provided for the power generation turbine and capable of adjusting the rotation speed of the power generation turbine, and the rotation speed adjusting means according to the inclination angle detected by the detection unit are controlled. By changing the rotation speed of the power generation turbine, the turbine thrust is changed, and around the mooring point according to the product of the distance between the rotation axis and the center of gravity in the vertical direction of the submersible floating power generator and the amount of change in the turbine thrust. It is provided with a control unit that generates a moment of the above and corrects the posture of the underwater floating power generator in the pitch direction.

In this attitude control system, an underwater floating power generation device moored by a mooring rope floats in water, and a power generation turbine rotates to generate power. The control unit changes the rotation speed of the power generation turbine according to the tilt angle in the pitch direction of the submersible floating power generation device. When the rotation speed of the power generation turbine is changed, the thrust of the power generation turbine changes. Here, one end of the mooring rope is connected to a mooring point provided in a portion below the rotation axis in the underwater floating power generator. As a result of the mooring point being provided at the lower part, the thrust in the direction of the rotation axis generates a moment around the mooring point. The generated moment acts to stabilize the posture of the underwater floating power generator in the pitch direction. As a result, the attitude of the underwater floating power generator in the pitch direction can be corrected.

In some embodiments, the submersible floating power generator is disposed away from the power generation turbine in a direction intersecting the direction of the rotation axis, with a second power generation turbine including a second rotation axis and a second of the second rotation axis. A second pod arranged along the two rotation axis and provided with a second power generation turbine, and a connecting portion connecting the pod and the second pod are further provided , and the center of gravity of the underwater floating power generation device is the second rotation. It is located below the axis . The mooring point of the underwater floating power generator is provided in a portion below the second rotation axis. The attitude control system is provided for the second power generation turbine, further includes a second rotation speed adjusting means capable of adjusting the rotation speed of the second power generation turbine, and the control unit is an inclination angle detected by the detection unit. By controlling the second rotation speed adjusting means according to the above and changing the rotation speed of the second power generation turbine , the second turbine thrust is changed, and the second rotation axis and the center of gravity in the vertical direction of the submersible floating power generation device are changed. A moment around the mooring point is generated according to the product of the distance between the two turbines and the amount of change in the thrust of the second turbine, and the attitude of the underwater floating power generator in the pitch direction is corrected . In this case, since the rotation speed of the power generation turbine and the rotation speed of the second power generation turbine are changed, it is possible to control not only the posture in the pitch direction of the submersible floating power generation device but also the posture in the roll direction.

Another aspect of the present invention is an attitude control system for an underwater floating power generator comprising a turbine for power generation including a rotary shaft and a pod arranged along the axis of rotation of the rotary shaft and provided with a turbine for power generation. Therefore, the turbine for power generation includes two blades with variable pitch angles, the center of gravity of the submersible floating power generation device is located below the rotation axis, and a mooring rope for mooring the submersible floating power generation device. One end of the mooring rope is connected to one or more mooring points provided below the rotation axis of the underwater floating power generator and below the center of gravity of the underwater floating power generator. , A mooring rope, a detection unit that detects at least the inclination angle of the submersible floating power generation device in the pitch direction, a pitch angle adjustment device that is provided in the power generation turbine and can adjust the pitch angle of the two blades, and a detection unit. By controlling the pitch angle adjuster according to the tilt angle detected by the turbine and changing the pitch angle of the two blades in the power generation turbine, the turbine thrust is changed and the submersible floating power generation device rotates in the vertical direction. It is provided with a control unit that generates a moment around the mooring point according to the product of the distance between the axis and the center of gravity and the amount of change in the turbine thrust, and corrects the attitude of the submersible floating power generator in the pitch direction.

In this attitude control system, an underwater floating power generation device moored by a mooring rope floats in water, and a power generation turbine rotates to generate power. The control unit changes the pitch angle of the two blades according to the tilt angle of the underwater floating power generator in the pitch direction. When the pitch angle of the two blades is changed, the thrust of the power generation turbine changes. Here, one end of the mooring rope is connected to a mooring point provided in a portion below the rotation axis in the underwater floating power generator. As a result of the mooring point being provided at the lower part, the thrust in the direction of the rotation axis generates a moment around the mooring point. The generated moment acts to stabilize the posture of the underwater floating power generator in the pitch direction. As a result, the attitude of the underwater floating power generator in the pitch direction can be corrected.

In some embodiments, the submersible floating power generator is disposed away from the power generation turbine in a direction intersecting the direction of the rotation axis, with a second power generation turbine including a second rotation axis and a second of the second rotation axis. A second pod arranged along the two rotation axis and provided with a second power generation turbine, and a connecting portion connecting the pod and the second pod are further provided , and the center of gravity of the underwater floating power generation device is the second rotation. It is located below the axis . The second power generation turbine includes two second blades having a variable pitch angle. The mooring point of the underwater floating power generator is provided in a portion below the second rotation axis. The attitude control system is further provided in the second power generation turbine and further includes a second pitch angle adjusting device capable of adjusting the pitch angles of the two second blades, and the control unit adjusts the tilt angle detected by the detection unit. By controlling the second pitch angle adjusting device accordingly and changing the pitch angle of the two second blades in the second power generation turbine , the second turbine thrust is changed in the vertical direction of the submersible floating power generation device. A moment around the mooring point is generated according to the product of the distance between the second rotation axis and the center of gravity and the amount of change in the thrust of the second turbine, and the attitude of the underwater floating power generator in the pitch direction is corrected . In this case, since the pitch angle of the blades of the power generation turbine and the pitch angle of the second blade of the second power generation turbine are changed, not only the attitude in the pitch direction of the submersible floating power generation device but also the attitude in the roll direction can be changed. Can be controlled.

In some embodiments, the power generation turbine is provided at the first end of the pod in the direction of rotation axis, and the mooring point is provided at the portion on the second end side opposite to the first end in the direction of rotation axis. Be done. When the power generation turbine is a downwind type turbine arranged on the downstream side of the pod with respect to the direction of the water flow, a mooring point is provided on the upstream side opposite to the power generation turbine. In this case, the thrust produces a larger restoring moment. As a result, the posture correction effect (for example, responsiveness) is enhanced.

In some embodiments, the pod is cylindrical and the mooring point is provided on the cylindrical surface of the pod. When the mooring point is provided on the cylindrical surface of the pod, the thrust produces a larger restoring moment than when the mooring point is provided on the end face of the pod in the direction of the axis of rotation. As a result, the posture correction effect (for example, responsiveness) is enhanced.

Yet another aspect of the present invention is an attitude control method for an underwater floating power generation device including a power generation turbine including a rotation shaft and a pod arranged along the rotation axis of the rotation shaft and provided with a power generation turbine. The center of gravity of the underwater floating power generation device is located below the rotation axis , and one end of the mooring rope for mooring the underwater floating power generation device is below the rotation axis of the underwater floating power generation device. A detection step that is connected to one or more mooring points provided below the center of gravity of the underwater floating power generator and detects an inclination angle of at least the pitch direction of the underwater floating power generator, and an inclination. By changing the rotation speed of the turbine for power generation according to the angle, the turbine thrust is changed, and the product of the distance between the rotation axis and the center of gravity in the vertical direction of the submersible floating power generator and the amount of change in the turbine thrust. It includes a rotation speed change step that generates a corresponding moment around the mooring point and corrects the pitch direction orientation of the underwater floating power generator.

According to this attitude control method, the above-mentioned thrust generated based on the change in the rotation speed of the power generation turbine and the mooring point provided at the lower part of the underwater floating power generation device cause the underwater floating power generation device to interact with each other. The attitude of the pitch direction can be corrected.

Yet another aspect of the present invention is an attitude control method of an underwater floating power generation device including a power generation turbine including a rotation shaft and a pod arranged along the rotation axis of the rotation shaft and provided with a power generation turbine. The center of gravity of the underwater floating power generation device is located below the rotation axis, and the power generation turbine includes two blades having a variable pitch angle and is moored for mooring the underwater floating power generation device. One end of the rope is connected to one or more mooring points provided below the axis of rotation of the floating underwater power generator and below the center of gravity of the floating underwater power generator. The turbine thrust is changed by changing the pitch angle of the two blades in the power generation turbine according to the detection step that detects the tilt angle at least in the pitch direction of the power generation device and the submersible floating power generation device. A pitch angle change step that corrects the pitch direction orientation of the underwater floating power generator by generating a moment around the mooring point according to the product of the distance between the rotation axis and the center of gravity in the vertical direction and the amount of change in the turbine thrust. And, including.

According to this attitude control method, the above-mentioned thrust generated based on the change in the pitch angle of the blades of the power generation turbine and the mooring point provided in the lower part of the underwater floating power generation device cause the floating type underwater. The attitude of the power generator in the pitch direction can be corrected.

According to some aspects of the present invention, the attitude of the underwater floating power generator in the pitch direction can be efficiently corrected.

It is a figure which shows the schematic structure of the underwater floating power generation apparatus to which the attitude control system which concerns on one Embodiment of this invention is applied. It is a figure which shows the schematic structure of the equipment provided in a pod. It is a figure which shows the steady state of the underwater floating type power generation apparatus. It is a figure which shows the attitude control method when the attitude of the underwater floating power generation apparatus is inclined in the pitch direction. It is a flow chart which shows the processing procedure of the attitude control performed by the control unit. It is a figure which shows the balance of the force in the underwater floating type power generation apparatus. It is a figure which shows the balance of the moment in the underwater floating type power generation apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

In the following description, the terms "upstream" or "downstream" are used with reference to water flow. The word "before" means the upstream side of the stream of water, and the word "after" means the downstream side of the stream of water. For example, when a downwind turbine is used, blades are placed on the rear side of the pod. The terms "left" or "right" mean a direction perpendicular to and horizontal to the flow of water and are used relative to the rear or downstream view. The terms "upper" and "lower" are used with reference to the vertical direction line in a state where the posture of the underwater floating power generator 1 is stable. The terms "pitch" and "pitching" relating to the posture of the submersible floating power generator 1 mean rotation about an axis perpendicular to and horizontal to the central axis of the pod, that is, the axis in the left-right direction. The term "roll" means an axis parallel to the central axis of the pod, i.e., a rotation about an axis in the anteroposterior direction.

The underwater floating power generation device 1 to which the attitude control system S of the present embodiment is applied will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the underwater floating power generation device 1 is installed in seawater, for example, floats, and generates power by using an ocean current. The submersible floating power generator 1 is a cross beam (connecting portion) that connects the first pod 2A and the second pod 2B, which are a pair of pods arranged apart from each other on the left and right, and the first pod 2A and the second pod 2B. 3 and. The first pod 2A is a pod arranged on the right side, and the second pod 2B is a pod arranged on the left side. A first power generation turbine 4A is provided at the rear of the first pod 2A. A second power generation turbine 4B is provided at the rear of the second pod 2B. In the following description, the underwater floating power generation device 1 is referred to as an ocean current power generation device 1. Further, the first power generation turbine 4A and the second power generation turbine 4B are referred to as a first turbine 4A and a second turbine 4B, respectively.

The first pod 2A rotatably supports the first turbine 4A and imparts an appropriate buoyancy to the first turbine 4A. The second pod 2B rotatably supports the second turbine 4B while imparting an appropriate buoyancy to the second turbine 4B. The first pod 2A and the second pod 2B have a cylindrical shape and have, for example, the same size and structure.

Between the first pod 2A and the second pod 2B, a cross beam 3 which is a structure connecting them extends (that is, extends so as to cross left and right). The cross beam 3 has a predetermined length in the front-rear direction and a predetermined thickness. The cross beam 3 has, for example, a wing shape in order to stabilize the attitude of the floating ocean current power generation device 1. The left and right ends of the cross beam 3 are fixed to, for example, substantially the center of the body of the first pod 2A and the second pod 2B, respectively. The position where the cross beam 3 is fixed is not limited to the above position. The cross beam 3 may be fixed to the top or bottom of the pod, or to the front or back of the pod. The cross beam 3 may have the same cross-sectional shape in the extending direction (that is, the left-right direction), or may have a cross-sectional shape that changes in the extending direction. One or more objects may be provided near the center of the cross beam 3. Further, a mooring line may be connected from this object.

The ocean current power generation device 1 is connected to the sinker 14 fixed to the seabed via the first mooring rope 11A and the second mooring rope 11B. The first mooring rope 11A and the second mooring rope 11B are so-called V-shaped mooring ropes in which these branch points are provided in the sinker 14. The lower end (the other end) of the first mooring rope 11A and the lower end (the other end) of the second mooring rope 11B are connected so as to be rotatable 360 degrees with respect to the sinker 14, for example. The connection portion of the first mooring rope 11A and the second mooring rope 11B to the sinker 14 may have a fastening structure using, for example, a shackle or the like. The first mooring rope 11A and the second mooring rope 11B may be in a Y shape by providing a branch point in the middle portion between the sinker 14 and the ocean current power generation device 1. An anchor may be used instead of the sinker 14 as a fixing portion for fixing the other end of the mooring rope to the seabed.

The ocean current power generator 1 is moored at two different points by, for example, the first mooring rope 11A and the second mooring rope 11B. More specifically, the upper end (one end) of the first mooring rope 11A is connected to the first pod 2A located on the right side. The upper end (one end) of the second mooring rope 11B is connected to the second pod 2B located on the left side. The mooring point 12A of the first mooring rope 11A and the mooring point 12B of the second mooring rope 11B are separated from each other by a predetermined length in the left-right direction.

As shown in FIG. 1, a power transmission cable 10 for transmitting the electric power generated in the first turbine 4A and the second turbine 4B is provided along the first mooring rope 11A and the second mooring rope 11B. ing. More specifically, a first cable 10A for transmitting the electric power generated by the first turbine 4A is provided along the first mooring rope 11A, and a second cable for transmitting the electric power generated by the second turbine 4B is provided. The cable 10B is provided along the second mooring rope 11B. One end of the first cable 10A is connected to the generator 17 (see FIG. 2) in the first pod 2A. One end of the second cable 10B is connected to the generator in the second pod 2B. The other end of the power transmission cable 10 is connected to, for example, a repeater (or a transformer or the like) provided in the sinker 14. A power transmission cable laid on the seabed and extending to the ground is connected to the repeater so that the electric power generated by the first turbine 4A and the second turbine 4B is transmitted to the ground through these power transmission cables. It has become.

The form in which each cable is provided is not limited to the above form. For example, the power transmission cable 10, the first cable 10A, and the second cable 10B may be integrated with the power supply cable for starting. The first cable 10A connected to the first turbine 4A may be a power supply cable, and the second cable 10B connected to the second turbine 4B may be a power transmission cable. The repeater may be set on the seabed outside the sinker 14.

The first turbine 4A and the second turbine 4B applied to the ocean current power generation device 1 are so-called downwind type turbines. The first pod 2A and the second pod 2B float in a posture facing the direction of the ocean current. In this floating state, the rotation axes L1 and L2 of the first turbine 4A and the second turbine 4B (the axes of the rotation axis 16 shown in FIG. 2) are parallel to each other and are maintained substantially horizontal.

The first turbine 4A includes a first hub 5A and two first blades 6A provided on the first hub 5A. The second turbine 4B includes a second hub 5B and two second blades 6B provided on the second hub 5B. The first hub 5A is located at the rear end of the first pod 2A. The second hub 5B is located at the rear end of the second pod 2B. In the ocean current power generation device 1 that employs a downwind type turbine, the first blade 6A is arranged on the downstream side of the first pod 2A and the second blade 6B is arranged on the downstream side of the second pod 2B with reference to the direction of the ocean current. Is arranged (see FIG. 1).

In the first turbine 4A and the second turbine 4B, the blade pitches are opposite to each other. That is, the pitch of the second blade 6B is opposite to the pitch of the first blade 6A. As a result, the first turbine 4A and the second turbine 4B rotate in opposite directions in response to the ocean current. For example, the first turbine 4A rotates in the clockwise rotation direction when viewed from the upstream side, and the second turbine 4B rotates in the counterclockwise rotation direction when viewed from the upstream side.

Subsequently, the posture control system S for controlling the posture of the ocean current power generation device 1 (particularly, the posture in the pitch direction) will be described. The attitude control system S includes a first mooring rope 11A and a second mooring rope 11B connected to the mooring point 12A and the mooring point 12B, respectively, and a gyro sensor (detection unit) that detects an inclination angle of at least the pitch direction of the marine current power generator 1. ) 23, and a rotation speed adjusting means capable of adjusting the rotation speeds of the first turbine 4A and the second turbine 4B.

The attitude control system S may include a pitch angle adjusting device 20 capable of adjusting the pitch angles of the first blade 6A and the second blade 6B in place of the rotation speed adjusting means or in addition to the rotation speed adjusting means. In the following description, a case where the attitude control system S includes a rotation speed adjusting means and a pitch angle adjusting device 20 will be described. Further, in the following description, the configuration included in the first pod 2A will be mainly described. Since the second pod 2B also has the same configuration as the first pod 2A, the description of the second pod 2B will be omitted.

As shown in FIG. 2, a first blade 6A is attached to the first hub 5A at the rear end of the first pod 2A, and the first blade 6A can rotate integrally with the first hub 5A. It has become. The rotation of the first turbine 4A is transmitted to the generator 17 via the rotating shaft 16. The rotation shaft 16 is provided, for example, along the central axis of the first pod 2A.

In the ocean current power generation device 1, the pitch angle of the first blade 6A is variable. The pitch angle adjusting device 20 described above includes a hydraulic drive device 21 and a blade shaft 22. More specifically, the hydraulic drive device 21 is connected to the blade shaft at the base end of each of the first blades 6A. The hydraulic drive device 21 is mounted in, for example, the first hub 5A. The hydraulic drive device 21 includes, for example, a gear mechanism. As the hydraulic drive device 21, a known mechanism can be used. The hydraulic drive device 21 is controlled by the control unit 25, and the pitch angle of the first blade 6A can be adjusted to an arbitrary angle. One first blade 6A is rotated about the blade shaft 22 by the hydraulic drive device 21, and at the same time, the other first blade 6A is rotated about the same angle about the blade shaft 22. Similarly, the pitch angle of the second blade 6B is also variable. That is, the second turbine 4B is also provided with the pitch angle adjusting device 20. The mechanism for changing the pitch angles of the first blade 6A and the second blade 6B is not limited to the hydraulic drive device 21, and a servomotor or the like may be used. When the posture of the ocean current power generation device 1 is adjusted only by the rotation speed adjusting means, the pitch angles of the first blade 6A and the second blade 6B are not variable and may be fixed.

The first pod 2A is equipped with a resolver that detects the rotation speed of the first turbine 4A. The detection mechanism for detecting the rotation speed of the first turbine 4A is not limited to the resolver, and a sensor such as an encoder may be used. The resolver, the rotation speed sensor, and the like sequentially output the detected rotation speed of the first turbine 4A (rotation speed of the first blade 6A) to the control unit 25. Further, the hydraulic drive device 21 is equipped with a sensor for measuring the drive amount.

A gyro sensor 23 for detecting the inclination of the posture of the ocean current power generation device 1 is provided in the first pod 2A. The gyro sensor 23 detects the tilt angles of the ocean current power generation device 1 in the roll direction, pitch direction, and yaw direction. The gyro sensor 23 sequentially outputs each detected tilt angle to the control unit 25. A depth sensor (pressure sensor) for measuring the depth of the ocean current power generation device 1 may be provided in the first pod 2A.

A generator 17 and a brake device 30 as the above-mentioned rotation speed adjusting means are provided in the first pod 2A. The generator 17 includes, for example, an inverter 17a. The generator 17 can adjust the load torque with respect to the rotating shaft 16 by electrically controlling the inverter 17a. The generator 17 adjusts the rotation speed of the first turbine 4A (the rotation speed of the first blade 6A) by adjusting the load torque. The generator 17 may be a hydraulic drive train or the like. The brake device 30 is connected to, for example, a rotating shaft 16. The braking device 30 includes, for example, a pad for reducing the rotation speed of the first turbine 4A by using a frictional force, and the braking force can be applied to the first turbine 4A. The brake device 30 may be, for example, a hydraulic brake device or the like. The braking device 30 adjusts the rotation speed of the first turbine 4A (the rotation speed of the first blade 6A) by adjusting the braking force. Either the generator 17 or the brake device 30 may be used as the rotation speed adjusting means. As the rotation speed adjusting means, for example, a gear mechanism for changing the reduction ratio may be used.

The attitude control system S may include a buoyancy compensator (not shown) that injects and drains seawater from the outside of the first pod 2A to change the weight of the entire ocean current power generation device 1. The buoyancy compensator may include a tank provided in the first pod 2A, a water injection / drainage pipe connecting the tank and the outside of the first pod 2A, and a pump provided in the water injection / drainage pipe (both). Not shown).

The marine current power generation device 1 is provided with a control unit 25 that obtains information from each sensor, controls each actuator, and controls the entire marine current power generation device 1. The control unit 25 constitutes a part of the attitude control system S. The control unit 25 controls the inverter 17a and / or the brake device 30 of the generator 17 according to the inclination angle of the ocean current power generation device 1 in the pitch direction detected by the gyro sensor 23. Further, the control unit 25 controls the buoyancy compensator to adjust the buoyancy of the entire ocean current power generation device 1. The control unit 25 is provided in, for example, the first pod 2A. The control unit 25 is a computer composed of hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and software such as a program stored in the ROM. ..

The control unit 25 stores in advance two threshold values related to the inclination angle in the pitch direction used for the attitude control of the ocean current power generation device 1. The control unit 25 may store the threshold value in the roll direction. The control unit 25 stores the first threshold value and the second threshold value as the threshold values in the pitch direction. The second threshold is larger than the first threshold. The first threshold value and the second threshold value can be determined, for example, based on the allowable moment of the stability based on the center of gravity and the buoyancy of the ocean current power generation device 1.

In the ocean current power generation device 1 of the present embodiment, the first mooring rope 11A and the second mooring rope 11B are connected to the lower front portion of the ocean current power generation device 1. That is, the mooring point 12A and the mooring point 12B are provided in the portion below the first rotation axis L1 and the second rotation axis L2 in the ocean current power generation device 1. More specifically, the mooring point 12A is provided at the lower front portion of the first pod 2A, and the mooring point 12B is provided at the lower front portion of the second pod 2B. The mooring point 12A and the mooring point 12B are in plane-symmetrical positions with respect to a virtual plane that is parallel to both the rotation axis L1 and the rotation axis L2 and equidistant from the rotation axis L1 and the rotation axis L2.

The connection structure of the first mooring rope 11A to the first pod 2A will be described. The connection structure of the second mooring rope 11B to the second pod 2B is the same as the connection structure of the first mooring rope 11A to the first pod 2A. The mooring point 12A is provided on the cylindrical surface of the cylindrical first pod 2A. For example, a flat plate-shaped rib protruding outward is fixed to the cylindrical surface of the first pod 2A. A through hole is formed in the rib. For example, a bolt inserted through the through hole, a U-shaped connecting metal fitting attached to the bolt, and a nut constitute a connecting structure of the first mooring rope 11A. The upper end of the first mooring rope 11A is connected to the U-shaped connection fitting. The first mooring rope 11A is rotatably connected to the first pod 2A. Therefore, the angle of the first mooring rope 11A with respect to the first pod 2A can change freely. The connection structure of the mooring rope is not limited to the above, and other known connection structures may be adopted.

The position of the mooring point 12A also has an important meaning with respect to the positions of the center of gravity GC and the floating center BC of the ocean current power generation device 1. As shown in FIG. 3, the center of gravity GC of the ocean current power generation device 1 is located below, for example, the first rotation axis L1. The buoyancy BC of the ocean current power generator 1 is located above, for example, the first rotation axis L1.

In FIG. 3, the positions of the center of gravity GC and the floating center BC are projected in the left-right direction. The illustration of the center of gravity GC and the floating center BC is the same in FIGS. 4, 6 and 7. The center of gravity GC and the buoyancy center BC are located, for example, on the virtual plane at the center of the device described above. The center of gravity GC is located below the plane containing the first rotation axis L1 and the second rotation axis L2, and the floating center BC is located above the plane including the first rotation axis L1 and the second rotation axis L2.

It is necessary to centroid GC is located below the center of buoyancy BC.

The mooring point 12A is provided in front of the center of gravity GC and the floating center BC. That is, the first turbine 4A is provided at the rear end of the first pod 2A on the first rotation axis L1, but the mooring point 12A is provided at the front end side portion opposite to the first turbine 4A. There is. More specifically, the mooring point 12A is provided somewhat rearward of the front end face of the first pod 2A, rather than the front end face (ie, the end face that closes the cylindrical surface). The mooring point 12A is provided in a portion below the center of gravity GC.

As described above, the mooring point 12A is provided at the lower front portion of the cylindrical surface of the first pod 2A. Since the arrangement of the mooring points 12A can generate a large restoration moment, it contributes to the stability of the attitude of the ocean current power generation device 1. The positions of the mooring points 12A and 12B can be determined by regarding the ocean current power generator 1 as one rigid body. From the viewpoint of attitude control in the pitch direction by turbine thrust, the mooring point 12A may be provided at a portion below the first rotation axis L1. As long as this condition is satisfied, a restoration moment can be generated no matter where the mooring point 12A is, so that the attitude can be controlled.

In addition, unlike the present embodiment, when the mooring point is provided on the upper part of the pod, when the ocean current power generation device rises to the water surface, the attitude of the ocean current power generation device may be tilted due to the weight and tension of the mooring rope. .. In the ocean current power generation device 1, since the mooring point 12A is provided in the lower part of the first pod 2A, the posture can be stabilized even when the ocean current power generation device 1 rises to the water surface.

Subsequently, the attitude control method of the ocean current power generation device 1 by the attitude control system S will be described. First, the ocean current power generation device 1 is suspended in seawater and is in a normal operating state in response to the flow of seawater. As shown in FIG. 5, the control unit 25 acquires the tilt angle of the ocean current power generation device 1 detected by the gyro sensor 23 in the pitch direction (step S01; detection step). Then, the control unit 25 determines whether or not the inclination angle of the ocean current power generation device 1 is less than the first threshold value (step S02).

During the operation of the ocean current power generation device 1, the attitude of the ocean current power generation device 1 in the pitch direction or the roll direction may change due to a change in the flow or some external force (collision of suspended matter or aquatic organisms, etc.). For example, as shown in FIG. 4, a state in which the posture in the pitch direction is lost due to disturbance may occur. In this case, the front portion of the ocean current power generation device 1 is lower than the rear portion, and pitching occurs in the negative direction. This is the so-called "head down" condition.

When the control unit 25 determines that the inclination angle of the marine current power generation device 1 is equal to or greater than the first threshold value (step S02: NO), the control unit 25 controls the inverter 17a and / or the brake device 30 to control the first turbine 4A and the second turbine. The rotation speed of 4B is changed (step S03; rotation speed change step). When the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is less than the first threshold value (step S02: YES), the control unit 25 returns to the process of step S01. Here, the attitude control by the buoyancy compensator may be performed. Attitude control by the buoyancy compensator can be performed according to a known method.

For example, in the case of the "head down" state shown in FIG. 4, the control unit 25 weakens the electromagnetic brake or the resistance brake so that the turbine thrust becomes large in step S03. As a result, the control unit 25 increases the number of revolutions in the first turbine 4A and the second turbine 4B. The control unit 25 may perform the same rotation speed increase control for the first turbine 4A and the second turbine 4B, but may perform different rotation speed increase control. Hereinafter, the turbine thrust is also referred to as a thrust force.

The control unit 25 may change the pitch angles of the first blade 6A and the second blade 6B so that the turbine thrust becomes large. For example, the larger the angle formed by the direction of the first blade 6A with respect to the flow FL (see FIG. 1), the easier it is for the first blade 6A to rotate in the direction of rotation, and the more easily the first blade 6A receives the thrust force F. The smaller the angle formed by the direction of the first blade 6A with respect to the flow FL, the more difficult it is for the first blade 6A to rotate in the direction of rotation and the less likely it is to receive the thrust force F. To reduce the thrust force F, the thrust force acting on the blades 6A and 6B is reduced. For example, changing the pitch angle so that the first blade 6A is less likely to receive the thrust force F means that the direction of the first blade 6A is brought closer to the direction of the flow FL. On the contrary, changing the pitch angle so that the first blade 6A is susceptible to the thrust force F means that the direction of the first blade 6A flows away from the direction of FL.

The moment generated with the change of the thrust force F will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing the balance of forces in the ocean current power generation device 1. FIG. 7 is a diagram showing the balance of moments around the center of gravity GC of the ocean current power generation device 1. In FIGS. 6 and 7, each force acting on the ocean current power generation device 1 is projected in the left-right direction. The forces acting on each of the first pod 2A and the second pod 2B, such as thrust force, tension, and fluid drag, may be considered as one resultant force.

As shown in FIG. 6, in the marine current power generation device 1, the buoyancy applied to the buoyancy center BC, the gravity applied to the center of gravity GC, the thrust force applied in the axial direction of the turbine, the tension from the mooring rope, and the fluid drag force received from the flow FL. The following relational expression holds between them.

機体の垂直方向では、式（２）の関係が成り立つ。

ここで、
Ｂ:浮力、
Ｇ:重力、
Ｆ:スラスト力、
Ｔ：張力、
θ:タービンの軸線と係留ロープの角度、
Ｒ:流体抗力、
Ｒｖ:流体抗力の鉛直成分、
Ｒｈ:流体抗力の垂直成分、である。 In the horizontal direction of the airframe (ocean current power generator 1), the relationship of equation (1) holds.

In the vertical direction of the airframe, the relationship of equation (2) holds.

here,
B: Buoyancy,
G: Gravity,
F: Thrust force,
T: Tension,
θ: Angle between turbine axis and mooring rope,
R: Fluid drag,
Rv: Vertical component of fluid drag,
Rh: A vertical component of fluid drag.

ここで、
ｈ_Ｆ：機体の垂直方向におけるタービンの軸線と重心との間の距離、
ｈ_Ｒ：機体の垂直方向における流体抗力の作用点と重心との間の距離、
ｈ_Ｔ：機体の垂直方向における重心と係留点との間の距離、
Ｌ_Ｂ：機体の水平方向における浮心と重心との間の距離、
Ｌ_Ｒ：機体の水平方向における重心と流体抗力の作用点との間の距離、
Ｌ_Ｔ：機体の水平方向における重心と係留点との間の距離、である。 Further, as shown in FIG. 7, the balance of the moment around the center of gravity GC is as shown in the equation (3).

here,
h _F : Distance between the turbine axis and the center of gravity in the vertical direction of the aircraft,
h _R : Distance between the point of action of fluid drag and the center of gravity in the vertical direction of the aircraft,
h _T : Distance between the center of gravity of the aircraft and the mooring point in the vertical direction,
L _B: distance between the center of buoyancy and the center of gravity in the horizontal direction of the machine body,
_LR : Distance between the center of gravity of the aircraft in the horizontal direction and the point of action of fluid drag,
L _T: is the distance, between the centroid and the anchor point in the horizontal direction of the aircraft.

制御量ΔＦ×ｈ_Ｆはスラスト力の増減量である。制御量ΔＦ×ｈ_Ｆは、タービンの回転数、および／または、タービンのブレードのピッチ角度によって制御され得る。 However, disturbance may be added to the ocean current power generation device 1. Therefore, by adding the control amount [Delta] F × h _F, as shown in equation (4), it cancels the disturbance component.

Control amount [Delta] F × h _F is the amount of change in thrust force. Control amount [Delta] F × h _F is the rotation speed of the turbine, and / or may be controlled by the pitch angle of the turbine blades.

Returning to FIG. 5, the control unit 25 again determines whether or not the inclination angle of the ocean current power generation device 1 is less than the first threshold value (step S04). When the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is less than the first threshold value (step S04: YES), the control unit 25 returns to the process of step S01 and corrects the posture using only the buoyancy compensator. On the other hand, when the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is equal to or greater than the first threshold value (step S04: NO), the control unit 25 again executes the change process of the rotation speed in step S03.

In the case of the "head down" state shown in FIG. 4, the control unit 25 increases the thrust force in step S03, so that the control amount ΔF × h _F is set on the left side of the equation (4) showing the balance of the moments. In addition, a moment M around the mooring point is generated (see FIG. 4). As a result, the moment M is generated in the direction of raising the head, and the rear portion of the ocean current power generation device 1 is lowered. Then, the ocean current power generation device 1 returns to the steady state shown in FIG. Control amount [Delta] F × h _F of this case is the increased amount of the thrust force (a positive value). As described above, the moment M is a restoration moment for correcting (that is, restoring) the posture of the ocean current power generation device 1.

Further, contrary to FIG. 4, when the rear part of the ocean current power generation device 1 is lower than the front part and pitching occurs in the positive direction, that is, in the "head-up" state, the control unit 25 , Strengthen the electromagnetic brake or resistance brake so that the thrust force (turbine thrust) is reduced. As a result, the control unit 25 reduces the number of revolutions in the first turbine 4A and the second turbine 4B. The control unit 25 may change the pitch angles of the first blade 6A and the second blade 6B so that the thrust force becomes smaller.

When the control unit 25 reduces the thrust force in step S03, the left side of the equation (4) showing the balance of moments is reduced, and the moment around the mooring point is reduced. As a result, the moment is generated in the downward direction, and the rear part of the ocean current power generation device 1 rises. Then, the ocean current power generation device 1 returns to the steady state shown in FIG. Control amount [Delta] F × h _F of this case is the reduction of the thrust force (a negative value).

In the attitude control system and attitude control method of the present embodiment, power is generated by floating an underwater floating power generation device moored by a mooring rope in water and rotating a power generation turbine. The control unit changes the rotation speed of the power generation turbine according to the tilt angle in the pitch direction of the submersible floating power generation device. When the rotation speed of the power generation turbine is changed, the thrust of the power generation turbine changes. Here, one end of the mooring rope is connected to a mooring point provided in a portion below the rotation axis in the underwater floating power generator. As a result of the mooring point being provided at the lower part, the thrust in the direction of the rotation axis generates a moment around the mooring point. The generated moment acts to stabilize the posture of the underwater floating power generator in the pitch direction. As a result, the attitude of the underwater floating power generator in the pitch direction can be corrected. The submersible floating power generator may be provided with a posture adjusting device for moving a fluid by a pump to change its center of gravity. It is also possible to correct the posture in the pitch direction by using the posture adjusting device. However, the attitude control system of the present embodiment does not require the attitude correction in the pitch direction by the attitude adjusting device. The moment generated based on the thrust enhances the responsiveness regarding the posture correction in the pitch direction as compared with the case of using the posture adjusting device. Therefore, it is possible to cope with a sudden change in posture. In addition, the amount of power consumption required for posture correction in the pitch direction can be reduced. The size of the posture adjusting device can be reduced as compared with the case where the posture adjusting device is also used for posture correction in the pitch direction.

Further, since the rotation speed of the power generation turbine and the rotation speed of the second power generation turbine are changed by the control unit, it is necessary to control not only the posture in the pitch direction of the submersible floating power generation device but also the posture in the roll direction. Can be done.

When the power generation turbine is a downwind type turbine arranged on the downstream side of the pod with respect to the direction of the water flow, a mooring point is provided on the upstream side opposite to the power generation turbine. In this case, the thrust produces a larger restoring moment. As a result, the posture correction effect (for example, responsiveness) is enhanced.

When the mooring point is provided on the cylindrical surface of the pod, the thrust generates a larger restoring moment than when the mooring point is provided on the end face of the pod or the cross beam (connecting portion) in the direction of the rotation axis. As a result, the posture correction effect (for example, responsiveness) is enhanced.

In the attitude control system S, since the rotation speed is adjusted and the attitude is controlled by using the originally provided generator 17, it is possible to efficiently control the attitude without requiring a separate means.

In the attitude control system S, since the rotation speed is adjusted and the attitude is controlled by using the brake devices 30 provided on the first turbine 4A and the second turbine 4B, no separate means is required and the attitude is efficiently controlled. Is possible.

Although the embodiment of the present invention has been described, the present invention is not limited to the above embodiment.

For example, in addition to the judgment based on the first threshold value, a judgment based on a larger second threshold value may be added. In that case, when the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is equal to or greater than the first threshold value, the control unit 25 changes the amount of water stored in the buoyancy compensator. After that, when the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is equal to or greater than the first threshold value, the control unit 25 determines whether or not the inclination angle of the ocean current power generation device 1 is less than the second threshold value. When the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is less than the second threshold value, the control unit 25 changes the amount of water stored in the buoyancy compensator. When the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is equal to or greater than the second threshold value, the control unit 25 controls the change of the rotation speed and / or the pitch angle of the blade. Then, the control unit 25 determines whether or not the inclination angle of the marine current power generation device 1 is less than the second threshold value, and when it is determined that the inclination angle is equal to or more than the second threshold value, the rotation speed and / or the blade Control the change of the pitch angle. When the control unit 25 determines that the inclination angle of the ocean current power generation device 1 is less than the second threshold value, the control unit 25 acquires the inclination angle again. The first threshold value may be used instead of the second threshold value described above. In this way, the attitude control by the attitude control system S and the attitude control by the buoyancy compensator may be used together.

The cross beam 3 may be provided with one or more mooring points. Even in that case, it is desirable that the mooring points be provided in front and below. The cross beam 3 may be provided below the plane including the first rotation axis L1 and the second rotation axis L2. When the cross beam 3 is installed at a low position, the center of gravity GC can move away from the point of force of the turbine thrust. As a result, the amount of control by the turbine thrust force (that is, the restoration moment) becomes large, and the attitude control becomes easy. Since the ocean current power generator 1 is regarded as one rigid body, the mooring point may be provided on any member included in the rigid body.

One mooring rope may be connected to the ocean current power generator 1. That is, there may be one mooring point. In that case, the mooring point may be located on the virtual plane at the center of the device described above.

The control unit 25 may perform both the change control of the rotation speed and the change control of the pitch angle of the blade. When the control unit 25 controls the change of the rotation speed, the pitch angle of the blade may be fixed rather than variable. When the control unit 25 controls the change of the pitch angle of the blade, the rotation speed adjusting means may be omitted. Even if only the change control of the pitch angle is performed, the above-mentioned effects such as high responsiveness, power saving, and miniaturization of the posture adjusting device can be obtained.

One aspect of the present invention may be an underwater floating power generation device including a single-engine turbine. In that case, one power generation pod may be provided, and a counter-rotating rotor mechanism may be provided at the rear end or the front end of the pod. Even in the case of an underwater floating power generator composed of a single-engine turbine, attitude control can be performed by the same method as the attitude control method in the above-described embodiment.

One aspect of the present invention may be an underwater floating power generator including three or more pods and three or more turbines. In that case, all the turbines may be provided only on the first end side, and the mooring point may be provided on the second end side. The first turbine 4A and the second turbine 4B may be upwind type turbines. In that case, the mooring point may be provided on the same side (first end side) as the first turbine 4A and the second turbine 4B.

1 Ocean current power generation equipment (underwater floating power generation equipment)
2A 1st pod (pod)
2B 2nd pod 3 Cross beam (connecting part)
4A 1st turbine (turbine for power generation)
4B 2nd turbine (2nd power generation turbine)
6A 1st blade (blade)
6B 2nd blade 11A 1st mooring rope 11B 2nd mooring rope 12A Mooring point 12B Mooring point 16 Rotating shaft 17 Generator (rotation speed adjusting means)
17a Inverter (rotation speed adjustment means)
20 Pitch angle adjustment device 23 Gyro sensor (detector)
25 Control unit 30 Brake device (rotation speed adjusting means)
BC Floating center GC Center of gravity L1 1st rotation axis (rotation axis)
L2 2nd rotation axis S posture control system

Claims (8)

An attitude control system for an underwater floating power generation device including a power generation turbine including a rotating shaft and a pod arranged along the rotating axis of the rotating shaft and provided with the power generation turbine.
The center of gravity of the underwater floating power generator is located below the rotation axis.
A mooring rope for mooring the underwater floating power generation device, one end of which is below the rotation axis of the underwater floating power generation device and below the center of gravity of the underwater floating power generation device. A mooring rope connected to one or more mooring points provided in the part of
A detector that detects at least the tilt angle in the pitch direction of the underwater floating power generator,
A rotation speed adjusting means provided for the power generation turbine and capable of adjusting the rotation speed of the power generation turbine,
The turbine thrust is changed by controlling the rotation speed adjusting means according to the inclination angle detected by the detection unit and changing the rotation speed of the power generation turbine, and the vertical direction of the submersible floating power generation device. A control unit that generates a moment around the mooring point according to the product of the distance between the rotation axis and the center of gravity of the turbine and the amount of change in the turbine thrust, and corrects the attitude of the underwater floating power generator in the pitch direction. And, the attitude control system of the underwater floating power generator. The underwater floating power generation device is arranged apart from the power generation turbine in a direction intersecting the rotation axis direction, and includes a second power generation turbine including a second rotation shaft and a second rotation of the second rotation shaft. A second pod arranged along the axis and provided with the second power generation turbine, and a connecting portion connecting the pod and the second pod are further provided, and the center of gravity of the underwater floating power generation device is It is located below the second rotation axis and
The mooring point of the underwater floating power generator is provided in a portion below the second rotation axis.
Further provided with a second rotation speed adjusting means provided for the second power generation turbine and capable of adjusting the rotation speed of the second power generation turbine.
The control unit controls the second rotation speed adjusting means according to the inclination angle detected by the detection unit, and changes the rotation speed of the second power generation turbine to change the thrust of the second turbine. Then, a moment around the mooring point is generated according to the product of the distance between the second rotation axis and the center of gravity in the vertical direction of the underwater floating power generator and the amount of change in the thrust of the second turbine. The attitude control system for an underwater floating power generator according to claim 1, wherein the attitude of the underwater floating power generator in the pitch direction is corrected. An attitude control system for an underwater floating power generation device including a power generation turbine including a rotating shaft and a pod arranged along the rotating axis of the rotating shaft and provided with the power generation turbine.
The power generation turbine includes two blades having a variable pitch angle.
The center of gravity of the underwater floating power generator is located below the rotation axis.
A mooring rope for mooring the underwater floating power generation device, one end of which is below the rotation axis of the underwater floating power generation device and below the center of gravity of the underwater floating power generation device. A mooring rope and a mooring rope connected to one or more mooring points provided in the portion.
A detector that detects at least the tilt angle in the pitch direction of the underwater floating power generator,
A pitch angle adjusting device provided in the power generation turbine and capable of adjusting the pitch angle of the two blades, and a pitch angle adjusting device.
By controlling the pitch angle adjusting device according to the inclination angle detected by the detection unit and changing the pitch angles of the two blades in the power generation turbine, the turbine thrust is changed and the floating in water is performed. A moment around the mooring point is generated according to the product of the distance between the rotation axis and the center of gravity in the vertical direction of the turbine power generator and the amount of change in the turbine thrust, and the moment is generated in the pitch direction of the submersible floating power generator. An attitude control system for an underwater floating power generator equipped with a control unit that corrects the attitude. The underwater floating power generation device is arranged apart from the power generation turbine in a direction intersecting the rotation axis direction, and includes a second power generation turbine including a second rotation shaft and a second rotation of the second rotation shaft. A second pod arranged along the axis and provided with the second power generation turbine, and a connecting portion connecting the pod and the second pod are further provided, and the center of gravity of the underwater floating power generation device is It is located below the second rotation axis and
The second power generation turbine includes two second blades having a variable pitch angle.
The mooring point of the underwater floating power generator is provided in a portion below the second rotation axis.
A second pitch angle adjusting device provided in the second power generation turbine and capable of adjusting the pitch angles of the two second blades is further provided.
The control unit, that the detection unit controls the second pitch angle adjustment device according to the inclination angle detected by changing the pitch angle of said two second blades in the second power generating turbine The mooring point corresponds to the product of the distance between the second rotation axis and the center of gravity in the vertical direction of the submersible floating power generator and the amount of change in the second turbine thrust. The attitude control system for an underwater floating power generator according to claim 3 , wherein a surrounding moment is generated to correct the attitude of the underwater floating power generator in the pitch direction. The power generation turbine is provided at the first end of the pod in the direction of the rotation axis.
The attitude of the underwater floating power generation device according to any one of claims 1 to 4, wherein the mooring point is provided at a portion on the second end side opposite to the first end in the direction of the rotation axis. Control system. The attitude control system for an underwater floating power generator according to any one of claims 1 to 5, wherein the pod has a cylindrical shape, and the mooring point is provided on the cylindrical surface of the pod. A method for controlling the attitude of an underwater floating power generation device including a power generation turbine including a rotating shaft and a pod arranged along the rotating axis of the rotating shaft and provided with the power generation turbine.
The center of gravity of the underwater floating power generator is located below the rotation axis.
One end of the mooring rope for mooring the underwater floating power generation device is provided in a portion below the rotation axis of the underwater floating power generation device and below the center of gravity of the underwater floating power generation device1. Connected to one or more mooring points
A detection step for detecting at least a tilt angle in the pitch direction of the underwater floating power generator, and
By changing the rotation speed of the power generation turbine according to the inclination angle, the turbine thrust is changed, and the distance between the rotation axis and the center of gravity in the vertical direction of the submersible floating power generation device and the turbine thrust. Attitude control of the underwater floating power generator, including a rotation speed changing step of generating a moment around the mooring point according to the product of the amount of change of the above, and correcting the posture of the underwater floating power generator in the pitch direction. Method. A method for controlling the attitude of an underwater floating power generation device including a power generation turbine including a rotating shaft and a pod arranged along the rotating axis of the rotating shaft and provided with the power generation turbine.
The center of gravity of the underwater floating power generator is located below the rotation axis.
The power generation turbine includes two blades having a variable pitch angle.
One end of the mooring rope for mooring the underwater floating power generation device is provided in a portion below the rotation axis of the underwater floating power generation device and below the center of gravity of the underwater floating power generation device1. Connected to one or more mooring points
A detection step for detecting at least a tilt angle in the pitch direction of the underwater floating power generator, and
By changing the pitch angle of the two blades in the power generation turbine according to the inclination angle, the turbine thrust is changed, and between the rotation axis and the center of gravity in the vertical direction of the submersible floating power generation device. Underwater floating, including a pitch angle changing step of generating a moment around the mooring point according to the product of the distance of the turbine and the amount of change in the turbine thrust to correct the attitude of the underwater floating power generator in the pitch direction. A method of controlling the attitude of a power generator.

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