US 9,068,552 B2 · Wave power generation device and method of controlling the same

Abstract

Provided is a wave power generation device improved in power generation efficiency and a method of controlling the same, the wave power generation device generating electric power by extracting energy from a wave. The wave power generation device includes: a wave sensor configured to measure the waveform; a position sensor configured to measure a position of a float relative to a column; a drive mechanism configured to apply an external force to the float; and a controller configured to control the drive mechanism. The controller is configured to calculate a speed at which the float is to be controlled to move, from values of the wave sensor and the position sensor, and to control the drive mechanism in such away that the float moves at the calculated speed.

Drawings

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Drawings

Claims5

Dependent claims

A wave power generation device comprising:

a column;
a float configured to move relative to the column in response to a wave impacting the float,
a power generator configured to generate electric power through the movement of the float;
a wave sensor configured to measure a position ηx=0 of the wave one of relative to the mean water level WL in the vertical direction and relative to the column in the vertical direction;
a position sensor configured to measure a position z of the float one of relative to the mean water level WL in the vertical direction at a position (x=0) of the float and relative to the column in a vertical direction at a position (x=0) of the float;
a drive mechanism configured to apply an external force to the float;
and
a controller configured to receive the height ηx=0 measured by the wave sensor and the position z of the float measured by the position sensor, and to control the drive mechanism, wherein
the controller is configured to calculate a speed z′ at which the float is to be controlled to move, from the height ηx=0 measured by the wave sensor and the position z of the float measured by the position sensor, and to control the drive mechanism in such a way that the float moves at the calculated speed z′,
in accordance with one of the formulas
z′=KA(ηx=0−KCz) (19)
and
z′=KA(ηx=0−Kcz)/3 (24)
where KA is a constant equal to the frequency ω of the waveform divided by the wave formation efficiency Ā, and KC is a constant C, which is determined based on a boundary condition of the wave.

11 more elements

A method of controlling a wave power generation device including:

a float configured to move relative to one of a column moored in the sea and a water level WL;
a power generator configured to generate electric power through the movement of the float;
a wave sensor configured to measure the height ηx=0 of a waveform;
a position sensor configured to measure a position of the float relative to the column or the mean water level WL in the vertical direction at a position (x=0) of the float;
a drive mechanism configured to apply an external force to the float;
and a controller configured to receive the height ηx=0 measured by the wave sensor and the position z of the float measured by the position sensor, and to control the drive mechanism, the method comprising:
using the wave sensor to measure a position ηx=0 of the wave one of relative to the mean water level WL in the vertical direction and relative to the column in the vertical direction;
using the position sensor to measure a position z of the float one of relative to the mean water level WL in the vertical direction at a position (x=0) of the float and relative to the column in a vertical direction at a position (x=0) of the float;
using the controller to calculate a speed z′ at which the float is to be controlled to move from the measured position z of the float and the measured position ηx=0 of the wave, in accordance with one of the formulas
z′=KA(ηx=0−KCz) (19)
and
z′=KA(ηx=0−KCz)/3 (24)
where KA is a constant equal to a frequency ω of the waveform divided by the wave formation efficiency Ā, Kc is a constant C, which is determined based on a boundary condition of the wave;
and
applying an external force to the float with the drive mechanism in such a way that the float moves at the speed z′.

12 more elements

Dependencies are inferred from the claim text.

Description6,316 words

Summary1,511 words

#1. Field of the Invention

#The present invention relates to a wave power generation device which generates electric power by extracting energy from a wave through movement of a float floating on the sea and a method of controlling the same.

#2. Description of related art including information disclosed under 37 CFR §§1.97 and 1.98

Brief description of the drawings10 figures

#FIG. 1 is a schematic cross-sectional view of a wave power generation device of a first embodiment of the present invention.

#FIG. 2 is a schematic plan view of the wave power generation device of the first embodiment of the present invention.

#FIG. 3 is a schematic cross-sectional view of a wave power generation device of a second embodiment of the present invention.

Detailed description4,603 words

#Descriptions are given below of a wave power generation device of a first embodiment of the present invention with reference to the drawings. FIG. 1 shows a schematic cross-sectional view of a wave power generation device 1 of the embodiment of the present invention. The wave power generation device 1 includes a column 2 moored in a sea, a float 3 configured to move relative to the column 2, and a power generator (hereafter, also referred to as motor) 4 configured to generate electric power through the movement of the float 3. Specifically, the wave power generation device 1 includes the column 2 whose longitudinal direction is vertical and the float 3 which moves up and down along the column 2. The float 3 is configured such that the volume of a portion on a downstream side R (left side in FIG. 1) of the column 2 is smaller than the volume of a portion on an upstream side F (right side in FIG. 1) of the column 2, the upstream side F being a side from which a wave W comes, the downstream side R being the opposite side to the side from which the wave W comes. Moreover, a back surface 8 of the float 3 on the downstream side R is configured to have a profile identical to a trajectory of the movement of the float 3 which is shown by the arrow. Specifically, since the float 3 moves up and down in the vertical direction, the back surface 8 is configured to be a flat surface parallel to the vertical direction. This configuration can suppress the occurrence of wave (transmitted wave) transmitted to the downstream side R of the float 3 via the back surface 8 when the float 3 moves up and down. This is because the back surface 8 does hardly any work on water when the float 3 moves up and down.

#Although the wave power generation device 1 is illustrated to include a frame body 5, a rack 6 formed in a portion of the frame body 5, and a pinion 7 provided in the motor 4 as a power transmission mechanism configured to transmit motion energy of the float 3 to the motor 4, the present invention is not limited to this configuration. The power transmission mechanism and the power generator 4 may have any configuration which extracts energy from the upward and downward movement of the float 3 and generates electric power, such as power generation using electromagnetic induction and adoption of a piezo-electric device. Moreover, a column which is fixed to a wall along a shore or a column which is directly fixed to a sea floor can be used as the column 2 instead of the column moored in the sea.

#FIG. 2 shows a schematic plan view of the wave power generation device 1. The float 3 is formed such that the volume of the portion on the upstream side F of a center line (two-dot chain line) C passing through the center of the column 2 in a plan view is larger than the volume of the portion on the downstream side R. Specifically, the float 3 is configured to have an annular shape (ring shape) having a portion cut away. The shape of the float 3 is not limited to the one described above. For example, a square-shaped float 30 protruding on the upstream side F in the plan view as shown by the broken line may be used. In other words, the float 3 of the wave power generation device 1 may be any float which is formed such that the volume of the portion on the upstream side F is larger than the volume of the portion on the downstream side R. The larger the difference in volume between the portion of the float on the upstream side F and the portion of the float on the downstream side R, the more the occurrence of the wave (transmitted wave) transmitted to the downstream side R is suppressed (see a sea surface 10 of FIG. 1).

Facts

Application

13/561,270Filed 30 Jul 2012

Priority

JP 2012-0470542 Mar 2012

Published

US 2013/0229011 A15 Sep 2013

Granted

30 Jun 2015

Term ends

3 Nov 2032

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 96 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification7 codes

F03B 13/1815
For limited rotation: with an up-and-down movement
F03B 13/186
Where the connection between wom and conversion system takes tension and compression: the connection being of the rack-and-pinion type
F05B 2270/404
Type of control system: active, predictive, or anticipative
Y02E 10/30
Energy generation through renewable energy sources: energy from the sea, e.g. using wave energy or salinity gradient

Timeline

2 Mar 2012Priority claimedJP 2012-047054
30 Jul 2012Application filedUS 13/561,270
9 Oct 2012Assigned to Mitsui Engineering & Shipbuilding Co., Ltd.assignment of assignor's interest
5 Sep 2013PublishedUS 2013/0229011 A1
30 Jun 2015GrantedUS 9,068,552 B2
23 Oct 2018Assigned to Mitsui E&S Holdings Co., Ltd.change of name
7 Mar 2019Assigned to Mitsui E&S Shipbuilding Co., Ltd.assignment of assignor's interest
13 Dec 2021Assigned to Mitsubishi Heavy Industries Maritime Systems Co., Ltd.nunc pro tunc assignment
12 Oct 2026TodayWithin its term
3 Nov 2032Term endsEstimated, includes 96 days of adjustment

Wave power generation device and method of controlling the same

Life of this patent

Wave power generation device and method of controlling the same

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims5

Description6,316 words

Drawings

Classification7 codes

Life of this patent

Description6,316 words