JP2017218987A - Floating body type wind generator system and control method of floating body type wind generator system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating body type wind generator system in which the failure of a mooring rope and a power line can be prevented even when a floating body rotates in the floating body type wind generator system.SOLUTION: The floating body type wind generator system is provided that comprises: a rotor for converting wind force energy into revolution energy; a nacelle for rotatably supporting the rotor; a tower for supporting the nacelle; and a floating body which is moored at the ocean bed with a mooring rope and supports the tower. The mooring rope and the floating body are connected via a bearing so that the floating body is rotatable with respect to the mooring rope, and the bearing is provided with a drive mechanism for generating a torque in a rotational direction.SELECTED DRAWING: Figure 3

Description

  The present invention mainly relates to a mooring method for a floating wind turbine generator installed on a floating body moored on the sea, and more particularly to a technique effective when applied to a downwind floating wind turbine generator.

  A wind power generation system is a device that receives kinetic energy of airflow with a blade, converts it into rotational energy of a rotor, and further generates electrical energy by a generator. In recent years, it has been put into practical use as a fourth power generation means following thermal power, hydropower, and nuclear power, and is becoming widespread all over the world.

  In particular, floating wind power generation systems installed on floating bodies moored offshore will increase in the future because they can obtain a stable wind speed without being affected by ground structures and are relatively easy to secure land. It is said that it will spread.

  Various types of mooring systems have been proposed for floating wind power generation systems. When downwind wind turbines are targeted, mooring lines fixed to the bottom of the ocean can be rotated around a vertical axis with respect to the water surface. The supporting system is advantageous.

  Generally, a horizontal axis wind power generation system maximizes the amount of power generated when the wind direction and the rotation axis of the windmill are parallel, so the wind direction and the rotation axis of the windmill are usually parallel by the yaw control mechanism that exists between the tower and the nacelle. It is necessary to control the nacelle direction to follow the wind direction so that When the yaw is supported so as to rotate freely, the rotor is downstream of the airflow with respect to the rotation axis of the yaw and has the property that the wind direction and the rotation axis of the rotor are parallel (the weathercock effect). The downwind type windmill can obtain the maximum amount of power generation by simply supporting the yaw rotatably.

  In the case of a downwind type floating wind power generation system installed on a moored floating body, the tower and the floating body rotate together by supporting the floating body around a vertical axis with respect to the water surface. And the yaw control mechanism can be omitted.

  For example, in the wind power generation system disclosed in Patent Document 1, the floating body is moored on the sea floor by an elongated tubular support member, and is freely supported by bearings in the roll, pitch, and yaw directions. A weathercock effect is obtained, and the wind direction and the rotation axis of the windmill are automatically matched.

Special table 2014-504697 gazette

  Incidentally, in the bearing structure disclosed in Patent Document 1, when a relatively low-rigidity mooring line such as a wire rope is employed, the mooring line may be twisted due to the frictional resistance of the bearing. Due to the influence of the twist, it is assumed that the transmission line and the mooring line are entangled. If the twisting is repeated, there is a possibility that a failure such as deterioration of the mooring line or disconnection of the transmission line may occur.

  Accordingly, an object of the present invention is to effectively prevent the mooring line from twisting and prevent the mooring line and the power line from failing even in the case where the floating body rotates in the floating wind power generation system. A floating wind power generation system and a control method thereof are provided.

  In order to solve the above problems, the present invention is moored to the sea floor by a rotor that converts wind energy into rotational energy, a nacelle that rotatably supports the rotor, a tower that supports the nacelle, and a mooring line, A floating wind power generation system having a floating body supporting the tower, wherein the mooring line and the floating body are connected to the mooring line via a bearing so that the floating body is rotatable, and the bearing And a drive mechanism for generating torque in the rotational direction.

  Further, the present invention detects the torque value generated in the state of the floating body or the mooring line mooring the floating body to the seabed, and when the detected state of the floating body or the torque value of the mooring line becomes a predetermined value or more, A control method for a floating wind power generation system, wherein a torque provided in a rotational direction is generated in a bearing provided at a connecting portion between the floating body and the mooring line.

  According to the present invention, in the floating wind power generation system, even when the floating body rotates, it is possible to effectively prevent the twisting of the mooring line and to prevent the mooring line and the transmission line from being broken. it can.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is an external view of a floating wind power generation system according to an embodiment of the present invention. 1 is a partial cross-sectional view of a floating wind power generation system according to an embodiment of the present invention. It is a perspective view which shows the bearing part of the floating body type wind power generation system which concerns on one Embodiment of this invention. It is sectional drawing of the bearing part of the floating body type wind power generation system which concerns on one Embodiment of this invention. It is a perspective view which shows the bearing part of the floating body type wind power generation system which concerns on one Embodiment of this invention. It is a flowchart which shows the control method of the floating body type wind power generation system which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description of overlapping portions is omitted.

  The configuration and operation of the floating wind power generation system according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is an external view of a floating wind power generation system according to the present embodiment. Reference numeral 1 denotes a rotor having blades and a hub, which is rotated by wind power around a horizontal main shaft, and converts wind energy into rotational energy of the main shaft. A nacelle 2 has a generator (not shown) that rotatably supports the rotor 1 by the main shaft and converts the rotational energy of the main shaft into electric energy. A tower 3 supports the nacelle 2.

  4 is a floating body floating on the ocean, and is moored to the seabed 8 by a mooring line 5 and an anchor 7 to support the tower 3. Reference numeral 6 denotes a power transmission line that sends the electric power generated by the floating wind power generation system to the substation.

  FIG. 2 is an enlarged cross-sectional view of the floating body 4 and the tower 3 in FIG. Reference numeral 10 denotes a power converter, which converts the frequency of electricity obtained by the generator into the frequency of the power system. Reference numeral 11 denotes a bearing portion according to the present invention. The bearing 11 is connected to one end of the mooring line 5, and the other end of the mooring line 5 is connected to the anchor 7 as shown in FIG. Is done. Further, the power transmission line 6 in the tower 3 and the power transmission line 6 in the floating body 4 are electrically connected via a bearing portion 11.

  3 is a perspective view of the bearing portion 11 in FIG. 2, and FIG. 4 is a vertical sectional view of the bearing portion 11. In FIG. 4, a portion that rotates integrally with the tower 3 is indicated by hatching. Reference numeral 12 denotes a bearing (radial thrust bearing). In this embodiment, a roller bearing that restrains movement of the inner ring 12b in the radial thrust direction and supports the ring 12b in a freely rotating manner. The outer ring 12 a of the radial thrust bearing 12 is fixed to the floating body 4, and the inner ring 12 b is connected (fixed) to the mooring line 5.

  Reference numeral 13 denotes a power transmission mechanism, which includes, for example, a belt and a pulley. Reference numeral 14 denotes a slip ring, for example, which rotatably connects the power transmission line 6. Reference numeral 15 denotes a drive mechanism, for example, an electric motor. The drive mechanism 15 transmits torque to the inner ring 12 b of the radial thrust bearing 12 via the power transmission mechanism 13. Reference numeral 16 denotes a control device that controls the rotation direction, rotation amount, and rotation speed of the drive mechanism 15. Reference numeral 17 denotes a floating body direction detection mechanism, which detects the state of the floating body 4 with respect to the ground axis, such as the direction, position, posture, and the like, and transmits the information to the control device 16, for example.

  With the above configuration, the floating wind power generation system according to the present embodiment can control the drive mechanism 15 so that the control device 16 obtains the state of the floating body 4 (rotation information or the like) and the rotational torque is not transmitted to the mooring cable 5. Thus, twisting of the mooring cable 5 and entanglement of the power transmission line 6 can be prevented.

  Further, unlike a plain bearing using a friction ring in Patent Document 1, since a roller bearing (rolling bearing) is used, the frictional resistance of the bearing is reduced, and smoother rotation can be performed, such as a wire rope. Even when a mooring line having a relatively low rigidity is employed, the mooring line can be prevented from being twisted.

  For example, when trying to prevent the twisting of the mooring body in the sliding bearing structure as in Patent Document 1, there is a concern about troubles such as wear and sticking of the bearing due to long-term operation. By providing a drive mechanism in the part and actively generating torque that counteracts the torque (torsion) generated in the bearing and mooring body (mooring line), the twisting generated in the mooring body (mooring line) can be prevented more effectively. This makes it possible to operate a stable wind power generation system.

  In addition to the gyroscope, the floating body direction detection mechanism 17 of the present embodiment is, for example, a floating body state detection based on the shape of the seabed by SONAR (SONAR: Sound navigation and ranging), or a GPS (Global Positioning System). Methods such as floating body state detection and floating body state detection using a compass may be used.

  Moreover, as shown in FIGS. 1 and 2, the present invention is applied to a one-point mooring type floating wind power generation system in which a floating body is moored by a single mooring line in terms of cost and maintainability. Although more effective, it is needless to say that the present invention can also be applied to a floating wind power generation system of a two-point mooring method or a three-point mooring method.

  In addition, as in this embodiment, by applying the present invention to a downwind type wind power generation system in which the rotor is arranged on the leeward side of the nacelle, it is necessary to provide a conventional yaw control mechanism at the connecting portion between the nacelle and the tower This makes it possible to manufacture a wind power generation system at a lower cost.

  The floating body wind power generation system according to the second embodiment will be described with reference to FIG. FIG. 5 is a perspective view of the bearing portion 11 corresponding to FIG. As described above, in FIG. 3, the drive mechanism 15 is controlled by the control device 16 based on the state (rotation information or the like) of the floating body 4 obtained by the floating body direction detection mechanism 17, and the mooring line 5 is twisted or the power transmission line 6 is entangled. Is preventing.

  On the other hand, in FIG. 5, instead of the floating body direction detection mechanism 17, a torque detection mechanism 18 such as a strain gauge is provided on the mooring line 5, and the torque (torsion) generated in the mooring line 5 is directly measured. Is transmitted to the control device 16 and the drive mechanism 15 is driven to prevent the mooring cable 5 from being twisted and the power transmission line 6 from being entangled.

  A control method of the floating wind power generation system described in the first and second embodiments will be described with reference to FIG.

The state (direction, position, posture, etc.) of the floating body 4 is detected by the floating body direction detection mechanism 17 such as a gyroscope, sonar, GPS, or azimuth magnet, or the torque value (twist amount) generated in the mooring line 5 is measured. (Step S1)
Next, the detected state of the floating body 4 or the measured torque value of the mooring line 5 is compared with a preset reference value. (Step S2)
When the detected state of the floating body 4 or the measured torque value of the mooring line 5 is less than a preset reference value, the process proceeds to step S3, and the power generation operation of the wind power generation system is continued without driving the drive mechanism 15. To do. (Step S3)
On the other hand, when the detected state of the floating body 4 or the measured torque value of the mooring line 5 is greater than or equal to a preset reference value, the process proceeds to step S4, where the state of the floating body 4 (direction, position, posture, etc.) or the mooring line 5 Rotation information (rotation direction / rotation amount / rotation speed) of the bearing portion 11 at which the torque value is equal to or less than the reference value is calculated. (Step S4)
Subsequently, the drive mechanism 15 is driven so as to cancel the torque generated in the mooring line 5 based on the calculated rotation information (rotation direction / rotation amount / rotation speed) of the bearing unit 11. (Step S5)
According to the control method of the floating wind power generation system of the present embodiment, the drive mechanism 15 can be driven so as to cancel the torque generated in the mooring line 5, and the twisting of the mooring line 5 and the entanglement of the transmission line 6 can be prevented. Can do. Thereby, the more stable power generation operation of the floating wind power generation system becomes possible.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Nacelle, 3 ... Tower, 4 ... Floating body, 5 ... Mooring line, 6 ... Power transmission line, 7 ... Anchor, 8 ... Seabed, 10 ... Power converter, 11 ... Bearing part, 12 ... Radial thrust Bearings, 12a ... outer ring, 12b ... inner ring, 13 ... power transmission mechanism, 14 ... slip ring, 15 ... drive mechanism, 16 ... control device, 17 ... floating body direction detection mechanism, 18 ... torque detection mechanism.

Claims (14)

A rotor that converts wind energy into rotational energy;
A nacelle for rotatably supporting the rotor;
A tower that supports the nacelle;
A floating wind power generation system having a floating body moored to the sea floor by a mooring line and supporting the tower,
The mooring line and the floating body are coupled via a bearing so that the floating body is rotatable with respect to the mooring line,
A floating wind power generation system comprising a drive mechanism for generating torque in a rotational direction at the bearing. The floating wind power generation system according to claim 1,
The floating wind power generation system includes state detection means for detecting the state of the floating body,
The floating wind power generation system, wherein the drive mechanism is controlled based on the state of the floating body detected by the state detection means. The floating wind power generation system according to claim 2,
The state detection means is any one of a gyroscope or a compass magnet that detects the state of the floating body with respect to the earth axis, a sonar that detects the state of the floating body from the shape of the seabed, and a GPS that detects the state of the floating body. Floating wind power generation system. The floating wind power generation system according to claim 1,
Comprising torque detecting means for detecting torque acting on the mooring line or the bearing;
The floating wind power generation system, wherein the drive mechanism is controlled based on a torque value detected by the torque detection means. The floating wind power generation system according to claim 4,
The floating wind power generation system according to claim 1, wherein the torque detection means is a strain gauge. A floating wind power generation system according to any one of claims 1 to 5,
A floating wind power generation system characterized in that a torque in a rotational direction is generated in the bearing by the drive mechanism so as to cancel torque generated in the mooring line or the bearing. A floating wind power generation system according to any one of claims 1 to 6,
The floating wind power generation system is a downwind system. Detecting the state of the floating body or the torque value generated in the mooring line mooring the floating body to the seabed;
When the detected state of the floating body or the torque value of the mooring line is equal to or greater than a predetermined value, torque in the rotational direction is generated on a bearing provided at a connection portion between the floating body and the mooring line. A control method for a floating wind power generation system. A control method for a floating wind power generation system according to claim 8,
A control method for a floating wind power generation system, wherein a torque value generated in the bearing is calculated based on the detected state of the floating body or the torque value of the mooring line. A control method for a floating wind power generation system according to claim 9,
The state of the floating body is detected by any one of a gyroscope or a compass magnet that detects the state of the floating body with respect to the earth axis, a sonar that detects the state of the floating body from the shape of the seabed, and a GPS that detects the state of the floating body. A control method for a floating wind power generation system. A control method for a floating wind power generation system according to claim 8,
A control method for a floating wind power generation system, wherein a torque value to be generated in the bearing is calculated based on the detected torque value of the mooring line. It is a control method of the floating type wind power generation system according to claim 11,
A control method for a floating wind power generation system, wherein a torque value of the mooring line is detected by a strain gauge. A method for controlling a floating wind power generation system according to any one of claims 8 to 12,
A control method for a floating wind power generation system, wherein torque in a rotational direction is generated in the bearing so as to cancel torque generated in the mooring line or the bearing. It is a control method of the floating type wind power generation system according to any one of claims 8 to 13,
The method of controlling a floating wind power generation system, wherein the floating wind power generation system is a downwind system.

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