The present invention relates generally to renewable electricity generation, and more particularly, although not exclusively, to a power plant for wave energy extraction.

There are many applications where it is desirable to control the up and down movement of an element placed in a body of water and subjected to the forces of the waves.

For example, in the case of wave energy converters (WECs), the system includes a buoy having a float and an elongated structure which, when placed in a body of water, can move relative to each other in response to a motion of the waves. The WEC includes a power take off device (PTO) responsive to the relative motion between the elongated structure and the float for producing _T mechanical and/or electrical energy. In the case of the WEC, to improve the efficiency of power production, it is desired that the float move up and down generally in phase with the waves in the body of water in which the WEC is placed. However, it is desired that the elongated structure move out of phase with respect to the waves and the float. This may be effectuated by attaching a heave (damping) plate to the submerged portion of the elongated structure.

The heave plate is disposed in a plane which is generally transverse (perpendicular) to the up or down direction of motion of the elongated structure for increasing the effective mass of the elongated structure. A plate so attached affects the dynamic behavior of the elongated structure by increasing the effective mass and the viscous drag in the heave (vertical) direction. In general, the benefit of attaching one, or more, heave plates is to allow for a shorter vertical elongated structure that will still have a heave natural period outside of the prevailing wave period for the operating conditions (so that the elongated structure will not respond to the prevailing wave conditions) and to increase the viscous damping of the spar in order to decrease near-resonance responses. The heave plates that have been employed in the past include thin square, circular, or rectangular plates that are either solid or have holes punched in them.

US 2018306164 A1 relates to a submergible wave energy converter and method for using the same are described. Such a wave energy converter may be used for deep water operations. In one embodiment, the wave energy converter apparatus comprises an absorber having a body with an upper surface and a bottom surface and at least one power take-off (PTO) unit coupled to the absorber and configured to displace movement of the absorber body relative to a reference, where the power take-off unit is operable to perform motion energy conversion based on displacement of the absorber body relative to the reference in response to wave excitation, and where the power take-off unit is operable to return the absorber body from a displaced position to a predefined equilibrium position and to provide a force acting on the absorber body for energy extraction.

WO 2017189455 A1 relates to a submerged wave energy conversion apparatus and pressurized fluid or electricity production system are provided that harvests energy from a motive force derived from pressure differentials created by the interaction of the system with ocean water. The system is capable of capturing energy from up to six different modes of motion of the absorber body in response to the energy of incident waves. The apparatus has an absorber body that is attached to one or more damping mechanisms like a hydraulic cylinder, a hydraulic circuit that can create useful mechanical torque, a restoring mechanism such as an air spring to restore the absorber system to stable equilibrium, and a buoyant artificial floor to create an opposing reaction force. The apparatus may also have a controller for system monitoring and control, to maintain optimized energy extraction, and for load management to avoid damaging loads.

WO 2018108220 A1 relates to a wave power device for extracting energy from water waves. The waver power device comprise a reference structure and effectors moving relative to the reference structure. The effectors are connected to two hydraulic rams, symmetrically positioned around each effector. The hydraulic rams have an effective hydraulic area which is stepwise increased as the length of the hydraulic rams are compressed and stepwise increased as the length of the hydraulic rams are increased.

US 2016108883 A1 relates to a carpet of wave energy conversion (CWEC) device mechanically couples an absorber carpet to one or more energy converters, thereby allowing for wave energy extraction from passing waves. The absorber carpet may be flexible material of a composite material that has a low elastic modulus in a longitudinal direction (to allow for stretching), and a relatively higher elastic modulus in a transverse direction (to better couple energy from wave to converters). Such designs have minimal wave reflections and high efficiencies within a relatively short extent of deployment. The resultant converted useful energy is available as either: 1) mechanical power including direct desalinization or electrical production; or 2) hydraulic power for a number of applications (including hydraulically powered motors supplying power to powered devices including generators), or pumping of the wave medium under pressure to an alternate location for irrigation or energy storage.

It is an object of the present invention to minimize and possibly alleviate one or more of the disadvantages of the prior art, or to provide a useful alternative. The objects are achieved by a wave energy converter power plant in accordance with the invention with the features of independent claim 1 . Advantageous embodiments of the invention are indicated in dependent claims.

The present invention relates to a wave energy converter power plant for extracting energy from waves, where the wave energy converter power plant comprises a substantially stationary structure, a submerged wing profile being directly or indirectly connected to the substantially stationary structure, and where the wing profile is configurated for moving relative to the substantially stationary structure, where a control, elevation and adjustment system for the substantially stationary structure is used to position the substantially stationary structure in a set water depth and heading, and an adjustment system for the submerged wing profile to position the submerged wing profile in a set position, to control the set position the submerged wing profile oscillates around.

According to one aspect, the control, elevation and adjustment system may also include to control and adjust the heading of the substantially stationary structure.

According to the present invention the phrase “substantially stationary structure” is to be understood that the structure initially is kept at a constant depth in a body of water, but where the structure due to environmental factors such as current, wind etc. necessarily will move somewhat in the body of water.

The substantially stationary structure may for some applications be designed to have a positive buoyancy. However, it could also be envisaged that the substantially stationary structure could be designed to have a neutral or even a negative buoyancy.

According to one embodiment, the control and elevation adjustment system for the substantially stationary structure may be used to position the substantially stationary structure in a set position, i.e. a desired position relative a still water level, based on wave heights and wave lengths.

In one embodiment the control and elevation adjustment system may also comprise control and adjustment of heading of the substantially stationary structure in order to position the substantially stationary structure (and thereby also the submerged wing profile) in a desired direction in relation to incoming waves. The control and elevation adjustment system for the substantially stationary structure may further carry out the adjustment of the substantially stationary structure continuously or with given or desired time intervals.

A still water level is an average water surface elevation at any instant, excluding local variation due to waves and wave set-up, but including the effects of tides, storm surges and long period seiches.

In one embodiment the control and elevation adjustment system for the substantially stationary structure may comprise a number of pressure sensors to monitor wave height, wavelength, wave direction and water depth of the substantially stationary structure relative a still water level, a number of winches for moving the substantially stationary structure up and down in the body of water and a control system for controlling at least the number of winches.

According to one aspect, the control and elevation adjustment system may further comprise a direction rotation device and/or a directional hold system and a yoke for control of a heading of the substantially stationary structure and a control system for controlling the direction rotation device and/or the directional hold system.

In another embodiment the control and elevation adjustment system for the substantially stationary structure may comprise a number of pressure sensors to monitor wave height, wave length, wave direction and water depth of the substantially stationary structure relative a still water level, an adjustable arm or one or more angular devices for moving the substantially stationary structure up and down in the body of water and a control system for controlling at least the adjustable arm or one or more angular devices.

The submerged wing profile may, according to one embodiment of the wave energy converter power plant, be designed to have a neutral buoyancy.

However, it could also be envisaged that the submerged wing profile could be constructed to have a positive or even a negative buoyancy

The substantially stationary structure may be connected to a seabed through a mooring system, where the mooring system may be arranged in such a way that the substantially stationary structure is prevented from rotating uncontrollably around its own axial axis. According to one aspect the substantially stationary structure may comprise at least two adjustable mooring connections, such that the substantially stationary structure may be connected to, via two or more mooring lines, to two or more anchors arranged on a seabed.

However, the substantially stationary structure may also be connected to the seabed through one or more adjustable mooring lines and a directional hold system comprising one or more directional hold arms, a number of directional hold and a power and communication cable.

According to another aspect, the substantially stationary structure may be connected to other bodies through the at least two adjustable mooring connections, for instance a floating structure, a hinged structure, or the like.

The submerged wing profile may, in one embodiment, comprise a plate element and a sleeve-shaped element, where a number of struts, beams or the like may be arranged between the plate element and the sleeve-shaped element in order to support the plate element.

According to one aspect, the submerged wing profile may also comprise one or more spring suspensions or the like in order to allow the plate element to flex relative the sleeve-shaped element when the submerged wing profile, for instance, is exposed to forces from waves or the like.

The plate element of the submerged wing profile may have many shapes, such as a rectangular form, an oblong, a square form, a circular form, an oval form or the like.

When the plate element of the submerged wing profile has a rectangular or oblong form, the length/width ration may, for instance, be 3 to 1 . However, it could be envisaged that the submerged wing profile may have other length/width ratios.

Furthermore, the plate element of the submerged wing profile may be formed, when seen in a cross section, to have a same thickness over the entire plate element. However, it could also be envisaged that the plate element of the submerged wing profile may be formed with a thickness that will vary over a length of the plate element.

In one embodiment the submerged wing profile may be manufactured to have a neutral buoyancy. However, it could also be envisaged that the submerged wing profile may be manufactured to have a weight providing the neutral buoyancy +/-20% of the weight providing the neutral buoyancy.

According to one embodiment, a total buoyance for the submerged wing profile, a power transmission plate and a gear rack may be between 80% and 120% of a total mass of the submerged wing profile, the power transmission plate and gear rack.

According to another embodiment, a total buoyancy for the submerged wing profile and the power transmission plate may be between 80% and 120% of a total mass of the submerged wing profile and power transmission plate.

In yet an embodiment, a total buoyancy of the submerged wing profile, the power transmission plate and a hydraulic cylinder stem of a hydraulic cylinder may be between 80% and 120% of a total mass of the submerged wing profile, power transmission plate and the hydraulic cylinder stem.

According to one aspect, the submerged wing profile may be provided with rounded outer edges, in order to prevent damage to marine animals.

According to one aspect, the substantially stationary structure may be provided with at least one axially extending slot, where the at least one axially extending slot extends at least over a part of a length of the substantially stationary structure.

The adjustment system for the submerged wing profile may be used to position the submerged wing profile in a set position, i.e. a position at a desired average depth at which the submerged wing profile may oscillate around, when the submerged wing profile 2 is connected to the substantially stationary structure 1 , and where the set position is based on a continuous calculation of wave heights and wave lengths.

When the submerged wing profile positioned in the set position, the submerged wing profile may, due to incoming waves, oscillate around the set position.

The adjustment system for the submerged wing profile may, in one embodiment, comprise a number of pressure sensors arranged at a distance from each other, upper and lower dampers, at least a generator speed sensor, at least a transmission plate position sensor, a gear rack and a number of gears, whereby the adjustment system is configured to continuously adjust a position of the submerged wing profile relative to the still water level, in order to allow the submerged wing profile to oscillate around the set position.

In another embodiment of the present invention the adjustment system for the submerged wing profile may comprise a number of pressure sensors arranged at a distance from each other, at least a generator speed sensor, at least a transmission plate position sensor, an upper and a lower damper, and a wire arranged around an upper wire wheel, a middle wire wheel and a lower wire wheel.

In yet an embodiment of the present invention, the adjustment system for the submerged wing profile may comprise a number of pressure sensors arranged at a distance from each other, at least a generator speed sensor, at least a hydraulic fluid flow sensor, at least a hydraulic fluid pressure sensor, at least a transmission plate position sensor, an upper damper and a lower damper and at least one hydraulic cylinder, where the hydraulic cylinder may comprise a stem.

According to one aspect, the number of pressure sensors may be arranged or grouped in one or more levels along the length of the substantially stationary structure, where the levels of pressure sensors are spaced apart from each other. Each level of pressure sensors may then comprise a plurality of pressure sensors.

The pressure sensors are further arranged in such a way that a number of the plurality of pressure sensors are grouped around a circumference of the central part 1a of the substantially stationary structure 1 and moreover are located at a same level.

The wave energy converter power plant according to the present invention comprises also a generator system, where the generator system according to one embodiment may comprise at least one generator, a number of gears, one or more clutches, a generator controller and/or generator control, at least one battery, one or more capacitors and a control system.

There are many types of electric generators and many ways to control the generator shaft torque and power output.

A person skilled in the art would know which types of generators and controllers that may be used in order to achieve the desired purpose according to the present invention, whereby this is not described in more detail herein. What is described is how to produce the control signal to the generator controller for adjusting generator shaft torque and power output.

The generator system may, according to another embodiment, further comprise at least a hydraulic cylinder, a flow sensor, a flow directional valve, a one-way valve, a pressure sensor, a hydraulic motor, an accumulator high pressure on supply line and an accumulator low pressure on return line.

According to one embodiment, an adjustment system for the submerged wing profile may comprise a number of pressure sensors, at least one generator speed sensor, at least one transmission plate position sensor, an upper and lower damper, a wire arranged around an upper wire wheel, a middle wire wheel, a lower wire wheel and an area for the transmission plate in order to prevent a contact between the transmission plate and upper and lower damper.

According to another embodiment, the adjustment system for the submerged wing profile may comprise a number of pressure sensors, at least one generator speed sensor, at least one hydraulic fluid sensor, at least one hydraulic fluid pressure sensor, at least one transmission plate position sensor, a upper and lower damper, an area for the transmission plate in order to prevent a contact between the transmission plate and upper and lower damper, at least one hydraulic cylinder, where the hydraulic cylinder comprises a stem.

According to one aspect, a generator system may comprise a number of gears, a clutch, a generator controller and at least one battery, one or more capacitors and a control system, where the control system may comprise a programmable logic controller (PLC).

The generator system may further comprise a hydraulic cylinder, a high pressure accumulator, a low pressure accumulator, a flow directional valve and a hydraulic motor.

The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, wherein:

Figures 1 A-1 B shows a perspective view of a wave energy converter power plant according to the present invention, where figure 1 A shows the wave energy converter power plant used in small waves, while figure 1 B shows the wave energy converter plant according to figure 1A used in large waves, Figures 2A-2E show an adjustment system for a submerged wing profile of the wave energy converter power plant, where figure 2A shows the wave energy converter power plant in an axial cross section, figure 2B shows in greater detail an adjustment system for the submerged wing profile according to figure 2A, figure 2C shows in greater detail a damper system for the submerged wing profile, figure 2D shows the submerged wing profile of the wave energy converter power plant in a side view and from above, and figure 2E shows an enlarged center part and a control element for the wing profile,

Figures 3A-3C show an alternative embodiment of the adjustment system for the submerged wing profile according to figures 2A-2E, where figure 3C shows in greater detail a damper system for the submerged wing profile for embodiments according to figures 3A-3B and figures 4A-4B,

Figures 4A-4B show yet an alternative embodiment of the adjustment system for the submerged wing profile according to figures 2A, 2B, 2D, 2E and 3C,

Figure 5 shows a generator system connected to the submerged wing profile according to the present invention,

Figure 6 shows wave directions towards the submerged wing profile and a center part of the substantially stationary structure, as well as four pressure sensors arranged around the center part,

Figure 7 shows a schematic diagram for a control system for regulation and adjustment of a depth and heading of a center part, and generator or hydraulic cylinder controlling a speed and/or position of the submerged wing profile, and

Figures 8A-8E show different areas for application of the wave energy converter power plant according to the present invention.

Figures 1 A-1 B show a first embodiment of a wave converter power plant P according to the present invention in different positions, where figure 1 A shows the wave energy converter power plant P according to the present invention in different positions in small waves, i.e. on a wave crest, on its way down from a wave crest and to a wave trough, in a wave trough and on its way up from a wave trough and to a wave crest again, while figure 1 B shows the wave energy converter power plant P in different positions in large waves, i.e. on a wave crest, on its way down from a wave crest and to a wave trough and in a wave through.

In this embodiment the wave energy converter power plant P for extracting energy from incoming waves 3b, 3c comprises a substantially stationary structure 1 , where a submerged wing profile 2 is arranged around a central part of the substantially stationary structure 1 .

The submerged wing profile 2 is arranged to move relative to the substantially stationary structure 1 through an adjustment system, and where the submerged wing profile 2 is connected to at least one electric generator 16 arranged inside the substantially stationary structure 1 in order to extract wave energy from incoming waves 3b, 3c.

The wing profile 2 may have many shapes and in one embodiment the wing profile 2 may have a rectangular shape, as shown in figure 2c, where a length/width ratio may be 2:1 . However, it could be envisaged that the submerged wing profile 2 may have other length/width ratios.

However, it is also conceivable that the wing profile 2 may have other shapes or forms, for example a circular shape as shown in figure 2c, a square shape, an oblong shape or an oval shape.

It is also conceivable that the wing profile in some embodiments may have a polygonal shape.

Furthermore, the submerged wing profile 2 may be designed symmetrically or asymmetrically about a given line or plane.

The wing profile 2 comprises a plate element 2a and a sleeve-shaped element 2f, where the sleeve formed element 2f will form a wing guiding section relative to the substantially stationary structure 1 . A number of struts 2i, beams, spring suspensions or the like extend between an underside of the plate element 2a and an outer side of the sleeve-shaped element 2f in order to support and affix the plate element 2a to the sleeve-shaped element 2f.

The number of spring suspensions 2i may be arranged to allow a certain “movement” or twist of the plate element 2a relative to the sleeve-shaped element 2f, for instance when the plate element 2a is subjected to forces from waves (from front and from side), when the plate element 2a turns from downward to upward movement (and vice versa) etc.

The number of struts 2i, beams, spring suspensions or the like are arranged at a distance from each other, around a circumference of the sleeve-shaped element 2f.

An adjustment system for the submerged wing profile 2 is used to position the submerged wing profile in a set position on the substantially stationary structure 1 , where the adjustment system for the submerged wing profile 2 comprise a power transmission plate 8a, a movement arrangement 34, an upper and lower damper 10a, 10c, a number of sensors 7, 9, 13a-13c, at least one electric generator 16 and a control and regulation system for the at least one electric generator 16.

When the submerged wing profile 2 is arranged in the set position, the submerged wing profile may oscillate (lower and rise) around the set position.

The set position (or a set water depth relative to a still water level 4) is based on or determined by the wave height and wavelength for a certain time period. Still water level 4 is defined to be an engineering abstract calculated by adding the effects of tides and storm surge to the water depth but excluding variations due to waves, where it can be above or below mean sea level.

When the submerged wing profile 2 is subjected to incoming waves, the submerged wing profile 2 will be forced to oscillate (i.e. to raise and lower), along a longitudinal length of the substantially stationary structure 1 .

The submerged wing profile 2 will then follow the wave or waves passing over the submerged wing profile 2, such that when, for example, a wave crest passes over the submerged wing profile 2, will the submerged wing profile 2 be close to its uppermost position which the submerged wing profile 2 is allowed to move towards before turning in an opposite direction. When a wave trough passes over the submerged wing profile 2, the submerged wing profile 2 will be close to its lowermost position which the submerged wing profile 2 is allowed to move towards before turning in an opposite direction.

A generator 16 is then used to brake down the movement and speed of the submerged wing profile 2 in both directions (i.e. when the submerged wing profile 2 is moving in one direction and is to turn to an opposite direction), so as to slow down a speed of the submerged wing profile 2 to almost zero, whereafter the submerged wing profile’s 2 movement will stop, turn and start to move in the opposite direction, following the incoming wave form.

A control/regulation system is used to regulate the generator 16, such that the generator 16 apply a variable braking to the submerged wing profile 2 during its motion, where the braking force may be from zero to a maximum braking force required to control the movement speed of the submerged wing profile 2.

The braking force made by the generator 16 is controlled by controlling an output of voltage and current from the generator 16 by a generator controller 30. When the generator 16 applies braking forces to the submerged wing 2, the movement up and down of the submerged wing profile 2 will be less than an up and down velocity of water particles around the submerged wing profile 2. A difference in the velocity of the submerged wing profile 2 and the velocity of water particles can be controlled by controlling the generator braking force. By controlling the braking force of the generator 16 at the up and down movement of the submerged wing profile 2, an average position of the submerged wing profile 2 relative to the substantially stationary structure 1 and a still water level 4 may be controlled.

A main parameter for the control of the generator controller 30 is a speed measurement on the submerged wing 2 relative to the substantially stationary structure 1 , this giving an input value to a proportional-integral-derivative regulator (PID regulator) 35b. The signal from the PID regulator 35b will be adjusted in a programmable logic controller (PLC) block 35c before the control signal is sent to the generator controller 30 for the generator 16. The PLC block 35c receives information on average wave height, average wave time period, the substantially stationary structure 1 water depth relative to a still water level 4 and the submerged wing profile’s 2 current position relatively to the substantially stationary structure 1 . This information is used to adjust the PID 35c output signal to generator controller 30. The submerged wing profile’s 2 current positions relative to the substantially stationary structure 1 and the substantially stationary structure 1 water depth are used to adjust the signal to generator controller 30 to maintain the submerged wing profile’s 2 average position close to the set position (i.e. a set water depth relative to a still water level 4) based on average wave height and wave time period over a certain time period.

The set water depth relative to a still water level 4 for the submerged wing 2 may be adjusted, for instance, by remote control. The adjustment system for the submerged wing profile 2 comprises further an upper damper 10a and lower damper 10c arranged within the substantially stationary structure 1 , as an additional safety device. One end of the upper damper 10a facing away from the lower damper 10c is provided with a damper plate 10b, while one end of the lower damper 10c facing away from the upper damper 10a is provided with a damper plate 10d. A distance between the damper plates 10b, 10d defines the initial area for the submerged wing profile 2. The upper and lower dampers 10a, 10c are then arranged to assist the generator 16 or the hydraulic cylinder 24a to brake or slow down and stop the movement of the submerged wing profile 2 when the submerged wing profile 2 moves and is outside the initial area. If the submerged wing profile 2, for some reason, compress the upper damper 10a or lower damper 10c, then the upper or lower damper 10a, 10c add a force to move the submerged wing profile 2 towards the initial area again.

The adjustment system for the submerged wing profile 2 will then calculate the set position the submerged wing profile 2, whereafter the submerged wing profile 2 will be allowed to oscillate about this set water depth, following the incoming waves form. The varying brake force applied to the submerged wing profile 2 from the generator 16 (or the hydraulic cylinder 24a) will allow the submerged wing profile 2 to move a certain distance from the set position in both directions (up and down), and if the submerged wing profile 2 reaches upper damper 10a or lower damper 10c, the damper 10a, 10c will add extra braking force to the submerged wing profile 2 in order to slow down the speed or movement of the submerged wing profile 2 until the submerged wing profile 2 stops completely. When the submerged wing profile 2 has stopped completely, the upper damper 10a or lower damper 10c will add an additional force to the submerged wing profile 2, such that the submerged wing profile 2 is forced towards its initial area again, whereby the submerged wing profile 2 begins to move in an opposite direction due to the wave form and force from upper or lower damper 10a, 10c if the upper or lower damper 10a, 10c is compressed.

A hydraulic cylinder 24a may also be used to break down the movement and speed of the submerged wing profile 2, by controlling hydraulic pressure and/or hydraulic flow to/from the hydraulic cylinder 24a.

The generator 16 and the hydraulic cylinder 24a will not only be used to slow down and stop the movement of the submerged wing profile 2 in one direction, but also to reposition the submerged wing profile 2 to oscillate around the set water depth relative to still water level 4. Furthermore, the adjustment system for the submerged wing profile 2 will continuously perform calculations to set and maintain the submerged wing profile 2 to oscillate around the set water depth relative to still water level 4.

The submerged wing profile 2 will be located closer to a surface of water in small waves, while the submerged wing profile 2 will be located deeper in the body of water the larger the waves are, the larger the waves are, the deeper is the set position for the submerged wing profile 2.

The submerged wing profile 2 will be located closer to a surface of water in waves with long time period, while the submerged wing profile will be located deeper in the body of water the shorter the wave time period is, the shorter time period the waves have, the deeper is the set position for the submerged wing profile 2.

However, below a given depth the submerged wing profile 2 positioning of the submerged wing profile 2 will be opposite, as the submerged wing profile 2 at this depth will be located deeper in the body of water in waves with long time period, while the submerged wing profile 2 will be located closer to a surface of water the shorter the wave period is.

The substantially stationary structure 1 is anchored to one or more anchors 46 placed on a seabed 47 through one or more mooring lines 45, wires or the like, see also figure 8A, where a number of winches 44a, 44b arranged between the substantially stationary structure 1 and the one or more anchors 46 are used to control, adjust and maintain the substantially stationary structure 1 in a desired position in the body of water.

Furthermore, the center part 1 a of the substantially stationary structure 1 is provided with an axially extending slot 6a, where the axially extending slot 6a extends over a part of a length of the substantially stationary structure 1 . The axially extending slot 6a is used to guide the submerged wing profile 2 along the length of the substantially stationary structure 1 when the submerged wing profile 2 oscillates in the waves and to prevent the submerged wing profile 2 from rotating around the substantially stationary structure 1 .

A plurality of pressure sensors 7 are arranged at a distance from each other around a circumference of the substantially stationary structure 1 . The pressure sensors 7 are used to measure the pressure in the incoming waves, where these measurements, when processed, are used to adjust the set position of the submerged wing profile 2. The plurality of pressure sensors 7 may further be arranged in such a way that a number of the plurality of pressure sensors 7 are grouped around a circumference of the central part 1a of the substantially stationary structure 1 and moreover are located at a same level in the substantially stationary structure 1 .

In one embodiment the substantially stationary structure 1 is also provided with one or more position sensors 9 for a power transmission plate 8 connected to the submerged wing profile 2 and one or more speed sensors 13a for the one or more generators 16, where measurements and data from the sensors 9, 13a are used to calculate and measure the position of the submerged wing profile 2 relative to the substantially stationary structure 1 .

In another embodiment the substantially stationary structure 1 is provided with one or more position sensors 9 for the power transmission plate 8 connected to the submerged wing profile 2 and one or more hydraulic cylinder oil flow sensors 13c for a speed of a stem 24b of the hydraulic cylinder 24a, where measurements and data from the sensors 9, 13c are used to calculate and measure the position of the submerged wing profile 2 relative to the substantially stationary structure 1 .

The position of the submerged wing profile 2 is then constantly calculated with the speed of the generator 16 or the speed of the oil flow from the hydraulic cylinder 24a. Every time the power transmission plate 8 is passing a position sensor 9 the calculated value for position of the submerged wing profile 2 relative to the substantially stationary structure 1 is calibrated I changed to the position for the position sensor 9.

Furthermore, the wave energy converter power plant P comprises an elevation adjustment system for the substantially stationary structure 1 , where such elevation adjustment system is based on a calculation of an average wave height and average wave time period over a certain time period, and is used to determine a set position (i.e. a desired position relative the still water level 4) for the substantially stationary structure 1 . The adjustment of elevation will then be done in steps within a certain time period between.

If the waves are small, the substantially stationary structure 1 will be adjusted and held closer to a still water level 4, than if the waves are larger. In this case the substantially stationary structure 1 will be adjusted and held in a set position deeper in the body of water/further away from the still water level 4. If wave time periods are long, the substantially stationary structure 1 will be adjusted and held closer to a still water level 4, than if the wave time periods are shorter. In this case the substantially stationary structure 1 will be adjusted and held in a set position deeper in the body of water/further away from the still water level 4.

The set water depth relative to a still water level 4 of the substantially stationary structure 1 may be adjusted, for instance, by remote control.

Figures 2A-2E show an adjustment system for a submerged wing profile 2 of the wave energy converter power plant P, where figure 2A shows the wave energy converter power plant P in an axial cross section, figure 2B shows in greater detail the adjustment for the submerged wing profile 2 according to figure 2A, figure 2C shows in greater details a principle for the submerged wing profile 2 “damper system”, figure 2D shows the submerged wing profile 2 of the wave energy converter power plant P in a side view and from above, and figure 2E shows an enlarged center part and a control element for the submerged wing profile 2.

A first embodiment of the adjustment system for the submerged wing profile 2 is shown in figures 2A-2E, where it can be seen that the adjustment system for the submerged wing profile 2 comprises a power transmission plate 8a extending through the axially extending slot 6a provided in the substantially stationary structure 1 , where the power transmission plate 8a is connected to the sleeve-shaped element 2f of the submerged wing profile 2.

The power transmission plate 8a is furthermore fixedly connected to movement arrangement 34a in the form of an axially extending gear rack 11 a, where the gear rack 11 a in turn is in contact with a number of gears 12 arranged within a cavity 5 provided in the substantially stationary structure 1 . One end of the axially extending gear rack 11a is provided with an upper damper plate 11d, while an opposite end of the axially extending gear rack 11a is provided with a lower damper plate 11 e. Upper and lower damper 10a, 10c is also arranged within the cavity 5, and the upper and lower damper 10a, 10c is arranged in such a way that the axially extending gear rack 11 a may move relative to the upper and lower damper 10a, 10c. Each of the upper and lower damper plate 10b, 10d is then provided with an opening (not shown) or hole, such that the axially extending gear rack 11 a may move up and down within the upper and lower damper 10a, 10c. Each of the upper and lower damper plates 10b, 10d is also provided with a slit (not shown) or recess, such that the power transmission plate 8a, being fixedly connected to the axially extending gear rack 11 a and the sleeveshaped element 2f of the submerges wing profile 2, is allowed to pass the upper or lower damper plate 10b, 10d when the submerged wing profile 2 (and thus also the axially extending gear rack 1 1 a) oscillates in the body of water.

In one embodiment, each of the upper and lower damper plate 10b, 10d may comprise a sleeve element, where one end of the sleeve element is closed, and an opposite end of the sleeve element is provided with a flange or abutment plate. The flange or abutment plate is then arranged to be in contact with the damper, while the closed end of the sleeve element is provided with an opening (not shown) or hole and a peripheral slit or recess, such that the axially extending gear rack 11 a is allowed to move in a longitudinal direction of the upper and lower damper 10a, 10c, and that the power transmission plate 8a is allowed to pass the upper and lower damper plate 10b, 10d when the submerged wing profile 2 oscillates.

A far left in figure 2A shows the submerged wing profile 2 in a central position within the initial area, the middle figure shows the submerged wing profile 2 in its upper, maximum position 2b and at the far right in figure 2A the submerged wing profile 2 is shown in its lower, maximum position 2c. The middle and far right figure show the power transmission plate 8a, transmission plate position sensor 9, axially extending gear rack 1 1 , gear 12, upper dampers 10a, upper damper plate 10b, lower damper 10c and lower damper plate 10d arranged in a cavity 5 provided in the substantially stationary structure 1 .

An upper, maximum position of the submerged wing profile 2 should, according to the present invention, be understood to be a position where the submerged wing profile 2 has been dampened and stopped by the lower damper 10c, the lower damper 10c then being fully compressed (as the damper plate 11 e of the axially extending gear rack 11 a is in contact or abutment with the lower damper plate 10d of the lower damper 10c and through the movement has “dragged” the lower damper plate 10d with it, so that the lower damper 10c has been compressed through this movement), whereafter the submerged wing profile 2 will start to move in an opposite direction, i.e. downwards. Similarly, a lower, maximum position of the submerged wing profile 2 should, according to the present invention, be understood to be a position where the submerged wing profile 2 has been dampened and stopped by the upper damper 10a, the lower damper 10a then being fully compressed (as the damper plate 11 d of the axially extending gear rack 1 1 a is in contact or abutment with the upper damper plate 10b of the upper damper 10a and through the movement has “dragged” the upper damper plate 10b with it, so that the upper damper 10a has been compressed through this movement), whereafter the submerged wing profile 2 will start to move in an opposite direction, i.e. upwards. Figure 2B shows further details of the adjustment system for the submerged wing profile 2, where it can be seen that the axially extending gear rack 11a is connected to an electric generator 16 with a generator speed sensor 13a, through a first gear 12, a second gear 20, a clutch 21 and a transmission gear 22, in order to” transfer” the movement of the submerged wing profile 2 and the axially extending gear rack 11a to the electric generator 16. A dynamic seal 19 may furthermore be arranged between the first gear 12 and the second gear 20. Bearings 18 will then allow the first gear 12, the second gear 20, clutch 21 and transmission gear 22 to rotate.

Furthermore, the embodiment according to figure 2B shows use of two electric generators 16. However, a person with skill in the art would know that both fewer or more electric generator may be used.

Figure 2C shows in greater detail a principle on how the upper and lower damper 10a, 10c act during the movement of the submerged wing profile 2, where it can be seen how the upper and lower damper plate 11d, 11e of the axially extending gear rack 11a, due to the movement of the submerged wing profile 2 and the axially extending gear rack 11a, will cooperate with the upper and lower damper plate 10b, 10d of the upper and lower damper 10a, 10c respectively.

An upper left on figure 2C shows the submerged wing profile 2 in its upper, maximum position (i.e. a position where the generator 16 has not been able to brake or slow down the submerged wing profile 2 to move the submerged wing profile 2 in an opposite direction), where the movement of the submerged wing profile 2 towards this upper, maximum position has resulted in that the lower damper 10c has been compressed through the cooperation of the lower damper plate 11 e of the axially extending gear rack 11 a and the lower damper plate 10d of the lower damper 10c. In this upper, maximum position of the submerged wing profile 2, the lower damper 10c will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again (i.e. the area where the submerged wing profile 2 mainly oscillates within and where the upper and lower damper 10a, 10c are not compressed.

An upper right on figure 2C shows the submerged wing profile 2 when the submerged wing profile 2 has returned from the upper, maximum position and where the submerged wing profile 2 is in its initial area, where the submerged wing profile 2 moves towards the lower damper 10c. A lower left on figure 2C shows the submerged wing profile 2 in a position just before the upper damper plate 11d of the axially extending gear rack 11a has begun to cooperate with the upper damper plate 10b of the upper damper 10a in order to compress the upper damper 10c. A lower right on figure 2C shows the submerged wing profile 2 in a lower, maximum position (i.e. a position where the generator 16 has not been able to brake or slow down the submerged wing profile 2 to move the submerged wing profile 2 in an opposite direction), where the movement of the submerged wing profile 2 towards this lower, maximum position has resulted in that the upper damper 10a has been compressed through the cooperation of the upper damper plate 11 d of the axially extending gear rack 11 a and the upper damper plate 10c of the upper damper 10a. In this lower, maximum position of the submerged wing profile 2, the upper damper 10a will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again.

Upper part of figure 2D shows the submerged wing profile 2 of the wave energy converter power plant P according to the present invention, where the submerged wing profile 2 is shown in a cross-section in a side view, while lower part of figure 2D shows the submerged wing profile 2 arranged around an outer surface of the center part 1 a of the substantially stationary structure 1 , and where the submerged wing profile 2 is connected to the electric generator 16, the submerged wing profile 2 and the substantially stationary structure 1 being shown from above.

The submerged wing profile 2 is shown to either have a rectangular form or a circular form in the lowermost part of figure 2D.

Furthermore, figure 2E shows how the outer surface of the center part 1 a of the substantially stationary structure is provided with spaced apart guiding elements 23, and where the submerged wing profile 2, around an inner circumference of the sleeve-shaped element 2f is provided with corresponding guiding elements 23a extending axially along the sleeve-shaped element 2f, where the guiding elements 23 and the guiding elements 23a will prevent the submerged wing profile 2 to rotate around the substantially stationary structure 1 .

However, it could also be envisaged that the submerged wing profile 2 could be provided with the spaced apart guiding elements 23, whereby the center part 1 a of the substantially stationary structure 1 could be provided with corresponding guiding elements 23a extending axially along the central part 1 a of the substantially stationary structure 1 .

Figure 2E shows further details around the connection of the submerged wing profile 2 and the adjustment system for the submerged wing profile 2, where one or more set of bearings 18 are connected to the second gears 20 and the gears 12. Figures 3A-3C show an alternative embodiment of the adjustment system for the submerged wing profile 2, where the center part 1a of the substantially stationary structure 1 is provided with an axially extending slot 6, where the axially extending slot 6a extends over a part of a length of the substantially stationary structure 1 , as described in accordance with figure 2A, and where plurality of pressure sensors 7 are arranged at a distance from each other along the length of the substantially stationary structure 1 , where the pressure sensors 7 are located within a length of the axially extending slot 6.

The pressure sensors 7 are further arranged in such a way that a number of the plurality of pressure sensors 7 are grouped around a circumference of the central part 1a of the substantially stationary structure 1 and moreover are located at a same level,

The adjustment system for the submerged wing profile 2 comprises a power transmission plate 8b extending through the axially extending slot 6, where the power transmission plate 8b is connected to the sleeve-shaped element 2f of the submerged wing profile 2.

The power transmission plate 8b is also connected to a movement arrangement 34b in form of an endless wire 15 and an upper, middle and lower wire wheel 14a, 14b, 14c, where the endless wire 15 is arranged over the upper wire wheel 14a, middle wire wheel 14b and the lower wire wheel 14c. When the submerged wing profile 2 moves or oscillates in the waves, the power transmission plate 8b will move in a straight line between upper wire wheel 14a and middle wire wheel 14b.

The endless wire 15, upper wire wheel 14a, middle wire wheel 14b and lower wire wheel 14c are arranged within a cavity 5 provided in the substantially stationary structure 1 , An upper damper 10a and lower damper 10c are also arranged in the cavity 5. The upper and lower damper 10a, 10c will be arranged spaced apart, whereby the upper damper 10a is arranged towards an upper end of the cavity 5, and the lower and lower damper 10c is arranged towards a lower end of the cavity 5.

One end of the upper damper 10a facing the lower damper 10c is provided with an upper damper plate 10b, while one end of the lower damper 10c facing the upper damper 10a is provided with a lower damper plate 10d. A distance between the upper and lower damper plate 10b, 10d defines the initial area for the submerged wing profile 2. The upper and lower damper 10a, 10c are then arranged to assist the generator 16 or the hydraulic cylinder 24a to brake or slow down and stop the movement of the submerged wing profile 2 when the submerged wing profile 2 moves and is outside the initial area. If the submerged wing profile 2, for some reason, compress the upper damper 10a or lower damper 10c, then the upper or lower damper 10a, 10c add a force to move the submerged wing profile 2 towards the initial area again.

When the submerged wing profile 2 is moving towards the upper damper 10a, the power transmission plate 8b will eventually be brought into contact with the upper damper plate 10b of the upper damper 10a. A further movement of the submerged wing profile 2 will cause that the power transmission plate 8b is pushing on the upper damper plate 10b, such that the upper damper 10a begin to compress. Similarly, if the submerged wing profile 2 moves in the opposite direction, i.e. towards the lower damper 10c, the power transmission plate 8b will eventually be brought into contact with the lower damper plate 10d of the lower damper 10c, whereafter the lower damper 10c will start to compress, as the power transmission plate 8b pushes the lower damper plate 10d.

A far left on figure 3A shows the submerged wing profile 2 in a central position within the initial area, the middle figure shows the submerged wing profile 2 in its upper, maximum position 2b and at the far right the submerged wing profile 2 is shown in its lower, maximum position 2c. The middle and far right figure show furthermore that the power transmission plate 8b, transmission plate position sensor 9, upper wire wheel 14a, middle wire wheel 14b, lower wire wheel 14c, endless wire 15, upper damper 10a, lower damper 10c, upper damper plate 10b and lower damper plate 10d arranged in a cavity 5 provided in the substantially stationary structure 1 .

An upper, maximum position of the submerged wing profile 2 should, according to the present invention, be understood to be a position where the submerged wing profile 2 has been dampened and stopped by the upper damper 10a, the upper damper 10a then being fully compressed, whereafter the submerged wing profile 2 will start to move in an opposite direction, i.e. downwards. Similarly, a lower, maximum position of the submerged wing profile 2 should, according to the present invention, be understood to be a position where the submerged wing profile 2 has been dampened and stopped by the lower damper 10c, the lower damper 10c then being fully compressed, whereafter the submerged wing profile 2 will start to move in an opposite direction, i.e. upwards.

Figure 3B shows in greater detail the adjustment system for the submerged wing profile 2 where it can be seen that middle wire wheel 14b, through a transmission gear 22 and a clutch 21 , is connected to an electric generator 16. Furthermore, a bearing 18 is used to support the middle wire wheel 14b and a dynamic seal 19 is arranged between the middle wire wheel 14b and the transmission gear 22. Similarly, the lower wire wheel 14c is connected to an electric generator 16 through a transmission gear 22 and a clutch 21 , where the lower wire wheel 14c is supported by a bearing 18. A dynamic seal 19 is arranged between the lower wire wheel 14c and the transmission gear 22.

The upper wire wheel 14a, middle wire wheel 14b and lower wire wheel 14c are driven by the endless wire 15 extending over the wire wheels 14a, 14b, 14c.

Figure 3C shows in greater detail a principle on how the upper and lower damper 10a, 10c act during the movement of the submerged wing profile 2, where it can be seen that the power transmission plate 8b at upper part of travel, push the upper damper plate 10b for compression of upper damper 10a, and that the power transmission plate 8b at mid travel between submerged wing position 2g and submerged wing position 2h have a travel without connection to upper damper plate 10b or lower damper plate 10d, not compressing upper 10a or lower damper 10c, and that the power transmission plate 8b at lower part of travel push the lower damper plate 10d for compression of lower damper 10c.

In this embodiment each of the upper and lower damper plate 10b, 10d may comprise an elongated element, where each end of the elongated element is provided with a flange or abutment plate. The flange or abutment plates are arranged in such a way that they extend in opposite radial directions, i.e. one flange or abutment plate will extend out radially left from the elongated element, while the flange or abutment plate arranged on the opposite end of the elongated element will extend out radially right from the elongated element.

An upper left on figure 3C shows the submerged wing profile 2 in its upper, maximum position where the movement of the submerged wing profile 2 towards this upper, maximum position has resulted in that the upper damper 10a has been compressed through the cooperation of the power transmission plate 8b and the upper damper plate 10b. In this upper, maximum position of the submerged wing profile 2, the upper damper 10a will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again. The lower damper 10c is not compressed when the submerged wing profile 2 is in its upper, maximum position.

An upper right on figure 3C shows the submerged wing profile 2 when the submerged wing profile 2 has returned from the upper, maximum position and where the submerged wing profile 2 is located within its initial area (i.e. the area where the submerged wing profile 2 oscillates mainly within and where the upper and lower damper 10a, 10c are not compressed), where the submerged wing profile 2 moves towards the lower damper 10c.

A lower left on figure 3C shows the submerged wing profile 2 in a position just before the power transmission plate 8b has begun to cooperate with the lower damper plate 10d of the lower damper 10c in order to compress the lower damper 10c.

A lower right on figure 3C shows the submerged wing profile 2 in a lower, maximum position, where the movement of the submerged wing profile 2 towards this lower, maximum position has resulted in that the lower damper 10c has been compressed through the cooperation of the power transmission plate 8b and the lower damper plate 10d of the lower damper 10c. In this lower, maximum position of the submerged wing profile 2, the lower damper 10c will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again. The upper damper 10a is not compressed when the submerged wing profile 2 is in its lower, maximum position.

Figures 4A-4B show yet an alternative embodiment of the adjustment system for the submerged wing profile 2, where the center part 1a of the substantially stationary structure 1 is provided with an axially extending slot 6, where the axially extending slot 6 extends over a part of a length of the substantially stationary structure 1 , as described in accordance with figure 2A, and where plurality of pressure sensors 7 are arranged at a distance from each other along the length of the substantially stationary structure 1 , where the pressure sensors 7 are located within a length of the axially extending slot 6c.

The pressure sensors 7 are further arranged in such a way that a number of the plurality of pressure sensors 7 are grouped around a circumference of the central part 1a of the substantially stationary structure 1 and moreover are located at a same level.

The adjustment system for the submerged wing profile 2 comprises a power transmission plate 8c extending through the axially extending slot 6, where the power transmission plate 8c is connected to the sleeve-shaped element 2f of the submerged wing profile 2.

The power transmission plate 8c is also connected to a movement arrangement 34c in the form of a stem 24b of a hydraulic cylinder 24a.

Furthermore, figure 4A shows in greater detail a principle on how the upper and lower damper 10a, 10c act during the movement of the submerged wing profile 2, where it can be seen how the power transmission plate 8c being connected to the stem 24b of the hydraulic cylinder 24a, due to the movement of the submerged wing profile 2 and the stem 24b, will cooperate with the upper and lower damper plate 10b, 10d of the upper and lower damper 10a, 10c respectively.

In this embodiment each of the upper and lower damper plate 10b, 10d may comprise an elongated element, where each end of the elongated element is provided with a flange or abutment plate. The flange or abutment plates are arranged in such a way that they extend in opposite radial directions, i.e. one flange or abutment plate will extend out radially left from the elongated element, while the flange or abutment plate arranged on the opposite end of the elongated element will extend out radially right from the elongated element.

A far left on figure 4A shows the submerged wing profile 2 is shown in a central position within the initial area, where the submerged wing profile 2, through the power transmission plate 8c, is not compressing the upper or lower damper 10a, 10c, whereby the upper and lower damper 10a, 10c are not compressed.

The middle figure on figure 4A shows the submerged wing profile 2 in its upper, maximum position, where the movement of the submerged wing profile 2 towards this upper, maximum position has resulted in that the upper damper 10a has been compressed through the cooperation of the power transmission plate 8c connected to the stem 24b of the hydraulic cylinder 24a and the upper damper plate 10b. In this upper, maximum position of the submerged wing profile 2, the upper damper 10a will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again (i.e. an area where the submerged wing profile 2 is not compressing the upper or lower damper 10a, 10c). The lower damper 10c is not compressed when the submerged wing profile 2 is in its upper, maximum position.

A far right on figure 4A shows the submerged wing profile 2 in its lower, maximum position, where the movement of the submerged wing profile 2 towards this lower, maximum position has resulted in that the lower damper 10c has been compressed through the cooperation of the power transmission plate 8c connected to the stem 24b of the hydraulic cylinder 24a and the lower damper plate 10d. In this lower, maximum position of the submerged wing profile 2, the lower damper 10c will add a force to the submerged wing profile 2 in order to move the submerged wing profile 2 towards the initial area again. The upper damper 10a is not compressed when the submerged wing profile 2 is in its lower, maximum position. Figure 4B shows in greater detail the adjustment system for the submerged wing profile 2, where it can be seen that the hydraulic cylinder 24b through the hydraulic cylinder stem 24b is connected to the power transmission plate 8c, where the power transmission plate 8c and the hydraulic cylinder 24a are arranged in a cavity 5 provided within the substantially stationary structure 1 .

Since the embodiments of the adjustment system for the submerged wing profile 2 according to figures 2A-4B are used in the same way as the adjustment system described in relation to figures 1A-1 B, we refer to the description of figures 1A-1 B, where it is explained in more detail how the set position of the submerged wing profile 2 is calculated and adjusted, how the generator 16 is used to brake down the movement of the submerged wing profile 2, how the control/regulation system is used to regulate the generator 16 etc.

The different embodiments of the adjustment system for the submerged wing profile 2 will then calculate the set position (i.e. set water depth relative to still water level 4) for the submerged wing profile 2, whereafter the submerged wing profile 2 will be allowed to oscillate about this set water depth, following the incoming waves form. The varying brake force applied to the submerged wing profile 2 from the generator 16 (or the hydraulic cylinder 24a) will allow the submerged wing profile 2 to move a certain distance from the set position in both directions (up and down), and if the submerged wing profile 2 reaches upper damper 10a or lower damper 10c, the damper 10a, 10c will add extra braking force to the submerged wing profile 2 in order to slow down the speed or movement of the submerged wing profile 2 until the submerged wing profile 2 stops completely. When the submerged wing profile 2 has come to a complete stop, the wave form, and possibly also the upper or lower damper 10a, 10c (if the upper or lower damper 10a, 10c has been compressed), will begin to move the submerged wing profile in an opposite direction.

An uppermost part of figure 5 shows a driveline for supply of electric current, where it can be seen that the driveline comprises a generator system (33) including one or more generators 16, a generator controller 30 and a unit 31 comprising variable DC-DC converter, battery, capacitors and a control system, and gears 12 and a clutch 21 , where the electric current can be exported to a central power station 32 or the like.

The gears 12 are, via the clutch 21 , in direct connection with the electric generator 16 and the generator controller 30, where the generator controller 30 regulates the braking force in the electric generator 16 and converts from varying frequency and voltage to direct current DC, whereafter the direct current is sent to a variable DC-DC converter and battery. A lowermost part of figure 5 shows the hydraulic cylinder 24a with a slide valve 25c which uses a left square of the slide valve when the submerged wing 2 is on its way up and the right square when the submerged wing 2 is on its way down.

An accumulator 25a, being connected to the slide valve 25c, is then used to dampen a pressure build-up from the hydraulic cylinder 24a. An accumulator 25b, also being connected to the slide valve 25c, will ensure a minimum overpressure, and will also compensate for changes in volume on a return side due to a varying volume in accumulator 25a, varying total volume in the hydraulic cylinder 24a and temperature variations.

A one-way valve 25d connected to the slide valve 25c will open when accumulated pressure exceed force/pressure built up in the hydraulic cylinder 24a and will also prevent the hydraulic cylinder 24a to be pushed back before wave force pulls the submerged wing 2 into an opposite direction.

A one-way valve 25e connected to a hydraulic motor 26 will prevent the hydraulic motor 26 and the electric generator 16 from being forced to stop when stopping supply of oil from the hydraulic cylinder 24a and accumulator 25a.

The electric generator 16 is in turn connected to a generator controller 30, where the generator controller 30 regulates the braking force in the electric generator 16 and converts from varying frequency and voltage to direct current DC, whereafter the direct current is sent to the unit 31 comprising variable DC-DC converter, battery, capacitors and a control system, whereafter the electric current can be exported to a central power station 32 or the like.

Figure 6 shows wave directions 3d, 3e, 3f towards the submerged wing profile 2 and a center part of the substantially stationary structure 1 , as well as four pressure sensors 7a-7d arranged around the center part.

The wave direction is then measured by comparing pressure on at least two of the pressure sensors 7a-7d, for instance may it be compared which of the two pressure sensors 7a, 7d has the highest pressure when the pressure on both pressure sensors 7a, 7d are increasing, after the pressure on both pressure sensors 7a, 7d has been decreasing simultaneously for a certain time period. Comparison is made in counting the number of times the pressure on sensor 7d is greater than the pressure on sensor 7a. Within a period of time, for instance 30 minutes, the direction of the substantially stationary structure 1 can be adjusted a small step, for instance 15 degrees, clockwise or counterclockwise if the counter difference is above or below a certain %-value, in order to position the submerged wing profile 2, and thereby also the substantially stationary structure 1 , in the most favorable position relative to the directions 3d, 3e, 3f of the incoming waves.

The substantially stationary structure 1 may be turned 180 degrees so that the waves come in towards the opposite long side of the submerged wing 2, then sensors 7b, 7c may be used for adjustment.

In addition to use of the pressure sensors 7a-7d, one may use external weather, wave data and/or manual controls to adjust the substantially stationary structure relative to the direction of the incoming waves.

Figure 7 show a principle for the control system from sensors 7, 9, 13 and remote-control 36 trough PLC 35 to and from generator controller 30, PLC 35 to and from winches 44a, 44b and joints 57, 62, PLC 35 to and from the heading rotation device 42.

In one embodiment a value for the submerged wing profile’s 2 position relatively to the substantially stationary structure 1 is calculated by the PLC block 35a on input from generator speed sensor 13a and digital signal input from transmission plate position sensor 9. The transmission plate position sensor 9 calibrate the position calculation to sensor position when transmission plate 8 move past the sensor 9. PLC function 35a send the calculated position value to the PLC block 35c.

In another embodiment the value for submerged wing profile’s 2 position relatively to the substantially stationary structure 1 is calculated by the PLC block 35a on input from flow meter 13b on hydraulic fluid to from the hydraulic cylinder 24 and a digital signal input from transmission plate position sensor 9. When the power transmission plate 8 moves past the position sensor 9, the calculation in the PLC block 35a is adjusted (calibrated) to the position for the position sensor 9. PLC block 35a send the calculated position value to the PLC block 35c.

In one embodiment the value from generator speed sensor 13a is sent as input to PID controller 35b, and the PID controller will thereafter send a 0-100% signal to PLC block 35c. In another embodiment the value from flow meter 13b is sent as input to PID controller 35b, and the PID controller will thereafter send a 0-100% signal to PLC block 35c.

The PLC block 35c use input from PID controller as main parameter for the output to the generator controller 30. The signal from PID controller is multiplied with different factors, from one or more of the average wave height calculated by block 35e, wavelength calculated by block 35f and calculated submerged wing 2 water depth relative to still water level 4. The calculated submerged wing 2 water depth relative to still water level 4 is a sum of the substantially stationary structure 1 submerged depth 35g, and submerged wing 2 position relatively to the substantially stationary structure 1 from calculation block 35a. The factor for calculated submerged wing 2 water depth relative to still water level 4 will vary during the submerged wing 2 position relatively to the set position for the submerged wing 2. When the submerged wing 2 is on its way up relative to the substantially stationary structure 1 , the factor will be larger the closer the submerged wing profile 2 get to the still water level 4.

When the submerged wing profile 2 is on its way down, the factor will be larger the deeper or further away the submerged wing profile 2 get from the still water level 4. When the submerged wing profile 2 is in the set position, the factor for the submerged wing profile 2 up and down directions is equal. The PLC block 35c has a database to select the submerged wing profile’s 2 set position based on the average height calculated by the block 35e and wavelength calculated by block 35f.

In addition, the pressure reading from hydraulic pressure 13c can with a factor be added to or multiplied with the signal from PID controller 35b.

Furthermore, a remote signal 36 may, in addition, be used to increase or reduce the output signal from block 35b to the generator controller 30 by adding a factor to be multiplied with the signal from PID controller.

The PLC block 35d calculates an average pressure reading from the pressure sensors 7a, 7b, 7c and 7d.

The PLC block 35e calculates a factor for the average wave height at a certain time period by use of variable pressure reading from PLC block 35d.

The PLC block 35f calculates a factor for the average wave length wavelength at a certain time period by use of variable pressure reading from PLC block 35d. The PLC block 35g calculates a factor for the substantially stationary structure 1 submerged depth by use of variable pressure reading from PLC block 35d.

The PLC block 35h use the average wave height calculated by block 35e, wavelength calculated by block 35f, calculation on substantially stationary structure 1 submerged depth by block 35g and feedback signal from winches 44a, 44b or joints 57, 62 and a database to calculate and/or select a raise lower command for winches 44a, 44b or joints 57, 62, causing a standstill, raise or lower signal for adjusting the substantially stationary structure 1 water depth.

In addition, a remote signal 36 to block 35h can be used to raise and lower the substantially stationary structure 1 .

The PLC block 35i use the pressure sensors 7a, 7b, 7c and 7d to calculate if the average wave direction is perpendicular to the long side of an oblong wing 2, see also 3e figure 6, or if the average wave direction is coming with an angle less than a certain value to the long side of an oblong wing 2, see also 3d and 3f figure 6. If the average wave direction is coming with an angle less than a certain value to the long side of an oblong wing 2 the PLC block 35i send a command to rotation device 42 to make a small adjustment clockwise or counterclockwise.

In addition, a remote signal 36 to block 35i can be used to change heading of the substantially stationary structure 1 and oblong wing.

In addition, readings for all equipment connected to the PLC 35 may be sent to the remote station 36 for information to perform manual adjustment and control.

Based on the above, the submerged wing profile 2 is adjusted to stay at an average depth in relation to the set position with a variable factor, where the factor constantly changes according to the submerged wing profile’s 2 depth relative the still water level 4 and the direction of movement of the submerged wing profile 2 (i.e. whether the submerged wing profile 2 is moving up or down).

When the submerged wing profile 2 is on its way up, the factor will increase the higher the submerged wing profile 2 moves upwards. Correspondingly, when the submerged wing profile 2 is descending, the factor will increase the lower the submerged wing profile 2 moves downwards. A higher factor will cause the electric generator 16 to be braked more forcefully (and possibly also the upper or lower damper 10a, 10c), so that the submerged wing profile 2 is braked, thereby also narrowing the submerged wing profile’s 2 range of motion. This will result in that the submerged wing profile 2 will oscillate mainly within the initial area.

Figures 8A-8E show different areas for application of the wave energy converter power plant according to the present invention, where figure 8A shows the wave energy converter power plant P as an anchored buoy with positive buoyancy, where the substantially stationary structure 1 is anchored to a seabed 47 through anchors 46 and mooring wires 45. One end of the mooring lines 45 is connected to a lower winch 44b, while an opposite end of the mooring lines 45 is connected to an upper winch 44a. The upper winches 44a are in turn connected to a yoke 43 connected to a direction rotation device 42.

The control and elevation adjustment system for the substantially stationary structure 1 is used to position the substantially stationary structure 1 in the set position and to maintain the substantially stationary structure 1 in the set position.

Furthermore, as the control and elevation adjustment system may comprise control and adjustment of heading of the substantially stationary structure 1 to position the substantially stationary structure 1 (and also the submerged wing profile 2) in a desired direction relative to the incoming waves.

The adjustment of the substantially stationary structure 1 with regard to elevation and/or heading may be carried out continuously or with given or desired time intervals.

Figure 8B shows an alternative mooring of the substantially stationary structure 1 as an anchored buoy with positive buoyancy, where the substantially stationary structure 1 in this embodiment comprises one mooring wire 45 connected to an anchor 46 through a lower winch 44b and to an upper winch 44a which is connected to a direction rotation device 42. A direction hold system 48 is also connected to the direction rotation device 42, where the direction hold system 48 comprises a direction hold arm 48a, and a line 48b connected to the direction hold arm 48a and an anchor 46 arranged on the seabed 47.

Furthermore, a weight 48c is connected to the line 48b, together with a buoyant element 48d. The purpose of the direction hold system 48 is to keep the substantially stationary structure 1 in a position (i.e. heading) after the control and elevation adjustment system has adjusted the substantially stationary structure 1 in a desired direction relative to the incoming waves.

Figures 8C-8E show additional areas for the application of the wave energy converter power plant according to the present invention with the substantially stationary structure 1 as a hanging structure with negative buoyancy by use of weight 55. The substantially stationary structure 1 may then be “hang off’ from another structure 50 through mooring wires 52, winches 44a, 44b, yoke 53 and direction rotation device 42 (figure 8C), “hang off’ from another structure 50 through an arm 56, one or more joints (adjustable mounting points) 57 and direction rotation device 42 (figure 8D) or even “hang off’ from another structure 50 through a base 60, one or more articulated arms 61 , 62 and direction rotation device 42.

Figures 8A-8E do not describe the wave energy converter plant P with regards to the submerged wing profile 2, the substantially stationary structure 1 , the adjustment systems for the submerged wing profile 2 and the substantially stationary structure 1 , but it should be understood that the wave energy converter plant P according to figures 8A-8E comprises an adjustment system for both the submerged wing profile 2 and the substantially stationary structure 1 described according to figures 2A-4B, a drive line for supplying electric current according to figure 5 and a control system according to figure 7, whereby a person skilled in the art on the basis of this will be able to practice the present invention.

The set position for the substantially stationary structure 1 and the submerged wing profile 2 will therefore be adjusted in relation to a “table” or database for a desired water depth at different wave heights and a table or database with different factors for different wavelengths, where these are multiplied with each other and will give a set position for the substantially stationary structure 1 and submerged wing profile 2.

The invention has now been explained with several different embodiments. Only elements related to the invention are described and a skilled person will understand that one may make several alterations and modifications to the wave energy converter power plant as described and shown through the different embodiments that are within the scope of the invention as defined in the following claims.