GB2611264A

GB2611264A - Wave generator doing work in one direction by using buoyancy

Info

Publication number: GB2611264A
Application number: GB2300192.8A
Authority: GB
Inventors: Qu Yanming
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-07
Filing date: 2020-04-07
Publication date: 2023-03-29
Anticipated expiration: 2040-04-07
Also published as: GB2611264B; WO2021203224A1

Abstract

A wave generator doing work in one direction by using buoyancy, comprising a wave energy convert system and a pretensioning system; the wave energy convert system comprises a sea surface assembly (129), an energy collecting cable (30) and an underwater relative motion reference object (17); the sea surface assembly comprises floating bodies (1), members (3, 19) moving relative to the floating bodies, a hydraulic system and a generator (7), the hydraulic system can be a closed circulation/open circulation; a single chip microcomputer/PLC receives a signal from a second sensor (126) monitoring a working state/a wave surface state of the sea surface assembly, so as to control the pretensioning system, thereby increasing the utilization rate of wave height.

Description

A Wave Generator Using Buoyancy to Work in One Direction

Technical Field

The present disclosure relates to a wave generator, which belongs to the field of wave power generation. Background Technology CN 107255060A and CN 103 104408A are the closest prior arts to the present disclosure, but with the problem of wave height utilization loss.

Contents of the Disclosure

The purpose of the present disclosure is to provide a wave generator using buoyancy to work in one direction, capable of pre-tensioning the energy harvesting line compared with prior arts.

The Technical Scheme of the Present Disclosure:

A wave generator using unidirectional work done by buoyancy (using the unidirectional work done by wave's buoyancy), includes a wave energy collection and conversion system (WECS), which includes a sea surface assembly, an energy harvesting line, and an underwater relative motion reference.

The sea surface assembly means: the most basic part of the WECS (excluding the rope control device), which is close to the sea surface and harvests and converts wave energy into electrical energy, including a floating body, a member moving relative to the floating body, a hydraulic system and a generator; the sea surface assembly are classified as single floating body spring reset type, single floating body pressure difference reset type (A and B), and double floating body gravity reset type (A and B).

Definition of the energy harvesting line: a elongated and flexible tension-transferring component (such as a hawser/chain/O-belt, preferably a UHMWPE rope) that connects the "member moving relative to the floating body" to the underwater relative motion reference, which is subject to pulse tension and is the key force transferring member for wave energy harvesting; in addition, if there is a rope control device, the energy harvesting line is part of the rope control device, and the member moving relative to the floating body is indirectly connected to the underwater relative motion reference via the energy harvesting line of the rope control device.

The underwater relative motion reference means: a solid that provides a reference for the relative motion of the floating body, such as a suspending anchor (a gravity anchor suspended in the water) or a gravity anchor on the seabed, or a friction pile/suction anchor inserted in the seabed.

The member moving relative to the floating body means: together with the floating body, it forms a pair of relative movements mechanism; the wave buoyancy force acts upward on the floating body, while the tension force of the energy harvesting line acts downward on the member to drive a hydraulic cylinder of a hydraulic system which connects the two to output high pressure hydraulic oil. The hydraulic system is classified into a closed cycle type and a open cycle type, and the route of the closed cycle is: a hydraulic cylinder, an outlet check valve, a high pressure accumulator, a hydraulic motor, a low pressure accumulator, an inlet check valve; and the route of the open cycle is: a hydraulic cylinder, an outlet check valve, a high pressure accumulator, a hydraulic motor, an oil tank, an inlet check valve. The hydraulic motor drives the generator to generate electricity.

Refer to CN 107255060A for details of several disclosed WECS sea surface assembly technologies. Representative embodiments in several types of sea surface assemblies are also presented in the specific embodiments in this specification.

This article introduces a new WECS sea surface assembly of single floating body pressure difference reset B type. The scheme VIII is as follows: The structure of the sea surface assembly: A floating body whose structure can be interpreted as: A closed shell is penetrated by a vertical straight pipe through the center and then the part of the shell in the straight pipe is removed, therefore a closed shell with a through-hole in the center is formed; an inverted L rigid frame has a square tube or a thin and long straight cuboid rod as the vertical park the vertical part passes through two 4-roller fairleads installed in the through-hole and spaced by a certain vertical distance and its four side faces tightly cling to the four rollers of each 4-roller fairlead respectively; the two 4-roller fairleads may be replaced with two upper and lower guide rails that guide the vertical motion of the inverted L rigid frame; The horizontal part of the inverted L rigid frame is located above the floating body and connected to the plunger rod of a vertical/inclined (inclining in the plane of the inverted L rigid frame will be best) plunger cylinder. The back end of the body of the plunger cylinder is connected to the top surface of the floating body. The plunger cylinder may be connected inversely, i.e.: The back end of the body of the plunger cylinder is connected to the horizontal part of the inverted L rigid frame and the plunger rod is connected to the top of the floating body; The connection between the plunger cylinder and other components (the floating body/inverted L rigid frame) may be fixed connection/hinged shaft/earring connection (if the plunger cylinder is inclined, a fixed connection is not applicable. The types of fixed connection include flange connection and threaded connection); The bottom of the inverted L rigid frame is connected to one end of the energy harvesting line and the other end of the energy harvesting line harvesting line is connected to the underwater relative motion reference object: Alternatively, the bottom of the inverted L rigid frame may be connected to a top of a rope control mechanism and the bottom of the energy harvesting line of the rope control mechanism is connected to the underwater relative motion reference object. The connection between the inverted L rigid frame and the top of the rope control mechanism is fixed connection/moveable connection (flexible/universal cormection, e.g., double locking rings/cross universal connection will be the best).

The hydraulic system forms a closed circulation. The route of the cycle is from the chamber of the plunger cylinder to an outlet check valve (relative to the plunger cylinder), a high pressure accumulator, a hydraulic motor, a low pressure accumulator and an inlet check valve (relative to the plunger cylinder). The hydraulic motor drives the generator to generate power; Preferably: the hydraulic lines connected to the oil inlet and outlet (not the oil drain) of the plunger cylinder enter the floating body from its top cover and the entrance should be sealed. Preferably: The generator and hydraulic system except the plunger cylinder are in the chamber of the floating body; The lower one of the two fairleads/guide rails may be installed at the bottom in a vertical straight tube. Specifically, a vertical straight tube is added. The top of the straight tube is fixed and connected to the bottom surface of the floating body, the axis of the straight tube coincides with the axis of the through-hole and the inner diameter of the straight tube is larger than the inner diameter of the through-hole, or the inner diameter of the straight tube is smaller than the through-hole and a flange is fixed and comiected to the top of the straight tube so that the straight tube can be fixed and connected to the bottom surface of the floating body through the flange; The lower one of the two fairleads/guide rails may be moved downward and installed at the bottom in the straight tube and the upper fairlead/guide rail may be installed in the through-hole of the floating body and near the top. The above part describes the scheme VIII.

The scheme VIII has the preferable scheme V111-1: A oil filter is connected in series in the closed hydraulic system and located between the inlet check valve and the low pressure accumulator; The scheme VIII has the preferable scheme VIII-2: The generator is a bnishless and pennanently magnetic AC or DC generator; The scheme VIII has the preferable scheme The motor is an valve plate type axial plunger motor; The scheme VIII has the preferable scheme The body of the plunger cylinder is placed at a lower level and the plunger rod is placed upwards. A hood is added on the top of the body of the plunger cylinder. The hood and the top surface of the body of the plunger cylinder jointly fonn a sealing cavity for collecting the oil drained from the place where the plunger rod extends. The plunger rod extends through the seal ring at the top hole of the cavity. An oil drain line is guided out of the sealing cavity and then downward and then enters the cavity through the top cover of the floating body. The entrance should be sealed and the full closure of the floating body should not be affected. The oil drain line finally enters the oil tank; Preferably, the oil drain line of the hydraulic motor also enters the oil tank; The scheme has the preferable scheme An electric oil charge pump is used to pump the hydraulic oil from the oil tank and then inject the oil into the closed circulation type hydraulic system. Further preferable: The oil is injected through the pipelines next to the low pressure accumulator. Further preferable: The electric oil supplement pump is a electromotor-driven cycloid pump.

Preferable scheme for the scheme An MC U module and its ancillary power supply circuit may be added. It controls the start and stop of the electric oil charge pump based on the data transmitted by the liquid level sensor of the oil tank or the hydraulic sensor of the dosed circulation hydraulic system.

The scheme VIII has the preferable scheme The structure of the floating body is as follows: It is a cylinder-shaped closed shell with a through-hole along the axis and fully enclosed shell; The further preferable scheme is that the floating body is made of Steel/fiber glass-reinforced plastic/high-density poly:ethylene/poly urea.

The scheme VIII has the preferable scheme The plunger rod is coated with a protective cover (soft rubber material will be the best). One end of the protective cover is abutted to the plunger rod and sealed and the other end is abutted to the outside of the body of the plunger cylinder and sealed; The scheme VIII has the preferable scheme The inverted L rigid frame and straight tube are both rigid components; The scheme VIII has the preferable scheme The straight tube is round pipe-shaped, Its connection with the floating body is a welding/flanged connection.

The scheme VIII has the preferable scheme Preferably: The electric cable of the rope control mechanism starts from the inside of t the floating body and exits on top of the floating body, then extends upward spirally and finally enters a horizontal steel pipe. The steel pipe is welded to the side of the vertical part of the inverted L rigid frame and their cavities were also merged. The electric cable extends horizontally along the steel pipe successively, and enters the vertical square tube of the inverted L rigid frame and then extends downward; If the inverted L rigid frame and the top surface of the rope control mechanism are connected flexibly, the electric cable exits from a side surface at the bottom of the inverted L rigid frame and finally enters the shell of the control rope rack; if the connection between the inverted L rigid frame and the top surface of the rope control mechanism is flexible, the electric cable exits out from the bottom side of the inverted L rigid frame and finally enters the cavity of the rope control frame; If the inverted L rigid frame is fixed to the shell of the rope control mechanism, the electric cable may enter the rack shell of the rope control mechanism through the outlet at the bottom of the inverted L rigid frame, but the inlet should be sealed; Or if the inverted L rigid frame is an inverted L-shaped square steel pipe, the electric cable enters the steel pipe from the opening of the horizontal part, exits from the opening at the bottom of the vertical part and then enters the cavity of the rope control mechanism.

A pre-tension system may be added to various sea surface assemblies in the instructions for pre-tension the energy harvesting line in advance and thereby improving the wave height availability. There are two categories of pre-tension system schemes, namely external accumulator scheme and high pressure side backflow pre-tension scheme.

External accumulator pre-tension scheme 1: A wave generator using unidirectional work done by buoyancy including a wave energy collection and conversion system which includes a sea surface assembly, an energy harvesting line and an underwater relative motion reference object. The sea surface assembly is of the single floating body spring reset type/single floating body pressure difference reset type/double floating body gravity reset type and includes a floating body, a member moving relative to the floating body, a hydraulic system and a generator; The hydraulic system is of then closed circulation/open circulation type. The route of the closed circulation is as follows: Hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, low pressure accumulator and inlet check valve; The route of the open circulation is as follows: Hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, oil tank and inlet check valve; It is characterized by: A new hydraulic branch may be led out from the hydraulic line (i.e., the pipeline between the hydraulic cylinder and the outlet check valve) at an oil inlet /outlet port of the hydraulic cylinder of the hydraulic system. The hydraulic branch passes through a solenoid switch valve/electric switch valve and is finally connected to a third accumulator; A MCU (Single-chip microcomputer) /PLC receives signals from a second sensor used to monitor operating status of the sea surface assembly/status of the wave surface where the sea surface assembly is located and controls on-off actions of the solenoid switch valve/electric switch valve; The solenoid switch valve may be replaced with a reversing branch. The specific scheme is as follows: A two-position four-way solenoid valve is under operating status: P>>A. B>>T or P>>B, A>>T. A branch containing a third check valve is added for connecting the B port to A port and thereby forming a circuit of B>>the third check valve>>A. The connections of the solenoid switch valve is replaced with the P and T ports of the two-position four-way solenoid valve and the MCU/PLC receives the signals of the second sensor used to monitor the operating status of the sea surface assembly/status of the wave surface where the assembly is located and control the two-position four-way solenoid valve; The scheme 1 has the preferable scheme 1-1: The solenoid switch valve is of the direct-acting type/step direct-acting type/pilot-operated type; The scheme 1 has the preferable scheme 1-2: The third energy accumulator/high pressure accumulator/low pressure accumulator is of the bladder type/piston type/diaphragm type/spring type. The scheme 1 has the preferable scheme 1-3: The underwater relative motion reference object is a suspended anchor or a gravity anchor/friction pile/suction anchor on the seabed.

High pressure side backflow pre-tension scheme 11: A wave generator using unidirectional work done by buoyancy, including a wave energy collection and conversion system which includes a sea surface assembly, an energy harvesting line and an underwater relative motion reference object. The sea surface assembly is of the single floating body spring reset type/single floating body pressure difference reset type/double floating body gravity reset type and includes a floating body, a member moving relative to the floating body, a hydraulic system and a generator. The hydraulic system is of then closed circulation/open circulation type. The route of the closed circulation is as follows: Hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, low pressure accumulator and inlet check valve; The route of the open circulation is as follows: Hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, opening oil tank and inlet check valve; It is characterized by: A hydraulic branch is connected in parallel with the outlet check valve of the hydraulic system. A solenoid switch valve/electric switch valve is connected in the hydraulic branch and the a MCU/PLC receives the signals from the second sensor used to monitor operating status of the sea surface assembly/status of the wave surface where the sea surface assembly is located and controls on-off actions of the solenoid switch valve/electric switch valve. The solenoid switch valve may be replaced with a reversing branch. The specific scheme is as follows: A two-position four-way solenoid valve is under the operating status: P>>A, B>>T or P>>B, A>>T. A branch containing a third check valve is added for connecting the B port to A port and thereby forming a circuit of B>>the third check valve>>A. The connections of the solenoid switch valve is replaced with the P and T ports of the two-position four-way solenoid valve and the MCU/PLC receives signals of the second sensor used to monitor operating status of the sea surface assembly/status of the wave surface where the sea surface assembly is located and control the two-position four-way solenoid valve; The solenoid switch valve/electric switch valve/reversing branch is taken as a demarcation point, and the section of the parallel hydraulic branch closer to the hydraulic cylinder is defined as the front half and the section closer to the high pressure accumulator is defined as the rear half The scheme II has the preferable scheme II-1 The solenoid switch valve is of the direct-acting type/step direct-acting type/pilot-operated type.

The scheme II has the preferable scheme 11-2: The underwater relative motion reference object is a suspended anchor or a gravity anchor/friction pile/suction anchor on the seabed. The scheme TT has the preferable scheme 11-3: The high pressure accumulator/low pressure accumulator is of the bladder type/piston type/diaphragm type/spring type.

According to external energy accumulator pre-tension scheme I. The preferable scheme 111 is as follows: An oscillating cylinder/pump&motor (can be used as both a positive displacement pump and a positive displacement motor) may be inserted (The expression "insert" here means the serial connection with other hydraulic elements in the hydraulic line) into the new hydraulic branch before or after the solenoid switch valve/electric switch valve/reversing branch. A shaft of the oscillating cylinder/pump&motor is coupled by a shaft (the expression "coupled by a shaft" means their main shafts are coaxial) to a flywheel, or the shaft of the oscillating cylinder/pump&motor is Finked to the flywheel through a belt/gear/chain transmission mechanism; According to the scheme III a preferable scheme III-1 is provided: A rotation speed sensor is added and the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve according to rotating speed of the flywheel monitored by the rotation speed sensor; Or a flow direction sensor/flow sensor/hydraulic sensor is added to the new hydraulic branch and the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve according to the change of the flow direction/flow of hydraulic oil monitored by the flow direction/flow sensor or the change of hydraulic pressure monitored by the hydraulic sensor; According to the scheme 111 a preferable scheme 111-2 is provided: The oscillating cylinder is of a blade type/pinion rack type/screw type/lever type; According to the scheme 111 a preferable scheme 111-3 is provided: The belt/gear/chain drive mechanism is used to increase the rotating speed of the flywheel.

According to the scheme Iff a preferable scheme I11-4 is provided: The pump& motor is an valve plate type axial plunger pump or an axis distribution flow type radical plunger motor.

According to the high pressure side backflow pre-tension scheme If a preferable scheme TV is provided: An oscillating cylinder/pump&motor may be inserted into the front half or rear half of the parallel branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism; The scheme IV has the preferable scheme IV-1: The oscillating cylinder is of a blade type/pinion rack type/screw type/lever type; The scheme IV has the preferable scheme 1V-2: The belt/gear/chain drive mechanism is used to increase the rotating speed of the flywheel; The scheme IV has the preferable scheme IV-3: The oscillating cylinder/pump&motor is inserted into the front half of the parallel branch. A continuous flow branch is led out from the hydraulic line between the solenoid switch valve/electric switch valve/reversing branch and the oscillating cylinder/pump&motor and connected to the low pressure accumulator/opening oil tank of the hydraulic system through a check valve, it is connected to the low pressure accumulator if the hydraulic system is of the closed circulation type, and connected to the oil tank if the hydraulic system is of the open circulation type; The check valve allows a flow direction from the low pressure accumulator/oil tank to the position between the solenoid switch valve/electric switch valve/reversing branch and the oscillating cylinder/pump &motor; The scheme IV has the preferable scheme IV-4: A reset spring is installed on the oscillating cylinder and the reset force of the reset spring makes the hydraulic oil in the oscillating cylinder flow from the end closer to the hydraulic cylinder to the other end.

The scheme IV has the preferable scheme IV-5: The pump& motor is a valve plate type axial plunger pump or an axis distribution flow type radical plunger motor; The scheme I has the preferable scheme V: A pressure amplifier cylinder is inserted into the new hydraulic branch; The scheme V has the preferable scheme V-1: An oscillating cylinder/pump&motor may be inserted into the new hydraulic branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism.

The scheme 11 has the preferable scheme VI: A pressure amplifier cylinder is inserted into the parallel branch; The scheme VI has the preferable scheme V1-1: In the pressure amplifier cylinder, the effective working area of the side closer to the hydraulic cylinder is larger than that of the side closer to the high pressure accumulator; The scheme VI-1 has the preferable scheme V1-2: An oscillating cylinder/pump&motor may be inserted into the parallel branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism.

The scheme VI-2 has a further preferable scheme: A rotation speed sensor is added for monitoring the flywheel, or a flow direction/flow sensor is inserted into the parallel branch, or a hydraulic pressure sensor is inserted into the section between the hydraulic cylinder and the oscillating cylinder/pump&motor; the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve/reversing branch according to the rotation speed sensor/flow direction sensor/flow sensor/hydraulic pressure sensor.

The scheme 1 or 11 has the preferable scheme VII: The second sensor may be one of the following types: 1) Distance sensor: A sensor installed on the floating body and used to monitor the change of distance between a member linked to the energy harvesting line (not limited to the member moving relative to the floating body) and a top surface of the floating body; Preferably: The sensor is installed on the top surface of the floating body and the monitored member is above the top surface of the floating body; Preferably: The distance sensor is of a laser/ultrasonic wave/infrared type; 2) Linear displacement sensor: consists of two components that can move linearly relative to each other, one connected to the floating body and the other connected to a member linked to the energy harvesting line. Preferred: One of the components is connected to the top surface of the floating body, and the other component is connected to the member above the top surface of the floating body; Preferred: The linear position sensor is a pull lever/pull rope type.

3) Linear speed sensor: consists of two components that can move linearly relative to each other, one connected to the floating body and the other connected to a member Finked to the energy harvesting line. Preferred: The first component is connected to the top surface of the floating body and the member to which the second component is connected is above the top surface of the floating body.

4) Acceleration sensor: It is installed on the floating body and used to measure the acceleration of the floating body; 5) Draft sensor: A water pressure sensor installed outside the bottom surface of the floating body and used to monitor the draft depth of the floating body; 6) Tension sensor: It is connected in series with the energy harvesting line (the tension sensor replaces a section of the energy harvesting line or connected in series with the energy harvesting line) and used to monitor the tensile force of the energy harvesting line; 7) Hydraulic pressure sensor: it is installed in the hydraulic line at the oil inlet/outlet port of the hydraulic cylinder and used to monitor the hydraulic pressure at the oil inlet/outlet port: 8) Flow sensor: It is installed in the hydraulic line at the oilinlet/outlet port of the hydraulic cylinder and used to monitor the flow at the oil inlet/outlet port; The scheme VII has the preferable scheme VH-1: The MCU/PLC receives external wave data/manually pre-set parameters/orders through a wireless communication module.

A derivative scheme of suspended anchor technology is also presented here. Suspended anchor is a gravity anchor suspended in the water, and please refer to the patent application CN107255060A for details. A brief description of the suspending anchor scheme is as follows: 1) Direct-connected suspended anchor: Two buoys moored at a certain distance from each other on the sea surface are each tied to a cable, and the other end of the two cables is connected to the underwater relative motion reference of the WECS, i.e. a gravity anchor, and suspends the gravity anchor in the water; the floating body of the WECS is located in the middle position of the two buoys.

2) Pulley suspended anchor: The two ends of a cord are tied to two buoys moored at a certain distance from each other on the sea surface, and the middle of the cable bypasses around a pulley close to the underwater relative motion reference of the WECS, i.e. a gravity anchor; the bottom end of the pulley bracket of the pulley is connected to the top surface of the gravity anchor, and the cable suspends the gravity anchor in the water; the energy harvesting line coming down from above which was to be connected to the gravity anchor is instead connected to the top of the pulley bracket, and the floating body of the WECS is located in the middle position of the two buoys.

3) Double Double-ropeway suspended anchor: The underwater relative motion reference of WECS, i.e. a gravity anchor, is a horizontal cuboid; the four vertices on the top surface of the gravity anchor are each installed with a pulley, so that there are two pulleys on each of the two opposite sides of the top surface of the gravity anchor; the pulleys (two) on each opposite side roll on one ropeway, and the two ropeways merge into one on the left side of the gravity anchor and bypasses around a pulley, the pulley bracket of which is connected to the cable used to suspend the gravity anchor on the left side, and likewise on the right side, and the left and right are symmetrically. The pulleys on both sides distribute the tension from the buoys on the cable equally across the two ropeways, which provide upward tension on the pulleys through which they pass and which are installed at the vertices of the gravity anchor so that the gravity anchor can be suspended in the water.

4) Lateral-passing-by suspended anchor: The underwater relative motion reference of the WECS, i.e., the gravity anchor, is a horizontal cuboid; a fairlead is installed on the front and rear sides of the gravity anchor respectively, and two guide pulleys are installed on the right two vertical edges of the gravity anchor; a cable passes through the rear fairleard pass by the guide pulley of the right rear edge and the guide pulley of the right front edge, and passes through the front cable guide, successively; the two fairleads and the two guide pulleys are at equal distances from the top surface of the gravity anchor; it is equivalent to the suspending cable bypassing one side of the gravity anchor, and the acting point of force is on the fairleads on both sides. It is obvious that the gravity anchor can slide along the ropeway with the help of the fairlead and guide pulley.

5) Stretcher suspended anchor: Two parallel rigid straight rods, with aligned end-faces, pass through two transverse through-holes separated by a certain distance on the underwater relative motion reference (i.e., gravity anchor) of the WECS. The left ends of the two rigid straight rods are fixed to a rigid frame, and the right ends of the two rigid straight rods are fixed to another rigid frame. The suspending cables on both sides are fixed to the rigid frames on both sides by V-shaped ropes, that is, the two vertices of the V-shaped rope are connected to the two ends of the rigid frame, and the bottom end of the V-shaped ropes is connected to the suspending cable. The suspending cables on both sides provide upward tension on the two rigid straight rods, and the rigid straight rods provide an upward lifting force to the gravity anchor, similar to a stretcher. The gravity anchor can slide left and right with the rigid straight rods as guide rails.

In the above suspended anchor schemes 3), 4) and 5), the other ends of the suspending cables on both sides of the gravity anchor are connected to two buoys moored at a certain distance from each other on the water surface, and the floating body of the wave generator is located in the middle position of the two buoys.

Preferred: In the above suspended anchor schemes, the floating body is connected to the two buoys on its left and right sides respectively with a cord. Further preferred: A weight may be tied in the middle of the cord or a tension spring may be tandem connected in the middle of the cord to provide a cushion.

The above is the suspended anchor scheme IX. In addition, the wet weight of the gravity anchor (the net weight in the water, that is, the gravity force exerted on it minus the buoyancy exerted on it) is preferably greater than the upward tension of the WECS when doing work; the maximum buoyancy available from the two buoys is preferably greater than the wet weight of the gravity anchor, preferably with sufficient redundant reserve buoyancy.

For the suspended anchor scheme IX, there is a preferred scheme the bottom of the suspended gravity anchor is fixed to a horizontally placed damping plate, and the gravity anchor is positioned at the central upper part of the damping plate.

For the suspended anchor scheme, there is a preferred scheme IX-2: the middle section of the cable suspending the gravity anchor is replaced by a tension spring. Further preferred: if the suspended anchor is a direct-connected/stretcher anchor, there are tension springs (preferably with the same elastic coefficient) tandem connected to the suspending cables on both sides.

For the suspended anchor scheme, there is a preferred scheme IX-3: the buoy that suspends the gravity anchor has a lathy capsule shape with an upright axis, and the suspending cable is attached to the bottom center of the capsule-shaped buoy.

A power transmission scheme X based on a floating body queue on the water surface is also presented here: There is a queue of floating bodies on the sea surface, and the floating bodies at the beginning and end of the queue are moored. In this queue, adjacent floating bodies are connected to each other by cords, that is, the whole queue of floating bodies is coimected by multiple cords in a string. hi the queue, some floating bodies are the floating bodies of the wave generator, and the circuit starts from the generator of the wave generator penetrates out of the floating body, attaches to the cord and extends along it.

For the power transmission scheme X, there is a preferred scheme X-I: part of the circuit is a section of electric cable which is loosely tied to the cord by a plurality of spaced strings, or the electric cable is spirally wound around the cord, or the electric cable is a spiral electric cable sleeved onto the cord.

For the power transmission scheme X, there is a preferred scheme X-2: the circuit passes through a coaxial rotating joint/universal joint/spherical hinge type circuit connector at the point where the circuit penetrates out of the floating body, specifically: as a part of the circuit, a single core cable led from one of the electrodes of the generator is connected to a terminal (end A) of a coaxial rotating joint/universal joint/spherical hinge type circuit connector. The terminal is fixed to the shell of the floating body (If the shell of the floating body is electrically conductive, end A should be insulated from the shell of the floating body. For example, an insulating spacer may be used to separate end A from the shell of the floating body, and when bolting end A, an insulating spacer shall be used to separate the nut from end A). The other terminal of this circuit connector (end B) is outside the floating body and is connected to one end of a single core cable extending along the cord (the other part of the circuit). Preferred: The circuit connector and its connection point with the electric cable are sealed on the shell of the floating body with a hemispherical flexible insulation cover to avoid contact with seawater The electric cable connecting the end B penetrates through a hole in the flexible insulation cover, and the hole is to be sealed. Further preferred: The cord is outside the hemispherical flexible insulation cover and is connected to one end of an insulation connecting rod. The other end of the insulation connecting rod penetrates through a hole in the insulation cover and is connected to end B, and the hole is to be sealed.

For the power transmission scheme X, there is a preferred scheme X-3: the cord is provided with a weight in the middle, and the circuit extension passes through a coaxial rotating joint/universal joint/spherical hinge type circuit connector there, with two design schemes: I) A certain point in the middle of a cord between the floating bodies is set as a mooring point to connect to the weight by a short string/chain/connecting rod. One terminal of the circuit connector is fixed to the cord on the left side of the mooring point using a fixing support and connected to a single core cable on the left side (part of the circuit), and the other terminal is fixed to the cord on the right side of the mooring point using another fixing support and connected to a single core cable on the right side (part of the circuit).Make a straight line through the tic point and perpendicular to the plane on which the ropes lie on both sides of the tie point. The straight line should coincide with the common axis of the rotary circuit connector Preferred: A flexible insulation bush is used to wrap and seal the circuit connector and its connection to the electric cable completely to protect against water and leakage of electricity. The fixing support is insulated and the fixing support and the electric cable penetrate out of the hole from the flexible insulation bush, and the hole is to be sealed 2) A cord between the floating bodies is broken in the middle, and the two end points formed after the break are connected to the two terminals of the circuit connector respectively. These two terminals are connected to single core cables (part of the circuit) on their left and right sides respectively; the circuit connector may be of the coaxial rotating joint type with its common axis connected to the weight; or the circuit connector is of the cross universal joint type with one of the ends of the cross (one of four ends) connected to the weight; or the circuit connector is of the rzeppa universal joint type, and the weight is connected to the outside surface of the bell jar of the universal joint; or the circuit connector is of the spherical hinge type, and the weight is connected to the outside surface of the spherical lunge.

Preferred: A flexible insulation bush (such as a rubber bush) is used to seal the circuit connector and its connection to the electric cable to protect against water and leakage of electricity. The cord is connected to the tenninal using an insulation connecting rod, specifically: The cord is outside the flexible insulation bush and is connected to one end of the insulation connecting rod, the other end of the insulation connecting rod penetrates through a hole in the flexible insulation bush and is connected to the terminal, and the hole is to be sealed. The weight may be located inside the flexible insulation bush, and is connected to the common axis/cross end /outside surface of the bell jar/outside surface of the hinge base using a short string/chain/connecting rod, or is connected directly. The weight may also be located outside the flexible insulation bush, and the weight is connected to one end of an insulation connecting rod. The other end of this insulation connecting rod pierces through a hole in the flexible insulation bush and is connected to the common axis/cross end point/outside surface of the bell jar/outside surface of the ball seat, and the hole is to be sealed against water.

In addition, the coaxial rotating joint (whose plug and socket can rotate around a common axis while keeping circuit connection) mentioned in this specification is available in the market, and the universal joint (including cross universal joint type and rzeppa type)/spherical hinge type circuit connector has the same structure as the universal joint/spherical hinge in the mechanical field, except that the material must be a conductor so that the current can flow from one end to the other end.

For scheme X. there is a preferred scheme X-4: one of die floating bodies, not the floating body of the wave generator, is herein named the buoy, and the circuit passes the buoy in three ways: 1) A coaxial rotating joint/universal joint/spherical hinge type circuit connector is installed on each of the left and right sides of the buoy; the circuit connectors on the left and right sides are installed in the same way. Taking one side for illustration, as follows: one terminal (end A) of the circuit connector is fixed to the shell of the buoy (if the shell of the buoy is electrically conductive, end A should be insulated from the shell of the buoy; for example, an insulating spacer can be used to separate end A from the shell of the buoy, and an insulating spacer may be used to separate the nut from end A when bolting end A): the other terminal (end B) of the circuit connector is outside of the buoy and connected to one end of a single core cable (part of the circuit) extending along the cord on that side; an additional single core cable is used to connect the two ends A of the two circuit connectors.

Preferred: The circuit connector and its confection point with the single core cable are sealed on the shell of the buoy with a hemispherical flexible insulation cover to avoid contact with seawater. The electric cable connecting the end B pierces through a hole in the flexible insulation cover, and the hole is to be sealed. Further preferred: The cord is connected to the buoy using an insulation connecting rod, specifically: The cord is outside the hemispherical flexible insulation cover and connected to one end of the insulation connecting rod. The other end of the insulation connecting rod pierces through a hole in the insulation cover and connected to the end B of the circuit connector, and the hole is to be sealed.

2) The circuit extension passes through the coaxial rotating joint/universal joint/spherical hinge type circuit connector at the buoy. specifically: The ends of the cord on the left and right sides of the floating body are connected together, and the connection point, named the mooring point, is connected to the bottom of the buoy; one terminal of the circuit connector is fixed to the cord on the left side of the mooring point using a fixing support and connected to a single core cable on the left side (part of the circuit); the other terminal of it is fixed to the cord on the right side of the mooring point using another fixing support and connected a single core cable on the right side (part of the circuit). The plane in which the cords on both sides pass through the mooring point and is perpendicular to the mooring point is a straight line, and the straight line shall coincide with the common axis of the coaxial rotating joint or with the center of the universal joint/spherical hinge type circuit connector.

Preferred: A flexible insulation bush is used to wrap and seal the circuit connector and its connection to the electric cable completely to protect against water and leakage. The fixing support is insulated, and the fixing support and the electric cable are sealed at the hole pierced from the flexible insulation bush.

3) The circuit extension passes through the coaxial rotating joint/universal joint/spherical hinge type circuit connector at the buoy, specifically: The cord on the left side of the buoy and the single core cable on the left side (part of the circuit) are both coimected to one terminal of the circuit connector, and the cord on the right side of the buoy and the single core cable on the right side (part of the circuit) are both connected to the other terminal of the circuit connector; the circuit connector may be of the coaxial rotating joint type with its common axis connected to the buoy; or the circuit connector may be of the cross universal joint type with one of the ends of the cross connected to the buoy; or the circuit connector is of the rzeppa universal joint type, and the buoy is connected to the outside surface of the bell jar of the universal joint; or the circuit connector is of the spherical hinge type. and the buoy is connected to the outside surface of the spherical hinge.

Preferred: A flexible insulation bush is used to wrap and seal the circuit connector and its connection to the electric cable completely to protect against water and leakage. The cord is connected to the terminal through an insulation connecting rod, specifically: the end point of the cord is outside the flexible insulation bush and connected to one end of the insulation connecting rod, the other end of the insulation connecting rod pierces the flexible insulation bush through a hole and connected to the terminal, and the hole is to be sealed; the buoy may be located inside the flexible insulation bush, and is connected to the common axis/cross end point/outside surface of the bell jar/outside surface of the ball seat using a short string/chain/connecting rod, or is connected directly; the buoy may also be located outside the flexible insulation bush, and is connected to one end of an insulation connecting rod. The other end of this insulation connecting rod pierces through a hole in the flexible insulation bush and is connected to the common axis/cross end point/outside surface of the bell jar/outside surface of the ball seat, and the hole is to be sealed against water.

For scheme X. there is a preferred scheme X-5: the floating body queue is arranged in a circle queue (like a clock scale); to maintain the circle, some of the floating bodies are moored by anchors. There is a plurality of (3) floating bodies of wave generators in the queue, and the generators of wave generators are all DC generators or AC generators with rectified output. The positive and negative output circuits of the generators respectively extend out from the floating bodies in two opposite directions and continue to extend along the cord in their respective directions, connecting the generators of the wave generators in series through the circuits in the queue order, but without making a direct connection between the generators of the first and last wave generators, thus forming a general power supply with an output voltage equal to the sum of the voltages of all the generators.

The advantage of this scheme is: the circuit can use single core cables for simple energy aggregation, automatic voltage boost, and low cost. For scheme X-5, it is preferred that: A weight is installed in the middle of the cords between the floating bodies; scheme X-3 is adopted when the circuit passes through the weight tied in the middle of the cord; scheme X-1 may be adopted when the circuit extends along the cord; scheme X-1 may be adopted when the circuit goes from the generator to the outside of the floating body; scheme X-4 may be adopted when the circuit passes the buoy.

Scheme X. X-1, X-2, X-3, X-4, and X-5 can be used in any combination as required. Scheme X and its subordinate schemes (X-1, X-2, etc.) are applicable to each wave generator mentioned in this specification. Advantages of the Present Disclosure: I) The inverted L-type WECS of the present disclosure is simple in structure, easy to disassemble, and convenient to maintain, and the inverted L rigid frame and the top of the rope control mechanism are connected by a flexible/universal joint, which can reduce the wear and tear of the energy harvesting line.

2) The external accumulator type pre-tensioning schemes and high pressure side return flow type pre-tensioning schemes of the present disclosure make it possible to actively pretension the energy harvesting line during wave troughs, thus increasing the draft of floating bodies and improving wave height utilization. The external accumulator type pre-tensioning schemes and some high pressure side return flow type pre-tensioning schemes can also enable the floating body to use the remaining net buoyancy to do work during the wave crest, thus further improving the efficiency of wave energy utilization.

3) The additional designs of the present disclosure for the suspended anchor technology, such as the capsule-shaped buoy, the tension springs in the cable suspending the gravity anchor, and the damping plate fixed below the suspended anchor, not only enable the wave generator to retain the merits that the gravity anchor can shift with the floating body and the length of the energy harvesting line may be reduced, but also make the gravity anchor more stable and reduce the amount of variation of the relative motion amplitude between the floating body of the wave generator and the gravity anchor, thus facilitating the judgment of the operating state of the WECS by the external accumulator type pre-tensioning scheme and the high pressure side return flow type pre-tensioning scheme.

4) In the wave generator power transmission scheme, the electric cable is loosely tied to the cord by a plurality of strings spaced apart, or spirally wrapped around the cord, or in a spiral cable scheme, ensuring that the electric cable can adapt to the expansion and contraction of the cord and that the cord can provide support to protect the electric cable from being washed out in the event that seawater strikes the electric cable. The circuit extension passes through a coaxial rotating joint/universal joint/spherical hinge type circuit connector, which avoids the breakage caused by frequent bending of the electric cable; and the circle queue serie scheme of the wave generators allows the electrical energy of multiple generators to be aggregated using a single core cable, eliminating the need for booster stations and ensuring low cost.

Description of Figures

Figure 1: Structure Diagram of Single Floating Body Spring Reset Type WECS Figure 2: Structure Diagram of Single Floating Body Pressure Difference Reset A Type WECS Figure 3: Structure Diagram of Single Floating Body Pressure Difference Reset B type WECS (including the high pressure side return flow basic type pre-tensioning system) Figure 3A: Schematic Diagram of the Reversing Branch Figure 3B: Control Scheduling table after Replacing the Solenoid Switch Valve with the Reversing Branch in Figure 3 Figure 4: Stmcture Diagram of Single Floating Body Pressure Difference Reset B Type WECS (including the square tube) Figure 5: Structure Diagram of Double Floating Body Gravity Reset A Type WECS Figure 6: Structure Diagram of Double Floating Body Gravity Reset B Type WECS Figure 7: Schematic Diagram of the External Accumulator Basic Type pre-tensioning Scheme Applied to the Single Floating Body Pressure Difference B Type WECS (inverted L-type) Figure 7A: High Pressure Side Return Flow Type pre-tensioning Scheme (hydraulic amplifier + solenoid switch valve) Figure 7B: Control schedule of Figure 7A Figure 7C: High Pressure Side Return Flow Type pre-tensioning Scheme (hydraulic amplifier + oscillating cylinder + solenoid switch valve) Figure 7D: Control schedule of Figure 7C Figure 8: Functional Relationship Diagram of the Electrical Components of the pre-tensioning System Figure 9: Circuit Diagram of the Electrical Part of the pre-tensioning System Figure 10: MC U Flow Chart of the External Accumulator Basic Type pre-tensioning System Figure 11A: MCU Flow Chart of High Pressure Side Return Flow Basic Type pre-tensioning System (basic type) Figure 11B: MCU Flow Chart of High Pressure Side Return Flow Type pm-tensioning System (including oscillating cylinder + flywheel + continuous current branch) Figure 12: Schematic Diagram of the Application Effect of the Pre-tensioning System Figure13: External Accumulator Type pre-tensioning Scheme (gear rack type oscillating cylinder + rotation speed sensor) Figure 14: High Pressure Side Return Flow Type Pm-tensioning System (belt-type transmission + continuous current branch) Figure 15: External Accumulator Type pre-tensioning System (open cycle) Figure 16: High Pressure Side Return Flow Type pre-tensioning System (continuous current branch) Figure 17: Schematic Diagram of A Queue of Wave Generators Working with Suspended Anchors (with damping plate or tension spring) Figure 18: Schematic Diagram of the Combination of Suspended Anchor System and Generators Series Connection (spiral electric cable between floating bodies coaxial rotating joint/spherical hinge type circuit connector) Figure 19: Installation Diagram of the Cross Universal Joint Circuit Connector on the Shell of the Floating Body Figure 20: Structure Diagram of the Circuit at the Weight Passing Through the Spherical Hinge Type Circuit Connector Figure 20A: Structure Diagram of the Circuit at the Weight Passing Through the Coaxial Rotating Joint Figure 20B: Wave Generator Circle Queue Achieving Power Aggregation Figure 21: External Accumulator Type pre-tensioning System (reversing branch) Figure 2IA: Control Schedule of Figure 3 Figure 22: External Accumulator Type pro-tensioning System (reversing branch + hydraulic amplifier) Figure 22A: Control Schedule of Figure 22 Figure 23: High Pressure Side Return Flow Type pre-tensioning System (reversing branch + pump&motor) Figure 23A: Control Schedule of Figure 23 Figure 24: External Accumulator Type pre-tensioning System (reversing branch + oscillating cylinder) Figure 24A: Control Schedule of Figure 24 Figure 25: High Pressure Side Return Flow Type pro-tensioning System (hydraulic amplifier + reversing branch) Figure 25A: Control Schedule of Figure 25 Figure 26. High Pressure Side Return Flow Type pre-tensioning System (hydraulic amplifier + pump&motor + reversing branch) Figure 26A: Control Schedule of Figure 26 I -Floating body-Steel/fiber reinforced plastic/high-density polyethylene/polyurea shell; 2-Hydraulic cylinder-piston or plunger cylinder; 3-piston or plunger rod; 4-High pressure accumulator; 5-Oil filter; 6-Hydraulic motor; 7-Generator; 8-Low pressure accumulator; 10-Protective cover: Retractable rubber hose in the shape of a corrugated tube; 12-Electric cable: Single core cable coated by insulation cover, e.g., 1W flexible cable or BV hard cable; 13-housing of a rope control mechanism: A part of rack of the rope control mechanism; 17-Gravity anchor; 18-Counterweight: It has a specific gravity larger than that of water and will be used to provide the mechanical power for rope collection; 19-Inverted L rigid frame: A steel frame in the shape of an inverted L, where the horizontal part is a tube/rod and the vertical part is a thin cube or a square tube. It may be made of carbon steel/stainless steel/aluminum alloy materials, such as Q235; 20-Double roller warping choke; 21-Main rope; 22-Chain; 24-Hawser; 27-Piston; 30-Energy harvesting line; 33-Tension spring; 35-Hydraulic pipe; 44-String; 46-grip anchor; 47-Gear; 49-Short string; 50-Reset line; 5I-Weight: It has a specific gravity larger than that of water; 56 -Pulley; 57-cable 58-Anchor chain; 59-Buoy: A floating body on the sea surface that provides a buoyant force of a certain magnitude; 62-Pulley bracket; 63-Straight tube: A straight tube with a large inner diameter; It may be made of carbon steel/stainless steel/aluminum alloy/fiber glass-reinforced plastic materials; 68-Tripod; It was composed of three steel rods with their one end connected and fixed together and the other end forked by equal included angles. Its structure is similar to that of a camera tripod; 69-Top cover of floating body; 71-Steel pipe; 72-Openning oil tank; 73-Charge pump; 76-Third string; 79 rope control mechanism; 80-annular floating body: Column-shaped hollow shell with a through-hole along its axis. Its revolved section around the axis is rectangular; 81-Upright column; 82-Guide roller: It has the same shape as a fixed caster and guides the moving direction of a component by rolling 83-11-shaped support: A 11-shaped support or a trivet same as the Powerbuoy of OPT, i.e., a trivet-structured support that has a Y-shaped beam and 3 downward legs projecting from 3 terminals of the beam respectively; 84-Flexible/universal connection: A connection method by a chain/string, double locking rings (a pair of rings hooked together and fixed on two components to be connected respectively), a cross universal joint or a spherical hinge, etc.; It is a connection method that allows two components mutually connected to change the connection angle moderately. 86-Guide rail; 88-rigid frame: A frame of steel. The preferable materials include carbon steel/stainless steel/aluminum alloy; 89-Cushion block; 94-Rack; 97-damping plate: For displacement limit; 104-Second tension spring; 106-Limit block: A projecting solid that prevents the motion displacement of a fixed component from exceeding the design stroke; 108-Square tube; 111-Rectangular steel frame: A rectangular steel frame installed vertically; 113-Square steel; 114-Lug; 115-Oil drain tube; 116-Rubber hose; 121-Spiral cable; An elastic and retractable electric cable like a tension spring; 122-Solenoid switch valve It may be replaced with an electric switch valve that responds quickly; 123-Flywheel: A rotor with a large moment of inertia; 124-Belt-type transmission; 125-Oscillating cylinder; 126-Second sensor; 127-Pump&motor; 128-Third accumulator; 129-Sea surface assembly; 138-Plunger cylinder; 139-Piston cylinder; 140-Wave surface; 141-reset spring; 143-Sea floor; 144-Liquid level sensor; 145-Rotation speed sensor; 146-Wireless data transmission module; I47-Hydraulic amplifier; 148-coaxial rotating joint: its plug and socket can rotate around a common axle and keep the electrical connection; 149-Spherical hinge type circular connector: It is made of conductor materials (e.g., copper/aluminum); 150-Flexible insulation bush/cover: Thin, used for sealing; 15I-Cross universal joint; 152-Shell of floating body; 153-Insulation connecting rod: (e.g., a bar-shaped insulator); 154-Fixing support; 155-String;

Detailed description

The following is further illustrated in combination with the accompanying figures. All embodiments herein are representative examples intended to aid in the understanding of the present disclosure, not exclusive in form, and not intended to limit the protection scope of the present disclosure.

Section 1: The wave generator of the present invention, which uses unidirectional work done by buoyancy, generates electricity by using the wave buoyancy when the wave is rising and resets when the wave is descending. The core is the wave energy collection and conversion system, or WECS for short (without the rope control device), which includes a sea surface assembly, an energy harvesting line, and an underwater relative motion reference (e.g., gravity anchor/suspended anchor/vacuum suction anchor/pile). The sea surface assembly refers to the part of the wave generator close to the sea surface, which is the part that converts the relative motion into electrical energy, including the floating body, the member moving relative to the floating body, the hydraulic system, and the generator. The member moving relative to the floating body is connected to the underwater relative movement reference using an energy harvesting line or using an energy harvesting line of the rope control device.

Section IIA: The above wave energy convert system is divided into single floating body spring reset type, single floating body pressure difference reset type, and double floating body gravity reset type according to different reset forms of the hydraulic cylinder. There are two types of single floating body pressure difference reset type WECS. A type with a piston cylinder (when working, the hydraulic cylinder is pulled) and B type with a plunger cylinder (when working, the hydraulic cylinder is compressed).

The single floating body spring reset type sea surface assembly of the WECS in Figure 1 is referenced from Figure 6 of CN 103104408 A, and it is constructed as: The cylinder body of a single-acting piston cylinder 2 is installed in the bottom of the cavity of a floating body 1, and its piston rod extends downward to the outside of the floating body. One end of a hawser 24 is connected to the handle of the piston rod 3 of the single-acting piston cylinder, and the other end extends down through a fairlead 11 installed in the lower part of the floating body 1 and is connected to the top of a rope control mechanism 79 (this specification only discusses the rope control mechanism with the frame on the top and the energy harvesting line on the bottom). The bottom of the energy harvesting line 30 of the rope control mechanism 79 is connected to a gravity anchor. A hydraulic cycle is: rod chamber, outlet check valve, high pressure accumulator, hydraulic motor, oil tank, and inlet check valve, and the hydraulic motor drives the generator for power generation. The single-acting piston cylinder 2 is installed with a reset tension spring 33. Refer to CN 103104408 A for the principle.

The single floating body pressure difference reset A type WECS in Figure 2 is referenced from Figure 12 of CN107255060 A. The stmcture of floating body 1 in this figure may be: A closed shell, with a vertical tube running through the center, forms a fully closed shell with a hole running through the center after removing the shell part of the vertical tube, and it may also be seen as a thin-walled hollow shell structure created by a rectangle rotating around an axis (it is called a square section swimming ring structure in this specification). The axis is parallel to one of the sides of the rectangle and is at a certain distance from the rectangle. The bottom of the floating body 1 is fixed to the top of a vertical straight tube 63, and the axis of the through-hole of the equipment chamber coincides with the axis of this vertical straight tube 63. A fair lead 11 is installed at the bottom of the vertical straight tube 63, and the three legs (only 2 are shown in the figure) of a tripod 68 are fixed to the top surface of the floating body. The top of the tripod is connected to the top of the cylinder block of a single-acting hydraulic cylinder 2 by a chain 22, and the hawser 24 (which can also be replaced by a chain) is connected to the piston rod handle of the single-acting hydraulic cylinder 2 passes through the central hole of the floating body and the fair lead I I and is finally connected to the top surface of the shell 79 of the frame of the rope control device frame. The generator and the hydraulic system, except for the single-acting hydraulic cylinder 2, are all located in the cavity of the floating body 1 (the actual location of which in the dashed rounded rectangular box in this specification is marked by arrows).

The hydraulic system is a closed cycle, and the cycle route is: the rod cavity of the single-acting piston cylinder, exit one-way valve, high pressure accumulator, hydraulic motor, low pressure accumulator, and access one-way valve, and the hydraulic motor drives the generator for power generation. Refer to CNI07255060 A for the principle.

Section 11B: The single floating body pressure difference reset B type WECS of Figure 3 is referenced from CN107255060 A and includes a plunger cylinder 138, a floating body 1, and a fair lead II, specifically: The floating body 1 is a square section swimming ring structure. The cylinder block of the plunger cylinder 138 cylinder is in the lower part and the plunger rod 3 is in the upper part and is upright, and the end of the plunger rod 3 of the plunger cylinder 138 is fixed near the top hole of the floating body 1. The top of the plunger rod 3 of the plunger cylinder 138 is connected to the center of the top edge of a rectangular steel frame 111, and the plunger cylinder 138 and its plunger rod 3 are always surrounded by the rectangular steel frame 111 on all sides. The two vertical sides and bottom sides of this rectangular steel frame 111 remain out of contact with the top surface of the floating body 1 and the central hole wall at all times. The center of the bottom edge of the rectangular steel frame 11 I is connected to the top of a hawser 24. The other end of the hawser 24 passes successively through the vertical central hole of the floating body 1 and the fair lead 11 installed below the central hole of the floating body and then extends downwards to connect to the rope control mechanism 79.

The hydraulic system is a closed cycle, with the cycle route of the cavity of the single-acting piston cylinder, exit one-way valve, high pressure accumulator, hydraulic motor, low pressure accumulator, and access one-way valve, and the hydraulic motor drives the generator for power generation. Refer to CN107255060 A for the principle.

The hydraulic pipe 35 connected to the oil inlet and outlet of the bottom end of the plunger cylinder 138 extends into the top cover of the floating body 1.

In the foregoing, the bottom end of the cylinder block of the plunger cylinder 138 may also be connected close to the top hole of the floating body 1 using a lug/hinged shaft/ear loop. However, if the plunger cylinder 138 is not constrained to be tilted in a certain direction or the vertical side frame of the rectangular steel frame Ill can be moved unconstrained in a certain horizontal direction, a guide roller set shall be added to the two opposite sides on that vertical frame, perpendicular to the unconstrained direction. The support of the guide roller set is installed on the top surface of the floating body 1. The guide roller set is a pair of the same two cylindrical rollers with parallel axes, aligned end faces, and gaps between them, which are pressed against the opposite sides of the vertical frame of the rectangular steel frame 111, and the vertical frame is sandwiched between the two cylindrical rollers. The guide roller set limits the horizontal oscillation of the rectangular steel frame 111 in this free direction so that the rectangular steel frame 111 always coincides with the axial section of the plunger cylinder 138 and avoids tipping of the plunger cylinder 138. The two vertical frames (square steel 113) of the rectangular steel frame in Figure 4 are guided by the guide roller set 82 in both the vertical and horizontal directions.

In the foregoing, the hawser 24 + fair lead 11 in Figure 1, Figure 2, and Figure 3 may all be replaced with a square tube + double fair lead, specifically: in Figure 1, the square tube + double fair lead may replace the hawser 24 + fair lead 11. The bottom end of the piston rod 3 of the hydraulic cylinder is connected to the top of the square tube. The square tube passes through the two fair leads installed at the bottom of the floating body 1 at a certain vertical distance apart, and the bottom end of the square tube is then connected to the frame of the rope control mechanism 79. The bottom end of the piston rod 3 protruding from the bottom of the single rod piston cylinder 2 is instead connected to the top of a vertical square tube (fixed/flexible connection). The square tube passes through two upper and lower fair leads mounted at a certain vertical distance apart at the bottom of the floating body 1, and the bottom end of the square tube is connected to the top surface of the rope control mechanism. In Figure 4, the bottom frame of the rectangular steel frame 111 is instead connected to a vertical square tube 108 (fixed/flexible connection). The square tube 108 passes through the upper and lower fair leads II mounted on the bottom of the floating body I, and the bottom end of the square tube 108 is connected to the top surface of the rope control mechanism 79. In the above replacement examples, the four rollers of the fair lead I I are pressed tightly against the four sides of the square tube 108 respectively, and the fair lead acts as a guide rail to direct the up and down movement of the square steel.

Section 111: Another type of rope control hydraulic cylinder WECS is the double floating body gravity reset type WECS, with A type and B type. A type (Figure 5) has the following structure: A hollow upright column 81 (cylindrical) is vertically placed, open at the top and closed at the bottom, and an annular floating body 80 is set over the column 81. There is a certain gap between the inner wall of the annular floating body 80 and the side of the upright column 81. The annular floating body 80 has a vertical H-shaped support 83/ (or a trivet) fixed on the top surface, and the vertical center line of the H-shaped support 83/trivet coincides with the axis of the upright column 81. The piston rod handle of a vertical single-acting piston cylinder 2 is connected to the bottom center of the beam of the H-shaped support 83 (or trivet) by a flexible/universal joint 84. The end of the cylinder block of the single-acting piston cylinder 2 and the bottom surface of the cavity of the upright column 81 may be connected by a flexible/universal joint, or by a chain 22 + a cushion block 89 (a type of flexible connection).

The cycle route of the hydraulic system is: oil tank 72, access one-way valve, rod cavity of the single-acting piston cylinder, exit one-way valve, high pressure accumulator, and hydraulic motor, and the hydraulic motor drives the generator for power generation.

Preferred: If the diameter of the upright column 81 is too small for buoyancy, a cylindrical/ellipsoidal underwater buoyancy chamber 52 may be fixed to the bottom of upright column 81 to increase buoyancy, and the center lines of the two coincide. Preferred: The bottom end of the upright column 81 or the underwater buoyancy chamber 52 is fixed to the top of a vertical rod/vertical straight tube 63, and the center lines of the two coincide; the upright column 81 + underwater buoyancy chamber 52 -f vertical rod/vertical straight tube 63 is a whole fixed together and forms an overall upright column. The bottom end of the overall upright column is connected to the rope control device 79.

The hydraulic system is installed inside the upright column 81 or the undenvatcr buoyancy chamber 52.

The second is the double floating body gravity reset B type WECS. Taking Figure 6 for illustration, it is the same as most of the structure of the A type, except that the hydraulic cylinder 2 in Figure 6 has the cylinder block at the top and the piston rod at the bottom, and the annular floating body 80 moves up and down along the guide rail 86. Another difference is: It is not necessary for the whole of the overall upright column + rope control mechanism 79 to maintain sufficient net buoyancy, and even the specific gravity can be greater than water, but a pulley weight mechanism shall be added. Specifically: The pulley bracket of the pulley 56 is connected to the bottom surface of the annular floating body 80. A third string 76 is connected to the weight 51 at one end, and the other end extends upwards, winds around the pulley 56 and then extends downwards, and is finally tied to the overall upright column 81 (only a single side pulley 56 + a third string 76 is drawn in the figure, which should actually be 2 sets of pulley + string and symmetrical to the column axis). The top of the rope control device 79 is connected to the bottom end of the overall upright column. The hydraulic system is the same as that of the double floating body gravity reset A type, except that most of it is installed in the cavity of the annular floating body 80.

Refer to CN107255060 A for the principle of double floating body gravity reset A type and B type WECS.

The piston rod 3 in Figure 1, the piston rod 3 in Figure 2, the rectangular steel frame 111 in Figure 3, the square tube 108 in Figure 4, the overall upright column (81+52+63) in Figure 5, and the overall upright column (81+53) in Figure 6 are all members moving relative to the floating body, and their bottom ends (for the rectangular steel frame, it is the center of the bottom edge) can also be connected directly to the top of an energy harvesting line instead of the rope control mechanism. They are connected to their respective gravity anchors through the energy harvesting lines. After eliminating the rope control device, the WECS can still use wave energy for power generation, only losing the ability to adjust the distance between the sea surface assembly and the underwater gravity anchor.

Section IV: The inverted L-type WECS, to be precise, belongs to the single floating body pressure difference B type. In Figure 7, the sea surface assembly of the inverted L-type WECS includes the floating body 1, the inverted L rigid frame 19, the closed hydraulic system, and the two upper and lower fair leads 11 that act as guide rails The floating body 1 is structured as a fully enclosed hollow shell of cylindrical shape with a through-hole in the axis, and the rotating profile of its axis is a rectangle. The vertical side of the inverted L rigid frame 19 with square tube section passes through two upper and lower four-roller fair leads spaced at a certain distance, where the upper fair lead is installed at the upper end in the through-hole and the lower fair lead is installed at the bottom inside the straight tube 63. The straight tube 63 is upright and fixed at the top to the bottom of the floating body The inner diameter of the straight tube 63 is greater than (and may be less than or equal to) the through-hole of the floating body, and its central axis coincides with the axis of the through-hole of the floating body. The four sides of the vertical sides of the inverted L rigid frame are pressed tightly against the four rollers of the two fair leads respectively. The fair lead acts as a guide rail guiding the up and down movement of the inverted L rigid frame 19. The straight tube 63 here is equivalent to a support, but there can also be no straight tube 63, and the fair lead 11 below is installed at the bottom in the through-hole of the floating body 1.

The end of the horizontal side of the inverted L rigid frame 19 is connected to the end of the plunger rod 3 of the vertical plunger cylinder, which can be in a fixed/hinged shaft/ear loop way. The rear end of the plunger cylinder 138 is connected to the top surface of the floating body 1, which can be in a fixed/hinged shaft/ear loop way. Of course, the plunger cylinder 138 may also be inverted and connected to the end of the horizontal side of the inverted L rigid frame and the top surface of the floating body 1 respectively. The plunger cylinder 138 may also have a certain inclination, preferably in the plane where the inverted L rigid frame is located. The effect is: When the inverted L rigid frame presses the hydraulic cylinder downward, higher pressure in the hydraulic cylinder can be driven at the end of work than at the beginning, because as the inverted L rigid frame descends, the inclination of the plunger cylinder 138 will increase, and the component force required to compress the plunger cylinder 138 in the vertical direction is reduced, which is conducive to making fuller use of the remaining net buoyancy on the floating body 1 when the wave rises. Of course, for the plunger cylinder 138 tilt installation of this case, its connection with the inverted L rigid frame and the top of the floating body 1 may not be used in a fixed connection.

Preferred: The bottom end of the inverted L rigid frame 19 is connected to the housing of the rope control mechanism 79 with a flexible/universal connection. The advantage is that the housing of the rope control mechanism 79 can follow the swing of the energy harvesting line 30, which can reduce the pressure of the energy harvesting line 30 on the fairlead 11 of the rope control mechanism 79. When the energy harvesting line 30 swings in the axial direction along the pair of rollers at the bottom of the fair lead, the wear of the energy harvesting line 30 on the fairlead 11 can be greatly reduced with the help of the following motility of the rope control mechanism 79. Preferably the flexible/universal connection is a cross universal joint/double lock ring connection, which can prevent the rotation of the rope control mechanism 79 and avoids the twine of the energy harvesting line with the reset line.

Preferred: A limit block 106 is fixed to the upper part of the vertical side of the inverted L rigid frame. When the plunger rod 3 moves downward close to the bottom of the plunger cylinder 138, the limit block 106 collides with the top surface of die floating body 1 first, thus protecting the plunger cylinder 138.

The hydraulic system is a closed cycle, and the cycle route is: the cavity of the plunger cylinder, outlet check valve, high pressure accumulator, hydraulic motor, low pressure accumulator, access inlet check valve, and the cavity of the plunger cylinder, and the hydraulic motor drives the generator for power generation. The hydraulic pipe connected to the oil inlet and outlet of the bottom end of the plunger cylinder 138 goes through the top cover of the floating body 1, and the hole is to be scaled. The generator and the hydraulic system except the plunger cylinder are all located in the cavity of the floating body Principle: The principle is basically the same as that of the aforementioned single floating body pressure difference reset B type. In the case that the hydraulic cylinder 138 does not work beyond the stroke and does not trigger the rope control device, the floating body 1 undulates with the wave, while the length of the hawser 30 between the bottom of die inverted L rigid frame and the gravity anchor is locked, so the maximum height of the top of the plunger rod 3 is also locked, and the bottom of the cylinder block of the plunger cylinder 138 moves up and down with the floating body 1. When the floating body 1 rises, the plunger cylinder 138 is compressed and outputs high pressure hydraulic oil, and because hydraulic oil can not flow through the access one-way valve, the hydraulic oil can only flow through the exit one-way valve (only allowed out for the plunger cylinder) to reach the high pressure accumulator. The pressure of high pressure accumulator >the pressure of low pressure accumulator >the atmospheric pressure. The pressure difference between the high pressure accumulator and the low pressure accumulator drives the hydraulic motor to rotate and the generator to generate electricity, while the hydraulic oil flows from the high pressure accumulator to the low pressure accumulator. When the floating body 1 descends, the tension of the energy harvesting line 30 is reduced rapidly, and the pressure in the cavity of the plunger cylinder is also reduced rapidly. Then the low pressure accumulator and atmospheric pressure difference push the plunger upwards to achieve the reset of the plunger cylinder Preferred: An oil filter 5 is added.

Preferred: The plunger rod 3 is snapped with a protective cover I (preferably made of soft rubber), which is sealed against the handle of the plunger rod at one end and the outside of the cylinder block of the plunger cylinder 108 at the other end.

Preferred: The generator is a brushless permanent magnet generator; preferably: A overflow valve is connected in parallel beside the motor. so that if the motor stops for some reason, the high pressure oil from the high pressure accumulator can enter the low pressure accumulator through the overflow valve, thus avoiding excessive pressure in the high pressure accumulator Preferred: The motor is an axial piston motor with valve plate flow distribution.

Preferably, with regard to the refill system: A cover is added to the top of the cylinder block of the plunger cylinder 138, and the cover and the cylinder block form a sealing cavity to collect the oil drain. The plunger rod 3 extends through the seal ring of the hole at the top surface of the cavity, and the oil drain tube 115 leads out of the sealed cavity, then extends downward and enters into the cavity from the top cover of the floating body 1 (the entering point is to be sealed without destroying the full closure of the floating body), and finally enters an oil tank.

Preferred: An electric charge pump 73 driven by the electricity generated by the wave generator pumps hydraulic oil from the tank and fills into the closed hydraulic circulation system. Further preferably: A MCU and an auxiliary power supply circuit are added. The MCU starts and stops the electric charge pump 73 according to signals from a liquid level sensor 144 of the tank/a hydraulic sensor on the closed cycle hydraulic system. When the liquid level sensor 144 monitors that there is excessive oil in the tank or the hydraulic sensor monitors that the pressure in the closed cycle hydraulic system is too low, the MCU will start the motor and drive the charge pump to pump oil from the tank into the closed cycle hydraulic system.

Preferred: A electric cable 12 of the rope control device starts from the cavity of the floating body, extends upwards out of die top surface of the floating body (the opening should be sealed), then becomes spiral and extends upwards, and finally extends into a horizontal steel pipe 71. The steel pipe 71 is welded to the side of the inverted L rigid frame 19 and the cavities of them are connected. The electric cable 12 extends horizontally along the steel pipe 71, enters the square tube of the vertical side of the inverted L rigid frame and extends downwards, comes out of the bottom side of the inverted L rigid frame, and finally enters the housing of the rope control mechanism 79, if the inverted L rigid frame 19 is fixed to the housing of the rope control mechanism 79, the electric cable 12 may enter the housing of the rope control mechanism directly through the opening at the bottom of the inverted L rigid frame, but the opening should be sealed. Function: a spiral shape is adopted for part of the electric cable 12 to adapt to the change in relative distance between the inverted L rigid frame and die top surface of the floating body, and the electric cable 12 can be protected inside the square tube of the inverted L rigid frame.

Section V: Pre-tensioning System The pre-tensioning system may be added to the hydraulic systems of the aforementioned WECS sea surface assemblies in this specification, and there are two main types of pre-tensioning schemes: external accumulator type and high pressure side return flow type.

(i The external accumulator basic type is adopted in Figure 7. A new hydraulic branch leads out from the hydraulic line at the inlet and outlet of the hydraulic cylinder 138, and the hydraulic branch is connected to a third accumulator 128 via a solenoid switch valve 122. The solenoid switch valve 122 is controlled by an MCU (Micro programmed Control Unit, which may also be replaced by a PLC in this specification), and the MCU receives signals from a second sensor 126 that monitors the operating status of the sea surface assembly 19 of WECS (Wave Energy Convert System).

The energy harvesting line 30 of the rope controlled hydraulic cylinder wave generator works under the impulse tension condition. When the floating body 1 descends, the tension on the energy harvesting line is equal to the reset force of the hydraulic cylinder (the wet weight of the rope control mechanism, the self-weight of various components, and the friction force are not considered here), and the tension is relatively small. When the floating body rises and does work on the hydraulic cylinder 138, there is great tension on the energy harvesting line 30, as a result, the energy line 30 is stretched and contracts. In addition, the lateral impact of seawater (such as sea currents) will also lead to the bending of the energy harvesting line 30. When the hydraulic cylinder 138 is resetting, the bending is large, and when the hydraulic cylinder 138 does work, the bending is small. This will lead to a decrease in the wave height utilization efficiency, because in the early stage of the rise of the floating body I driven by waves, the buoyancy (including the impact force) of the wave can not immediately drive the hydraulic cylinder 138 to do work, but is delayed for some time. During the period from the time when the wave starts to rise to the time when the hydraulic cylinder 138 is driven, the height of the wave surface rise is actually not utilized. Part of the height of the wave height utilization loss is used to increase the draft of the floating body to increase the net buoyancy it receives, and the other part is to straighten the energy harvesting line 30 On this case, the floating body 1 rises, but the hydraulic cylinder 138 does not move). The purpose of pre-tensioning is to reduce the loss of wave height utilization, tighten the energy harvesting line 30, and increase the draft of the floating body 1 before the wave surface rises so that the hydraulic cylinder 138 can be driven immediately when the wave surface rises.

In Figure 7, the MCU determines which stage of the wave surface the floating body 1 is in by obtaining the motion of the member on the sea surface assembly (inverted L rigid frame 19) linked to the energy harvesting line relative to the floating body 1 through a second sensor 126 (the motion of the floating body 1 may also be acquired through an acceleration sensor, or the draft status of the floating body may be obtained by a water pressure sensor at the bottom of the floating body). Once the MCU determines that the WECS is in the reset stage and is near the end of the reset stage, that is, it is now at the wave trough, it opens the solenoid switch valve 122 immediately and holds it for some time (for example, 0.3s) before closing it. The high pressure hydraulic oil in the third accumulator 128 thus flows partially to the plunger cylinder 138, driving the plunger rod 3 to move up. This process also results in a reduction of the pressure in the third accumulator 128. Since the rope control device is locked, the distance between the inverted L rigid frame 19 and the gravity anchor 17 remains unchanged. Therefore, the plunger rod 3 cannot actually rise, and only the floating body 1 descends. The descending of the floating body I will lead to a draft increase and a buoyancy force increase of the floating body 1, and a tension increase on the energy harvesting line 30, so as to achieve the purpose of pre-tensioning. Then the rise of the wave surface immediately drives the hydraulic cylinder, or only a small rise of the wave surface can drive the hydraulic cylinder 138 to do work.

When the work stroke of the hydraulic cylinder 138 is near the end, that is, the floating body rises with the wave to the wave crest, although the wave surface is no longer rising, the tension of the energy harvesting line and the net buoyancy of the floating body (net buoyancy = the buoyancy of the floating body at the moment minus the gravity) is still equal to the force exerted on the hydraulic cylinder and the floating body's draft is still as deep as when the wave is rising, which means that there is still remaining buoyancy potential energy. Then the MCU monitors that the floating body is at the wave crest through the second sensor 126, and immediately opens the solenoid switch valve 122 and holds it for some time (for example, 0.3s). The high pressure hydraulic oil in the plunger cylinder 138 flows to the third accumulator 128, and the hydraulic pressure in the third accumulator 128 rises, while the hydraulic pressure in the plunger cylinder 138 decreases. The floating body 1 will rise for a certain distance, which means that the wave buoyancy is doing work on the floating body 1 again, thus increasing the wave height utilization again. Then the MCU opens the solenoid switch valve 122 again at the wave trough, and so on...

Figure 10 shows the processing flow chart of the MCU of the external accumulator basic type.

Figure 8 shows the functional relationship of the electrical components of the pre-tensioning system. The MCU/PLC obtains the states of the sea surface assembly or wave surface from the second sensor. For the wave surface, the so-called states include wave surface rise, wave crest, wave surface fall, wave trough, etc.; and for the sea surface assembly of the wave generator, the states include work, end of the work stroke, reset, end of the reset stroke, etc. It is difficult to directly measure the state of the wave surface on which the wave generator is located, and such a sensor is expensive, so the state of the wave surface is usually determined by measuring the working state of the wave generator. The second sensor may take several forms as follows: 1) Distance sensor: For Figure I, it may be installed on the top surface inside the shell of the floating body to monitor the distance between the piston 27 and the top surface inside the shell of the floating body. For other figures, it may be installed on the top surface of the floating body to monitor the distance changes between the member (the end of the piston rod 3 in Figure 2, the top edge of the rectangular steel frame 111 in Figure 3 and Figure 4, the limit block 106 in Figure 4, the top end of the upright column 81 in Figure 5, the top edge of the rigid frame 88 in Figure 6, and the horizontal edge of the inverted L rigid frame in Figure 7) linked to the energy harvesting line and above the top surface of the floating body and the top surface of the floating body. For Figure 7, when the distance increases, it is the stage that the hydraulic cylinder is resetting and the floating body is descending; when the distance increases and then stops, it is the end of the reset process and the floating body is at the wave trough; when the distance decreases, it is the stage that work is done on the hydraulic cylinder and the floating body is rising; when the distance decreases and then stops, the floating body rises to the top and is at the wave crest. The judgments in the other figures are similar.

Preferred: The distance sensor is a laser/ultrasonic/infrared type.

2) Linear displacement sensor: consists of two components that can move linearly relative to each other, one connected to the floating body and the other connected to the member linked to the energy harvesting line. Preferred: One of the components is connected to the top surface of the floating body, and the other component is connected to the member above the top surface of the floating body; the judgement method is similar to that of the distance sensor. Preferred: The linear position sensor is a pull lever/pull rope type.

3) Linear speed sensor: consists of two components that can move linearly' relative to each other, one connected to the floating body and the other connected to the member linked to the energy harvesting line. Preferred: The first component is connected to the top surface of the floating body and the member to which the second component is connected is above the top surface of the floating body.

When the speed of the member moving relative to the floating body is downward, it is the stage that work is done on the hydraulic cylinder and the floating body is rising; when the speed is down and then stops, it is the end of work and the floating body is at the wave crest; when the speed is up, it is the stage that the hydraulic cylinder is resetting and the floating body is descending; when the speed is upward and then stops, it is the end of the reset and the floating body is at the wave trough.

4) Acceleration sensor: installed on the floating body to measure the motion acceleration of the floating body.

After subtracting the gravitational acceleration, when the acceleration of the floating body is maximum upward, it is the wave trough, and when the acceleration of the floating body is maximum downward, it is the wave crest. The period from the wave trough to the wave crest is the stage that work is done on the hydraulic cylinder and the floating body is rising, and the period from the wave crest to the wave trough is the stage that the hydraulic cylinder is resetting and the floating body is descending.

5) Draft sensor: a water pressure sensor installed on the outer bottom of the floating body to monitor the draft depth of the floating body.

When the water pressure sensor detects that the pressure reaches the maximum, which means the maximum draft, it is the stage that work is done on the hydraulic cylinder and the floating body is rising; when the water pressure and draft reach the maximum and then start to decrease, it is the wave crest; when the water pressure and draft is small, it is the stage that the floating body is descending and the hydraulic cylinder is resetting; when the water pressure and draft reach the minimum and then start to increase, it is the wave trough.

6) Tension sensor: connected in series to the energy harvesting line 30 to monitor the tension of the energy harvesting line.

When the tension is large, it is the stage that work is done on the hydraulic cylinder and the floating body is rising; when the tension reaches the maximum and starts to reduce, it is the end of the work and the floating body is at the wave crest; when the tension is very small, it is the stage that the floating body is descending and the hydraulic cylinder is resetting; when the tension reaches the minimum and starts to increase, it is the end of the hydraulic cylinder reset and the floating body is at the wave trough.

7) Hydraulic pressure sensor: installed in the hydraulic line at the inlet and outlet of the hydraulic cylinder to monitor the hydraulic pressure at the inlet and outlet. When the hydraulic pressure is very large, it is the stage that work is done on the hydraulic cylinder and the floating body is rising; when the pressure is very large and then becomes smaller, it is the end of the work and the floating body is at the wave crest; when the pressure is very small, it is the stage that the floating body is descending and the hydraulic cylinder is resetting; when the pressure is very small and then becomes larger, it is the end of the hydraulic cylinder reset and the floating body is at the wave trough.

8) Flow sensor: installed in the hydraulic line at the inlet and outlet of the hydraulic cylinder to monitor the flow and direction (flowing into the hydraulic cylinder or out of the hydraulic cylinder) at the inlet and outlet.

When the hydraulic oil flows out from the hydraulic cylinder and the flow is very large, it is the stage that work is done on the hydraulic cylinder and the floating body is rising.

When the hydraulic oil stops flowing out from the hydraulic cylinder, it is the end of the work done by the hydraulic cylinder and the floating body is at the wave crest.

When the hydraulic oil flows into the hydraulic cylinder and the flow is very large, it is the stage that the hydraulic cylinder is resetting and the floating body is descending.

When the hydraulic oil stops flowing into the hydraulic cylinder, it is the end of the hydraulic cylinder reset and the floating body is at the wave trough.

Figure 9 is the circuit diagram of the electrical part of the pre-tensioning system, in which the MCI] controls the solenoid switch valve through a solid-state relay (SSR). Preferably: The MCU receives data from the wireless communication module AS62 via the 485 communication module.

It should be noted that Figure 8 and Figure 9 are applicable to all pre-tensioning schemes in this specification.

Figure 12 shows the pre-tensioning effect of the external accumulator type, a): the wave trough state; b: the solenoid switch valve is opened for a while for pre-tensioning; c: the wave surface is rising and work is done on the hydraulic cylinder; d: at the wave crest, the solenoid switch valve is opened for a while, and the remaining net buoyancy of the wave is used to charge pressure for the third accumulator; c: end of pressure charging and start of descent; f the floating body is descending and the hydraulic cylinder is resetting. Then it is back to process a) again. and so on.

(ii) High pressure side return flow basic type pre-tensioning scheme (i) As shown in Figure 3, another hydraulic branch is connected in parallel next to the outlet check valve of the hydraulic system, which is provided with a solenoid switch valve 122. The solenoid switch valve 122 is controlled by an MCC, and the MCU receives signals from a second sensor 126 that monitors the state of the floating body. The process mode when the floating body is at the wave trough state is the same as that of the aforementioned external accumulator basic type pre-tensioning scheme. During the descent of the floating body, the hydraulic pressure in the plunger cylinder 138 is equal to the low pressure accumulator. When the MCU detects that the floating body 1 is at the wave trough state through the second sensor 126, it opens the solenoid switch valve 122 immediately and holds for a certain time. Then part of the hydraulic oil from the high pressure accumulator flows directly to the plunger cylinder 138 through the solenoid switch valve 122, bypassing the outlet check valve, and the hydraulic pressure in the plunger cylinder 138 rises suddenly, driving the plunger rod 3 to rise. Now the rope control device is in the locked state, so the plunger rod 3 can not rise, and only the floating body 1 descends. Therefore, the draft of the floating body 1 and the net buoyancy of the floating body I increase, so that the tension of the energy harvesting line 30 increases to achieve the purpose of pre-tensioning. Refer to Figure I IA for the algorithm flow of the MCU.

Unlike the aforementioned external accumulator basic type pre-tensioning scheme, the MCU does not give commands when the floating body is at the wave crest state, and the solenoid switch valve 122 does not operate, which means that this scheme cannot use the remaining buoyancy at the wave crest to do work. As shown in Figure 12, there is no state c), and it is from directly d): the end of the work of the hydraulic cylinder directly to f): the floating body is descending.

Both the aforementioned external accumulator basic type and the high pressure side return flow basic type hydraulic pre-tensioning schemes have shortcomings. For example, during the pre-tensioning process at the wave trough, when the solenoid switch valve is just opened, the high pressure from the third accumulator or the high pressure hydraulic oil from the high pressure accumulator will impact the hydraulic cylinder, and the pressure of the hydraulic cylinder rises abruptly from low to high, resulting in impact. The energy consumed by the hydraulic cylinder to reset a distance at such high pressure is almost the same as the energy gained during the work stage at the same distance. The result is that it is pre-tensioned, but a lot of energy is consumed, and ultimately not too much wave energy is obtained. In order to solve this problem, the scheme of oscillating cylinder + flywheel is introduced. The application of oscillating cylinder + flywheel achieves a better pre-tensioning effect with the same energy consumption, and for the external accumulator type pre-tensioning scheme, the remaining buoyancy during the wave crest can be made fuller use to do work.

Figure 13 shows the external accumulator type pre-tensioning scheme. An oscillating cylinder 125 is added to the hydraulic branch between the solenoid switch valve and the third accumulator 128. The figure shows a gear rack type oscillating cylinder, and the gear of the oscillating cylinder is linked to the shaft of the flywheel 123 (it can also be linked to die flywheel 123 by a gear/chain/belt speed change mechanism). Then at the moment when the solenoid switch valve is just opened at the wave trough, the high pressure hydraulic oil from the third accumulator must first push the oscillating cylinder to drive the flywheel 123 to rotate, and part of the hydraulic energy is converted into kinetic energy of the flywheel 121 The inertia of the flywheel 123 is great, so the acceleration is slow and the hydraulic oil flows into the hydraulic cylinder 2 slowly, thus avoiding the impact. At the beginning of the pre-tensioning process, the hydraulic pressure in the hydraulic cylinder 2 is rising slowly, thus reducing the energy consumption required for pre-tensioning. The MCU may set the time Atl for the solenoid switch valve to open based on a prediction. During the second half of the time Atl the hydraulic pressure in the third accumulator 128 has been reduced and the pressure in the hydraulic cylinder 2 is already very high, but the flywheel 123 uses its previously stored kinetic energy to continue to push the oscillating cylinder 125 to oscillate and continue to press more hydraulic oil to flow into the plunger cylinder 2. Finally, the flywheel 123 is rotating very slowly and almost stops, and at this moment, the MCU closes the solenoid switch valve to complete the pre-tensioning process. During this pre-tensioning process, the hydraulic pressure in the hydraulic cylinder 2 rises slowly without impact, and makes full use of the pressure potential energy of the third accumulator.

The aforementioned time Atl during which the solenoid switch valve is opened is preset by the MCU (in Figure 15, it is preset), and this approach is not flexible enough. Preferred: As shown in Figure 13, a rotation speed sensor 145 that monitors the speed of the flywheel 123 may be used to tell the MCU when to close the solenoid switch valve, and the MCU closes the solenoid switch valve as soon as the flywheel 123 stops rotating; or a flow direction sensor for fluid may also be added to the hydraulic branch between the third accumulator 128 and the solenoid switch valve, and the MCU monitors the flow direction of the hydraulic oil based on this flow direction sensor, and closes the solenoid switch valve as soon as the direction changes; or a flow sensor may also be added to the hydraulic branch between the third accumulator 128 and the solenoid switch valve, and the MCU receives the flow signal from the flow sensor and closes the solenoid switch valve as soon as the flow reaches 0; or a hydraulic sensor may also be added to the hydraulic branch between the oscillating cylinder 125 and the third accumulator 128, and the MCU monitors the hydraulic pressure according to the hydraulic sensor and closes the solenoid switch valve as soon as the hydraulic pressure changes from dropping to stagnant or rising.

The external accumulator type pre-tensioning scheme with flywheel + oscillating cylinder also allows the work to be done by making full use of the remaining net buoyancy on the floating body when it is at the wave crest. The implementation process is as follows: When the MCU monitors that the hydraulic cylinder has just finished doing work and the floating body is at the wave crest according to the second sensor 126, it immediately opens the solenoid switch valve and holds it for a certain time At2. Then the high pressure hydraulic oil in the hydraulic cylinder 2 pushes the oscillating cylinder 125 to oscillate and drives the flywheel 123 to rotate. Due to the inertia of the flywheel 123, the hydraulic energy is converted into kinetic energy of the flywheel 123 at the beginning of At2, and the kinetic energy of flywheel 123 continues to drive the oscillating cylinder 125 to oscillate at the end of At2. The hydraulic pressure in the hydraulic cylinder 2 decreases slowly, while the hydraulic pressure in the third accumulator 128 increases slowly. There is no impact and no violent pressure change throughout the process. Compared to the schemes without oscillating cylinder + flywheel, more hydraulic oil flows into the third accumulator 128 from the hydraulic cylinder 2, thus making fuller use of the remaining net buoyancy on the floating body to do work. And if a sensor that monitors the rotation speed of the flywheel 123 or a flow direction/flow/hydraulic sensor that monitors the motion of the flywheel 123 is added, the MCU can (lac/mine the point-in-time to close the solenoid switch valve more accurately rather than relying on a prediction of At2.

The external accumulator type pre-tensioning scheme can be applied not only to closed hydraulic systems, but also to open hydraulic systems, as shown in Figure 15.

The design with the addition of oscillating cylinder + flywheel can be applied not only to the external accumulator type pre-tensioning scheme, but also to the high pressure side return flow type pre-tensioning scheme. As shown in Figure 14, an oscillating cylinder 125 is added to the front half of the parallel branch, the shaft of which is linked with (or directly coupled by a shaft) to the flywheel 123 via a drive mechanism ---belt transmission 124. Preferred: Another continuous current branch (marked as a dashed line) leads out from the hydraulic line between the solenoid switch valve and the oscillating cylinder 125, and connected to the low pressure accumulator via a check valve. The conducting direction of the check valve is from the low pressure accumulator to the position between the solenoid switch valve and the oscillating cylinder. Preferred: The oscillating cylinder 125 is provided with a reset spring 141, and the reset force of the reset spring 141 makes the hydraulic oil in the oscillating hydraulic cylinder 125 flow from the end of the oscillating cylinder near the hydraulic cylinder to the end near the solenoid switch valve.

Principle: Based on Figure 14 and Figure 11B, during the descent of the floating body, the MCU monitors whether the WECS reset is over and whether the floating body reaches the wave trough through the second sensor 126, and once it reaches the wave trough, the MCU immediately opens the solenoid switch valve and keeps it on for a period of time Atl. The hydraulic pressure of the hydraulic cylinder 2 is equal to the pressure of the low pressure accumulator during the previous reset, so when the solenoid switch valve is just opened, the oscillating cylinder 125 is driven by the pressure difference between the pressure of the high pressure accumulator and that of the low pressure accumulator, and then drives the flywheel 123 to rotate through the belt transmission mechanism 124. The high pressure hydraulic energy output from the high pressure accumulator is partially converted into the kinetic energy of the flywheel 123, partially increasing the pressure in the hydraulic cylinder 2 and pushing the hydraulic cylinder 2 to reset, thus making the floating body descend to achieve the pre-tensioning effect (mentioned before). The flywheel 123 is accelerating from 0, so the pressure in the hydraulic cylinder 2 is rising slowly, without the impact caused by the previous sharp increase in pressure. When the time Atl is over, the pre-tensioning process is only halfway through, but now the MCU controls the solenoid switch valve to close, while the flywheel 123 is still rotating. Then the flywheel 123 will drive the oscillating cylinder 125 to continue its action, and the pressure between the oscillating cylinder 125 and the solenoid switch valve drops rapidly. Then the hydraulic oil from the low pressure accumulator will be replenished through the continuous current branch, so that the oscillating cylinder can continue to inject the hydraulic oil into the hydraulic cylinder 2, thus making full use of the previously stored kinetic energy of the flywheel 123 until it stops. The oscillating cylinder rotated at a certain angle due to the pre-tensioning process, so it needs to be reset. The reset time is set at the stage when the floating body is rising to do work on the hydraulic cylinder. The MCU will open the solenoid switch valve and hold it for a period of time At2 when it monitors that it is currently at the rise stage through the second sensor 126. The front and rear ends of the oscillating cylinder 125 are both with high pressure. The pressure of the end near the hydraulic cylinder 2 is equal to the pressure of the hydraulic cylinder and the pressure of the end near the high pressure accumulator is equal to the pressure of the hydraulic cylinder 2 minus the pressure drop of the outlet check valve. The pressure of the front end is slightly higher. If the pressure difference acting on the oscillating cylinder 125 is sufficient to push it to reset, the reset spring 141 can be eliminated, and if not, the reset force of the reset spring 141 is needed. After the reset of the oscillating cylinder 125 is finished, the MCU closes the solenoid switch valve.

In addition, the oscillating cylinder mentioned in this section can be replaced by a pump8anotor (which can be used as a pump or a motor, such as an axial piston pump with valve plate flow distribution). The pump&motor can be considered as an oscillating cylinder with no rotation angle limitation, so there is no need to reset and the reset spring can be eliminated, and the MCU does not need to open the solenoid valve again to reset during the stage when the floating body is rising and work is being done on the hydraulic cylinder. Figure 16 shows an embodiment of the pump&motor 127 replacing the oscillating cylinder and an example of the high pressure side return flow pre-tensioning scheme applied to an open hydraulic system. A parallel branch is added next to the outlet check valve of the open hydraulic system of the WECS, and the branch is provided with a solenoid switch valve. The solenoid switch valve is controlled by an MCU, and die MCU receives signals from a second sensor 126 that monitors the state of the WECS. A pump&motor 127 is added on the first half of the parallel branch, whose shaft is connected to the shaft of the flywheel 123 (it can also be linked to the flywheel by a chain/gear/belt transmission mechanism). Another continuous current branch leads out from the hydraulic line between the solenoid switch valve and the pump&motor 127, and the continuous current branch is connected to the oil tank via a check valve. The conducting direction of the check valve is from the oil tank to the pump&motor 127.

Principle: The pre-tensioning process is the same as before. At the wave trough, the MCU opens the solenoid switch valve and the high pressure hydraulic oil from the high pressure accumulator drives the pump&motor and flows into the hydraulic cylinder 2, and at the same time, the pump&motor drives the flywheel 123 to rotate. At the beginning of the pre-tensioning, the hydraulic energy is partially converted into the kinetic energy of the flywheel 123, while in the later stage of the pre-tensioning. the MCU closes the solenoid switch valve and the continuously rotating flywheel 123 releases kinetic energy to drive the pump&motor 127 to continue to rotate. Since the solenoid switch valve has been closed, the pump&motor 127 can only pump oil from the oil tank to the hydraulic cylinder 2 via the check valve of the continuous current branch. The pump&motor does not need to be reset, so there is no need to open the solenoid switch valve again during the stage when the floating body is rising and work is done on the hydraulic cylinder 2.

For the high pressure side return flow type pre-tensioning scheme, the pressure of the hydraulic cylinder increases and the floating body descends in the pre-tensioning process. The floating body is subjected to the resistance of water during the descending process (resistance to motion), and as the floating body descends deeper and deeper, the buoyancy on the floating body becomes larger and larger, which in turn is a buoyancy resistance. For the external accumulator type pre-tensioning scheme, in addition to the resistance mentioned above, the third accumulator 128 is also subjected to increasing pressure in the pre-tensioning process.

For the high pressure side return flow basic type pre-tensioning scheme with flywheel + oscillating cylinder/pump&motor (Figure 14), if there is no follow current branch, when the solenoid switch valve is closed too early and the flywheel is not completely stopped, the inertia of the oscillating cylinder + flywheel will produce negative pressure between the oscillating cylinder 125 and the solenoid switch valve. So enough time shall be reserved to close the solenoid valve, and the solenoid switch valve should be closed after the flywheel + oscillating cylinder/pumpecmotor stops (sooner or later it will stop, because the floating body is subjected to more and more resistance when it descends). The inertia of the oscillating cylinder + flywheel may lead to excessive pre-tensioning (after pre-tensioning, the draft depth of the floating body may even exceed the draft depth when the wave is rising and work is being done on the hydraulic cylinder; of course, it's only a possibility, not a certainty, because if the water resistance of the floating body is strong enough and the inertia of the oscillating cylinder -1 flywheel is not enough, it may not reach the draft depth required for the hydraulic cylinder to do work), but the pre-tensioning effect is still achieved. Therefore, if it is only for the pre-tensioning purpose, the continuous current branch is not necessary (the continuous current branch is also not necessary for Figures 16 and 23, which is indicated by the dashed line).

The following four points need to be noted for the various pre-tensioning systems in this specification: 1) A series of processes for the MCU to open the solenoid switch valve is discussed under the premise that the wave height does not exceed the stroke of the hydraulic cylinder, that is, the rope control device is not triggered, but the effect that the pre-tensioning system can achieve has been explained clearly. If the wave height exceeds the stroke of the hydraulic cylinder and the rope control device is triggered, the MCU program should be able to identify it.

2) In the case of simple surge waves, it is easy for the MCU to judge the wave crest and trough, but in the case of wind waves and irregular waves, sometimes there will be false wave troughs (the floating body stops descending and then continues to descend) and false wave height (the floating body stops rise and then continues to rise). The MCU may misjudge in this case, so the MCU should be able to combine the experience data of dozens or even more waves before to identify the law to further improve the accuracy of j udgment.

3) Preferred: The MCU receives data or manual commands/parameters from external sources through a wireless communication module, which is from the marine environment monitoring buoy, to enable the MCU to grasp the current wave condition information more accurately. When multiple queues of wave generators are operating together, the data from the second sensors of the wave generators can also be shared. The MC U of the wave generator at the front facing waves may send the data monitored by its second sensor to the other wave generators through die wireless data transmission module, and the subsequent wave generators can combine the data monitored by their second sensors with the data from the second sensor of the wave generator at the front to better grasp the coining wave situation, thus bcttcr grasping the timing to control the solenoid switch valve/reversing branch.

4) The pre-tensioning operation and the operation of using the remaining net buoyancy during the wave crest will affect the working state of the sea surface assembly and the hydraulic cylinder, so the MCU should be programmed to separate the effect due to the pre-tensioning operation from the change of the second sensor data due to the wave motion. During the period of pre-tensioning or when the remaining net buoyancy is doing work, it should be clear in the MCU program that it is now in this state, and the pre-tensioning process should not be determined as the reset stage during wave descent, and the process when the remaining net buoyancy is doing work should not be determined as the work stage of the wave rise.

Control scheduling tables are also adopted in this specification to help understand various schemes. The meanings of the symbols in the control scheduling tables are explained as follows. The first and second columns are the operating status of the wave surface and sea surface assembly determined by the MCU based on the second sensor, and then the MCU operates them according to the operating symbols of the reversing branch or the solenoid switch valve in the table respectively at each stage. The third column shows the pressure of the hydraulic cylinder at each stage, and the fourth column shows the pressure of the high pressure accumulator/third accumulator at each stage. The pressure of the hydraulic cylinder is positively correlated with the tension of the energy harvesting line. According to the pressure trend of the hydraulic cylinder, the tension trend of the energy harvesting line can be judged.

Symbol interpretation: >>: gradual change from the previous value to the latter value, the solenoid switch valve opens. x: the solenoid switch valve closes. T: For the reversing branch, it means that the MCU controls the solenoid two-position four-way valve so that the single conducting direction of the reversing branch is flowing into the hydraulic cylinder; for the oscillating cylinder or the pumpezmotor, , it means that its internal hydraulic oil flows into the hydraulic cylinder. 1: the opposite of T. 0: the flow rate of the hydraulic oil in it is 0, that is, it stops. -: the check valve is on.

For Figure 3B, Figure 7A, Figure 7C, Figure 21, Figure 22 to 26, the control scheduling tables are all listed, and it should be noted that: In these examples, the pressure drop loss of the valve, the pressure drop loss in the pipe, and mechanical friction are ignored, and the pressure change of the high pressure accumulator during a wave cycle is ignored (normally there will be changes, and the greater the capacity, the smaller the range of changes). The values in the control scheduling tables are intended to be examples to help understand the working principle, not limited to the values. If a hydraulic amplifier is used, the example is based on the pressure ratio of k=2. The following are examples to illustrate how to interpret these control scheduling tables.

Figure 7A and Figure 7B show the high pressure side return flow type pre-tensioning system with a hydraulic amplifier, which is suitable for the WECS in Figure 4.

The first stage: The MC U determines that the floating body 1 is descending with the wave according to the second sensor, then the hydraulic oil flows from the low pressure accumulator (internal pressure: 0.5Mpa) to the hydraulic cylinder, and then hydraulic cylinder 2 is in the reset stage. its internal pressure is 0.5Mpa, and now the pressure of high pressure accumulator is 10Mpa. Now the solenoid switch valve controlled by the MCU is in the "X" state, and the parallel branch is in the cut-off state.

The second stage: The MCU learns that the floating body 1 is no longer descending according to the second sensor and determines that the floating body 1 is at the wave trough. Then it turns the solenoid switch valve to -\/, that is, the solenoid switch valve is opened, and then the hydraulic oil flows from the high pressure accumulator to the hydraulic cylinder. The plunger rod 3 is connected to the rope control device 79, so the height of the plunger rod 3 remains unchanged when the rope control device is not in action. Therefore, only the cylinder block of the hydraulic cylinder has descended, and then the floating body connected to the cylinder block starts to descend, resulting in the draft depth increase and the net buoyancy increase of the floating body and the tension increase of the energy harvesting line. When this stage is over, the hydraulic amplifier is balanced on both sides and the pressure of the hydraulic cylinder rises to 5Mpa (the pressure ratio of the hydraulic amplifier is k=2), and then the tension of the energy harvesting line is increased and the pre-tensioning effect is achieved.

The third stage: The MCU determines that the floating body 1 is in the rising stage according to the second sensor and immediately closes the solenoid switch valve, and the parallel branch is in the cut-off state. Now the WECS is in the work stage, and high pressure hydraulic oil flows from the hydraulic cylinder to the high pressure accumulator.

The fourth stage: The MCU learns that the floating body 1 is no longer rising based on the second sensor and determines that the floating body 1 is at the wave crest state, and immediately opens the solenoid switch valve. At the beginning of this stage, the pressure of the hydraulic cylinder is still 10Mpa of the work phase, which is amplified to 20Mpa by the hydraulic amplifier, greater than the 10Mpa in the high pressure accumulator. So the hydraulic oil flows from the hydraulic cylinder to the high pressure accumulator, and the floating body 1 rises with less draft. The pressure of hydraulic cylinder 2 starts to drop, and the tension of the energy harvesting line decreases slowly. The work done on the hydraulic cylinder by the remaining net buoyancy of the floating body during this process is converted into hydraulic energy. When the equilibrium is reached, the pressure of the high pressure accumulator remains almost unchanged at 10Mpa, while the pressure of the hydraulic cylinder drops to 5Mpa. 5Mpa x 2 on the left side of the hydraulic amplifier is equal to 10Mpa on the right side.

Then it goes back to the first stage. and so on.

Next, in combination with Figure 2, Figure 24 and Figure 24A is interpreted. Starting from the first line of the control scheduling table, the floating body of the wave generator is descending with the wave, and the tension of the energy harvesting line is minimum. The pressure of the low pressure accumulator is 0.5Mpa (the pressure drop of the access inlet check valve is not considered here), and the hydraulic oil flows into the hydraulic cylinder and makes it reset. When the MCU monitors through the second sensor 126 that the floating body is descending and the hydraulic cylinder is being reset, it controls the solenoid two-position four-way valve in the reversing branch to tum the single conducting direction of the reversing branch to L. that is, flowing out of the hydraulic cylinder. The pressure of the third accumulator is 8Mpa, which is much greater than the internal pressure of the hydraulic cylinder of 0.5Mpa, so it is blocked by the check valve of the reversing branch, and the hydraulic oil in the third accumulator can not flow into the hydraulic cylinder.

At the second stage of die timing table, when the floating body descends to the wave trough, the wave surface has not yet risen, the tension of the energy harvesting line is still very small and in a relaxed state, and the draft depth of the floating body is also minimal. The MCU monitors through the second sensor 126 that it is at the wave trough at this moment, and immediately switches the solenoid two-position four-way valve in the reversing branch to turn the single conducting direction of the reversing branch to that is, only flowing into the hydraulic cylinder. The hydraulic oil can flow into the hydraulic cylinder (0.5Mpa) from the third accumulator (8Mpa) through the reversing branch. The internal pressure of the hydraulic cylinder rises gradually from 0.5Mpa, pushing the piston of the hydraulic cylinder to rise relative to its cylinder block. The piston rod is connected to the underwater relative motion reference through the energy harvesting line, so the piston rod can not rise and only the cylinder block descends. The cylinder block of the hydraulic cylinder is installed on the floating body and the floating body will descend, so the draft increases, the buoyancy increases, and the energy harvesting line is also pulled tight, achieving the purpose of pre-tensioning. This process also drives the oscillating cylinder 125, which is connected to the flywheel 123 and has a large inertia, so part of the hydraulic energy is converted into the kinetic energy of the flywheel in the first half of the pre-tensioning period, while in the second half of the pre-tensioning period, the kinetic energy of the flywheel enables the oscillating cylinder 125 to continue to rotate, pushing the hydraulic oil to continue to flow forward, so that die internal hydraulic pressure of the hydraulic cylinder exceeds the pressure equilibrium point between the hydraulic cylinder and the third accumulator (suppose it is 5Mpa), and rises from 5Mpa to 7Mpa. (If there is no oscillating cylinder + flywheel in this figure, although it can also achieve the purpose of pre-tensioning, the hydraulic pressure of the hydraulic cylinder can not rise to 7Mpa, possibly only 5Mpa). Now the pressure of the third accumulator drops to 3Mpa, and the kinetic energy of the oscillating cylinder + flywheel is exhausted and the rotation stops. The hydraulic pressure inside the hydraulic cylinder of 7Mpa is greater than the hydraulic pressure of the third accumulator of 3Mpa, but the reversing branch only allows the hydraulic oil to flow to the hydraulic cylinder and the reverse is cut off, so the hydraulic oil stops flowing.

At the third stage of the timing table, when the next wave arrives, the wave pushes the floating body up to do work, and the hydraulic cylinder has reached a working pressure of 10Mpa. The reversing branch still maintains the previous state, and the hydraulic oil of the new hydraulic branch is still stationary.

At the fourth stage, when the floating body reaches the wave crest, the wave can no longer push the floating body up, and the speed of the floating body in the vertical direction is 0, but the draft of the floating body is still very deep, and there is remaining net buoyancy (net buoyancy = the buoyancy of the floating body at this moment minus the gravitational force of the floating body). The MCU monitors this condition through the second sensor and immediately switches the solenoid two-position four-way valve to turn its single conducting direction to 1, that is, flowing out of the hydraulic cylinder. Now the hydraulic pressure of the hydraulic cylinder is 10Mpa, while the hydraulic pressure of the third accumulator is 3Mpa. The hydraulic oil of the hydraulic cylinder flows into the third accumulator, making the pressure of the third accumulator rise and the pressure of the hydraulic cylinder fall. Because the hydraulic oil flows out of the hydraulic cylinder, the cylinder block rises, and the draft of the floating body decreases. The work done by the remaining net buoyancy on the floating body in this process is converted into the pressure energy of the third accumulator. The flow of the hydraulic oil also drives the oscillating cylinder, making the hydraulic oil flow with high inertia. After exceeding the pressure equilibrium point between the hydraulic cylinder and the third accumulator, the hydraulic oil continues to flow towards the third accumulator under the action of the oscillating cylinder + flywheel, thus making fuller use of the net buoyancy to do work (if there is no oscillating cylinder + flywheel in this figure, the net buoyancy can also be used to do work, but the effect may not be as good). Finally, the pressure of the hydraulic cylinder gradually decreases from 10Mpa to 3Mpa, and the pressure of the third accumulator increases from 3Mpa to 8Mpa. Then it's back to the stage that the floating body is descending, mid so on.

Figure 26 and Figure 26A are interpreted below in conjunction with the single floating body pressure difference reset B type WECS in Figure 7. First, at the stage that the floating body is descending with the wave, the energy harvesting line is slack, the draft of the floating body is small, the pressure of the hydraulic cylinder is only 0.5Mpa, and the internal pressure of the high pressure accumulator is 10Mpa. Now the single conducting direction of the reversing branch controlled by the MCU is 1, that is, flowing out of the hydraulic cylinder. For the parallel branch, the hydraulic oil can't flow from 0.5Mpa to I OMpa, so it stops flowing.

When the floating body reaches the wave trough with the wave, it stops descending and the vertical speed is 0, and it is stationary relative to the inverted L rigid frame (the member moving relative to the floating body). The MCU monitors this condition through the second sensor 126 and immediately switches the reversing branch to turn its single conducting direction to that is, flowing into the hydraulic cylinder.

Now the hydraulic oil flows from the high pressure accumulator of I OMPa to the hydraulic cylinder 2 through the parallel branch, the reversing branch, the pump&motor 127, and the hydraulic amplifier 147, making the cylinder body descend relative to the plunger rod. The plunger rod is connected to the inverted L rigid frame, which in turn is connected to the underwater relative motion reference through the energy harvesting line, so the plunger rod cannot rise and only the cylinder will descend. Because the cylinder is installed on the floating body, the floating body will descend, the draft will increase, the buoyancy will increase, and the tension of the energy harvesting line will increase, thus the pre-tensioning effect is achieved. Meanwhile, the pressure of hydraulic cylinder 2 rises gradually from 0.5Mpa, while the high pressure accumulator has a large capacity and its pressure changes very little, which is ignored here. Under the rotatory inertia of the pump&motor + flywheel 123, the hydraulic oil continues to flow to the hydraulic cylinder after reaching the equilibrium point (set the pressure of the hydraulic cylinder at the equilibrium point =10Mpa/2=5Mpa) (of course, if there is no pump&motor 127+ flywheel 123 in this figure, a certain pre-tensioning effect can still be achieved, but the pre-tensioning effect will be reduced without inertia), and finally, the pressure of the hydraulic cylinder rises to 7Mpa. 7 x2Mpa is greater than the pressure of the high pressure accumulator of 10Mpa, but because the reversing branch is 1, only allowing the hydraulic oil to flow into the hydraulic cylinder, the hydraulic oil can not flow back from the hydraulic cylinder to the high pressure accumulator.

The next is the stage that the wave is pushing the floating body up to do work, and the reversing branch remains unchanged. Now the internal pressure of the hydraulic cylinder is 10Mpa, and the pressure of the high pressure accumulator is also 10Mpa, but the reversing branch is still l', so the hydraulic oil can only flow into the high pressure accumulator through the outlet check valve (the pressure drop of the valve is not considered here).

When the floating body reaches the wave crest, the wave can no longer push the floating body upward, and the vertical speed of the floating body is 0. The MCU monitors this condition through the second sensor and immediately switches the state of the reversing branch to that is, flowing out of the hydraulic cylinder. Now the pressure of the hydraulic cylinder is 10Mpa, and after the pressure boost by the hydraulic amplifier 147, a pressure of 20Mpa can be generated on the right side of the hydraulic amplifier 147. The pressure of the high pressure accumulator is 10Mpa, so the hydraulic oil flows from the hydraulic cylinder to the high pressure accumulator through the parallel branch. The capacity of the high pressure accumulator is large, resulting in small pressure changes (ignored here), so the outflow of the hydraulic oil in the hydraulic cylinder will make the cylinder block of the hydraulic cylinder rise relative to the plunger, which will result in a reduction in the draft of the floating body, a reduction in the tension of the energy harvesting line, and a rapid reduction in the hydraulic pressure of the hydraulic cylinder (from 10 Mpa to 31Mpa). In this process, the rotatory inertia of the pump&motor + flywheel makes the hydraulic oil continue to flow to the high pressure accumulator after the pressure of the hydraulic cylinder decreases to the equilibrium point of 5MPa, thus making fuller use of the remaining net buoyancy to do work (if there is no pump&motor + flywheel, the remaining net buoyancy can still be used, but less effective). Then it's back to the stage that the floating body is descending, and so on. In addition, the positions of the hydraulic amplifier, the pump&motor, and the reversing branch in Figure 26 are interchangeable.

For the hydraulic system in Figure 3 and Figure 7, and the hydraulic cylinder 2 in Figure 7A, Figure 7C, Figure13, Figure 14, Figure 15, Figure 16, Figure21, Figure 22, Figure23, Figure 24, Figure 25, and Figure 26, the piston cylinder and the plunger cylinder can be replaced with each other, the oil tank and the low pressure accumulator can be replaced with each other, and the oscillating cylinder and the pump&motor can be replaced with each other. The replaced embodiment can also be operated and achieve the pre-tensioning effect (but need to match with the actual needs of the WECS). For those with a solenoid switch valve, the solenoid switch valve can be replaced by a reversing branch. In this case, the MCU only needs to turn the conducting direction of the reversing branch against the direction of pressure (high pressure area to low pressure area) to achieve "off', and only needs to turn the direction of the reversing branch in line with the direction of pressure to achieve "on". For example, Figure 3B is the control scheduling table after replacing the solenoid switch valve with the reversing branch in Figure 3. At the stage that the floating body is descending, the pressure of the hydraulic cylinder is 0.5Mpa, while the pressure of the high pressure accumulator is 10Mpa. The parallel branch should be in the cut-off state, and the reversing branch should be against the direction of pressure, that is, f (only allowing it to flow out of the hydraulic cylinder). At the wave trough stage, the parallel branch should be in the open state, and the reversing branch should be in line with the pressure, that is, At the work stage when the floating body is rising, the pressure of the hydraulic cylinder is 10Mpa (actually it should be 10Mpa + the pressure drop of the exit one-way valve, which is ignored here), and the pressure of the high pressure accumulator is 10Mpa. Because the reversing branch itself also has pressure drop, the hydraulic oil can flow from the hydraulic cylinder to the high pressure accumulator either through the outlet check valve or the reversing branch, so either of the states of the reversing branch works, however, for the oscillating cylinder with a spring reset, the state of the reversing branch should be to make the oscillating cylinder reset under the action of the reset spring. At the wave crest stage, the pressure of the hydraulic cylinder is lower than 10Mpa at the beginning, while the pressure of the high pressure accumulator is still 10Mpa, so in order to avoid the high pressure hydraulic oil to flow back, the parallel branch should be in the cut-off state, that is, the reversing branch should be against the direction of pressure, that is, Similarly, the reversing branch in the figures mentioned in the previous paragraph can also be replaced with a solenoid switch valve. In addition to the on/off function, the reversing branch has another function of automatic non-return than the solenoid switch valve. If this function of the reversing branch is used in an embodiment (for example, for an embodiment with a oscillating cylinder/pump&motor, when the flow of the hydraulic oil exceeds the equilibrium point due to the inertia of the flywheel, the non-return function of the reversing branch automatically prevents the return of the hydraulic oil). The MCU can determine the optimal moment to close the solenoid switch (to prevent return flow) by means of a preset delay time (estimated) after replacing the reversing branch with the solenoid switch valve. Since the relative motion of the floating body to the member moving relative to the floating body and the flow rate/flow direction of the hydraulic oil into and from the hydraulic cylinder are correlated, the MCU may also refer to the information from the second sensor 126 to determine the optimal moment for the above dosing action.

In addition, in Figure 22, a hydraulic amplifier is added to the new hydraulic branch between the third accumulator 128 and the reversing branch, which belongs to the pre-tensioning scheme V. The addition of the hydraulic amplifier leads to a change in the hydraulic power response of the third accumulator 128, and technicians can achieve the desired performance with the assistance of the hydraulic amplifier.

Section VI: The suspended anchor technology has been described in CN107255060 A, as follows: 1) Direct connected suspending anchor: As shown in Figure 17, the buoy A and the buoy C are moored on each side of the floating body B. and each buoy is tied with a cable 57. The other end of the two cables is connected to a gravity anchor 17 of the WECS. The gravity anchor 17 under the floating body D in Figure 18 is also a direct connected suspending anchor 2) Pulley suspending anchor: As shown in Figure 17, the buoy 59 is moored on each side of the floating body D. The two ends of the cable 57 are lied to each of these two buoys 59, and the middle of the cable 57 is wrapped around a pulley 56 near the gravity anchor 17. The bottom end of the pulley bracket of the pulley 56 is connected to the top surface of the gravity anchor 17 of the WECS, and the energy harvesting line 30 coming down from above that would have been connected to the gravity anchor 17 is instead connected to the top of the pulley bracket 56. The gravity anchor below the floating body G of the WECS and the gravity anchor below the floating body B of the WECS in Figure 18 are both pulley suspending anchors.

3) Double rope suspending anchor: The gravity anchor is a horizontal cuboid. The four vertices of the top surface of the gravity anchor arc each installed with a pulley so that there arc two pulleys on each of the two opposite sides on the top surface of the gravity anchor Each pulley (two) on each opposite side rolls on a rope, and the two ropes merge into one on the left side of the gravity anchor and wind around a pulley, the pulley bracket of which is connected to the cable used to suspend the gravity anchor on the Ica side, and likewise on the right side, symmetrically on the left and right. The pulleys on both sides distribute the buoy's tension on the cable equally across the two ropes, which provide upward tension on the pulleys through which they pass and which are installed at the side of the gravity anchor, thus suspending the gravity anchor in the water.

4) Side winding suspending anchor: The gravity anchor is a horizontal cuboid. A fair lead is installed on the front and rear sides of the gravity anchor and two guide pulleys are installed on the two right vertical edges of the gravity anchor. The cable passes through the rear fair lead, winds around the guide pulley of the right rear edge and the guide pulley of the right front edge, and passes through the front fair lead. The two fair leads and the two guide pulleys arc at equal distances from the top surface of the gravity anchor. The suspending cable is equivalent to winding around one side of the gravity anchor, and the acting point of force is on the fair leads on both sides. It is obvious that the gravity anchor can slide along the cable with the help of the fair lead and guide pulley.

5) Stretcher suspending anchor: Two rigid straight rods, parallel and aligned end-to-end, pass through two transverse through-holes separated by a certain distance on the gravity anchor of the WECS. The left ends of the two rigid straight rods are fixed to a rigid frame, and the right ends of the two rigid straight rods are fixed to another rigid frame. The suspending cables on both sides are fixed to the rigid frames on both sides by V-shaped ropes, that is, the two vertices of the V-shaped ropes are connected to the two ends of the rigid frames, and the bottom ends of the V-shaped ropes are connected to the suspending cables. The suspending cables on both sides provide an upward tension on the two rigid straight rods, and the rigid straight rods provide an upward lifting force to the gravity anchor, similar to a stretcher. The gravity anchor can slide left and right with the rigid straight rods as guide rails.

In the above suspending anchor schemes 3), 4) and 5), the other ends of the suspending cables on both sides of the gravity anchor are connected to two buoys moored at a certain distance from each other on the water surface, and the floating body of the wave generator is in the middle of the two buoys, which is the same as suspending anchor schemes I) and 2). For the above five suspending anchor schemes, the wet weight (gravity minus buoyancy) of the gravity anchor is preferably greater than the upward tension of the WECS when doing work, and the maximum buoyancy force available from the two buoys is preferably greater than the wet weight of the gravity anchor, preferably with sufficient redundant reserve buoyancy.

Preferred: in the above suspending anchor schemes, the floating body is connected to the buoy by a cord 44 (as in Figures 17 and 18). In this way, they are interlocked as a whole, and the floating body will be pulled by the buoys on both sides when it moves, so as to avoid the floating body deviating too much and thus avoiding the floating body below the gravity anchor to follow the horizontal and vertical movement to reach the limit. Further preferred: A weight 51 is tied in the middle of the cord 44 to provide a cushion, or a tension spring 33 is tandem connected to replace the weight 51.

The above are the suspending anchor schemes. For the pre-tensioning hydraulic system of the WECS, if the suspending gravity anchor, acting as the underwater relative motion reference, is not stable, it will not be conducive to the MCU of the pre-tensioning hydraulic system of the WECS to judge the working status of the WECS. This relative motion is more complicated when both the floating body of the WECS and the gravity anchor are moving than when only the floating body of the WECS is moving and the gravity anchor is stable. For example, sometimes the floating body descends with the wave, and at the same time, the gravity anchor descends at a faster speed. Then the floating body is actually rising relative to the gravity anchor, arid the hydraulic cylinder is in the working state, so it is difficult for the MCU to determine which state the WECS is in. Therefore, it is necessary to keep the suspending anchor (the suspended gravity anchor) as stable as possible. The following are three specific measures to improve the suspending anchor technology.

For the suspending anchor scheme, it is preferred: As shown in Figure 18, the buoys (A, C, E) have a lathy capsule shape, mid the connection point to the buoy is located on the exterior center point of one end of the capsule. For a lathy capsule shape buoy and a flat buoy of the same volume, the change in buoyancy caused by the rise and fall of the waves is definitely smaller in the former. This allows the suspending anchor to be more stable.

Preferred: A horizontal damping plate is fixed to the bottom of the gravity anchor in the suspending anchor, and the gravity anchor is in the central upper position of the damping plate. The function is to use the resistance of water by the damping plate when moving in the water to make the gravity anchor more stable in the vertical direction.

Preferred: The central part of the cable 57 suspending the gravity anchor 17 is replaced by a tension spring 104 (Figure 18), and the function is to change the linkage motion characteristics of the gravity anchor 17 and the buoy 59 suspending it, so that the gravity anchor and the suspending buoy can be asynchronous, with the spring acting as a cushion. In addition: If the suspending cable is very elastic, such as a nylon rope, it can be equivalent to adding a spring.

In the case where only the damping plate 97 is available without the cushioning of the tension spring 104 on the suspending cable, if the cable 59 for suspension is too rigid, the movement of the gravity anchor with the damping plate added is subject to great resistance from the water, and the buoy will be subject to wave impact at the sea surface, which will result in a very large impact on the suspending cable. To solve this problem, it is further preferred that: The suspending anchor technology uses both the aforementioned cushion tension spring and damping plate schemes, which can greatly reduce the impact forces on the suspending cable.

A power transmission scheme X based on floating body queue on the water surface is also presented here. There is a queue of floating bodies on die sea surface. and the floating bodies at the beginning and end of the queue are moored. In this queue, adjacent floating bodies are connected to each other by cords, that is, the whole queue of floating bodies is connected by multiple cords in a string. In the queue, some floating bodies are the floating bodies of the wave generator, and the circuit leading out from the generator of the wave generator extends out of the floating body, attaches to the cord, and extends along it.

For scheme X. it is preferred: As shown in Figure 18, the electric cable 12 leading out from the generator of the WECS extends out of the floating body B and D, and then tied to the cord 44 and extends along it. This circuit runs from left to right, connecting two generators in series. The following three forms are attached: 1) the left side of the floating body B is a spiral cable 121 over the cord 44; 2) the electric cable on the right side of the floating body B is spirally wrapped around the cord 44; 3) the electric cable 12 on the right side of the floating body D is loosely tied to the cord 44 by a string 155.

Principle: As the cord between the floating bodies will stretch under the impulse pull, the ends of the electric cable 12 must be able to accommodate this stretch, and a spiral cable can meet die requirement, while for the latter two, the electric cable should be loose. In addition, the cord 44 may provide support for the electric cable 12 when seawater strikes it, preventing it from being bent and broken.

For the power transmission scheme X. it is preferred: As shown in Figure 18 for the floating body B, the circuit passes through a coaxial rotating joint/universal joint/spherical hinge type circuit connector at the point where it extends out of the floating body. As shown in Figure 19, as part of the circuit, a single core electric cable 12 led from the generator C is connected to one terminal (end A) of a universal joint circuit connector 151, and the terminal is fixed to the shell of the floating body 152 (if the shell of the floating body is electrically conductive, end A should be insulated from the shell of the floating body), while the other terminal (end B) of this universal joint circuit connector is connected to one end of the single core electric cable 12 extending along the cord 44.

Principle: The floating body B undulates with the waves on the sea, causing the cord 44 to which it is connected to oscillate in various ways. If the output electric cable of the generator simply conies out of the shell of the floating body and extends, it will soon break due to frequent bending. With the universal connection feature of the universal joint circuit connector 151 in this scheme, the bending movement of the electric cable 12 here can be eliminated, thus protecting the electric cable.

Preferred: The circuit connector 151 and its connection point with the electric cable 12 are sealed on the shell of the floating body 152 with a hemispherical flexible insulation cover 150 to avoid contact with seawater. The electric cable 12 connecting the end B extends through a hole in the flexible insulation cover, and the hole is to be sealed. Further preferred: The cord 44 is connected to the end B using an insulation connecting rod 153.

Principle: The cord 44 is connected to the end of the electric cable 12 in the same position, avoiding relative movement between the cord and the electric cable, which improves reliability. In addition, the insulation connecting rod 153 extends through the hole in the insulation cover 150, and the hole is to be sealed.

For the power transmission scheme X. it is preferred: As shown in Figure 18, at the weight 51 between the floating body D and the buoy C. the circuit extension passes through a spherical hinge type circuit connector 149 at the weight tied in the middle of the cord 44. As shown in Figure 20, a cord 44 between the floating bodies is connected to a weight 51 by a short string 49 in the middle. Due to the gravity of the weight, at the point of connection between the short string 49 and the cord 44, i.e. the mooring point, the cord 44 will have an angle of <1800. The terminal A of the spherical hinge type circuit connector is fixed to the cord 44 on the left side of the mooring point using a fixing support 154 and connected to a single core electric cable 12 on the left side (part of the circuit); the other terminal B of it is fixed to the cord 44 on the right side of the mooring point using another fixing support 154 and connected a single core electric cable 12 on the right side (part of the circuit). The plane in which the cords on both sides pass through the mooring point and is perpendicular to the mooring point is a straight line 00, and the straight line coincides with the center of the spherical hinge type circuit connector 149.

Principle: The cord 44, the fixing support 154 and a terminal on both sides of the mooring points are like on the two sides of a virtual hinge respectively, and the components on both sides rotate relative to each other around 00', in the real sea condition, the angle of the cord 44 is constantly changing and drives the spherical hinge type circuit connector to make corresponding changes through the fixing support 154. In this process, the electric cable 12 on one side will not be stressed and will not have relative motion with the cord 44 on the same side, thus avoiding the bending and swinging of the electric cable 12.

Preferred: The spherical hinge type circuit connector 149 and its connection point with the electric cable are sealed with a flexible insulation bush to avoid contact with seawater and leakage. The fixing support 154 is insulated, and the fixing support and electric cable 12 is to be sealed at the hole drilled on the flexible insulation bush 150.

For the power transmission scheme X, it is preferred: As shown in Figure 18, at the weight 51 between the buoy A and the floating body B, the circuit extension passes through a coaxial rotating joint 148 at the weight tied in the middle of cord 44, which can be understood that the cord 44 between the buoy A and the floating body B is disconnected in the middle and the two end points formed by the disconnection are connected to the two terminals A and B of the coaxial rotating joint 148 through the insulation connecting rod 153 (Figure 20A). The two terminals are directly connected to a single core electric cable 12 on each side of the circuit connector, and its common axis is connected to a weight 51.

Principle: Under the impact of seawater and sea breeze in real sea conditions, the distance between the floating bodies in Scheme X changes frequently, resulting in frequent changes in the angle between the cord 44 on both sides. The coaxial rotating joint 148 assumes both the circuit connection and the rope connection. and its two terminals follow the rope 44 to swing accordingly while maintaining the circuit connection. The electric cable 12 on one side does not move relative to the cord 44, avoiding damage caused by frequent bending of the electric cable 12.

Preferred: A flexible insulation bush 150 (such as a rubber bush) is used to seal the circuit connector 148 and its connection to the electric cable 12 completely to protect against water and leakage. The insulation connecting rod 153 passes through the hole in the flexible insulation bush 150, and the hole is to be sealed. The weight may be located outside the flexible insulation bush. The weight is connected to one end of an insulation connecting rod 153, and the other end of the insulation connecting rod pierces through a hole in the flexible insulation bush 150 and connected to the common axis. The hole is to be sealed against water.

For scheme X. it s preferred: One of the floating bodies, not the floating body of the wave generator, is herein named as a buoy (such as A, C, E in Figure 18), and the circuit passes the buoy in three ways: 1) As shown in Figure 18, a universal joint circuit connector 151 is installed on the left and right sides of buoy C. The circuit connectors on the left and right sides are installed in the same way as in Figure 19, except that the generator G is replaced with a single core cable (the dotted line inside the buoy C in Figure 18) that connects the end A of the two circuit connectors on the left and right sides.

Principle: The buoy C undulates in the waves, the cord 44 on the left and right sides swings in various ways relative to the buoy C, and the electric cable 12 on the cord 44 swings with it. With the universal connection feature of the circuit connector 151, the electric cable inside the buoy C can be connected to the external electric cable 12 of the buoy C in a universal way, thus avoiding damage caused by the bending of the electric cable.

Preferred: The circuit connector 151 and its connection point with the single core cable 12 are sealed on the shell of the buoy C with a hemispherical flexible insulation cover 150 to avoid contact with seawater. The electric cable connecting the end B extends through a hole in the flexible insulation cover, and the hole is to be sealed. Further preferred: On the left side of the buoy C, the cord 44 is connected to the buoy C using an insulation connecting rod 153, specifically: The cord 44 is connected to one end of the insulation connecting rod 153 outside the hemispherical flexible insulating cover 150. The other end of the insulation connecting rod 153 pierces through a hole in the insulating cover 150 and is connected to the end B of the circuit connector, and the hole is to be sealed. In this way, both the left side cord 44 and the left side electric cable 12 are connected to the end B of the left side circuit connector, avoiding relative movement between the cord 44 and the electric cable 12 and thus improving reliability.

(2) As shown at the buoy E in Figure 18 (the schematic diagram of this scheme can be obtained by flipping Figure 20 and replacing the weight 51 with a buoy), the ends of the cords 44 on the left and right sides of the buoy E are connected together. The connection point 0 is named the mooring point, and the bottom of the buoy E is connected to this mooring point 0. An angle of <180° is formed between the cords on the left and right side of the mooring point 0 due to the buoyancy of the buoy. One terminal of the circuit connector is fixed to the cord 44 on the left side of the mooring point using a fixing support 154 and is connected to a single core cable 12 on the left side, and the other terminal is fixed to the cord 44 on the right side of the mooring point using another fixing support and is connected to a single core cable 12 on the right side. The plane in which the cords 44 on both sides pass through the mooring point 0 and is perpendicular to the mooring point is a straight line, and the straight line shall coincide with the center of the spherical hinge type circuit connector 149.

Principle: The electric cables 12 on both sides of the mooring point are connected by the universal connection characteristics of the spherical hinge type circuit connector 154. The electric cable 12, the fixing support 154, and the cord 44 on both sides of the mooring points are like on the two sides of a virtual hinge respectively, and the shaft of the hinge is on 00'. The electric cable 12, the fixing support 154, and the cord 44 on each hinge face will not move relative to each other, thus avoiding bending damage to the electric cable 12 when the cord 44 swings.

Preferred: A flexible insulation bush 150 is used to wrap and seal the circuit connector 149 and its connection to the electric cable completely to protect against water and leakage. The fixing support 154 is insulated, and the fixing support 154 and the electric cable 12 are sealed at the hole drilled on the flexible insulation bush.

(3) As shown at buoy A in Figure 18 (similar in structure to Figure 20A, but replacing the weight 51 with the buoy 59), the other end of the insulation connecting rod 153 to which the end point of the cord 44011 the left side of the buoy A is connected and the single core cable 12 on the left side are connected to one terminal of the coaxial rotating joint 148. The other end of the insulation connecting rod 153 to which the end point of the cord 44 on the right side of the buoy A is connected and the single core cable 12 on the right side is connected to the other terminal of the circuit connector 148. The common axis of the circuit connector 148 is connected to the buoy A via the insulation connecting rod 153.

Principle: The buoy A undulates with the waves on the sea surface, and the angle between the cords 44 on both sides changes frequently. For the electric cable 12 tied to the cord, if the electric cables on both sides are directly connected, they are bound to break due to frequent bending. With the coaxial rotating joint 148, however, the change in angle between the electric cables 12 on both sides is made entirely by the circuit connector 148, and the electric cable 12 does not move relative to the cord 44, thus protecting the electric cable.

Preferred: A flexible insulation bush 150 (such as a rubber bush) is used to seal the circuit connector 148 and its connection to the electric cable 12 completely to protect against water and leakage. The buoy A is located outside the flexible insulation bush 150, and the insulation connecting rod 153 pierces through a hole in the flexible insulation bush 150. The hole is to be sealed to protect against water.

For scheme X, it is preferred: As shown in Figure 20B, the floating body queue is arranged in a circle queue (like a clock scale). To maintain the circle, some of the floating bodies are moored by anchors 46 (star-like), and there is a plurality of floating bodies of wave generators in the queue. The generators G of the wave generators are all DC generators/AC generators with rectified output. The generators of all wave generators are connected in series through the circuit (dashed lines) in queue order, but the first generator GI and the last generator G5 are not directly electrically connected to each other, thus forming a general power supply with an output voltage at the open loop equal to the sum of the voltages of all the generators. The advantage of this scheme is: It can use single core cables, with simple energy aggregation, eliminating the need for booster stations and ensuring low cost. In this embodiment, it is preferred that: Scheme X-1 may be adopted when the circuit extends along the cord 44 (black solid line); scheme X-2 may be adopted when the circuit goes from the generator to the outside of the floating body: scheme X-3 may be adopted when the circuit passes the weight (black square) tied in the middle of the cord: scheme X-4 may be adopted when the circuit passes the buoy (hexagon).

For this specification, the following paragraphs are all preferred recommendations. All the shells of the floating bodies and the rope control mechanism in this specification can be made of steel/fiber reinforced plastics/high density polyethylene/polyurea, such as Q235, all components and parts in this specification, except for hydraulic systems, gravity anchors, electrical parts, generators, hawsers, cords, ropes, cables, rollers of fair leads and parts that need to be deformed during operation, can be made of steel, such as carbon steel (preferably Q235) or stainless steel: the rollers on the fair leads can be made of nylon; the hawsers used as the energy harvesting lines mentioned in this specification, as well as the hawsers used in some embodiment to connect the end of the piston rod with the top of the rope control mechanism can be made of high strength and high modulus materials, such as UHMWPE. To reduce wear, it is preferred: it may be covered with soft and wear-resistant materials, such as rubber; the ropes, cords, cables and hawsers in this specification can be made of PP/polyethylene/nylon: copper-based graphite self-lubricating bearings/ceramic bearings may be used for all bearings (including bearings in the fair leads, double roller warping chokes, and guide rollers). Anti-corrosion means: If the shells of the floating body and rope control mechanism are made of steel, the steel shell covered by glass fiber reinforced plastics/polyurea/high density polyethylene may be used, or sacrificial anode protection or exterior painting may be adopted; gravity anchors, counterweights, and weights can be made of cement block/iron block. The hawsers/cords/ropes/cables in this specification may be connected to other rigid parts using a capel which is paired with a U-ring on other rigid parts.

Hydraulic and electrical systems: Solenoid switch valve may be a direct-acting/step direct-acting/pilot-operated type, preferably a normal closed type: accumulator (including the third accumulator, high pressure accumulator, and low pressure accumulator) may be a bladder type/piston type/diaphragm type/spring type, preferably a piston type (the gas loading type): the hydraulic oil pipe may be a steel wire type or clamped cloth type, and if the oil pipe is not moving, it may be a steel pipe; the generator may be a permanent magnet brushless DC or AC generator, the hydraulic motor may be an axial piston motor with valve plate flow distribution, the oscillating cylinder may be a gear rack type/blade type/screw type, and the charge pump may be a cycloid pump; the electric cables may be copper/aluminum cables.

The oil tank in this specification and the drawings may be an opening oil tank, but because the floating body undulates on the sea surface, a closed oil tank may be used to prevent the hydraulic oil from spilling out. There are inflatable type and isolated type, but the isolated type is preferred.

Stable speed of the generator is needed to ensure the voltage stability of the generator, and the flow rate of the hydraulic cylinder output is different under large and small waves. The hydraulic motor in this specification may be an electroic-hydraulic variable motor, and the MCU controls the displacement of the variable motor according to the output voltage of the generator to achieve the speed stability of the motor mid generator under different flow rates. A fixed displacement hydraulic motor may also be used, but a transmission shall be added between the hydraulic motor and the generator; it is preferably an electronically controlled transmission, and the MCU controls the transmission ratio of the electronically/ controlled transmission according to the voltage of the generator so that although the speed of the hydraulic motor is affected by wave conditions, the speed of the generator is kept stable by changing the transmission ratio.

Claims

Claims: 1.A wave generator using unidirectional work done by buoyancy, comprising a wave energy collection and conversion system, which comprises a sea surface assembly, an energy harvesting line and an underwater relative motion reference object; the sea surface assembly is of the single floating body spring reset type/single floating body pressure difference reset type/double floating body gravity reset type and comprises a floating body, a member moving relative to the floating body, a hydraulic system and a generator; the hydraulic system is of then closed circulation/open circulation type; the route of the closed circulation is as follows: hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, low pressure accumulator and inlet check valve; the route of the open circulation is as follows: hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, oil tank and inlet check valve; it is characterized in that: a new hydraulic branch may be led out from the hydraulic line at an oil inlet/outlet port of the hydraulic cylinder, that is, the pipeline between the hydraulic cylinder and the outlet check valve, of the hydraulic system; the new hydraulic branch passes through a solenoid switch valve/electric switch valve and is finally connected to a third accumulator; a MCU (Single-chip microcomputer) /PLC receives signals from a second sensor used to monitor operating status of the sea surface assembly/status of the wave surface where the sea surface assembly is located and controls on-off actions of the solenoid switch valve/electric switch valve; the solenoid switch valve may be replaced with a reversing branch; the specific scheme is as follows: a two-position four-way solenoid valve is under operating status: P>>A, B>>T or P>>B, A>>T; a branch containing a third check valve is added for connecting the B port to A port and thereby fonning a circuit of B>>the third check valve>>A; the connections of the solenoid switch valve is replaced with the P and T ports of the two-position four-way solenoid valve and the MCU/PLC receives the signals of the second sensor used to monitor die operating status of the sea surface assembly/status of the wave surface where die assembly is located and control the two-position four-way solenoid valve; preferably, the underwater relative motion reference object is a suspended anchor or a gravity anchor/friction pile/suction anchor on the seabed; preferably, the solenoid switch valve is of the direct-acting type/step direct-acting type/pilot-operated type; preferably, the third energy accumulator/high pressure accumulator/low pressure accumulator is of a bladder type/piston type/diaphragm type/spring type.
2: A wave generator using unidirectional work done by buoyancy, comprising a wave energy collection and conversion system which comprises a sea surface assembly, an energy harvesting line and an underwater relative motion reference object; the sea surface assembly is of a single floating body spring reset type/single floating body pressure difference reset type/double floating body gravity reset type and comprises a floating body, a member moving relative to the floating body, a hydraulic system and a generator; the hydraulic system is of then closed circulation/open circulation type; the route of the closed circulation is as follows: hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, low pressure accumulator and inlet check valve; the route of the open circulation is as follows: hydraulic cylinder, outlet check valve, high pressure accumulator, hydraulic motor, opening oil tank and inlet check valve; it is characterized by: a hydraulic branch is connected in parallel with die outlet check valve of the hydraulic system; a solenoid switch valve/electric switch valve is connected in the hydraulic branch and a MCU/PLC receives signals from a second sensor used to monitor operating status of the sea surface assembly/status of the wave surface where the sea surface assembly is located and controls on-off actions of the solenoid switch valve/electric switch valve; the solenoid switch valve may be replaced with a reversing branch; the specific scheme is as follows: a two-position four-way solenoid valve is under the operating status: P>>A. B>>T or P>>B, A>>T; a branch containing a third check valve is added for connecting the B port to A port and thereby forming a circuit of B>>the third check valve>>A; the connections of the solenoid switch valve is replaced with the P and T ports of the two-position four-way solenoid valve and the MC U/PLC receives signals of the second sensor used to monitor operating status of the said sea surface assembly/status of the wave surface where the sea surface assembly is located and control the two-position four-way solenoid valve; the solenoid switch valve/electric switch valve/reversing branch is taken as a demarcation point, and the section of the parallel hydraulic branch closer to the hydraulic cylinder is defined as the front half and the section closer to the high pressure accumulator is defined as the roar half; preferably, the underwater relative motion reference object is a suspended anchor or a gravity anchor/friction pile/suction anchor on the seabed; preferably, the high pressure accumulator/low pressure accumulator is of a bladder type/piston type/diaphragm type/spring type; preferably, the solenoid switch valve is of the direct-acting type/step direct-acting type/pilot-operated type.
3. A wave generator using unidirectional work done by buoyancy according to claim 1, wherein an oscillating cvlinder/plunp&motor is inserted into the new hydraulic branch before or after the solenoid switch valve/electric switch valve/reversing branch; a shaft of the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel, or the shaft of the oscillating cylinder/pump&motor is linked to the flywheel through a belt/gear/chain transmission mechanism; preferably, a rotation speed sensor is added and the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve according to rotating speed of the flywheel monitored by the rotation speed sensor; or a flow direction sensor/flow sensor/hydraulic sensor is added to the new hydraulic branch and the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve according to the change of the flow direction/flow of hydraulic oil monitored by the flow direction/flow sensor or the change of hydraulic pressure monitored by the hydraulic sensor; preferably, the oscillating cylinder is of a blade type/pinion rack type/screw type/lever type; preferably, the belt/gear/chain drive mechanism is used to increase the rotating speed of the flywheel; preferably, the pump&motor is an valve plate type axial plunger pump or an axis distribution flow type radical plunger motor.
4: a wave generator using unidirectional work done by buoyancy according to claim 2, wherein an oscillating cylinder/pump&motor is inserted into the front half or rear half of the parallel branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism; preferably, the oscillating cylinder is of a blade type/pinion rack type/screw type/lever type; preferably, the belt/gear/chain drive mechanism is used to increase the rotating speed of the flywheel; preferably, the oscillating cylinder/pump&motor is inserted into the front half of the parallel branch; a continuous current branch is led out from the hydraulic line between the solenoid switch valve/electric switch valve/reversing branch and the oscillating cylinder/pump&motor and connected to the low pressure accumulator/opening oil tank of the hydraulic system through a check valve; it is connected to the low pressure accumulator if the hydraulic system is of the closed circulation type, and connected to the oil tank if the hydraulic system is of the open circulation type; the check valve allows a flow direction from the low pressure accumulator/oil tank to the position between the solenoid switch valve/electric switch valve/reversing branch and the oscillating cylinder/pump&motor; preferably. A reset spring is installed on the oscillating cylinder and the reset force of the reset spring makes the hydraulic oil in the oscillating cylinder flow from the end closer to the hydraulic cylinder to the other end.
5. a wave generator using unidirectional work done by buoyancy according to claim 1, wherein a pressure amplifier cylinder is inserted into the new hydraulic branch; preferably, an oscillating cylinder/pump&motor is inserted into the new hydraulic branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism.
6, a wave generator using unidirectional work done by buoyancy according to claim 2, wherein a pressure amplifier cylinder is inserted into the parallel branch; preferably, in the pressure amplifier cylinder, the effective working area of the side closer to the hydraulic cylinder is larger than that of the side closer to the high pressure accumulator; preferably, an oscillating cylinder/pump&motor is inserted into the parallel branch and the oscillating cylinder/pump&motor is coupled by a shaft to a flywheel or linked to the flywheel through a belt/gear/chain drive mechanism: further preferably, a rotation speed sensor is added for monitoring the flywheel, or a flow direction/flow sensor is inserted into the parallel branch, or a hydraulic pressure sensor is inserted into the position between the hydraulic cylinder and the oscillating cylinder/pump&motor; the MCU/PLC controls off actions of the solenoid switch valve/electric switch valve/reversing branch according to the rotation speed sensor/flow direction sensor/flow sensor/hydraulic pressure sensor.7. a wave generator using unidirectional work done by buoyancy according to claim 1 or 2, wherein the second sensor is one of the following types: 1) distance sensor: a sensor installed on the floating body and used to monitor the change of distance between a member linked to the energy harvesting line and a top surface of the floating body; preferably: the sensor is installed on the top surface of the floating body and the monitored member is above the top surface of the floating body; preferably, the distance sensor is of a laser/ultrasonic wave/infrared type; 2) linear displacement sensor:: consists of two components that can move linearly relative to each other, one connected to the floating body and the other connected to a member linked to the energy harvesting line. Preferred: One of the components is connected to the top surface of the floating body, mid the other component is connected to the member above the top surface of the floating body; preferred: the linear position sensor is a pull lever/pull rope type.
3) linear speed sensor: consists of two components that can move linearly relative to each other, one connected to the floating body and the other connected to a member linked to the energy harvesting line. Preferred: One of the components is connected to the top surface of the floating body, and the other component is connected to the member above the top surface of the floating body; 4) acceleration sensor: it is installed on the floating body and used to measure the acceleration of the floating body; 5) draft sensor: a water pressure sensor installed outside the bottom surface of the floating body and used to monitor the draft depth of the floating body; 6) tension sensor: it is connected in series with the energy harvesting line and used to monitor the tensile force of the energy harvesting line; 7) hydraulic pressure sensor: it is installed in the hydraulic line at the oil inlet/outlet port of the hydraulic cylinder and used to monitor the hydraulic pressure at the oil inlet/outlet port; 8) flow sensor: it is installed in the hydraulic line at the oil inlet/outlet port of the hydraulic cylinder and used to monitor the flow at the oil inlet/outlet port; preferably: the MCU/PLC receives external wave data/manually pre-set parameters/orders through a wireless communication module.
8, a wave generator using unidirectional work done by buoyancy according to claim 1 or 2, wherein the sea surface assembly is of a single floating body pressure difference reset B type; the specific structure of the sea surface assembly is as follows: a floating body whose stmcture can be interpreted as: a closed shell is penetrated by a vertical straight pipe through the center and then the part of the shell in the straight pipe is removed, therefore a closed shell with a through-hole in the center is formed; an inverted L rigid frame has a square tube or a thin and long straight cuboid rod as the vertical part; the vertical part passes through two 4-roller fairleads installed in the through-hole and spaced by a certain vertical distance and its four side faces tightly cling to the four rollers of each 4-roller fairlead respectively; the two 4-roller fairleads may be replaced with two upper and lower guide rails that guide the vertical motion of the inverted L rigid frame; the horizontal part of the inverted L rigid frame is located above the floating body and connected to the plunger rod of a vertical/inclined plunger cylinder; the back end of the body of the plunger cylinder is connected to the top surface of the floating body; the plunger cylinder may be connected inversely i.e.: the back end of the body of the plunger cylinder is connected to the horizontal part of the inverted L rigid frame and the plunger rod is connected to the top of the floating body; the connection between the plunger cylinder and other components (the floating body/inverted L rigid frame) is fixed connection/hinged shaft/earring connection, but if the plunger cylinder is inclined, a fixed connection is not applicable; the bottom of the inverted L rigid frame is connected to one end of the energy harvesting line and the other end of the energy harvesting line harvesting line is connected to the underwater relative motion reference object; alternatively, the bottom of the inverted L rigid frame is connected to a top of a rope control mechanism and the bottom of the energy harvesting line of the rope control mechanism is connected to the underwater relative motion reference object; the connection between the inverted L rigid frame and the top of the rope control mechanism is fixed connection/movable connection, preferably flexible/universal connection, such as double locking rings/cross universal connection; the hydraulic system forms a closed circulation, and the route of the cycle is from the chamber of the plunger cylinder to an outlet check valve, a high pressure accumulator, a hydraulic motor, a low pressure accumulator and an inlet check valve; the hydraulic motor drives the generator to generate power; the lower one of the two fairleads/guide rails may be installed at the bottom in a vertical straight tube; specifically, a vertical straight tube is added; the top of the straight tube is fixed and connected to the bottom surface of the floating body; the axis of the straight tube coincides with the axis of the through-hole and the inner diameter of the straight tube is larger than the inner diameter of the through-hole; alternatively, the inner diameter of the straight tube is smaller than the through-hole and a flange is fixed and connected to the top of the straight tube so that the straight tube can be fixed and connected to the bottom surface of the floating body through the flange; the lower one of the two fairleads/guide rails may be moved downward and installed at the bottom in the straight tube and the upper fairlead/guide rail may be installed in the through-hole of the floating body and near the top; preferably, a oil filter is connected in series in the closed hydraulic system and located between the inlet check valve and the low pressure accumulator; preferably, the generator is a brushless and permanently magnetic AC or DC generator; preferably, the motor is an valve plate type axial plunger motor; preferably, the structure of the floating body is as follows: it is a cylinder-shaped closed shell with a through-hole along the axis and fully enclosed shell; the further preferable scheme is that the floating body is made of Steel/fiber glass-reinforced plastic/high-density polyethylene/polyurea; preferably, the plunger rod is coated with a protective cover; one end of die protective cover is abutted to the plunger rod and sealed and the other end is abutted to the outside of the body of the plunger cylinder and sealed; preferably, the inverted L rigid frame and straight tube are both rigid components; further preferably, they are made of steel or Aluminum alloy: preferably, the straight tube is round pipe-shaped, and its connection with the floating body is a welding/flanged connection.
9. a wave generator using unidirectional work done by buoyancy according to claim I or 2, wherein the underwater relative motion reference object is a gravity anchor suspended by buoys on both sides through a cable; preferably, the gravity anchor can be suspended by means of direct-connected/ pulley! double double-ropeway / lateral-passing-by/ stretcher suspended anchor; preferably, the bottom of the suspended gravity anchor is fixed to a horizontally placed damping plate, and the gravity anchor is positioned at the central upper part of the damping plate; preferably, the middle section of the cable suspending the gravity anchor is replaced by a tension spring; further preferred: if the suspended anchor is a direct-connected/stretcher suspended anchor, there are tension springs series connected to the suspending cables on both sides; preferably the buoy that suspends the gravity anchor has a lathy capsule shape with an upright axis, and the suspending cable is attached to the bottom center of the capsule-shaped buoy.
10. a wave generator using unidirectional work done by buoyancy according to claim 1 or 2, wherein the floating body is in a floating body queue, and the floating body of the wave generator is also counted as a member of the queue; the first and last floating bodies of the queue are moored, and the adjacent floating bodies in the queue are connected by cords; a circuit leading out from the generator of the wave generator drills out from the floating body, attaches to the cord and extends along it; schemes X-1, X-2, X-3, X-4 and X-5 can be adopted;