JP2013181433A - Wave power generation apparatus and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave power generation apparatus with which a larger power generation output than a conventional movable body type can be obtained, and which has a larger design flexibility, and can reduce power generating cost.SOLUTION: A wave power generation apparatus includes: a floating body 2 oscillated by wave; a ball screw shaft nut 16 and a ball screw shaft 24, which are a conversion mechanism for converting a relative displacement between a large structure 5 having less oscillation than the floating body 2 generated by wave, or no oscillation, into a rotational movement; a ball screw shaft 24 rotated by a rotational force taken out via the conversion mechanism; and a power generation machine unit 8 driven by the ball screw shaft 24 and generating power.

Description

  The present invention relates to a wave power generator and a control method thereof.

  As a wave power generation device, one that drives a generator by moving two objects relative to each other in the vertical direction is known. For example, Patent Document 1 discloses a wave power generation apparatus in which a vibrator is supported in a hermetically sealed buoy floating on the sea so as to be displaceable in the vertical direction via a spring. This wave power generation device extracts electrical energy from the relative kinetic energy between a buoy that vibrates due to a wave and a vibrator that vibrates in the buoy.

JP 2007-297929 A

However, the wave power generation device described in Patent Document 1 uses relative displacement between a buoy that vibrates due to waves and a vibrator that vibrates naturally, and does not directly use wave input energy for power generation. Therefore, it is disadvantageous when trying to obtain a large power generation output.
Further, in order to obtain the natural vibration of the vibrator, it is required to make the spring constant very small with respect to the load, and there is a problem that the degree of freedom in design is small.
In addition, mooring equipment is required to install floating bodies such as buoys on the sea, and power transmission equipment for transmitting generated power is also required. The cost of these mooring facilities and power transmission facilities accounted for a large proportion of the power generation cost, which hindered the reduction of power generation cost.

  The present invention has been made in view of such circumstances, and can obtain a large power generation output as compared with the conventional movable object type, has a high degree of design freedom, and can reduce power generation costs. An object of the present invention is to provide a simple wave power generator and a control method thereof.

In order to solve the above problems, the wave power generation apparatus and the control method thereof according to the present invention employ the following means.
That is, the wave power generation device according to the present invention converts a relative displacement between a floating structure that is shaken by a wave and a large structure that is less or less shaken by the wave than the floating structure into a rotational motion. And a rotating shaft body that is rotated by a rotational force extracted through the converting mechanism, and a generator unit that is driven by the rotating shaft body to generate electric power.

The relative displacement between the floating structure and the large structure was converted into rotational motion, and power was generated using the rotational motion. In this way, the relative displacement between the floating structure and the large structure can be used directly for power generation, so when using the natural vibration of the vibrator that vibrates relatively in the buoy as in the prior art. In comparison, a large output can be obtained. Further, since it is not necessary to use a spring for obtaining the natural vibration of the vibrator, the degree of freedom in design is increased, the structure can be increased in size, and the output can be further increased.
Further, since the wave power generation device can be provided for the large structure, the large structure can share the mooring facility and the power transmission facility, and the power generation cost can be reduced.
In addition, as a large structure of the present invention, a marine structure such as an offshore windmill, a ship, and the like are exemplified as those having small fluctuations by waves, and a coastal facility such as a breakwater is exemplified as those having no fluctuations caused by waves. .
Further, as the conversion mechanism of the present invention, for example, a ball screw method or a rack and pinion method is adopted.

  Furthermore, in the wave power generation device of the present invention, the generator unit includes a hydraulic pump driven by the rotating shaft body, an accumulator that accumulates oil boosted by the hydraulic pump, and oil guided from the accumulator. A hydraulic motor to be driven and a generator that is driven by the hydraulic motor to generate electric power are provided.

In the actual sea area, waves with various cycles synthesized arrive at the floating structure. Even in a wave with various cycles combined, the hydraulic pressure boosted by the hydraulic pump is accumulated in the accumulator, so that energy can be efficiently recovered as the hydraulic pressure.
In addition, since the energy is stored in the accumulator as hydraulic pressure, even if the displacement between the floating structure and the large structure cannot be increased, the hydraulic motor can be set to the desired value as long as the desired pressure accumulation amount is obtained. The speed can be changed, and a desired power generation amount can be obtained.

  Further, in the wave power generation device of the present invention, an additional mass adjusting means for adjusting a rotational inertia additional mass with respect to the rotary shaft body by a rotary inertia force generated by rotating the additional mass body by the rotary shaft body, and / or And a retained water amount adjusting means for adjusting the retained water amount in the floating structure.

By adjusting the rotational inertia additional mass by the additional mass body, the natural period of the floating structure can be matched with the wave period of the actual sea area. Thereby, the relative displacement between the floating structure and the large structure is increased, and a larger power generation output can be obtained.
Or the natural period of a floating body can be matched with the wave period of a real sea area by adjusting the amount of water held in the floating structure. Thereby, the relative displacement between the floating structure and the large structure is increased, and a larger power generation output can be obtained.

  Furthermore, in the wave power generation device of the present invention, a wave meter that is installed in the large structure and measures in advance a wave arriving at the floating structure, and the additional mass adjustment based on the measurement result of the wave meter And / or a control unit for controlling the retained water amount adjusting means.

A large structure has little or no fluctuation relative to a floating structure, and therefore accurate measurement can be performed by installing a wave meter.
And, the wave coming to the floating structure is measured in advance by this wave meter, and the additional mass adjusting means and / or the retained water amount adjusting means are controlled based on the measurement result. The wave power generator can be operated.

  Furthermore, in the wave power generation device of the present invention, the control unit calculates a significant wave height from the measurement result of the wave meter, and based on the fluctuation of the significant wave period, the additional mass adjusting means, and / or Alternatively, the holding water amount adjusting means is controlled.

The rotational inertia added mass and / or the amount of water retained in the floating structure were adjusted to the fluctuation of the period of the significant wave that greatly contributes to the fluctuation of the floating structure. Thereby, the natural period of a floating body can be adjusted efficiently with respect to the effective component of the incoming wave.
Here, “significant wave” means that when a wave incident within a predetermined time is analyzed according to the wave height, the value of the maximum wave height is equally divided into n, and the wave height is within a range of 1 / n. It means the wave that is the average value of the wave height to enter. The n is generally 3 or 10, but the wave component varies depending on the sea area or season in which the apparatus is installed, and other than 3 and 10 may be applied.

  Furthermore, the wave power generation device of the present invention includes the above-described generator unit, and the control unit controls a set pressure of the accumulator based on a change in the significant wave.

  By controlling the set pressure of the accumulator based on the fluctuation of the significant wave height, the swing amplitude of the floating body can be suppressed within the movable range of the apparatus. As a result, even when the wave height of the significant wave increases, it is possible to suppress the oscillation amplitude of the floating body within the movable range and to effectively recover energy.

  Further, the control method of the wave power generation device of the present invention includes a floating structure that is shaken by a wave, and a large structure that is larger than the floating structure and has less fluctuation or no fluctuation than the floating structure. A conversion mechanism that converts relative displacement between the object and the object into a rotational motion, a rotating shaft that rotates by a rotational force extracted through the converting mechanism, and a generator unit that is driven by the rotating shaft and generates power A method of controlling a wave power generation apparatus comprising: a rotary inertial force generated by rotating an additional mass body by the rotary shaft body, and / or adjusting a rotary inertia additional mass with respect to the rotary shaft body, and / or The amount of retained water in the floating structure is adjusted.

By adjusting the rotational inertia additional mass by the additional mass body, the natural period of the floating structure can be matched with the wave period of the actual sea area. Thereby, the relative displacement between the floating structure and the large structure is increased, and a larger power generation output can be obtained.
Or the natural period of a floating body can be matched with the wave period of a real sea area by adjusting the amount of water held in the floating structure. Thereby, the relative displacement between the floating structure and the large structure is increased, and a larger power generation output can be obtained.

  Since the relative displacement between the floating structure and the large structure is converted into rotational motion and power is generated using the rotational motion, the relative displacement between the floating structure and the large structure is used for power generation. Compared to the case of using the natural vibration of the vibrator that vibrates relatively in the buoy as in the prior art, a large output can be obtained. Further, since it is not necessary to use a spring for obtaining the natural vibration of the vibrator, the degree of freedom in design is increased, the structure can be increased in size, and the output can be further increased.

It is the figure which showed notionally one Embodiment concerning the wave power generator of this invention. It is the schematic which showed the dynamic model of the wave power generator shown in FIG. It is the longitudinal cross-sectional view which showed the specific structure of the wave power generator shown in FIG. It is the top view which showed the structure which adjusts the rotation inertia additional mass of the rotary body of FIG. It is the side view which showed the structure which provided the two rotary bodies of FIG. It is the front view which showed the modification which adjusts the radial position of a moving weight. It is the schematic block diagram which showed the electric power generation unit shown in FIG. It is the schematic longitudinal cross-sectional view which showed the structure which adjusts the water holding amount in the floating body shown in FIG. The wave power generation device made into the modification of FIG. 3 is shown, (a) is a longitudinal cross-sectional view, (b) is an enlarged view around a generator unit. It is the longitudinal cross-sectional view which showed the wave power generation device made into the further another modification of FIG. It is the schematic side view which showed the state which installed the wave power generator of FIG. 10 in the actual sea area. The process which decomposes | disassembles the wave of a real sea area by the control part of a wave power generator is shown, (a) shows the wave of a real sea area, (b) shows the wave which extracted the component of the significant wave. It is the flowchart which showed control of the wave power generator. It is the schematic side view which showed the modification of FIG.

FIG. 1 conceptually shows an embodiment of the wave power generation device of the present invention. As shown in FIG. 1, the wave power generation device 1 </ b> A includes a box-shaped floating body (floating structure) 2 that floats with its upper part exposed on the ocean water surface 7. A large structure 5 is installed in the vicinity of the floating body 2. Examples of the large structure 5 include a marine structure such as an offshore windmill, a ship, etc., as those with small fluctuations due to waves, and a coastal facility such as a breakwater, etc., as those without fluctuations due to waves.
Between the floating structure 2 and the large structure 5, a conversion mechanism 4 that converts the relative motion between the floating structure 2 and the large structure 5 into a rotational motion, and a rotational force extracted through the conversion mechanism 4. The rotating shaft body 6 rotated by the rotating shaft body 6, the rotating body (additional mass body) 9 rotated by the rotating shaft body 6, and the generator unit 8 that generates electric power by the rotational force of the rotating shaft body 6 are provided. The conversion mechanism 4 and the generator unit 8 are each displayed as a dynamic model, and the conversion mechanism 4 is shown as an attenuation element and the generator unit 8 is shown as an attenuation element.
In FIG. 2, the configuration of FIG. 1 is further shown as a dynamic model, and the relationship between the floating body 2 and seawater is indicated by a spring element 10.

FIG. 3 shows a specific configuration for realizing the dynamic model shown in FIGS. 1 and 2. As shown in the figure, the floating body 2 can hold seawater as retained water 11 therein. An outer guide cylinder 12 is fixed to the upper part of the floating body 2. An inner guide tube 14 fixed to the lower end of the large structure 5 is inserted into the outer guide tube 12 with substantially the same axis. Thus, the outer guide cylinder 12 and the inner guide cylinder 14 are relatively movable in the vertical direction with the relative movement of the floating body 2 and the large structure 5.
A fixed cylinder 18 for fixing the ball screw shaft nut 16 is provided further inside the outer guide cylinder 12 and the inner guide cylinder 14. The lower end of the fixed cylinder 18 is fixed to the upper surface of the floating body 2.
A bottom lid 20 is fixed to the lower end of the inner guide tube 14. The bottom lid 20 and the fixed cylinder 18 can move relative to each other.
A generator unit 8 is installed in the large structure 5. A ball screw shaft 24 extending in the vertical direction is provided between the generator unit 8 and the bottom lid 20. The ball screw shaft nut 16 described above is screwed into the ball screw shaft 24, and the ball screw shaft 24 and the ball screw shaft nut 16 constitute the conversion mechanism 4. That is, when a relative displacement occurs between the floating body 2 and the large structure 5, a relative displacement occurs in the vertical direction between the ball screw shaft 24 and the ball screw shaft nut 16, and the ball screw shaft nut 16 is moved to the fixed cylinder 18. The ball screw shaft 24 rotates around the axis because it is constrained so as not to rotate. The generator unit 8 is driven by the rotation of the ball screw shaft 24 to obtain a power generation output. Therefore, the ball screw shaft 24 also has the function of the rotating shaft body 6 shown in FIGS.

  The wave power generator 1A configured as described above rotates the ball screw shaft 24 when the ball screw shaft nut 16 moves relative to the ball screw shaft due to the relative displacement between the floating body 2 and the large structure 5. Electric power is generated by the generator unit 8 by the rotational power of the ball screw shaft 24. The natural period of the floating body 2 is adjusted by the rotational inertia added mass generated by the rotation of the rotating body 9 fixed to the ball screw shaft 24 together with the ball screw shaft 24.

FIG. 4 shows a configuration for adjusting the rotational inertia added mass by the rotating body 9. As shown in the figure, a ring body 26 having the same center of rotation as the ball screw shaft 24 and four ball screws shafts 28 for moving weights extending in the vertical and horizontal directions when viewed in plan as shown in FIG. And a moving weight 30 provided on each moving weight ball screw shaft 28 and a moving motor 32 for rotating the moving weight ball screw shaft 28 about its axis.
One end of the moving weight ball screw shaft 28 is fixed to the ball screw shaft 24, extends in the radial direction, passes through the ring body 26, and the other end is connected to the moving motor 32.
The moving weight 30 is displaced in the radial direction in accordance with the rotation of the moving weight ball screw shaft 28.
The moving motor 32 is driven based on a command from a control unit (not shown) and is fixed to the ring body 26.
In the rotating body 9, the ring body 26, the moving weight ball screw shaft 28, the moving weight 30 and the moving motor 32 rotate together with the ball screw shaft 24 in a state where the radial position of the moving weight 30 is determined by the moving motor 32. It is supposed to be. Therefore, the rotational inertia added mass due to the moment of inertia at the time of rotation of the rotating body 9 can be changed according to the radial position of the moving weight 30. Specifically, the moving weight 30 is moved in the radial direction. If it is located on the outer side (ring body 26 side), the center of gravity moves outward in the radial direction, the moment of inertia increases, and the rotational inertia added mass can be increased. If it is located on the 24th side), the moment of inertia is reduced by moving the center of gravity to the inside in the radial direction, and the rotational inertia added mass can be reduced.

  Further, as shown in FIG. 5, a plurality of large and small rotating bodies 9 may be provided. That is, a rotating body 9a having a small radius and a rotating body 9b having a large radius are provided. And as shown in FIG. 4, each rotary body 9a, 9b is equipped with the mechanism which can adjust a rotation inertia additional mass. As a result, the rotational inertia added mass can be finely adjusted by the rotating body 9a having a small radius, and the rotational inertia added mass can be adjusted largely by the rotating body 9b having a large radius. In this way, the natural period of the floating body 2 may be configured to be finely adjusted with a large adjustment width.

  Moreover, as shown in FIG. 6, the radial position of the movable weight 30 can also be adjusted by a link mechanism. Specifically, a fixed portion 34 that rotates together with the ball screw shaft 24, and a support slider 36 that reciprocates in the axial direction of the ball screw shaft 24 with respect to the fixed portion 34 to support an intermediate position of the arm 38 from below. An arm 38 that can swing is attached to the fixed portion 34 symmetrically, and a moving weight 30 is attached to the tip of each arm 38. With such a configuration, the radial position of the movable weight 30 can be adjusted by moving the support slider 36 forward and backward with respect to the fixed portion 34 by an actuator (not shown).

FIG. 7 shows the configuration of the generator unit 8 shown in FIG. The generator unit 8 includes a transmission 45 and a generator main body 46.
The transmission 45 includes a hydraulic pump 40 that is driven by the rotational force from the ball screw shaft 24, an accumulator 42 that guides and accumulates oil boosted by the hydraulic pump 40, and a hydraulic pressure that is driven by the oil guided from the accumulator 42. And a motor 44. The pressure in the accumulator 42 can be set by a control unit (not shown).
The generator body 46 generates electric power by the rotational force obtained from the hydraulic motor 44. The electric power obtained by the generator main body 46 is taken out to the outside as the electric power generated by the wave power generator 1A.
In this embodiment, the transmission is described on the premise of the above-described hydraulic type, but a mechanical transmission using a plurality of gears, planetary gears, or the like may be used instead.

FIG. 8 shows a configuration for adjusting the amount of retained water 11 in the floating body 2. As shown in the figure, a bottom valve 48 is provided at the bottom of the floating body 2. The bottom valve 48 is controlled to be opened and closed by a control unit (not shown), and is fully closed during normal operation (power generation) so that the amount of water retained in the floating body 2 is kept constant.
An air regulating valve 50 whose opening and closing is controlled by the control unit is provided on the upper part of the floating body 2. This air pressure adjusting valve 50 adjusts the pressure of air that occupies the upper space of the water surface 11 a in the floating body 2.
A submersible pump 52 whose operation is controlled by the control unit is installed at the bottom of the floating body 2. By starting the submersible pump 52 according to a command from the control unit, the retained water 11 is sucked and discharged to the outside.

When the floating body 2 is installed, the inside of the floating body 2 is left empty. When the floating body 2 is installed on the sea, the bottom valve 48 is fully opened and the air adjustment valve 50 is adjusted to a predetermined opening degree. Thereby, seawater is introduced into the floating body 2 from the bottom through the bottom valve 48. When the amount of seawater introduced into the floating body 2 reaches a predetermined value, the bottom valve 48 and the air adjustment valve 50 are fully closed by a command from the control unit. Even when the amount of the retained water 11 is adjusted after the floating body 2 is installed, the bottom valve 48 is fully opened and the opening degree of the air adjustment valve 50 is adjusted as described above.
When draining when adjusting the amount of retained water in the floating body 2, the air adjustment valve 50 is adjusted to a predetermined opening degree with the bottom valve 48 fully closed based on a command from the control unit, and the submersible pump 52 is started. Thereby, the retained water 11 sucked by the submersible pump 52 is discharged to the outside of the floating body 2, and the retained water level is lowered.
When draining the retained water 11 in the floating body 2, it is drained by lifting the entire floating body 2 to the sea level, fully opening the bottom valve 48 and adjusting the opening of the air adjustment valve 50. Good. In this case, when lifting the floating body 2 upward, the generator body 46 of the generator unit 8 shown in FIG. 7 is used as an electric motor, and the ball screw shaft 24 shown in FIG. 3 is rotated.

  FIG. 9 shows a modification of the wave power generation device 1 </ b> A of FIG. 3 that uses a ball screw system as a conversion mechanism that converts the vertical motion of the floating body 2 into rotational motion. The wave power generator 1B of FIG. 9 is a rack and pinion system. Here, the same components as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 9A, the wave power generation device 1 </ b> B includes a rack 60 fixed to the bottom cover 20 of the inner guide cylinder 14 fixed to the lower surface of the large structure 5. The rack 60 has a lower end fixed to the bottom lid 20 and extends upward, and meshes with the pinion 62 at the top. The rack 60 and the pinion 62 constitute a conversion mechanism 4 that converts the relative motion between the floating body 2 and the large structure 5 into a rotational motion.
The pinion 62 is installed in the large structure 5 and extends and rotates between the generator unit 8 and the shaft support bracket 64 as shown in FIG. 9B. The pinion shaft (rotary shaft body 6) 66 is fixed. As described with reference to FIG. 7, the transmission 45 and the generator main body 46 are disposed in the generator unit 8. A rotating body 9 is fixed to the pinion shaft 66, and an inertia added mass is given when rotating together with the pinion shaft 66. The rotating body 9 includes an additional mass changing mechanism as described with reference to FIG.

  The wave power generation device 1 </ b> B configured as described above rotates the pinion 62 when the rack 60 moves relative to the pinion 62 due to the relative displacement between the floating body 2 and the large structure 5, and the rotation of the pinion 62. Electric power is generated in the generator unit 8 by power. The natural period of the floating body 2 is adjusted by the rotational inertia added mass generated by the rotation of the rotating body 9 fixed to the pinion shaft 66 together with the pinion shaft 66.

  FIG. 10 shows a wave power generation device 1 </ b> C that is still another modified example, which is a rack and pinion system as in FIG. 9. Here, the same components as those in FIGS. 3 and 9 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 10, the wave power generation device 1 </ b> C includes a linear guide cylinder 68 fixed to the lower surface of the large structure 5. The upper end of the linear guide cylinder 68 is fixed to the lower surface of the large structure 5 and extends downward. A support column 70 is erected upward on the upper surface of the floating body 2 and is inserted from the lower end of the linear guide cylinder 68. A linear guide slider 72 is fixed to the upper portion of the column 70 and the lower end of the rack 60 is fixed. Accordingly, the support 70, the linear guide slider 72, and the rack 60 operate together with the operation of the floating body 2.
The linear guide slider 72 is housed in the linear guide cylinder 68, and smoothly moves relative to the linear guide cylinder 68 by the linear guide rollers 74.

The wave power generation devices 1A, 1B, and 1C described above are installed in an actual sea area as shown in FIG. 11 shows the wave power generator 1C shown in FIG. 10 as a representative example. Of course, the wave power generator 1A shown in FIG. 3 or the wave power generator 1C shown in FIG. The power generator 1B may be used.
As shown in FIG. 11, the wave power generation device 1 </ b> C generates power by obtaining rotational power from the relative displacement between the floating body 2 and the large structure 5. The wave power generation device 1 </ b> C includes an ultrasonic wave meter 76 that measures in advance the waves arriving at the floating body 2. The ultrasonic wave meter 76 is fixed to the large structure 5, and the large structure 5 does not sway with respect to the waves, so that the waves can be accurately measured. The data measured by the ultrasonic wave meter 76 is sent to a control unit (not shown), and the wave power generator 1C is controlled as will be described later.

The wave measurement data obtained from the ultrasonic wave meter 76 is analyzed as shown in FIG. 12 and used for control of the wave power generator 1C. That is, the data measured by the ultrasonic wave meter 76 has a waveform as shown in FIG. In FIG. 12, the horizontal axis represents time, and the vertical axis represents wave height. As can be seen from FIG. 12A, the waves in the actual sea area are a combination of waves of various wave heights and periods. In the control unit, as shown in FIG. 12B, the waves in the actual sea area are divided into a dominant wave having a wave period of a dominant wave height having a high wave height and a subordinate wave having a relatively small wave height. Decompose.
Here, “significant wave” means that when a wave incident within a predetermined time is analyzed according to the wave height, the value of the maximum wave height is equally divided into n, and the wave height is within the range of 1 / n. It means the wave that is the average value of the wave height to enter. The n is generally 3 or 10, but the wave component varies depending on the sea area or season in which the apparatus is installed, and other than 3 and 10 may be applied.

FIG. 13 shows a method for controlling the wave power generator using the ultrasonic wave meter 76.
First, in step S1, wave information (wave height, cycle) in the actual sea area is measured by the ultrasonic wave meter 76. The measured wave information is transmitted to the control unit, and wave components are analyzed in step S2. In step S2, a significant wave is calculated as described with reference to FIG.
In step S3, the load of the generator unit 8 (see, for example, FIG. 10) is adjusted with respect to fluctuations in the wave height of the dominant wave that contributes to the vibration of the floating body, and the motion amplitude of the floating body 2 is adjusted to the wave period. Control. Specifically, in the case of the hydraulic transmission shown in FIG. 7, the load on the generator unit 8 can be adjusted by changing the set pressure of the accumulator 42. When a mechanical transmission is used, the load on the generator unit 8 is adjusted by a method such as adjusting the number of revolutions applied to the generator body.
In step S4, it is determined whether or not the wave period of the significant wave has fluctuated significantly. This determination is made based on, for example, whether or not the wave period of the significant wave has fluctuated for 3 seconds or more within a predetermined time (for example, within 1 hour). If it is determined in step S3 that the wave period of the significant wave is changing, the process proceeds to step S5.
In step S5, the retained water amount of the floating body 2 is adjusted. The amount of retained water is adjusted, for example, by the method described with reference to FIG.

  On the other hand, if it is determined in step S4 that the wave period of the significant wave has not changed significantly, the process proceeds to step S6 to determine whether the period of the significant wave has slightly changed. Specifically, in step S6, it is determined whether or not there is a wave period variation of 1 second or more within one hour. If there is a wave period variation of 1 second or more within 1 hour, the process proceeds to step S7, and the rotational inertia added mass of the rotating body 9 (see, for example, FIG. 10) is adjusted. Adjustment of the rotational inertia additional mass of the rotating body 9 is performed by, for example, the mechanism shown in FIG.

  As shown in FIG. 14, a radar wave meter 78 may be used instead of the ultrasonic wave meter 76 used in FIG. If the radar type wave meter 78 is used, for example, waves can be measured as far as 500 m away, which is effective when it is desired to further improve the prediction accuracy.

As described above, the wave power generation device and the control method thereof according to the present embodiment have the following operational effects.
Since the relative displacement between the floating body 2 and the large structure 5 is converted into a rotational motion and the power is generated using the rotational motion, the relative displacement between the floating body 2 and the large structure 5 is used for power generation. Compared to the case of using the natural vibration of the vibrator that vibrates relatively in the buoy as in the prior art, a large output can be obtained. Further, since it is not necessary to use a spring for obtaining the natural vibration of the vibrator, the degree of freedom in design is increased, the structure can be increased in size, and the output can be further increased.
Moreover, since the wave power generators 1A, 1B, and 1C can be provided for the large structure 5, the large structure 5 can share the mooring facility and the power transmission facility, and the power generation cost can be reduced. .

In the actual sea area, waves with various periods arrive at the floating structure, and even if the waves have various periods, the hydraulic pressure boosted by the hydraulic pump 40 is accumulated in the accumulator as shown in FIG. Since the pressure is accumulated in 42, energy can be efficiently recovered as hydraulic pressure.
Further, since energy is stored in the accumulator 42 as hydraulic pressure, the hydraulic motor 44 is desired as long as the desired pressure accumulation amount is obtained even when the displacement between the floating body 2 and the large structure 5 cannot be increased. The speed can be changed to a value, and a desired power generation amount can be obtained.

The natural period of the floating body 2 can be adjusted to the wave period of the actual sea area by adjusting the rotational inertia additional mass by the rotating body 9 which is the additional mass body. Thereby, the relative displacement between the floating body 2 and the large structure 5 becomes large, and a larger power generation output can be obtained.
And the natural period of the floating body 2 can be matched with the wave period of a real sea area by adjusting the amount of water retained in the floating body 2. Thereby, the relative displacement between the floating body 2 and the large structure 5 becomes large, and a larger power generation output can be obtained.
When the significant fluctuation of the significant wave is small, the rotational inertia added mass of the rotating body whose response is fast is adjusted (step S7 in FIG. 13), and when the significant fluctuation of the significant wave is large, the response is relatively high. Since the amount of water retained in the slow floating body is adjusted (step S5 in FIG. 13), it is possible to efficiently cope with high response with a wide control width according to the fluctuation of the waves in the actual sea area.

1, 1A, 1B, 1C Wave power generator 2 Floating body 4 Conversion mechanism 5 Large structure 6 Rotating shaft 7 Ocean surface 8 Generator unit 9 Rotating body (additional mass body)
DESCRIPTION OF SYMBOLS 10 Spring element 11 Water 12 Outer guide cylinder 14 Inner guide cylinder 16 Ball screw shaft nut 18 Fixed tube 20 Bottom cover 24 Ball screw shaft 26 Ring body 28 Moving weight ball screw shaft 30 Moving weight 32 Moving motor 34 Fixed portion 36 Support slider 38 Arm 40 Hydraulic pump 42 Accumulator 44 Hydraulic motor 45 Transmission 46 Generator main body 48 Bottom valve 50 Air adjustment valve 52 Submersible pump 60 Rack 62 Pinion 64 Shaft support bracket 66 Pinion shaft 68 Linear guide cylinder 70 Strut 72 Linear guide slider 74 Linear guide roller 76 Ultrasonic wave meter 78 Radar wave meter

Claims (7)

A conversion mechanism that converts relative displacement between a floating structure that is shaken by a wave and a large structure that is less or less shaken by the wave than the floating structure into a rotational motion;
A rotating shaft that rotates by a rotational force extracted through the conversion mechanism;
A generator unit that is driven by the rotating shaft to generate power;
A wave power generation device comprising:   The generator unit includes a hydraulic pump driven by the rotating shaft body, an accumulator for accumulating oil boosted by the hydraulic pump, a hydraulic motor driven by oil guided from the accumulator, and the hydraulic motor. The wave power generation device according to claim 1, further comprising a generator that is driven to generate electric power. An additional mass adjusting means for adjusting a rotational inertia additional mass with respect to the rotary shaft body by a rotary inertia force generated by rotating the additional mass body by the rotary shaft body;
And / or
Retained water amount adjusting means for adjusting the retained water amount in the floating structure;
The wave power generation device according to claim 1, wherein the wave power generation device is provided. A wave meter installed in the large structure and measuring in advance the waves arriving at the floating structure;
Based on the measurement result of the wave meter, the control unit for controlling the additional mass adjusting means and / or the retained water amount adjusting means,
The wave power generation device according to claim 3, comprising: The control unit calculates a significant wave from the measurement result of the wave meter, and controls the additional mass adjusting means and / or the retained water amount adjusting means based on a change in the period of the significant wave. The wave power generation device according to claim 4. A generator unit according to claim 2,
The wave power generation device according to claim 5, wherein the control unit controls a set pressure of the accumulator based on a change in a wave height of the significant wave. A conversion mechanism that converts relative displacement between a floating structure that is shaken by a wave and a large structure that is less or less shaken by the wave than the floating structure into a rotational motion;
A rotating shaft that rotates by a rotational force extracted through the conversion mechanism;
A generator unit that is driven by the rotating shaft to generate power;
A method for controlling a wave power generation device comprising:
By adjusting the rotary inertia additional mass with respect to the rotary shaft by the rotary inertia caused by the additional mass being rotated by the rotary shaft,
And / or
A method for controlling a wave power generation device, wherein the amount of retained water in the floating structure is adjusted.

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