JP2018202892A - Attitude control system and attitude control method of underwater floating type-power generator - Google Patents

Abstract

To provide an attitude control system and an attitude control method of an underwater floating type-power generator capable of correcting the attitude when the underwater floating type-power generator is inclined in the pitch direction.SOLUTION: An attitude control system S of an underwater floating type-power generator 1 comprises mooring ropes 11A and 11B the one ends of which are connected to one or multiple mooring points 12A and 12B provided in the lower part than axes of rotation L1 and L2 in the underwater floating type-power generator 1, a detector 23 to detect at least the inclination angle in the pitch direction of the underwater floating type-power generator 1, rotational speed adjustment means provided for power generator turbines 4A and 4B and capable of adjusting rotational speed of the power generator turbines 4A and 4B, and a controller 25 to control the rotational speed adjustment means in response to the inclination angle detected by the detector 23 and to change the rotational speed of the power generator turbines 4A and 4B.SELECTED DRAWING: Figure 1

Description

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

  As an underwater floating power generation device, 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. This device is held by a mooring rope perpendicular to the seabed and two mooring ropes arranged at an angle to the seabed. The posture of the device can be corrected by the restoring force of the power generation device and the vertical mooring with respect to the anchor. In the apparatus described in Patent Document 2, a vehicle having a turbine is rotated in the pitch direction. Thereby, the attitude in the pitch direction can be controlled.

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

Japanese Patent No. 4920823 Special table 2009-525427 gazette JP-A-5-193484

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

  For example, in the apparatus described in the 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 tail is required. Moreover, in the apparatus described in the cited document 2, a mechanism for changing the thrust direction of the propeller is necessary. Therefore, if a large amount of power is required, the device is not suitable as an energy plant. Further, the structure having the swivel coupling portion may cause fatigue failure or water leakage. In the apparatus described in the cited document 3, the posture of the load in the yaw direction is controlled. Therefore, it is necessary to install a propeller and a power unit at a position deviated from the center of gravity of the load. 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 propeller. As a result, the load with the propeller attached thereto can tilt in the roll direction.

  An object of the present invention is to provide a posture control system and a posture control method for a submerged floating power generator that can correct the posture of the submerged floating power generator when tilted in the pitch direction.

  One aspect of the present invention is an attitude control system for a submerged floating power generation apparatus including a power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine. A mooring rope for mooring the submerged floating power generator, wherein one end of the mooring rope is connected to one or more mooring points provided below the rotational axis of the submerged floating power generator. A mooring rope, a detection unit for detecting an inclination angle of at least the pitch direction of the submerged floating power generation device, and a rotation speed adjusting means provided for the power generation turbine and capable of adjusting the rotation speed of the power generation turbine. And a control unit that controls the rotation speed adjusting means according to the inclination angle detected by the detection unit and changes the rotation speed of the power generating turbine.

  In this attitude control system, the underwater floating power generator moored by the mooring rope floats in the water, and the power generation turbine rotates to generate power. A control part changes the rotation speed of the turbine for electric power generation according to the inclination angle of the pitch direction of an underwater floating type power generator. When the rotational 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 points being provided at the lower portion in this way, the thrust in the rotational axis direction generates a moment around the mooring points. The generated moment acts to stabilize the posture of the underwater floating power generation device with respect to the pitch direction. Thereby, the attitude | position of the pitch direction of an underwater floating type electric power generating apparatus may be corrected.

  In some embodiments, the submerged floating power generation device is spaced apart from the power generation turbine in a direction intersecting the rotation axis direction, and includes a second power generation turbine including the second rotation shaft, and a second rotation shaft of the second rotation shaft. It further includes a second pod disposed along the two rotation axes and provided with the second power generation turbine, and a connecting portion that connects the pod and the second pod. The mooring point of the underwater floating generator is provided in a portion below the second rotation axis. The attitude control system is further provided with a second rotation speed adjusting means that is provided for the second power generation turbine and can adjust the rotation speed of the second power generation turbine, and the control section includes an inclination angle detected by the detection section. Accordingly, the second rotational speed adjusting means is controlled to change the rotational speed of the second power generating turbine. 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 but also the posture in the roll direction of the submerged floating power generation device.

  Another aspect of the present invention is an attitude control system for a submerged floating power generation apparatus including a power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine. The power generation turbine includes two blades having a variable pitch angle, and is a mooring rope for mooring the submerged floating power generator. One end of the mooring rope is from a rotation axis of the submerged floating power generator. And a mooring rope connected to one or more mooring points provided in the lower part, a detection unit for detecting an inclination angle of at least the pitch direction of the underwater floating power generator, and a power generation turbine. A pitch angle adjusting device capable of adjusting the pitch angle of two blades, and a pitch angle adjusting device that controls the pitch angle adjusting device in accordance with the inclination angle detected by the detection unit, and two blades in a power generation turbine And a control unit for changing the pitch angle of the blades.

  In this attitude control system, the underwater floating power generator moored by the mooring rope floats in the water, and the power generation turbine rotates to generate power. The control unit changes the pitch angle of the two blades according to the inclination angle in the pitch direction of the submerged floating power generator. When the pitch angle of the two blades is changed, the thrust of the power generating 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 points being provided at the lower portion in this way, the thrust in the rotational axis direction generates a moment around the mooring points. The generated moment acts to stabilize the posture of the underwater floating power generation device with respect to the pitch direction. Thereby, the attitude | position of the pitch direction of an underwater floating type electric power generating apparatus may be corrected.

  In some embodiments, the submerged floating power generation device is spaced apart from the power generation turbine in a direction intersecting the rotation axis direction, and includes a second power generation turbine including the second rotation shaft, and a second rotation shaft of the second rotation shaft. It further includes a second pod disposed along the two rotation axes and provided with the second power generation turbine, and a connecting portion that connects the pod and the second pod. The second power generation turbine includes two second blades having a variable pitch angle. The mooring point of the underwater floating generator is provided in a portion below the second rotation axis. The attitude control system further includes a second pitch angle adjustment device that is provided in the second power generation turbine and is capable of adjusting the pitch angle of the two second blades, and the control unit adjusts the inclination angle detected by the detection unit. Accordingly, the second pitch angle adjusting device is controlled to change the pitch angle of the two second blades in the second power generation turbine. In this case, since the pitch angle of the blades of the power generation turbine and the pitch angle of the second blades of the second power generation turbine are changed, not only the posture in the pitch direction but also the posture in the roll direction of the submersible power generator is changed. Can be controlled.

  In some embodiments, the power generation turbine is provided at the first end in the rotation axis direction of the pod, and the mooring point is provided in a portion on the second end side opposite to the first end in the rotation axis direction. It is done. When the power generation turbine is a downwind turbine disposed on the downstream side of the pod with reference to the direction of water flow, a mooring point is provided on the upstream side, which is the opposite side of the power generation turbine. In this case, the thrust generates a larger restoring moment. Thereby, the posture correction effect (for example, responsiveness, etc.) 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 generates a larger restoring moment than when the mooring point is provided on the end surface of the pod in the rotation axis direction. Thereby, the posture correction effect (for example, responsiveness, etc.) is enhanced.

  Still another aspect of the present invention provides an attitude control method for an underwater floating power generation apparatus including a power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine. The one end of the mooring rope for mooring the submerged floating power generator is connected to one or more mooring points provided in a portion below the rotation axis in the submerged floating power generator, It includes a detection step for detecting an inclination angle in at least the pitch direction of the underwater floating power generation device, and a rotation speed changing step for changing the rotation speed of the power generation turbine according to the inclination angle.

  According to this attitude control method, an underwater floating power generator is obtained by an interaction between the above-described thrust generated based on a change in the rotational speed of the power generating turbine and a mooring point provided at a lower portion of the submerged floating power generator. The posture in the pitch direction can be corrected.

  Still another aspect of the present invention provides an attitude control method for an underwater floating power generation apparatus including a power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine. The power generation turbine includes two blades having a variable pitch angle, and one end of the mooring rope for mooring the submerged floating power generator is a portion below the rotation axis of the submerged floating power generator. A detecting step for detecting an inclination angle of at least the pitch direction of the underwater floating power generation apparatus, and two blades in the power generation turbine according to the inclination angle. A pitch angle changing step of changing the pitch angle of the pitch angle.

  According to this attitude control method, the above-described thrust generated based on the change in the pitch angle of the blades of the power generation turbine and the mooring point provided at the lower part of the submersible power generation system, the submersion type The posture of the power generation device in the pitch direction can be corrected.

  According to some aspects of the present invention, it is possible to efficiently correct the attitude in the pitch direction of the underwater floating power generator.

It is a figure showing the schematic structure of the underwater floating type power generator to which the attitude control system concerning one embodiment of the present invention was applied. It is a figure which shows schematic structure of the equipment provided in the pod. It is a figure which shows the steady state of an underwater floating type generator. It is a figure which shows the attitude | position control method when the attitude | position of an underwater floating type | mold power generation apparatus inclines in the pitch direction. It is a flowchart which shows the process sequence of attitude | position control implemented by the control part. It is a figure which shows the balance of the force in an underwater floating type electric power generating apparatus. It is a figure which shows the balance of the moment in a submerged floating type electric power generating 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 denoted by the same reference numerals, and redundant descriptions are omitted.

  In the following description, the terms “upstream” or “downstream” are used with reference to the flow of water. The term “front” means upstream of the water flow, and the term “back” means downstream of the water flow. For example, when a downwind type turbine is used, blades (wings) are arranged on the rear side of the pod. The term “left” or “right” means a direction that is perpendicular and horizontal to the flow of water and is used as a reference when viewed from the rear or downstream. The terms “upper” and “lower” are used on the basis of a 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 attitude of the underwater floating power generation device 1 mean rotation about a vertical axis that is perpendicular to the central axis of the pod, that is, a horizontal axis. The term “roll” refers to rotation about an axis parallel to the central axis of the pod, ie, the longitudinal axis.

  With reference to FIG. 1 and FIG. 2, the submerged floating power generator 1 to which the attitude | position control system S of this embodiment is applied is demonstrated. As shown in FIG. 1, the underwater floating power generation apparatus 1 is installed in, for example, seawater and floats, and generates power using an ocean current. The underwater floating power generation apparatus 1 includes a first beam 2A and a second pod 2B, which are a pair of pods spaced apart from each other on the left and right sides, and a cross beam (connection unit) that connects the first pod 2A and the second pod 2B. 3. 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 generator 1 is referred to as the ocean current generator 1. 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 imparts appropriate buoyancy to the first turbine 4A while rotatably supporting the first turbine 4A. The second pod 2B imparts appropriate buoyancy to the second turbine 4B while rotatably supporting 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 from side to side). 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 posture of the floating ocean current power generation apparatus 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. 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 upper part or the lower part of the pod, or may be fixed to the front part or the rear part of the pod. The cross beam 3 may have an equal 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 a plurality of objects may be provided near the center of the cross beam 3. In addition, a mooring line may be connected from this object.

  The ocean current power generation apparatus 1 is connected to a sinker 14 fixed to the seabed via a first mooring rope 11A and a second mooring rope 11B. The first mooring rope 11 </ b> A and the second mooring rope 11 </ b> B are so-called V-shaped mooring lines 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 able to rotate 360 degrees with respect to the sinker 14, for example. The connection part of the 1st mooring rope 11A and the 2nd mooring rope 11B with respect to the sinker 14 may be the fastening structure which used the shackle etc., for example. Note that the first mooring rope 11 </ b> A and the second mooring rope 11 </ b> B may be Y-shaped by providing a branch point in the middle part 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 that fixes the other end of the mooring rope to the seabed.

  The ocean current power generation apparatus 1 is moored at two different points, for example, by a first mooring rope 11A and a 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 by a predetermined length in the left-right direction.

  As shown in FIG. 1, a power transmission cable 10 for transmitting 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, the first cable 10A for transmitting the power generated by the first turbine 4A is provided along the first mooring rope 11A, and the second cable for transmitting the power generated by the second turbine 4B. A 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 a repeater (or a transformer or the like) provided in the sinker 14, for example. A power transmission cable laid on the seabed and extending to the ground is connected to the repeater, and the power generated in the first turbine 4A and the second turbine 4B is transmitted to the ground via these power transmission cables. It has become.

  In addition, the form in which each cable is provided is not restricted to the said form. For example, the power transmission cable 10, the first cable 10A, and the second cable 10B may be integrated with a 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 apparatus 1 are so-called downwind 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 (the axis of the rotation shaft 16 shown in FIG. 2) of the first turbine 4A and the second turbine 4B 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 disposed at the rear end of the first pod 2A. The second hub 5B is disposed at the rear end of the second pod 2B. In the ocean current power generation apparatus 1 that employs a downwind turbine, the first blade 6A is disposed on the downstream side of the first pod 2A and the second blade 6B is disposed 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 pitches of the blades are reversed. 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.

  Next, the attitude control system S that controls the attitude (particularly, the attitude in the pitch direction) of the ocean current power generation device 1 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 (detecting unit) that detects an inclination angle of at least the pitch direction of the ocean current power generation device 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 adjustment device 20 that can adjust the pitch angle of the first blade 6A and the second blade 6B instead of or in addition to the rotation speed adjustment means. In the following description, the case where the attitude control system S includes the rotation speed adjusting means and the pitch angle adjusting device 20 will be described. In the following description, the configuration of the first pod 2A will be mainly described. Since the second pod 2B has the same configuration as that of the first pod 2A, the description regarding the second pod 2B is 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 4 </ b> A is transmitted to the generator 17 through 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 includes a hydraulic drive device 21 and a blade shaft 22. More specifically, a hydraulic drive device 21 is connected to the blade shaft at the base end portion of each first blade 6A. The hydraulic drive device 21 is mounted, for example, in the first hub 5A. The hydraulic drive device 21 includes, for example, a gear mechanism. A known mechanism can be used as the hydraulic drive device 21. The hydraulic drive device 21 is controlled by the control unit 25 and can adjust the pitch angle of the first blade 6A to an arbitrary angle. The first driving blade 21 </ b> A is rotated about the blade shaft 22 by the hydraulic drive device 21, and at the same time, the other first blade 6 </ b> A is rotated about the blade shaft 22 by the same angle. Similarly, the pitch angle of the second blade 6B is also variable. That is, the pitch angle adjusting device 20 is also provided in the second turbine 4B. The mechanism for changing the pitch angle of the first blade 6A and the second blade 6B is not limited to the hydraulic drive device 21, and a servo motor or the like may be used. When the attitude 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.

  A resolver that detects the rotational speed of the first turbine 4A is mounted on the first pod 2A. 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 (the rotation speed of the first blade 6A) to the control unit 25. 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 attitude 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 apparatus 1 in the roll direction, the pitch direction, and the yaw direction. The gyro sensor 23 sequentially outputs the detected inclination angles to the control unit 25. A depth sensor (pressure sensor) that measures the depth of the ocean current power generation device 1 may be provided in the first pod 2A.

  The first pod 2A is provided with the generator 17 and the brake device 30 as the above-described rotation speed adjusting means. The generator 17 includes an inverter 17a, for example. 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 rotational speed of the first turbine 4A (the rotational 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 the rotating shaft 16, for example. The brake device 30 includes, for example, a pad that reduces the rotational speed of the first turbine 4A using a frictional force, and can apply a braking force to the first turbine 4A. The brake device 30 may be, for example, a hydraulic brake device. The brake device 30 adjusts the rotational speed of the first turbine 4A (the rotational speed of the first blade 6A) by adjusting the braking force. In addition, any one of the generator 17 and the brake device 30 may be used as a rotation speed adjustment means. For example, a gear mechanism that changes the reduction ratio may be used as the rotation speed adjusting means.

  The attitude control system S may include a buoyancy adjustment device (not shown) that changes the weight of the ocean current power generation device 1 by pouring seawater between the first pod 2A and the outside. The buoyancy adjusting device may include a tank provided in the first pod 2A, a pouring / draining pipe connecting the tank and the outside of the first pod 2A, and a pump provided in the pouring / draining pipe (both are Not shown).

  The ocean current power generation apparatus 1 is provided with a control unit 25 that obtains information from each sensor and controls each actuator and the like to control the entire ocean current power generation apparatus 1. The control unit 25 constitutes a part of the attitude control system S. The control unit 25 controls the inverter 17 a and / or the brake device 30 of the generator 17 according to the inclination angle in the pitch direction of the ocean current power generation device 1 detected by the gyro sensor 23. Moreover, the control part 25 controls a buoyancy adjustment apparatus, and adjusts the buoyancy of the ocean current power generator 1 whole. The control unit 25 is provided in the first pod 2A, for example. The control unit 25 is a computer including hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and 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 attitude control of the ocean current power generation device 1. The controller 25 may store a roll direction threshold value. The control unit 25 stores a first threshold value and a second threshold value as 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 restoring force based on the center of gravity and buoyancy that the ocean current power generation apparatus 1 has.

  In the ocean current power generation device 1 of the present embodiment, the first mooring rope 11 </ b> A and the second mooring rope 11 </ b> B are connected to the lower front part of the ocean current power generation device 1. That is, the mooring point 12A and the mooring point 12B are provided in a 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 in the lower front part of the first pod 2A, and the mooring point 12B is provided in the lower front part of the second pod 2B. The mooring point 12A and the mooring point 12B are in plane symmetry 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.

  A 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 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 connection structure of the first mooring rope 11A is configured by a bolt inserted through the through hole, a U-shaped connection fitting attached to the bolt, and a nut. 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 be freely changed. The connection structure of the mooring rope is not limited to the above, and other known connection structures may be employed.

  The position of the mooring point 12A is also important for the position 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. For example, the floating core BC of the ocean current power generation device 1 is located above the first rotation axis L1.

  In FIG. 3, the positions of the center of gravity GC and the floating center BC are shown 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 floating center BC are located, for example, on the above-described virtual plane at the center of the apparatus. The center of gravity GC is located below the plane including 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.

  Although it is necessary that the center of gravity GC is located below the buoyancy BC, the position of the center of gravity GC is on or above the plane including the first rotation axis L1 and the second rotation axis L2. May be.

  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 rotation axis L1 of the first pod 2A, but the mooring point 12A is provided at a portion on the front end side opposite to the first turbine 4A. Yes. More specifically, the mooring point 12A is provided not on the front end surface of the first pod 2A (that is, on the end surface that closes the cylindrical surface) but on the rear part of the front end surface. The mooring point 12A is provided below the center of gravity GC.

  Thus, the mooring point 12A is provided in the lower front part of the cylindrical surface of the first pod 2A. Since the arrangement of the mooring points 12A can generate a large restoring moment, it contributes to the stability of the attitude of the ocean current power generation device 1. The positions of the mooring point 12A and the mooring point 12B can be determined after regarding the ocean current power generation apparatus 1 as one rigid body. In addition, from the viewpoint of posture control in the pitch direction by the turbine thrust, the mooring point 12A may be provided in a portion below the first rotation axis L1. If this condition is satisfied, a restoring moment can be generated no matter where the mooring point 12A is, so that attitude control is possible.

  Unlike the present embodiment, when the mooring point is provided at the upper part of the pod, when the ocean current power generator floats on the water surface, the attitude of the ocean current power generator may be inclined due to the weight or 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 floats on the water surface.

  Then, the attitude | position control method of the ocean current power generator 1 by the attitude | position control system S is demonstrated. First, the ocean current power generation device 1 is suspended in seawater and is in a normal operation state in response to the flow of seawater. As FIG. 5 shows, the control part 25 acquires the inclination angle of the pitch direction of the ocean current power generator 1 detected by the gyro sensor 23 (step S01; detection step). And the control part 25 judges whether the inclination angle of the ocean current power generator 1 is less than a 1st threshold value (step S02).

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

  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 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 rotational speed of 4B is changed (step S03; rotational speed changing step). In addition, if the control part 25 judges that the inclination-angle of the ocean current power generator 1 is less than a 1st threshold value (step S02: YES), it will return to the process of step S01. Here, attitude control by the buoyancy adjusting device may be performed. The posture control by the buoyancy adjusting device can be performed according to a known method.

  For example, in 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 is increased in step S <b> 03. Thereby, the control unit 25 increases the rotation speed in the first turbine 4A and the second turbine 4B. The control unit 25 may perform the same rotation speed increase control on the first turbine 4A and the second turbine 4B, but may perform different rotation speed increase controls. Hereinafter, the turbine thrust is also referred to as thrust force.

  The control unit 25 may change the pitch angle of the first blade 6A and the second blade 6B so that the turbine thrust is increased. For example, as the angle formed by the direction of the first blade 6A with respect to the flow FL (see FIG. 1) is larger, the first blade 6A is easier to rotate in the rotational direction and is more susceptible to the thrust force F. The smaller the angle formed by the direction of the first blade 6A with respect to the flow FL, the harder the first blade 6A rotates in the rotational direction and the less the thrust force F is received. In order 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 unlikely to receive the thrust force F means that the direction of the first blade 6A is close to the direction of the flow FL. On the contrary, changing the pitch angle so that the first blade 6A easily receives the thrust force F means that the direction of the first blade 6A is away from the direction of the flow FL.

  With reference to FIG. 6 and FIG. 7, the moment which generate | occur | produces with the change of the thrust force F is demonstrated. FIG. 6 is a diagram showing balance of forces in the ocean current power generation apparatus 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 FIG. 6 and FIG. 7, each force acting on the ocean current power generation apparatus 1 is shown projected in the left-right direction. 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 ocean current power generation device 1, the buoyancy applied to the buoyancy BC, the gravity applied to the center of gravity GC, the thrust applied to the axial direction of the turbine, the tension from the mooring rope, and the fluid drag received from the flow FL The following relational expression holds between:

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 (the ocean current power generation device 1), the relationship of Expression (1) is established.

In the vertical direction of the aircraft, the relationship of Equation (2) is established.

here,
B: Buoyancy,
G: Gravity,
F: Thrust force,
T: tension,
θ: Turbine axis and mooring rope angle,
R: Fluid drag,
Rv: vertical component of fluid drag,
Rh: 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 moments around the center of gravity GC is as shown in Expression (3).

here,
h _F : distance between the axis of the turbine 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 : the distance between the center of gravity in the vertical direction of the aircraft and the mooring point,
L _B : Distance between the floating center and the center of gravity in the horizontal direction of the aircraft,
L _R : 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 center of gravity in the horizontal direction of the aircraft and the mooring point.

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, a disturbance may be added to the ocean current power generation device 1. Therefore, by adding the control amount ΔF × h _F , the disturbance component is canceled as shown in the equation (4).

The control amount ΔF × h _F is an increase / decrease amount of the thrust force. The control amount ΔF × h _F can be controlled by the rotational speed of the turbine and / or the pitch angle of the blades of the turbine.

  Returning to FIG. 5, the control unit 25 determines again whether or not the inclination angle of the ocean current power generation device 1 is less than the first threshold (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 (step S04: YES), the control unit 25 returns to the process of step S01 and corrects the posture only by the buoyancy adjustment device. 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 performs the rotation speed changing process in step S03 again.

In 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 on the left side of the equation (4) indicating the moment balance. In addition, a moment M around the mooring point is generated (see FIG. 4). As a result, the moment M is generated in the head-up direction, 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. The control amount ΔF × h _{F in} this case is an increase amount (positive value) of the thrust force. Thus, the moment M is a restoring moment for correcting (that is, restoring) the attitude of the ocean current power generation device 1.

  Contrary to FIG. 4, when the rear portion of the ocean current power generation device 1 is lower than the front portion and pitching occurs in the positive direction, that is, in the “head-up” state, the control unit 25 The electromagnetic brake or the resistance brake is strengthened so that the thrust force (turbine thrust) becomes small. Thereby, the control part 25 reduces the rotation speed in the 1st turbine 4A and the 2nd turbine 4B. Note that the control unit 25 may change the pitch angle of the first blade 6A and the second blade 6B so that the thrust force becomes small.

When the control unit 25 decreases the thrust force in step S03, the left side of the equation (4) indicating the moment balance decreases, and the moment around the mooring point decreases. Thereby, a moment is generated in the head-down direction, and the rear portion of the ocean current power generation device 1 is raised. Then, the ocean current power generation device 1 returns to the steady state shown in FIG. The control amount ΔF × h _{F in} this case is a reduction amount (negative value) of the thrust force.

  In the attitude control system and attitude control method of the present embodiment, power generation is performed by the underwater floating power generator moored by the mooring rope floating in the water and the power generation turbine rotating. A control part changes the rotation speed of the turbine for electric power generation according to the inclination angle of the pitch direction of an underwater floating type power generator. When the rotational 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 points being provided at the lower portion in this way, the thrust in the rotational axis direction generates a moment around the mooring points. The generated moment acts to stabilize the posture of the underwater floating power generation device with respect to the pitch direction. Thereby, the attitude | position of the pitch direction of an underwater floating type electric power generating apparatus may be corrected. The underwater floating power generator can be provided with a posture adjusting device that moves the fluid by a pump and changes its center of gravity. The attitude in the pitch direction can also be corrected by the attitude adjustment device. However, the posture control system according to the present embodiment does not require the posture correction in the pitch direction by the posture adjustment device. The moment generated based on the thrust enhances the responsiveness regarding the posture correction in the pitch direction as compared with the case where the posture adjusting device is used. Therefore, it is possible to cope with a sudden posture change. In addition, it is possible to reduce the amount of power consumption required for correcting the posture in the pitch direction. The size of the posture adjusting device can be reduced as compared with the case where the posture adjusting device is also used for correcting the posture in the pitch direction.

  Moreover, 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 possible to control not only the attitude in the pitch direction but also the attitude in the roll direction of the submersible power generator. Can do.

  When the power generation turbine is a downwind turbine disposed on the downstream side of the pod with reference to the direction of water flow, a mooring point is provided on the upstream side, which is the opposite side of the power generation turbine. In this case, the thrust generates a larger restoring moment. Thereby, the posture correction effect (for example, responsiveness, etc.) is enhanced.

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

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

  In the attitude control system S, since the rotation speed is adjusted and the attitude is controlled using the brake device 30 provided in the first turbine 4A and the second turbine 4B, no additional means is required, and the attitude control is efficiently performed. 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 determination based on the first threshold, a determination based on a larger second threshold may be added. In that case, if the control part 25 judges that the inclination-angle of the ocean current power generator 1 is more than a 1st threshold value, it will change the water storage amount in a buoyancy adjusting device. Thereafter, when the controller 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 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, the control unit 25 changes the water storage amount in the buoyancy adjustment device. 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 performs change control of the rotation speed and / or the blade pitch angle. Then, 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, and when determining that the inclination angle is equal to or more than the second threshold value, the rotational speed and / or the blades again. Pitch angle change control is implemented. When the controller 25 determines that the inclination angle of the ocean current power generation device 1 is less than the second threshold value, the controller 25 acquires the inclination angle again. Note that the first threshold value may be used instead of the second threshold value. Thus, the attitude control by the attitude control system S and the attitude control by the buoyancy adjusting device may be used in combination.

  One or more mooring points may be provided on the cross beam 3. Even in such a case, it is desirable that the mooring points be provided at the front and the lower part. The cross beam 3 may be provided below a 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 be separated from the power point of the turbine thrust. Thereby, the control amount (that is, the restoring moment) by the turbine thrust force is increased, and the attitude control is facilitated. Since the ocean current power generation apparatus 1 is regarded as one rigid body, the mooring point may be provided in any member included in the rigid body.

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

  The control unit 25 may perform both the rotation speed change control and the blade pitch angle change control. When the control unit 25 performs the rotational speed change control, the pitch angle of the blades is not variable and may be fixed. When the control unit 25 performs the change control of the pitch angle of the blade, the rotation speed adjusting means may be omitted. Even if only the pitch angle change control is performed, the above-described effects such as high responsiveness, power saving, and downsizing of the posture adjusting device are obtained.

  One aspect of the present invention may be an underwater floating power generation device including a single-shot 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 front end of the pod. Even in the case of an underwater floating power generation apparatus including a single turbine, attitude control is possible by the same method as the attitude control method in the above-described embodiment.

  One embodiment of the present invention may be an underwater floating power generation device 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 portion. The first turbine 4A and the second turbine 4B may be upwind 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 Second pod 3 Cross beam (connection part)
4A 1st turbine (power generation turbine)
4B Second turbine (second 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 adjustment means)
17a Inverter (rotation speed adjusting means)
20 Pitch angle adjustment device 23 Gyro sensor (detection unit)
25 Control unit 30 Brake device (rotational speed adjusting means)
BC Floating center GC Center of gravity L1 First rotation axis (rotation axis)
L2 Second rotation axis S Attitude control system

Claims (8)

An attitude control system for an underwater floating power generator comprising: a power generation turbine including a rotation shaft; and a pod provided along the rotation axis of the rotation shaft and provided with the power generation turbine,
A mooring rope for mooring the submerged floating power generator, wherein one end of the mooring rope is at one or more mooring points provided in a portion below the rotation axis in the submerged floating power generator. Connected, mooring rope,
A detection unit that detects an inclination angle of at least the pitch direction of the underwater floating power generation device;
A rotational speed adjusting means provided for the power generating turbine, and capable of adjusting a rotational speed of the power generating turbine;
An attitude control system for an underwater floating power generator, comprising: a control unit that controls the rotation speed adjustment unit according to the inclination angle detected by the detection unit and changes the rotation speed of the power generation turbine. The submerged floating power generator is disposed 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 disposed along the axis and provided with the second power generating turbine; and a connecting portion for connecting the pod and the second pod;
The mooring point of the underwater floating power generator is provided at a portion below the second rotation axis,
A second rotational speed adjusting means provided for the second power generating turbine and capable of adjusting the rotational speed of the second power generating turbine;
The said control part controls the said 2nd rotation speed adjustment means according to the said inclination | tilt angle detected by the said detection part, and changes the rotation speed of the said 2nd turbine for electric power generation, The underwater floating of Claim 1 -Type power generator attitude control system. An attitude control system for an underwater floating power generator comprising: a power generation turbine including a rotation shaft; and a pod provided along the rotation axis of the rotation shaft and provided with the power generation turbine,
The power generation turbine includes two blades having a variable pitch angle,
A mooring rope for mooring the submerged floating power generator, wherein one end of the mooring rope is at one or more mooring points provided in a portion below the rotation axis in the submerged floating power generator. Connected, mooring rope,
A detection unit that detects an inclination angle of at least the pitch direction of the underwater floating power generation device;
A pitch angle adjusting device provided in the power generating turbine and capable of adjusting a pitch angle of the two blades;
A control unit that controls the pitch angle adjusting device according to the inclination angle detected by the detection unit and changes the pitch angle of the two blades in the power generation turbine. Attitude control system. The submerged floating power generator is disposed 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 disposed along the axis and provided with the second power generating turbine; and a connecting portion for connecting the pod and the second pod;
The second power generating turbine includes two second blades having a variable pitch angle,
The mooring point of the underwater floating power generator is provided at a portion below the second rotation axis,
A second pitch angle adjusting device provided in the second power generating turbine and capable of adjusting a pitch angle of the two second blades;
The control unit controls the second pitch angle adjusting device according to the inclination angle detected by the detection unit, and changes the pitch angle of the two second blades in the second power generation turbine. The attitude control system for an underwater floating generator according to claim 3. The power generation turbine is provided at a first end of the pod in the rotation axis direction,
The attitude of the submerged floating power generator according to any one of claims 1 to 4, wherein the mooring point is provided in a portion on a second end side that is opposite to the first end in the rotation axis direction. 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 a cylindrical surface of the pod. A power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine, and an attitude control method for a submerged floating power generation device comprising:
One end of a mooring rope for mooring the submerged floating power generator is connected to one or more mooring points provided in a portion below the rotation axis in the submerged floating power generator,
A detection step of detecting an inclination angle of at least the pitch direction of the underwater floating power generation device;
An attitude control method for an underwater floating power generator, comprising: a rotation speed changing step of changing a rotation speed of the power generating turbine according to the inclination angle. A power generation turbine including a rotation shaft, and a pod disposed along the rotation axis of the rotation shaft and provided with the power generation turbine, and an attitude control method for a submerged floating power generation device comprising:
The power generation turbine includes two blades having a variable pitch angle,
One end of a mooring rope for mooring the submerged floating power generator is connected to one or more mooring points provided in a portion below the rotation axis in the submerged floating power generator,
A detection step of detecting an inclination angle of at least the pitch direction of the underwater floating power generation device;
And a pitch angle changing step of changing a pitch angle of the two blades in the power generation turbine according to the inclination angle.

Images