JP2019019733A - Floating body type offshore wind power generator - Google Patents

Abstract

To suppress negative damping occurring by, for example, wave, and also compositely utilize wind power and wave energy.SOLUTION: A floating body type offshore power generation facility 100 comprises a rotor 106 rotating with wind, a nacelle 104 storing at least a rotational shaft of the rotor 106, and a tower-like floating structure 102 supporting the rotor 106 and the nacelle 104 and floating on water. The floating structure 102 includes an upper floating structure 102a and a lower floating structure 102b, which are energized by energization means so that they are in a reference state, and comprises oscillation power generation means 110 configured to generate power with relative oscillation between the upper floating structure 102a and the lower floating structure 102b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a floating offshore wind power generation facility.

  The wind power generation facility is installed in a place with good wind conditions (wind blowing). In particular, the offshore where there are no high structures around is suitable as a place where wind power generation facilities are provided. Thus, a floating wind power generation facility has been proposed in which a floating structure is provided and power is generated in a state where the blades and the power generation device are floated on water.

  In floating offshore wind power generation facilities, the floating structure may be tilted by waves. At this time, when the blade (blade) is inclined to the windward, the relative wind speed with respect to the blade is increased, and the rotational speed of the rotor of the generator is increased. In a wind power generation facility, since it is desired to maintain the power generation amount constant over time, in order to keep the rotor rotational speed constant, control is performed to adjust the blade pitch and reduce the rotational speed. If it does so, the resistance of the wind with respect to a braid | blade will become small, and also a floating body structure will incline to the windward. On the other hand, if the blade tilts leeward, the wind speed relative to the blade will decrease, and the rotational speed of the rotor of the generator will decrease, so the blade pitch should be adjusted to keep the rotor rotational speed constant. To increase the rotation speed. If it does so, the resistance of the wind with respect to a braid | blade will become large, and also a floating body structure will incline leeward. Such a phenomenon is called negative damping.

  Such negative damping may interfere with stable power generation in a floating offshore wind power generation facility. Therefore, techniques for suppressing negative damping have been developed and disclosed.

  Based on the number of rotations of the rotor shaft of the generator provided in the wind turbine provided at the tip of the floating structure or the tower installed on the sea floor, the pitch angle basic control including PI calculation is performed on the blade pitch angle of the wind turbine, In the correction control unit, a technique for correcting the pitch angle basic control based on the output of the generator, the swing of the wind turbine, and the like is disclosed (Patent Document 1). Further, a wind turbine generator is disclosed that includes active vibration damping means for generating a thrust force in a wind turbine blade that cancels the nacelle vibration based on the acceleration of the nacelle vibration (Patent Document 2).

JP 2014-111924 A Japanese Patent No. 4599350

  By the way, in the technology for suppressing negative damping, it is desired to use energy for power generation more effectively. However, in the prior art, negative damping is suppressed and energy of wind power and wave power cannot be effectively used in combination.

  A floating offshore wind power generation facility corresponding to claim 1 includes a rotor that rotates by wind, a nacelle that accommodates at least a rotating shaft of the rotor, and a tower-like floating structure that floats on water that supports the rotor and the nacelle. A floating offshore wind power generation facility, wherein the floating structure includes an upper floating structure and a lower floating structure that are biased by biasing means so as to be in a reference state, and the upper floating body A oscillating power generation means for generating power by relative oscillating motion of the structure and the lower floating structure is provided.

  Here, it is preferable that power is generated by a bending motion of the upper floating structure and the lower floating structure as the relative swinging motion. However, the present invention is not limited to this, and it is only necessary to use a relative motion between the upper floating structure and the lower floating structure, and the expansion and contraction motion of the upper floating structure and the lower floating structure. Alternatively, power generation may be performed by twisting motion.

  Further, it is preferable that the upper floating structure and the lower floating structure are connected by a universal joint that allows pitching motion and rolling motion.

  Further, it is preferable that the biasing means is a spring means for biasing the upper floating structure and the lower floating structure in the vertical direction. However, the urging means is not limited to this, and the urging means may be one that obtains an urging force by hydraulic pressure or air pressure, or an elastic body such as rubber.

  Further, it is preferable that the oscillating power generation means is a piezoelectric element generator pressed by the urging means. However, the present invention is not limited to this, and a generator using hydraulic pressure or air pressure or a generator using electromagnetic interaction between coils and magnets may be used.

A plurality of the oscillating power generation means, and any one of the plurality of oscillating power generation means generates power by a relative oscillating motion of the upper floating structure and the lower floating structure; Is preferred. In addition, it is preferable that the plurality of oscillating power generation means be arranged so that power generation can be performed in any direction with respect to the direction in which the oscillating motion is assumed.

  In addition, it is preferable that a power storage unit that stores power generated by the oscillating power generation unit is provided, and power is supplied to the load via the power storage unit. In addition, it is preferable that a storage voltage adjusting unit that adjusts a storage voltage between the oscillating power generation unit and the storage unit is provided. In addition, it is preferable that power conversion means for converting power between the power storage means and the load is provided.

  The power storage means can be used as a capacitor, a storage battery, or a combination thereof according to the load fluctuation of the target load. The storage voltage adjusting means preferably includes parts and circuits necessary for power storage such as a diode and a booster, and is individually provided corresponding to a plurality of oscillation power generation means. Moreover, an inverter, a DC / DC converter, etc. can be used for a power conversion means according to load.

  In addition, it is preferable that a mooring means for mooring the floating structure is provided. For example, it is preferable that the mooring means moor the lower floating structure by a mooring line, and the mooring line is locked to an anchor means on the bottom of the water. The mooring means is preferably anchored by locking the lower part of the lower floating structure in order to promote relative swinging motion of the upper floating structure and the lower floating structure.

  According to the floating offshore wind power generation facility corresponding to claim 1, a rotor that rotates by wind, a nacelle that accommodates at least the rotating shaft of the rotor, and a tower-like floating body that floats on water that supports the rotor and the nacelle A floating offshore wind power generation facility including a structure, the floating structure including an upper floating structure and a lower floating structure that are biased by biasing means so as to be in a reference state with each other, By providing an oscillating power generation means for generating electric power by the relative oscillating motion of the upper floating structure and the lower floating structure, the oscillation that results in negative damping caused by waves or the like can be converted into electrical energy. Moreover, by converting the kinetic energy of the swing into electric energy, the swing can be suppressed using the resistance during power generation as a braking force. That is, the oscillating power generation means can perform both the power generation function and the positive damping function.

  Here, as the relative oscillating motion, it is possible to effectively utilize the bending motion of the floating structure by negative damping by performing power generation by the bending motion of the upper floating structure and the lower floating structure. it can.

  In addition, the mooring means is a universal joint that allows pitching motion and rolling motion between the upper floating structure and the lower floating structure, thereby allowing waves from various directions to trigger negative damping. The motion can be converted into a bending motion as a pitching motion and a rolling motion between the upper floating structure and the lower floating structure, and the kinetic energy can be converted into electric energy for use.

  Further, the biasing means is a spring means for biasing the upper floating structure and the lower floating structure in the vertical direction, for example, by swinging motion of the upper floating structure and the lower floating structure. It is possible to bring about an effect of restoring the bending to the reference state.

  Further, the oscillating power generation means is a piezoelectric element generator that is pressed by the biasing means, thereby efficiently converting the pressure generated between the upper floating structure and the lower floating structure into electric power. And the damping function of the piezoelectric element generator can be utilized.

  A plurality of the oscillating power generation means, and any one of the plurality of oscillating power generation means generates power by a relative oscillating motion of the upper floating structure and the lower floating structure; Thus, the kinetic energy of swinging in various directions can be effectively converted into electric energy.

  In addition, power storage means for storing the power generated by the oscillating power generation means is provided, and by supplying power to the load via the power storage means, the power can be stored and used effectively. In addition, by storing a storage voltage adjusting unit that adjusts a storage voltage between the swing power generation unit and the power storage unit, the voltage between the swing power generation unit and the power storage unit is appropriately adjusted and stored. Can do. Further, by providing power conversion means for converting power between the power storage means and the load, power can be appropriately supplied from the power storage means to the load.

  Further, by providing mooring means for mooring the floating structure, the position of the floating offshore wind power generation facility on the ocean can be fixed, and the relative rocking motion can be promoted within an appropriate range.

It is a figure which shows the structure of the floating body type offshore wind power generation facility in embodiment of this invention. It is a figure which shows the structural example of the rocking | swiveling electric power generation means in embodiment of this invention. It is a figure which shows the functional block of the rocking | fluctuation electric power generation means in embodiment of this invention. It is a figure which shows the example of arrangement | positioning of the piezoelectric element in embodiment of this invention.

  As shown in FIG. 1, the floating offshore wind power generation facility 100 according to the embodiment of the present invention includes a floating structure 102, a nacelle 104, a rotor 106, mooring means 108, and an oscillating power generation means 110.

  The floating structure 102 is a tower-shaped structure for floating the structure of the floating offshore wind power generation facility 100 on the water (offshore). The floating structure 102 is configured to hold the nacelle 104 and the rotor 106 in a state of floating on the water. The floating structure 102 can be configured by combining, for example, a columnar upper floating structure 102a and a lower floating structure 102b. The upper floating body structure 102a and the lower floating body structure 102b may be hollow so that a power supply circuit board or the like is accommodated therein.

  The nacelle 104 is a structure that houses the speed increaser, the generator, and the control unit. The nacelle 104 is installed at the tip of the columnar upper floating structure 102a so as to be rotatable with respect to the axis of the upper floating structure 102a. The nacelle 104 includes a rotor 106 and rotates the rotor 106 based on the measurement result of the wind direction by the anemometer so that the blade rotates in a direction corresponding to the wind direction.

  The blades constituting the rotor 106 are blades that receive wind at the floating offshore wind power generation facility 100 and convert the wind force into a rotational force with respect to the rotor axis (rotation axis) of the rotor 106. In the floating offshore wind power generation facility 100, for example, three blades are arranged at an equal angle around the rotor shaft of the generator arranged in the nacelle 104. The blade is made of an insulator such as glass fiber reinforced plastic stitch (GFRP). The blade may have a hollow structure in order to reduce the weight. The rotational force obtained by the blades is transmitted to the rotor shaft of the generator via a speed increaser arranged in the nacelle 104, and the rotor 106 of the generator is rotated by the rotational force to generate power. The generated electric power is output to the outside of the floating offshore wind power generation facility 100.

  The mooring means 108 is means for mooring the floating structure 102 at a desired position. The mooring means 108 includes a mooring line 108a having one end attached to the lower end of the lower floating structure 102b, and anchor means (weight) 108b attached to the other end of the mooring line and placed on the bottom of the water. Is done. The mooring means 108 engages and anchors the lower part including the lower end part of the lower floating structure 102b in order to promote the relative swinging motion of the upper floating structure 102a and the lower floating structure 102b. Is preferred. The mooring means 108 not only anchors the floating body structure 102 at a predetermined position on the ocean, but also rotates and swings with respect to the axis of the floating body structure 102 (yaw motion: Z axis in FIG. 1 (axial direction of the floating body structure 102)). It functions to suppress the surrounding rotational movement).

  The oscillating power generation means 110 is a means for generating power based on the relative peristaltic mobility of the upper floating structure 102a and the lower floating structure 102b. As shown in the conceptual diagram of FIG. 2, the oscillating power generation means 110 is provided so as to be sandwiched between the upper floating structure 102a and the lower floating structure 102b, and the upper floating structure 102a and the lower floating structure 102a are Means for converting energy associated with the swinging operability when the floating structure 102b swings relative to the power into electric power is included.

  The oscillating power generation means 110 can include the universal joint 10, the elastic body 12, the pedestal 14, the power generation means 16 and the cover 18.

  The universal joint 10 is a member that connects the upper floating body structure 102a and the lower floating body structure 102b so that the pitching motion and the rolling motion can be relatively performed. The pitching motion and the rolling motion are rotational motions about axes (X axis, Y axis) orthogonal to the axis (Z axis) of the floating structure 102. Specifically, the pitching motion is a rotational motion around the X axis in FIG. 1, and the rolling motion is a rotational motion around the Y axis in FIG. By connecting the upper floating structure 102a and the lower floating structure 102b by the universal joint 10, the upper floating structure 102a and the lower floating structure 102b can be relatively bent by a wave or the like. The universal joint 10 can be used regardless of the type as long as the universal joint 10 can relatively perform pitching motion and rolling motion.

  The elastic body 12 is a member that is disposed between the upper floating body structure 102a and the lower floating body structure 102b and biases the upper floating body structure 102a and the lower floating body structure 102b so as to be in a reference state. When the universal joint 10 is biased by the elastic body 12 so that the upper floating structure 102a and the lower floating structure 102b are in the reference state, the upper floating structure 102a and the lower floating structure 102b can swing freely. It also serves as a locking means that is locked to the frame. The elastic body 12 can be comprised by elastic members, such as a spring and rubber | gum, for example. In the present embodiment, in the reference state, the columnar upper floating structure 102a and the lower floating structure 102b are upright, that is, the central axes of the upper floating structure 102a and the lower floating structure 102b are coaxially positioned. State. In this case, the elastic body 12 may urge the upper floating structure 102a and the lower floating structure 102b in the vertical direction (Z-axis direction). However, the reference state is not limited to this. For example, the rotor shaft in a state not receiving wind is in a horizontal plane so that the rotor shaft in a state tilted by wind is parallel to the wind direction. On the other hand, the upper floating structure 102a and the lower floating structure 102b show in a state where no external force is applied to the floating offshore wind power generation facility 100, such as supporting the nacelle 104 on the upper floating structure 102a with a predetermined angle. The posture is assumed.

  The pedestal 14 is a member that is sandwiched between the elastic body 12 and a power generation means 16 described later. The pedestal 14 is provided so that pressure is appropriately applied from the elastic body 12 to the power generation means 16. For example, when the power generation means 16 includes a piezoelectric element (piezo element), it is preferable that the plate-like base 14 has rigidity so that pressure is uniformly applied from the elastic body 12 to the piezoelectric element.

  The power generation means 16 is a means for generating electric power according to the swinging motion between the upper floating structure 102a and the lower floating structure 102b. In the present embodiment, the power generation means 16 is a piezoelectric element generator. As shown in the functional block diagram of FIG. 3, the power generation means 16 includes a piezoelectric element (piezo elements) 20 (20a to 20d), a voltage regulator 22, a battery 24, a power converter 26, and a power generation control means 28. Is done. The power generation means 16 is connected to the load 30 and supplies the generated power to the load 30. The load 30 may be outside the floating offshore wind power generation facility 100, or may be an auxiliary machine inside the floating offshore wind power generation facility 100. The power generation means 16 has a damping function in addition to a power generation function based on a relative swinging motion, and can perform both functions of a positive damping function that resists swinging due to negative damping caused by waves or the like. .

  The piezoelectric element (piezo element) 20 is an element that converts a pressing force applied to a piezoelectric body into a voltage. The piezoelectric element 20 can be configured by sandwiching a piezoelectric material such as crystal or ceramic between electrodes. The voltage generated by the piezoelectric element 20 is input to the voltage regulator 22. The piezoelectric element (piezo element) 20 is preferably a laminated piezoelectric element in terms of stress, displacement, and electromechanical conversion efficiency. Further, the piezoelectric element (piezo element) 20 has a hysteresis, and therefore can perform a positive damping function in addition to the power generation function.

  In the present embodiment, as shown in FIG. 4, the upper floating structure 102a and the lower floating structure 102a and the lower floating structure 102b can generate power when they are pitched or rolled in various directions. An example in which four piezoelectric elements 20 (20a to 20d) are arranged between the lower floating body structure 102b will be described. In this example, the piezoelectric elements 20 are arranged at equiangular intervals (90 ° intervals). Accordingly, the elastic body 12 and the base 14 are provided for each piezoelectric element 20. As a result, one of the piezoelectric elements 20 generates electric power with the relative swinging motion of the upper floating structure 102a and the lower floating structure 102b.

  However, the shape and arrangement of the piezoelectric element 20 are not limited to this, and the arrangement may be such that the swinging of the upper floating structure 102a and the lower floating structure 102b can be effectively used for power generation. For example, the piezoelectric element 20 may be arranged so as to cover the piezoelectric element 20 in a region between the upper floating structure 102a and the lower floating structure 102b. In order to spread closely, it is easier to spread with a shape based on a square or a triangle.

  The voltage regulator 22 is controlled by the control from the power generation control means 28, a diode that prevents the backflow of power generated by the piezoelectric element 20, and a storage voltage adjustment means that steps up and down the input voltage and outputs it to the battery 24. including. The voltage generated by the piezoelectric elements 20a to 20d differs in voltage state depending on the direction and timing of relative swing motion, and it is preferable to provide a diode and a voltage regulator 22 individually.

  The voltage regulator 22 can be configured to include a DC / DC converter. When a plurality of piezoelectric elements 20 are provided, the voltage is adjusted so that each output voltage matches the terminal voltage of the battery 24.

  The battery 24 is a power storage unit that stores the power generated by the piezoelectric element 20. The power storage means can be composed of a general secondary battery, a capacitor, or the like. The terminal voltage and battery capacity (SOC) of the battery 24 are input to the power generation control means 28 and used for controlling the voltage regulator 22 and the power converter 26. The voltage adjustment status of the voltage regulator 22, the storage status of the battery 24, and the conversion status of the power converter 26 are transmitted to the power generation control means 28, and are used for control of the power generation control means 28. . It is also possible to transmit information on the load 30 to the power generation control means 28 for use in control.

  The power converter 26 includes power conversion means for outputting the power supplied from the battery 24 in a manner corresponding to the load 30. The power converter 26 converts the voltage, current, frequency, phase, number of phases, and the like of the output voltage of the battery 24 according to the load 30 and outputs the converted voltage. For example, if the load 30 is an AC load, the power converter 26 includes an inverter circuit that converts DC power output from the battery 24 into AC power having a desired voltage, current, frequency, phase, and number of phases. The power converter 26 may include a DC / DC converter that steps up and down the output voltage of the battery 24.

  The power generation control unit 28 controls the voltage regulator 22 and the power converter 26. The power generation control means 28 controls the voltage regulator 22 in accordance with the terminal voltage of the battery 24 to increase / decrease the output voltage from the piezoelectric element 20. Further, the power generation control unit 28 controls the power converter 26 according to the terminal voltage of the battery 24, the SOC, and the required power of the load 30 to adjust the power from the battery 24 to the load 30.

  As shown in FIG. 3, the power generation control unit 28 may be configured to control the power generation setting unit 32 of the floating offshore wind power generation facility 100. The power generation setting unit 32 controls power generation by adjusting the characteristics of the generator installed in the nacelle 104. Since this control is the same as the conventional control, it is not particularly mentioned here.

  The cover 18 is a member that covers the piezoelectric element 20, the voltage regulator 22, the battery 24, the power converter 26, and the power generation control means 28 that are disposed between the upper floating structure 102 a and the lower floating structure 102 b. Since the connection part of the upper floating structure 102a and the lower floating structure 102b is located in water, it is preferable that the cover 18 has a configuration that prevents these members from getting wet. In addition, the upper floating structure 102a and the lower floating structure 102b need to be able to swing relative to each other, so that the structure is flexible.

  In addition, when the floating offshore wind power generation facility 100 is installed in the water area, from the viewpoint of relative swinging motion, the buoyancy adjustment may be performed so that the water surface comes to an intermediate position of the upper floating structure 102a. Most preferred is a position of ± 10% of the middle position, more preferred is a position of ± 20% of the middle position. Further, it is preferable that some tension is applied to the mooring means 108 due to the buoyancy of the lower floating structure 102b during mooring, and the buoyancy of the upper floating structure 102a is balanced with this to obtain the position of the water surface. It is preferable to set to.

  Further, the power generation means 16 is not limited to the piezoelectric element generator, and any power generation means may be used as long as it can generate power by relative swinging of the upper floating structure 102a and the lower floating structure 102b. For example, a configuration in which the relative swinging of the upper floating structure 102a and the lower floating structure 102b is converted into the relative movement of the coil and the magnet, and electric power is generated by electromagnetic interaction between the coil and the magnet. It is good.

  Further, the biasing means is configured to obtain a biasing force by hydraulic pressure or air pressure, and the relative swing motion is converted into hydraulic pressure or air pressure, and the power generation is performed by the swing power generation means using the hydraulic pressure or air pressure. Also good.

  Even in these cases, the power generation means 16 has a damping function by the power generation means 16 itself in addition to the power generation function by the relative swinging motion, and can perform a positive damping function to counter negative damping caused by waves or the like. it can.

  As described above, according to the floating offshore wind power generation facility 100 according to the present embodiment, it is possible to generate electric power while suppressing negative damping and converting fluctuations resulting from waves or the like to negative damping into electrical energy. . Further, the oscillation can be suppressed by using, as a damping element, the resistance during power generation when converting the kinetic energy of the oscillation into electric energy.

  In other words, the floating offshore wind power generation facility 100 enables simple speed constant control of the rotor 106 using blades as actuators, and fluctuations in the speed of the rotor 106 are suppressed. Even if negative damping is excited, the oscillating power generation means 110 By absorbing, the total power generation amount increases.

  As described above, the floating offshore wind power generation facility 100 can use wind power and wave energy in combination.

  In a floating offshore wind power generation facility having a maximum height of 96 m from the water surface, a floating structure diameter of 4.8 m, a rotor diameter of 80 m, and a rated output of 2 MW, a piezoelectric element (piezo element) 20 is used and an inclination speed of 1 is used. It is estimated that an electric power of 0.9 MW can be obtained by bending / oscillating power generation at degrees / second.

  The present invention can be applied to various types of floating offshore wind power generation facilities. For example, the floating body structure is not limited to a columnar shape, and can be applied to a floating body structure of any aspect having a swinging portion.

  DESCRIPTION OF SYMBOLS 10 Universal joint, 12 Elastic body, 14 Base, 16 Power generation means, 18 Cover, 20 Piezoelectric element, 22 Voltage regulator, 24 Battery, 26 Power converter, 28 Power generation control means, 30 Load, 32 Power generation setting means, 100 Floating body Offshore wind power generation facility, 102 floating body structure, 102a upper floating body structure, 102b lower floating body structure, 104 nacelle, 106 rotor, 108 mooring means, 108a mooring line, 108b weight, 110 rocking power generation means.

Claims (11)

A rotor rotating by wind,
A nacelle that houses at least the rotating shaft of the rotor;
A floating offshore wind power generation facility provided with a tower-like floating structure floating in water supporting the rotor and the nacelle,
The floating structure includes an upper floating structure and a lower floating structure that are biased by biasing means so as to be in a reference state with each other,
A floating offshore wind power generation facility, characterized by comprising oscillating power generation means for generating power by a relative oscillating motion of the upper floating structure and the lower floating structure. The floating offshore wind power generation facility according to claim 1,
A floating offshore wind power generation facility characterized in that power generation is performed by a bending motion of the upper floating structure and the lower floating structure as a relative swinging motion. The floating offshore wind power generation facility according to claim 1 or 2,
A floating offshore wind power generation facility characterized in that the upper floating structure and the lower floating structure are connected by a universal joint that allows pitching motion and rolling motion. The floating offshore wind power generation facility according to any one of claims 1 to 3,
The floating offshore wind power generation facility, wherein the biasing means is a spring means for biasing the upper floating structure and the lower floating structure in the vertical direction. The floating offshore wind power generation facility according to any one of claims 1 to 4,
The floating offshore wind power generation facility, wherein the oscillating power generation means is a piezoelectric element generator pressed by the urging means. A floating offshore wind power generation facility according to any one of claims 1 to 5,
A plurality of the oscillating power generation means,
A floating offshore wind power generation facility, wherein any one of the plurality of swing power generation means generates power by relative swinging motion of the upper floating structure and the lower floating structure. The floating offshore wind power generation facility according to any one of claims 1 to 6,
A power storage means for storing the generated power of the swing power generation means;
A floating offshore wind power generation facility characterized in that power is supplied to a load via the power storage means. The floating offshore wind power generation facility according to claim 7,
A floating offshore wind power generation facility comprising storage voltage adjustment means for adjusting a storage voltage between the oscillating power generation means and the power storage means. The floating offshore wind power generation facility according to claim 7 or 8,
A floating offshore wind power generation facility comprising power conversion means for converting electric power between the power storage means and the load. A floating offshore wind power generation facility according to any one of claims 1 to 9,
A floating offshore wind power generation facility comprising mooring means for mooring the floating structure. The floating offshore wind power generation facility according to claim 10,
The mooring means mooring the lower floating structure by a mooring line,
The floating offshore wind power generation facility, wherein the mooring line is locked to an anchor means at the bottom of the water.

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