A closed wave energy power generation device with adjustable center of gravity and power generation control method

Abstract

The present invention discloses a closed wave energy power generation device with adjustable center of gravity and a power generation control method. The power generation device includes a closed shell, in which: a shaft body is provided with an eccentric counterweight; a base, the base is used to install the shaft body, and the shaft body can rotate freely around its own axis; a hydraulic pump, the pump shaft of the hydraulic pump is connected to the shaft body through a speed increaser; a lifting unit is used to drive the base to rise or fall. The power generation device and power generation control method provided by the present application can actively adjust the center of gravity of the power generation device according to the size of the waves, so that the power generation device can survive reliably under extreme marine conditions and can efficiently capture wave energy under small wind and wave conditions, adjust the power generation capacity according to different wave conditions, improve the power generation efficiency and stability, and adapt to the complex and changeable marine environment.

Description

Technical Field

[0001] The invention relates to a closed wave energy power generation device with adjustable center of gravity and a power generation control method, belonging to the technical field of wave energy power generation systems. Background Art

[0002] The ocean contains abundant renewable energy, mainly in the form of wind energy, wave energy, tidal energy, etc., with a theoretical total amount of up to 2.1×10 6 TW·h. Among them, wave energy is the energy with the highest energy density among marine renewable energy sources. It has the characteristics of concentrated energy distribution, high theoretical energy capture efficiency, and long effective production time, which has attracted widespread attention.

[0003] There are many types of wave energy development and utilization devices. According to their structural forms, they can be divided into fixed pendulum consumption type, floating pendulum consumption type, pendulum cut-off type, raft consumption type, duck type, oscillating water column type, oscillating float type and other types. However, their basic principles can be roughly divided into three categories, namely: (1) using the oscillation and swaying motion of the structure under the action of waves to generate electricity; (2) using the change of wave pressure to generate electricity; (3) using the climbing of waves along the structure to convert wave energy into water potential energy to generate electricity. For example, the invention patent with application number 201811637778.8 discloses a wave energy power generation device that uses a free pendulum to capture energy. It can not only efficiently capture wave energy of different wave directions, but also convert wave energy into electrical energy output. The invention patent with application number 201811546204.X discloses a gyro wave energy power generation device, which adopts a two-stage energy conversion link and has the characteristics of simple structure, small size and light weight. The invention patent with application number 201910862898.6 discloses a wave pressure type wave energy conversion device, which improves the energy conversion rate of pneumatic wave energy power generation technology.

[0004] Although wave energy power generation devices come in various forms, the high R&D costs and large investment still restrict the promotion and application of wave energy power generation technology. Improving the reliability of wave energy power generation devices and extending the effective service life of the equipment are effective ways to reduce the cost of power generation. The invention patent with application number 201711369487.0 discloses a fully enclosed inertial point suction wave energy device with controllable system oscillation frequency and strong environmental adaptability. It effectively solves the problem of seawater corrosion resistance of wave energy devices and has high system reliability. However, under extreme marine conditions such as strong winds and huge waves, wave energy power generation devices are prone to capsizing, resulting in complete failure of the equipment. If the wind and wave resistance of the equipment is improved by lowering the center of gravity to increase the distance between the center of gravity and the center of buoyancy, the movement amplitude of the power generation device will be reduced, which will reduce the energy capture efficiency of the power generation device. Therefore, the coordination problem between the reliability and efficiency of wave energy power generation devices has not been effectively solved.

[0005] It should be noted that the above contents belong to the technical knowledge of the inventor and do not necessarily constitute prior art. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a closed wave energy power generation device with adjustable center of gravity position and a power generation control method, which can actively adjust the distance between the center of gravity and the center of buoyancy according to the characteristics of the sea conditions, thereby ensuring that the power generation device can survive reliably under extreme marine conditions and ensuring a higher energy capture efficiency of the power generation device under small wind and wave conditions.

[0007] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0008] On the one hand, the present application provides a closed wave energy power generation device with adjustable center of gravity, comprising a closed shell, wherein the shell is provided with:

[0009] A shaft body, the axis of which is arranged along the center of gravity of the shell, an eccentric weight is arranged on the shaft body, and the eccentric weight is arranged eccentrically relative to the axis of the shaft body;

[0010] A base, the base is used to install the shaft body, and the shaft body can rotate freely around its own axis;

[0011] A hydraulic pump, wherein the pump shaft of the hydraulic pump is connected to the shaft body through a speed increaser, the oil inlet of the hydraulic pump is connected to the oil tank through an oil supply pipeline, and the oil discharge port of the hydraulic pump is connected to the hydraulic motor generator set through an oil delivery pipeline;

[0012] A lifting unit, the lifting unit is connected to the base and is used to drive the base to rise or fall;

[0013] The control unit includes a controller and a rotation speed sensor, wherein the rotation speed sensor is used to detect the rotation speed of the shaft body, the rotation speed sensor is connected to the input end of the controller, and the lifting unit is connected to the output end of the controller.

[0014] Furthermore, the lifting unit is an electric drive, and the electric drive is connected to the output end of the control unit.

[0015] Furthermore, the lifting unit is a No. 1 hydraulic cylinder, which is connected to the oil pipeline. The No. 1 hydraulic cylinder controls the connection and disconnection of its rod chamber or rodless chamber and the oil pipeline through a first switch unit, and the first switch unit is connected to the output end of the control unit.

[0016] Furthermore, the first switch unit is a three-position four-way solenoid reversing valve or a two-position four-way solenoid valve.

[0017] Furthermore, the hydraulic pump is a bidirectional pump, and the two oil ports of the bidirectional pump are switched to oil inlets or oil outlets by the forward and reverse rotation of the pump shaft. Each oil port of the bidirectional pump is connected to the oil tank through an oil supply line, and is also connected to the hydraulic motor generator set through an oil delivery line. A second switch unit is arranged on the oil supply line and the oil delivery line, and the second switch unit is used to control the unidirectional conduction from the oil tank to the hydraulic motor generator set through the oil supply line, the hydraulic pump, and the oil delivery line.

[0018] Furthermore, the second switch unit includes one-way valves arranged on the oil supply pipeline and the oil delivery pipeline, wherein the one-way valve arranged on the oil supply pipeline is unidirectionally conductive to the two-way pump, and the one-way valve arranged on the oil delivery pipeline is unidirectionally conductive to the hydraulic motor generator set.

[0019] Furthermore, the eccentric weight comprises:

[0020] Counterweights;

[0021] No. 2 hydraulic cylinder, the counterweight block is installed on the cylinder rod of the No. 2 hydraulic cylinder, and the No. 2 hydraulic cylinder is connected to the oil pipeline.

[0022] Furthermore, the closed wave energy power generation device with adjustable center of gravity position also includes a hydraulic accumulator, which is connected to an oil pipeline. A third switch unit is arranged between the hydraulic accumulator and the oil pipeline, and the third switch unit is connected to an output end of the control unit. The third switch unit is used to control the on-off between the hydraulic accumulator and the oil pipeline.

[0023] On the other hand, the present application provides a power generation control method based on the above power generation device, comprising:

[0024] S1, setting the upper limit and lower limit of the rotation speed of the shaft body to n1 and n2 respectively;

[0025] S2, obtain the real-time rotation speed of the shaft as n0 through the rotation speed sensor;

[0026] S3, if n0>n1, control the lifting unit to push the base down;

[0027] If n0<n2, the lifting unit is controlled to push the base upward;

[0028] If n2≤n0≤n1, the lifting unit does not work and the base maintains the current position.

[0029] Furthermore, the power generation control method further includes:

[0030] S1, set the upper and lower limits of the oil pressure in the oil pipeline to p1 and p2 respectively;

[0031] S2, obtain the oil pressure of the oil pipeline as p0 through the pressure sensor;

[0032] S3, if p0>p1, control the third switch unit to conduct the hydraulic accumulator and the oil pipeline;

[0033] If p0<p2, control the third switch unit to conduct the hydraulic accumulator and the oil pipeline;

[0034] If p2≤p0≤p1, the third switch unit is controlled to disconnect the hydraulic accumulator and the oil pipeline.

[0035] The beneficial effects of this application include but are not limited to:

[0036] The power generation device and power generation control method provided in the present application can actively adjust the center of gravity position of the power generation device according to the wave size, so that the power generation device can not only survive reliably under extreme marine conditions, but also efficiently capture wave energy under small wind and wave conditions, adjust the power generation capacity according to different wave conditions, improve the power generation efficiency and stability, and adapt to the complex and changeable marine environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0038] Figure 1 This is a schematic diagram of the structure of the power generation device involved in this application;

[0039] Figure 2 A partial structural schematic diagram of a power generation device involved in an embodiment of the present application example;

[0040] Figure 3 for Figure 2 The hydraulic principle diagram of the power generation device involved;

[0041] Figure 4 for Figure 2 A schematic diagram of the structure of a rotary oil distributor in a power generation device involved;

[0042] Figure 5 A partial structural schematic diagram of a power generation device involved in another embodiment of the present application example;

[0043] Figure 6 A partial structural schematic diagram of a power generation device involved in another embodiment of the present application example;

[0044] Figure 7 This is a control logic diagram of the power generation control method involved in this application.

[0045] In the figure, 11 is an upper shell; 12 is a lower shell; 20 is a shaft body; 30 is a lifting unit; 31 is an electric drive; 311 is a guide rail; 312 is a sleeve; 313 is a counterweight; 314 is a No. 2 hydraulic cylinder; 315 is a rotary oil distributor; 316 is an oil storage chamber; 317 is an oil circuit; 318 is a sealing ring; 319 is a retaining spring; 32 is a No. 1 hydraulic cylinder; 321 is a three-position four-way solenoid reversing valve; 322 is a two-position four-way solenoid valve; 40 is a base; 50 is a hydraulic pump; 60 is a speed increaser; 70 is an oil supply pipeline; 80 is an oil delivery pipeline; 90 is an oil tank; 110 is a hydraulic motor; 120 is a generator; 710 is a No. 1 one-way valve; 720 is a No. 2 one-way valve; 810 is a No. 3 one-way valve; 820 is a No. 4 one-way valve; 100 is a hydraulic accumulator; 101 is a third switch unit. DETAILED DESCRIPTION

[0046] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0047] It should be noted that many specific details are described in the following description to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0048] Embodiment 1:

[0049] like Figure 1-Figure 2 As shown in , the enclosed wave energy power generation device with adjustable center of gravity provided in this embodiment includes a closed shell, a shaft body 20 is arranged in the shell, the axis of the shaft body 20 is arranged along the center of gravity line of the shell, an eccentric counterweight is arranged on the shaft body 20, and the eccentric counterweight is arranged eccentrically relative to the axis of the shaft body 20. The shaft body 20 is installed on the base 40, and the shaft body 20 can rotate freely around its own axis. A hydraulic pump 50 and a hydraulic motor generator set are also arranged in the shell, and the pump shaft of the hydraulic pump 50 is connected to the shaft body 20 through a speed increaser 60. The oil inlet of the hydraulic pump 50 is connected to the oil tank 90 through an oil supply pipeline 70, and the oil discharge port of the hydraulic pump 50 is connected to the hydraulic motor generator set through an oil delivery pipeline 80.

[0050] When working, the shell floats on the sea surface. Under the impact of waves, the power generation device shakes. When the line of action of the gravity of the power generation device is not in the plane formed by the eccentric counterweight and the shaft body 20, the eccentric counterweight will swing, thereby driving the shaft body 20 to rotate, and then driving the input shaft of the speed increaser 60 to rotate. After the speed increaser 60 increases the speed, the output shaft of the speed increaser 60 outputs a faster speed, driving the hydraulic pump 50 to work. Under the action of the hydraulic pump 50, the hydraulic oil is sucked into the hydraulic pump 50 from the oil tank 90 through the oil supply pipeline 70, and is discharged from the hydraulic pump 50 after being pressurized, and is transported to the hydraulic motor generator set through the oil pipeline 80, and then returns to the oil tank 90.

[0051] Specifically, the hydraulic motor generator set includes a hydraulic motor 110 and a generator 120, and the rotating shaft of the hydraulic motor 110 is drivingly connected to the rotating shaft of the generator 120. When the hydraulic oil passes through the hydraulic motor generator set, it drives the hydraulic motor 110 to work, and then drives the generator 120 to generate electricity.

[0052] Furthermore, the shell is spliced ​​by the upper shell 11 and the lower shell 12 to form a closed space, isolating the equipment inside the shell from the seawater. The diameter of the lower shell 12 is larger than that of the upper shell 11, and the equipment inside the shell is installed in the lower shell 12. The center of gravity of the device is below the buoyancy center, so that the power generation device can float stably on the sea surface. The speed increaser 60 is a planetary gear speed increaser, which is fixedly connected to the base 40. Its function is to increase the lower speed of the shaft 20 to a higher speed, so as to facilitate driving the hydraulic pump 50 to work.

[0053] More importantly, a lifting unit 30 is also provided in the shell, and the lifting output end of the lifting unit 30 is connected to the base 40 to push the base 40 up or down. When the wind and waves are small, the shaking amplitude of the power generation device is small, the rotation speed of the shaft 20 is slow, and the energy capture efficiency of the power generation device is low. At this time, the lifting unit 30 is controlled to push the base 40 on which the shaft 20, the speed increaser 60, the hydraulic pump 50 and other equipment are installed to move upward, so that the center of gravity of the wave energy power generation device moves upward, so that the center of gravity of the power generation device moves up close to the buoyancy center position, the stability of the power generation device deteriorates, the shaking amplitude increases, and the rotation speed of the shaft 20 increases, thereby improving the energy capture efficiency of the power generation device. When the wind and waves are large, the shaking amplitude of the power generation device is large, and there is a risk of capsizing. At this time, the lifting unit 30 is controlled to push the base 40 on which the shaft 20, the speed increaser 60, the hydraulic pump 50 and other equipment are installed to move downward, so that the center of gravity of the power generation device moves down away from the buoyancy center position, forming a "tumbler" structure, and improving the wind and wave resistance of the power generation device.

[0054] In order to realize automatic control, the power generation device also includes a control unit, which includes a controller and a speed sensor. The speed sensor is connected to the input end of the controller. The speed sensor is used to detect the speed of the shaft 20 and send a signal to the controller. After analyzing the speed signal of the shaft 20, the controller sends an instruction to the lifting unit 30 through the output end to control the lifting unit 30 to execute the action of driving the base 40 to rise or fall.

[0055] like Figure 3 As shown in the figure, in this embodiment, the lifting unit 30 is specifically an electric driver 31, which is installed in the lower housing 12, and its lifting output end is connected to the base 40 to push the base 40 up or down. Specifically, the electric driver 31 is a ball screw mechanism or an electric push rod.

[0056] Reference again Figure 2In order to guide the rise and fall of the base 40 and make it rise and fall smoothly, the lifting unit 30 also includes a guiding mechanism, which includes a guide rail 311, and the guide rail 311 is fixed to the lower shell 12. A slider, a sliding sleeve 312 or a sliding groove is set on the base 40, and the slider, the sliding sleeve 312 or the sliding groove is slidably matched with the guide rail 311.

[0057] Furthermore, the shaft 20 can rotate both clockwise and counterclockwise, so the hydraulic pump 50 is selected as a bidirectional pump that can rotate both forward and reverse, specifically a bidirectional gear pump, which can output high-pressure oil during the bidirectional movement of the bidirectional gear pump.

[0058] Reference again Figure 3 The bidirectional gear pump has two oil ports, which are switched to oil inlet or oil outlet by the forward and reverse rotation of the pump shaft. Each oil port of the bidirectional gear pump is connected to the oil tank 90 through an oil supply pipeline 70, and is also connected to the hydraulic motor generator set through an oil delivery pipeline 80. A second switch unit is provided on the oil supply pipeline 70 and the oil delivery pipeline 80. The second switch unit is used to control the one-way conduction from the oil tank 90 to the hydraulic motor generator set through the oil supply pipeline 70, the hydraulic pump 50, and the oil delivery pipeline 80.

[0059] Specifically, the second switch unit includes a one-way valve arranged on each oil supply pipeline 70 and oil delivery pipeline 80. Among them, the No. 1 one-way valve 710 and the No. 2 one-way valve 720 respectively arranged on the two oil supply pipelines 70 are one-way to the two-way gear pump, and the No. 3 one-way valve 810 and the No. 4 one-way valve 820 respectively arranged on the two oil delivery pipelines 80 are one-way to the hydraulic motor generator set. The No. 1 one-way valve 710 and the No. 2 one-way valve 720 are one-way valves without spring return, which can reduce the pressure loss during the oil suction process, and the No. 3 one-way valve 810 and the No. 4 one-way valve 820 are one-way valves with spring return, which can quickly close the oil delivery pipeline 80 when the flow direction of the hydraulic oil changes.

[0060] Each set of oil supply pipeline 70 and oil delivery pipeline 80 is controlled by a one-way valve respectively, so that the hydraulic oil can be unidirectionally conducted from the oil tank 90 through the oil supply pipeline 70, the hydraulic pump 50, and the oil delivery pipeline 80 to the hydraulic motor generator set when the shaft body 20 rotates forward or reversely, so that the hydraulic oil is pressurized by the hydraulic pump 50 and supplied to the hydraulic motor generator set for power generation.

[0061] Further, refer again Figure 2The eccentric counterweight comprises a counterweight block 313 and a No. 2 hydraulic cylinder 314, both of which are eccentrically mounted on the shaft body 20, and the counterweight block 313 is mounted on the cylinder rod of the No. 2 hydraulic cylinder 314, and the No. 2 hydraulic cylinder 314 is connected to the oil delivery pipeline 80. When the wind and waves are small, the rotation speed of the shaft body 20 is small, the hydraulic oil pressure output by the hydraulic pump 50 becomes small, the hydraulic oil pressure entering the rod chamber of the No. 2 hydraulic cylinder 314 decreases, the piston rod of the No. 2 hydraulic cylinder 314 extends, pushing the counterweight block 313 away from the shaft body 20, increasing the eccentricity of the counterweight block 313, and thus increasing the rotation speed of the shaft body 20. When the wind and waves are strong, the rotation speed of the shaft body 20 is large, the hydraulic oil pressure output by the hydraulic pump 50 becomes larger, the hydraulic oil pressure entering the rod chamber of the No. 2 hydraulic cylinder 314 increases, and the piston rod of the No. 2 hydraulic cylinder 314 retracts, pushing the counterweight block 313 closer to the shaft body 20, reducing the eccentricity of the counterweight block 313, and thereby reducing the rotation speed of the shaft body 20.

[0062] like Figure 4 As shown in , in order to normally supply oil to the No. 2 hydraulic cylinder 314 based on the rotation of the shaft body 20, a rotary oil distributor 315 is sleeved on the outer side of the shaft body 20 and is rotatably connected to the shaft body 20. Specifically, the rotary oil distributor 315 has an oil storage chamber 316 surrounding the outer periphery of the shaft body 20. An oil circuit 317 is arranged in the shaft body 20, and the oil circuit 317 in the shaft body 20 is communicated with the oil storage chamber 316 of the rotary oil distributor 315, and the oil storage chamber 316 is also communicated with the No. 2 hydraulic cylinder 314. During operation, the hydraulic oil enters the oil circuit 317 in the shaft body 20, then enters the oil storage chamber 316 of the rotary oil distributor 315, and then enters the No. 2 hydraulic cylinder 314. There are two rotary oil distributors 315 and two oil circuits 317, respectively, which are connected to the rod chamber and rodless chamber of the No. 2 hydraulic cylinder 314, respectively.

[0063] In addition, a sealing ring 318 is provided on the contact surface between the rotary oil distributor 315 and the shaft body 20 to achieve dynamic sealing and prevent the hydraulic oil in the oil storage chamber 316 from leaking out. A retaining spring 319 is provided between the two ends of the rotary oil distributor 315 and the shaft body 20 to limit the axial movement of the rotary oil distributor 315 along the shaft body 20. During the rotation of the shaft body 20, the rotary oil distributor 315 does not rotate and can normally deliver hydraulic oil to the No. 2 hydraulic cylinder 314.

[0064] In addition, hydraulic pressure gauges, hydraulic flow meters, etc. can be installed on the pipelines through which the hydraulic oil passes to monitor the hydraulic conditions of the power generation device in real time. Filters can also be installed to intercept pollutants in the hydraulic oil, keep the hydraulic oil clean, and ensure the normal operation of the hydraulic system.

[0065] Embodiment 2:

[0066] like Figure 5As shown in , this embodiment is a replacement of the electric driver 31 in Embodiment 1, specifically, the electric driver 31 is replaced by a No. 1 hydraulic cylinder 32, and the specific connection method is as follows:

[0067] The No. 1 hydraulic cylinder 32 is connected to the oil pipeline 80. The No. 1 hydraulic cylinder 32 controls the opening and closing of its rod chamber or rodless chamber and the oil pipeline 80 through the first switch unit. The first switch unit is connected to the output end of the control unit. The oil in the rod chamber or rodless chamber of the No. 1 hydraulic cylinder 32 drives the cylinder rod to retract or extend, pushing the base 40 to rise or fall.

[0068] In order to be able to quickly control the lifting and lowering of the base 40, in this embodiment, the first switch unit is specifically a three-position four-way solenoid reversing valve 321, having an oil inlet P, an oil return port T, a working oil port A and a working oil port B. The working oil port A and the working oil port B are respectively connected to the rod chamber and the rodless chamber of the No. 1 hydraulic cylinder 32, and the oil return port T is connected to the working oil port B.

[0069] When the three-position four-way electromagnetic reversing valve 321 is in the middle position, the connection between the No. 1 hydraulic cylinder 32 and the oil delivery pipeline 80 is cut off, and the position of the cylinder rod of the No. 1 hydraulic cylinder 32 is in a locked state; when it is in the left position, the high-pressure oil output by the hydraulic pump 50 enters the rodless cavity of the No. 1 hydraulic cylinder 32, pushing the base 40 to move upward; when it is in the right position, the high-pressure oil output by the hydraulic pump 50 enters the rod cavity of the No. 2 hydraulic cylinder 314, pushing the base 40 to move downward. Therefore, the center of gravity position of the power generation device can be directly controlled by using the hydraulic oil output by the hydraulic pump 50.

[0070] Embodiment 3:

[0071] like Figure 6 As shown in , this embodiment is a replacement of the three-position four-way solenoid reversing valve 321 in Embodiment 2. Specifically, the three-position four-way solenoid reversing valve 321 is replaced by a two-position four-way solenoid valve 322. The specific connection method is as follows:

[0072] The two-position four-way solenoid valve 322 has an oil inlet P, an oil return port O, a working oil port A and a working oil port B. The working oil port A and the working oil port B are respectively connected to the rod chamber and the rodless chamber of the No. 1 hydraulic cylinder 32, and the oil return port O is connected to the working oil port B.

[0073] There is a spring in the rodless cavity of the No. 1 hydraulic cylinder 32. When the two-position four-way solenoid valve 322 is in the left position, the cylinder rod position of the No. 1 hydraulic cylinder 32 is in a locked state. When it is in the right position, the cylinder rod of the No. 1 hydraulic cylinder 32 is in a floating state. Specifically, when the shaking amplitude of the power generation device is large, the hydraulic oil pressure output by the hydraulic pump 50 is high, the spring in the rodless cavity of the No. 1 hydraulic cylinder 32 is compressed, and the cylinder rod retracts to drive the base 40 to move downward, so that the center of gravity of the power generation device moves downward, the distance between the center of gravity and the center of buoyancy increases, and the stability of the power generation device is improved; when the shaking amplitude of the wave energy power generation device is small, the hydraulic oil pressure output by the hydraulic pump 50 is small, the spring in the rodless cavity of the No. 1 hydraulic cylinder 32 is extended, and the cylinder rod extends to drive the base 40 to move upward, so that the center of gravity of the power generation device moves upward, the distance between the center of gravity and the center of buoyancy decreases, and the energy capture efficiency of the power generation device is improved. Therefore, the power generation device can actively adjust the center of gravity position according to its own shaking conditions to adapt to different wave conditions.

[0074] Embodiment 4:

[0075] like Figure 3 , Figure 5 and Figure 6 As shown in , compared with embodiment 1, the power generation device in this embodiment further includes a hydraulic accumulator 100, the hydraulic accumulator 100 is connected to the oil pipeline 80, a third switch unit 101 is arranged between the hydraulic accumulator 100 and the oil pipeline 80, the third switch unit 101 is connected to the output end of the control unit, and the third switch unit 101 is used to control the on-off between the hydraulic accumulator 100 and the oil pipeline 80. When the pressure of the hydraulic oil suddenly increases, the hydraulic accumulator can store a part of the hydraulic oil; when the pressure of the hydraulic oil suddenly decreases, the hydraulic accumulator can release a part of the hydraulic oil, so the hydraulic accumulator can eliminate the pressure shock of the hydraulic oil in the hydraulic system and make the power generation stable.

[0076] Specifically, the third switch unit 101 is an electromagnetic switch valve. When the electromagnetic switch valve is in the left position, the accumulator is disconnected from the oil pipeline 80 and does not function; when the electromagnetic switch valve is in the right position, the accumulator is connected to the oil pipeline 80 and functions.

[0077] like Figure 7 As shown in , on the other hand, the present application provides a power generation control method, which adopts a speed closed-loop control strategy and is based on the power generation device of embodiments 1-3, comprising the following steps:

[0078] S1, setting the upper limit and lower limit of the rotation speed of the shaft 20 when the power generation device is working to n1 and n2 respectively;

[0079] S2, obtaining the real-time rotation speed of the shaft 20 as n0 through the rotation speed sensor;

[0080] S3, if n0>n1, it is determined that the waves in the current working environment are large, then the lifting unit 30 is controlled to push the base 40 down, thereby lowering the center of gravity of the power generation device, increasing the distance between the center of gravity and the center of buoyancy of the power generation device, improving the reliability of the operation of the power generation device, and reducing n0;

[0081] If n0<n2, it is determined that the waves in the current working environment are small, and the lifting unit 30 is controlled to push the base 40 upward, thereby raising the center of gravity of the power generation device, reducing the distance between the center of gravity and the center of buoyancy of the power generation device, and improving the power generation efficiency of the power generation device, so that n0 increases;

[0082] If n2≤n0≤n1, the lifting unit 30 does not work, the base 40 maintains the current position, the power generation device works under the rated working condition, the operation is reliable, and the power generation is stable.

[0083] Further, refer again Figure 7 The power generation control method of the power generation device according to the fourth embodiment adopts a strategy of speed closed-loop control in parallel with pressure closed-loop control. The pressure closed-loop control strategy includes the following steps:

[0084] S1, setting the upper limit and lower limit of the oil pressure of the oil pipeline 80 when the power generation device is working to p1 and p2 respectively;

[0085] S2, a pressure sensor is provided at the end of the oil pipeline 80, and the oil pressure of the oil pipeline 80 is obtained as p0 through the pressure sensor;

[0086] S3, if p0>p1, it is determined that the current pressure in the hydraulic system is high, and the third switch unit 101 is controlled to be turned on, connecting the hydraulic accumulator 100 and the oil pipeline 80, so that the accumulator absorbs the excess pressure, reducing p0 and avoiding excessively high power generation voltage;

[0087] If p0<p2, it is determined that the current pressure in the hydraulic system is low, and the third switch unit 101 is controlled to be turned on, connecting the hydraulic accumulator 100 and the oil pipeline 80, and the accumulator releases pressure to increase p0, thereby preventing the power generation voltage from being too low;

[0088] If p2≤p0≤p1, the third switch unit 101 is controlled to be closed, the hydraulic accumulator 100 and the oil pipeline 80 are disconnected, and the power generation device works under the rated working condition, with reliable operation and stable power generation.

[0089] In the description of the present invention, it is necessary to understand that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0090] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0091] The above specific implementation manner cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art, any substitution, improvement or change made to the implementation manner of the present invention falls within the protection scope of the invention.

[0092] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A closed wave energy power generation device with adjustable center of gravity, characterized in that: The invention comprises a closed housing, wherein the housing is provided with: A shaft body, the axis of the shaft body is arranged along the center of gravity of the shell, and an eccentric counterweight is arranged on the shaft body, and the eccentric counterweight is eccentrically arranged relative to the axis of the shaft body; A base, the base is used to install the shaft body, and the shaft body can rotate freely around its own axis; A hydraulic pump, wherein the pump shaft of the hydraulic pump is connected to the shaft body through a speed increaser, the oil inlet of the hydraulic pump is connected to the oil tank through an oil supply pipeline, and the oil discharge port of the hydraulic pump is connected to the hydraulic motor generator set through an oil delivery pipeline; A lifting unit, the lifting unit is connected to the base and is used to drive the base to rise or fall; A control unit, the control unit includes a controller and a rotation speed sensor, the rotation speed sensor is used to detect the rotation speed of the shaft, the rotation speed sensor is connected to the input end of the controller, and the lifting unit is connected to the output end of the controller; The eccentric weight comprises: Counterweights; A No. 2 hydraulic cylinder, the counterweight block is mounted on the cylinder rod of the No. 2 hydraulic cylinder, and the No. 2 hydraulic cylinder is connected to the oil pipeline; The lifting unit is a No. 1 hydraulic cylinder, which is connected to the oil pipeline. The No. 1 hydraulic cylinder controls the on-off of its rod chamber or rodless chamber and the oil pipeline through a first switch unit, and the first switch unit is connected to the output end of the control unit; the first switch unit is a three-position four-way solenoid reversing valve or a two-position four-way solenoid valve; When the wave energy power generation device shakes slightly, the hydraulic oil pressure output by the hydraulic pump is small, the spring in the rodless chamber of the No. 1 hydraulic cylinder is extended, and the cylinder rod is extended to drive the base to move upward, so that the center of gravity of the power generation device moves upward, and the distance between the center of gravity and the center of buoyancy is reduced, so that the energy capture efficiency of the power generation device is improved; The power generation control method of the power generation device adopts a speed closed-loop control strategy, including the following steps: S1, setting the upper limit and lower limit of the rotation speed of the shaft body to n1 and n2 respectively; S2, obtain the real-time rotation speed of the shaft as n0 through the rotation speed sensor; S3, if n0>n1, control the lifting unit to push the base down; If n0<n2, the lifting unit is controlled to push the base upward; If n2≤n0≤n1, the lifting unit does not work and the base maintains the current position.

2. The closed wave energy power generation device with adjustable center of gravity according to claim 1, characterized in that: The lifting unit is an electric drive, and the electric drive is connected to the output end of the control unit.

3. The closed wave energy power generation device with adjustable center of gravity according to claim 1, characterized in that: The hydraulic pump is a bidirectional pump, and the two oil ports of the bidirectional pump are switched to the oil inlet or the oil outlet through the forward and reverse rotation of the pump shaft. Each oil port of the bidirectional pump is connected to the oil tank through an oil supply pipeline, and is also connected to the hydraulic motor generator set through an oil delivery pipeline. A second switch unit is arranged on the oil supply pipeline and the oil delivery pipeline, and the second switch unit is used to control the one-way conduction from the oil tank to the hydraulic motor generator set through the oil supply pipeline, the hydraulic pump, and the oil delivery pipeline.

4. The closed wave energy power generation device with adjustable center of gravity according to claim 3, characterized in that: The second switch unit includes a one-way valve arranged on the oil supply pipeline and the oil delivery pipeline, wherein the one-way valve arranged on the oil supply pipeline is unidirectionally connected to the two-way pump, and the one-way valve arranged on the oil delivery pipeline is unidirectionally connected to the hydraulic motor generator set.

5. The closed wave energy power generation device with adjustable center of gravity according to claim 1, characterized in that: It also includes a hydraulic accumulator, which is connected to the oil pipeline. A third switch unit is arranged between the hydraulic accumulator and the oil pipeline. The third switch unit is connected to the output end of the control unit. The third switch unit is used to control the on-off between the hydraulic accumulator and the oil pipeline.

6. The power generation control method according to claim 1, characterized in that: The power generation device further provides a hydraulic accumulator connected to the oil pipeline, a third switch unit is arranged between the hydraulic accumulator and the oil pipeline, the third switch unit is connected to the output end of the control unit, and the third switch unit is used to control the on-off between the hydraulic accumulator and the oil pipeline; The control method further comprises: S1, set the upper and lower limits of the oil pressure in the oil pipeline to p1 and p2 respectively; S2, obtain the oil pressure of the oil pipeline as p0 through the pressure sensor; S3, if p0>p1, control the third switch unit to conduct the hydraulic accumulator and the oil pipeline; If p0<p2, control the third switch unit to conduct the hydraulic accumulator and the oil pipeline; If p2≤p0≤p1, the third switch unit is controlled to disconnect the hydraulic accumulator and the oil pipeline.

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