Oil bag type buoyancy adjusting device for ocean current energy generator set

Abstract

The invention belongs to the technical field of new energy power generation, and particularly relates to an oil bag type buoyancy adjusting device for an ocean current energy generator set, which comprises a shell, a left oil bag, a right oil bag, a main posture adjusting unit, a buoyancy adjusting unit and an inner oil tank, the left oil bag and the right oil bag are used for achieving overall volume change to achieve buoyancy adjustment, the main posture adjusting unit is used for adjusting the pitching angle, the buoyancy adjusting unit is used for adjusting the depth, and the emergency posture adjusting unit is used for rapidly returning to the posture under the emergency condition. The method can be applied to the field of ocean current energy power generation, and control over buoyancy and postures of the generator set is achieved; the maintenance convenience and the power generation efficiency of the ocean current energy generator set are improved, and the adaptability and the stability of equipment under complex ocean conditions are enhanced.

Description

Technical Field

[0001] This technical solution relates to the field of new energy power generation technology, specifically to an oil-filled buoyancy regulating device for ocean current power generator sets. Background Technology

[0002] Ocean current energy is a clean and renewable marine energy source, characterized by stable flow velocity, continuous operation day and night, and minimal impact from climate. With the development of marine energy development technologies, ocean current generator sets have been widely researched and applied in the field of offshore renewable energy. Ocean current generator sets are suitable for long-term operation in complex environments such as deep seas.

[0003] Existing ocean current power generation units mainly include pile-based, bottom-mounted, and floating structures. Pile-based and bottom-mounted units are typically fixed to the seabed. Because the buoyancy adjustment devices are constantly in the seabed environment, large salvage vessels are required for repairs when malfunctions occur. Furthermore, in some sea areas, low seabed current velocities and insufficient power generation efficiency exist. Floating ocean current power generation units are easily affected by wind and waves in harsh sea conditions, resulting in severe swaying or drifting, leading to unstable power generation or even equipment damage. Simultaneously, existing ocean current power generation units generally lack attitude adjustment capabilities. When facing changes in current direction or turbulence, they cannot adjust their angle of attack, and the impeller or turbine cannot always be in an optimal stress state, resulting in reduced energy capture efficiency.

[0004] The main reason for the above problems is that existing ocean current power generators generally lack a buoyancy adjustment device to regulate buoyancy and attitude, resulting in deficiencies in adaptability, stability and energy utilization efficiency. Summary of the Invention

[0005] To address the problems in the background art, this invention proposes an oil-filled buoyancy adjustment device for ocean current energy generator sets, which integrates buoyancy and attitude adjustment. This device enables the generator set to autonomously rise and sink under different operating conditions, thereby improving operational safety and maintenance convenience. Adjusting the generator set's attitude enhances the efficiency of ocean current energy capture and strengthens its adaptability and stability in complex sea conditions.

[0006] The technical solution of the present invention is as follows: An oil-filled buoyancy adjustment device for an ocean current power generator set includes: a shell, a left oil bladder, a right oil bladder, a main attitude adjustment unit, a buoyancy adjustment unit, and an inner oil tank; The outer shell, the left and right oil bladders located on opposite sides of the outer shell, the main attitude adjustment unit, the buoyancy adjustment unit, and the inner oil tank located inside the outer shell; The left oil bladder is connected to a left first pipeline, and the right oil bladder is connected to a right first pipeline. Both the left first pipeline and the right first pipeline are connected to the inner oil tank through the main attitude adjustment unit and the buoyancy adjustment unit. The main attitude adjustment unit includes a left electric ball valve and a right electric ball valve, both located inside the outer casing. The left electric ball valve is connected to the left oil bladder via the left first pipe, and the right electric ball valve is connected to the right oil bladder via the right first pipe. Both the left and right electric ball valves are connected to the inner oil tank. The main attitude adjustment unit is used to adjust the pitch attitude of the oil bladder-type buoyancy adjustment device. The buoyancy adjustment unit includes a first filter, a first gear pump, a first overflow valve, a first bidirectional flow meter, a first one-way valve, and a two-position four-way solenoid directional valve connected in sequence. One end of the first filter is connected to the inner oil tank through the two-position four-way solenoid directional valve. The two-position four-way solenoid directional valve is connected to the left oil bladder through the left electric ball valve and the left first pipeline, and is connected to the right oil bladder through the right electric ball valve and the right first pipeline.

[0007] Preferably, it further includes: The emergency attitude adjustment unit includes a second filter, a second gear pump, a second check valve, a second bidirectional flow meter, and a three-position four-way solenoid directional valve connected in sequence. The left oil bladder is connected to the second bidirectional flow meter via a left second pipeline and the three-position four-way solenoid directional valve, while the right oil bladder is connected to the second filter via a right second pipeline and the three-position four-way solenoid directional valve. The emergency attitude adjustment unit is used to quickly switch the hydraulic oil between the left and right oil bladders under abnormal operating conditions, thereby achieving emergency attitude correction of the oil bladder-type buoyancy adjustment device.

[0008] Preferably, it further includes: An accumulator is located between the first one-way valve and the two-position four-way solenoid directional valve, and is connected to a pressure relay.

[0009] Preferably, a first pressure sensor is provided between the two-position four-way solenoid directional valve and the pressure relay to detect the real-time pressure of the accumulator oil inlet channel and transmit the detection signal to the control system.

[0010] Preferably, both the left and right electric ball valves are electrically controlled ball valves with a movable ball as the valve core. The opening degree of the left and right electric ball valves is independently adjusted by the control system to achieve differential control of the two oil bladders.

[0011] Preferably, a second pressure sensor is provided on the left first pipeline and a third pressure sensor is provided on the right first pipeline. The second pressure sensor is used to monitor the internal pressure change of the left oil bladder and the third pressure sensor is used to monitor the internal pressure change of the right oil bladder, and the pressure signal is fed back to the control system.

[0012] Preferably, when the pitch angle of the bladder-type buoyancy adjustment device reaches the first set threshold, if the bladder-type buoyancy adjustment device tilts to the left, the left electric ball valve opens and the right electric ball valve remains closed; if the bladder-type buoyancy adjustment device tilts to the right, the right electric ball valve opens and the left electric ball valve remains closed, so that the hydraulic oil in the inner oil tank is injected only into the bladder on one side of the tilt direction, while the volume of the bladder on the other side remains unchanged. Subsequently, the left electric ball valve and the right electric ball valve open, and the two-position four-way solenoid directional valve is switched to the oil discharge circuit, so that the left and right bladders respectively discharge part of the hydraulic oil into the inner oil tank through the buoyancy adjustment unit.

[0013] Preferably, when the pitch angle deviation of the oil bladder buoyancy adjustment device exceeds the second set threshold, both the left and right electric ball valves remain closed, the three-position four-way solenoid directional valve switches to the corresponding oil filling or draining position, and the second gear pump drives the hydraulic oil to transfer between the left and right oil bladders via the emergency attitude adjustment unit.

[0014] Preferably, when the second pressure sensor and the third pressure sensor detect that the pressure of the left oil bladder and the right oil bladder are lower than the set threshold, the left electric ball valve and the right electric ball valve open to the set opening degree, the two-position four-way solenoid directional valve switches to the preset position of the oil injection channel, the accumulator releases hydraulic oil and flows into the left oil bladder through the left first pipeline and into the right oil bladder through the right first pipeline; When the first pressure sensor detects that the pressure in the accumulator's oil inlet is lower than a set threshold, the left electric ball valve and the right electric ball valve close, the first gear pump starts, and the hydraulic oil in the inner tank is delivered to the accumulator through the buoyancy adjustment unit.

[0015] Preferably, during the ascent of the oil bladder type buoyancy adjustment device, as the two-position four-way solenoid valve of the buoyancy adjustment unit switches to the oil injection state, the hydraulic oil output by the first gear pump is injected into the left oil bladder and the right oil bladder through the buoyancy adjustment unit.

[0016] During the sinking process of the oil bladder type buoyancy adjustment device, the two-position four-way solenoid valve of the buoyancy adjustment unit switches to the oil discharge state, and the hydraulic oil in the left oil bladder and the right oil bladder flows back to the inner oil tank through the buoyancy adjustment unit.

[0017] The key and beneficial technical effects of this technical solution compared to existing technologies are: This technical solution enables precise depth adjustment: by controlling the flow rate of hydraulic oil entering the left and right oil bladders respectively through the left and right electric ball valves, and combined with the real-time monitoring of the first bidirectional flow meter, the sinking and buoyancy depth of the buoyancy adjustment device for the ocean current generator set can be adjusted.

[0018] This technical solution features long-term energy-saving buoyancy adjustment capability: when the oil bladder buoyancy adjustment device is in a stable working state, the first gear pump stops working, and the pressure relay monitors the oil pressure in the oil inlet pipelines of the left and right oil bladders in real time; when the pressure is detected to be lower than the set threshold, the control system opens the left and right electric ball valves, and the accumulator releases hydraulic oil for compensation, thereby achieving automatic pressure maintenance; when the hydraulic oil in the accumulator is depleted, the first gear pump restarts to refill the accumulator. Through intermittent pump control, the energy consumption of continuous operation is effectively reduced, and the energy-saving performance and service life of the system are improved.

[0019] This technical solution has stable attitude adjustment capability: it adopts a dual oil bladder design, and by adjusting the opening ratio of the left and right electric ball valves, it can dynamically adjust the angle of the oil bladder buoyancy adjustment device under different operating conditions to adapt to different ocean current conditions and improve energy capture efficiency; at the same time, it is equipped with an emergency attitude adjustment unit, which can automatically intervene to adjust the buoyancy distribution when the generator set tilt angle exceeds the safety threshold, realize rapid attitude correction, and ensure the stable operation and structural safety of the system under complex sea conditions.

[0020] This technical solution features a structural design that facilitates maintenance: when the tidal current generator set requires manual maintenance, the oil-filled buoyancy adjustment device can actively drive the generator set to the surface of the water to achieve maintenance operations on the water, avoiding the problem of underwater maintenance that traditional generator sets require salvage operations, thus improving the convenience and safety of maintenance.

[0021] This technical solution has the ability to withstand harsh environments: when encountering extreme weather or sudden environmental changes at sea, the oil bladder buoyancy adjustment device can automatically control the generator set to sink to the seabed through the control system, avoid the impact of strong winds and waves, ensure the structural integrity and safety of the generator set, thereby improving the overall environmental adaptability and survivability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the main attitude adjustment unit and buoyancy adjustment unit of the present invention; Figure 3 This is a schematic diagram of the accumulator and pressure relay of the present invention; Figure 4This is a schematic diagram of the emergency attitude adjustment unit of the present invention; Figure 5 This is a schematic diagram of the sinking process of the present invention; Figure 6 This is a schematic diagram of the upward floating process of the present invention; Figure 7 This is a schematic diagram of the attitude adjustment process in an emergency situation according to the present invention; Figure 8 This is a schematic diagram of the invention during its long-term operation. Figure 9 This is a schematic diagram of the energy storage charging process of the present invention.

[0023] Reference numerals: 1. Left oil bladder; 2. Second pressure sensor; 3. Accumulator; 4. First pressure sensor; 5. Pressure relay; 6. First bidirectional flow meter; 7. First relief valve; 8. First gear pump; 9. First filter; 10. First check valve; 11. Two-position four-way solenoid directional valve; 12. Inner oil tank; 13a. Left electric ball valve; 13b. Right electric ball valve; 14. Third pressure sensor; 15a. Left first pipeline; 15b. Right first pipeline; 16. Right oil bladder; 17a. Left second pipeline; 17b. Right second pipeline; 18. Second gear pump; 19. Second filter; 20. Three-position four-way solenoid directional valve; 21. Second check valve; 22. Second bidirectional flow meter; 23. Second relief valve; 24. Housing; 25. Generator set. Detailed Implementation

[0024] The specific implementation of this technical solution will be further described in detail below with reference to the accompanying drawings.

[0025] This invention provides an oil-filled buoyancy adjustment device for ocean current energy generator sets. This device enables the generator set to autonomously rise and sink according to different ocean current conditions, and improves the capture efficiency of ocean current energy through attitude adjustment. This oil-filled buoyancy adjustment device is suitable for ocean current energy generator sets operating in complex sea conditions, improving power generation stability and energy utilization, and providing technical support for the development of renewable energy in remote sea areas.

[0026] like Figures 1-9 The present invention provides an oil bladder type buoyancy adjustment device for an ocean current energy generator set. The oil bladder type buoyancy adjustment device is equipped with a generator set 25. The generator set 25 is the prior art. The ocean current energy generator set 25 drives the motor shaft of the generator to rotate by the rotation of the impeller to generate electricity. For the specific structure, please refer to Chinese patent CN201610233452.3. The oil bladder buoyancy adjustment device includes: a shell 24, a left oil bladder 1 and a right oil bladder 16, a main attitude adjustment unit, a buoyancy adjustment unit, an emergency attitude adjustment unit, and an accumulator 3; The main attitude adjustment unit, in conjunction with the buoyancy adjustment unit, enables the adjustment of the pitch angle of the oil bladder buoyancy adjustment device, as well as the adjustment of the buoyancy adjustment device's ascent and descent. The emergency attitude adjustment unit is used to quickly restore the attitude in emergency situations. Both the left and right oil bladders (1 and 16) are made of pressure-resistant, waterproof, elastic materials. They are preferably constructed from composite rubber materials, with a preferred three-layer structure: an outer layer of seawater-resistant neoprene rubber; a middle layer of highly elastic reinforcing fiber braided layer to enhance pressure resistance; and an inner layer of high oil-resistant nitrile rubber suitable for long-term contact with hydraulic oil. A reinforced nylon mesh covering layer can be configured on the outside of the oil bladders for underwater dynamic restraint, preventing excessive deformation of the oil bladders that could lead to attitude deviation. like Figure 1 The left oil bladder 1 and the right oil bladder 16 are located on the left and right sides of the outer casing 24, respectively. The inlet end of the left oil bladder 1 is equipped with an externally threaded high-pressure metal connector, which connects to a left first pipeline 15a. Similarly, the inlet of the right oil bladder 16 is also equipped with a threaded connector of the same specifications as the left one, which connects to the right first pipeline 15b. The structure and function of the right oil bladder 16 are the same as those of the left oil bladder 1. The length, bending radius, and installation method of the connecting steel pipes of the left and right oil bladders are strictly symmetrical to ensure the attitude balance of the oil bladder buoyancy adjustment device when adjusting buoyancy in any direction. Combination Figures 2-5 The outer shell 24 is connected to the ocean current generator set 25 in the middle. The main attitude adjustment unit, buoyancy adjustment unit, and emergency attitude adjustment unit are all installed inside the outer shell 24. The left oil bladder 1 is connected to the system hydraulic circuit through the left first pipe 15a (that is, the left oil bladder 1 is connected to the second pressure sensor 2, the left electric ball valve 13a, and the three-position four-way solenoid valve 20 through the left first pipe 15a). The right oil bladder 16 is connected to the system hydraulic circuit through the right first pipe 15b (that is, the right oil bladder 16 is connected to the third pressure sensor 14, the right electric ball valve 13b, and the three-position four-way solenoid valve 20 through the right first pipe 15b). The left first pipe 15a and the right first pipe 15b are both connected to the inner oil tank 12 through the main attitude adjustment unit and the buoyancy adjustment unit, so that oil flows between the left oil bladder 1, the right oil bladder 16 and the inner oil tank 12, thereby generating volume changes of the left oil bladder 1 and the right oil bladder 16 to achieve buoyancy adjustment. When the bladder-type buoyancy adjustment device needs to sink, the buoyancy adjustment unit transfers hydraulic oil from the left bladder 1 and right bladder 16 to the inner oil tank 12, reducing the volume of the left bladder 1 and right bladder 16 to decrease buoyancy; when the bladder-type buoyancy adjustment device needs to float, the buoyancy adjustment unit transfers hydraulic oil from the inner oil tank 12 to the left bladder 1 and right bladder 16, increasing the volume of the left bladder 1 and right bladder 16 to increase buoyancy. The main attitude adjustment unit includes a left electric ball valve 13a and a right electric ball valve 13b, both located inside the housing 24. The left electric ball valve 13a is connected to the left oil bladder 1 via the left first pipe 15a, and the right electric ball valve 13b is connected to the right oil bladder 16 via the right first pipe 15b. The left electric ball valve 13a and the right electric ball valve 13b can be controlled independently. The left electric ball valve 13a and the right electric ball valve 13b control the flow rate of hydraulic oil into the left oil bladder 1 and the right oil bladder 16 by adjusting the opening of their respective internal ball valve cores. Both the left electric ball valve 13a and the right electric ball valve 13b are connected to the inner oil tank 12 via a buoyancy adjustment unit. The buoyancy adjustment unit includes a first filter 9, a first gear pump 8, a first overflow valve 7, a first bidirectional flow meter 6, a first one-way valve 10, and a two-position four-way solenoid directional valve 11 connected in sequence. One end of the first filter 9 is connected to the inner oil tank 12 through the two-position four-way solenoid directional valve 11. The two-position four-way solenoid directional valve 11 is connected at one end to the left oil bladder 1 via the left electric ball valve 13a and the left first pipeline 15a, and to the right oil bladder 16 via the right electric ball valve 13b and the right first pipeline 15b. That is, the two-position four-way solenoid directional valve 11 is connected to the left oil bladder 1 and the right oil bladder 16 via a three-way pipe connector. The adjustment of the two-position four-way solenoid directional valve 11 enables the first gear pump 8 to transport the hydraulic oil in the inner oil tank 12 to the left oil bladder 1 and the right oil bladder 16, or to transport the hydraulic oil in the left oil bladder 1 and the right oil bladder 16 to the inner oil tank 12. The opening degree of the left electric ball valve 13a and the right electric ball valve 13b is used to adjust the hydraulic oil level, thereby realizing the attitude adjustment of the oil bladder buoyancy adjustment device in terms of floating, sinking, and left and right angles.

[0027] The emergency posture adjustment unit includes a second filter 19, a second gear pump 18, a second one-way valve 21, a second bidirectional flow meter 22, and a three-position four-way solenoid valve 20 connected in sequence. The left oil bladder 1 is connected to one end of the second bidirectional flow meter 22 through the left second pipeline 17a via the three-position four-way solenoid valve 20. The right oil bladder 16 is connected to one end of the second filter 19 through the right second pipeline 17b via the three-position four-way solenoid valve 20. Both the first filter 9 and the second filter 19 are located at the beginning of the oil circuit, that is, at the liquid extraction port connected to the inner oil tank 12. They are made of high-precision stainless steel inner core filter element assembly and have detachable filter screen and differential pressure alarm function. They are used to effectively filter out impurities, particles and colloids in the oil to avoid wear or blockage of the downstream gear pump. Both the first gear pump 8 and the second gear pump 18 are electrically driven high-pressure gear pumps, equipped with noise-reducing tooth profiles and return oil buffer chambers to ensure stable output during long-term operation. The speed can be controlled by a frequency converter to achieve flexible adjustment to match actual working conditions, and can provide stable and continuous hydraulic energy.

[0028] The first relief valve 7 and the second relief valve 23 are used to limit the maximum operating pressure of the system to 110%.

[0029] The first bidirectional flow meter 6 and the second bidirectional flow meter 22 operate based on Hall effect magnetic sensing elements. Their built-in impellers are driven to rotate by the liquid flow, generating an electrical signal proportional to the flow velocity, which is then acquired and processed by the main control system. These flow meters possess high response speed and shock resistance, and can be used for real-time monitoring of liquid flow rate and direction. They can also be used to dynamically adjust the opening of electric ball valves to change the target buoyancy state, achieving closed-loop control.

[0030] The first check valve 10 is located downstream of the first bidirectional flow meter 6, and the second check valve 21 is located downstream of the second bidirectional flow meter 22. They allow liquid to flow in only one direction to prevent backflow of oil caused by reversal or vibration from interfering with the control accuracy.

[0031] The accumulator 3 is located between the first one-way valve 10 and the two-position four-way solenoid directional valve 11. That is, the accumulator 3 is connected to the two-position four-way solenoid directional valve 11 and the first one-way valve 10 through a three-way pipe connector. The accumulator 3 is connected to a pressure relay 5.

[0032] The accumulator 3 is preferably a gas-liquid separation type gas-filled accumulator, which has a pre-filling chamber inside. When the hydraulic oil stored in the accumulator 3 is depleted, the first gear pump 8 supplies hydraulic oil into the cavity of the accumulator 3, compressing the internal gas to store energy. When the pressure of the left oil bladder 1 and the right oil bladder 16 of the oil bladder type buoyancy adjustment device drops, the high-pressure gas inside the accumulator 3 can push the hydraulic oil to be quickly injected into the left and right oil bladders 16 to compensate for the pressure loss.

[0033] Both the left electric ball valve 13a and the right electric ball valve 13b are electrically controlled ball valves with a movable ball as the valve core. The opening degree of the left electric ball valve 13a and the right electric ball valve 13b can be adjusted independently.

[0034] The left electric ball valve 13a and the right electric ball valve 13b are intelligent adjustable opening ball valves, capable of continuous opening adjustment within the range of 0% to 100%. The valve body is an integral stainless steel structure, internally sealed with a chrome-plated stainless steel floating ball core, enabling zero-leakage control in high-pressure underwater environments and supporting bidirectional fluid flow. The electric ball valves are driven by a built-in stepper motor and equipped with a high-resolution potentiometer for precise opening feedback. Their control system can remotely receive opening commands and upload execution status in real time. Valve opening adjustment is based on data from the second pressure sensor, the third pressure sensor, the attitude sensor of the bladder-type buoyancy adjustment device, and the depth sensor. Through closed-loop control logic, the opening ratio of the two valves is dynamically adjusted to precisely control the hydraulic oil injection and discharge of the left bladder 1 and the right bladder 16, thereby adjusting the buoyancy difference and achieving attitude recovery or maintenance.

[0035] A first pressure sensor 4 is provided between the two-position four-way solenoid directional valve 11 and the pressure relay 5. The first pressure sensor 4 is used to detect the rise in hydraulic oil pressure in the oil inlet circuit of the accumulator 3.

[0036] A second pressure sensor 2 is installed on the left first pipeline 15a, and a third pressure sensor 14 is installed on the right first pipeline 15b.

[0037] Specifically, the oil-filled buoyancy regulating device has the following stages: I. The sinking process, see [link / reference] Figure 5 : Phase 1: The depth sensor mounted on the bladder-type buoyancy adjustment device monitors the depth data of the device in real time. When the collected depth data is less than the set depth, the two-position four-way solenoid valve 11 is adjusted to the oil discharge state, and the left electric ball valve 13a and the right electric ball valve 13b are opened at a set ratio. The initial opening degree of the left electric ball valve 13a and the right electric ball valve 13b is set to 60%. The first gear pump 8 of the buoyancy adjustment unit is started, so that the hydraulic oil in the left oil bladder 1 flows sequentially through the left first pipeline 15a and the left electric ball valve 13a. As oil flows out, the hydraulic oil in the right oil bladder 16 flows out sequentially through the right first pipeline 15b and the right electric ball valve 13b. The hydraulic oil from the left oil bladder 1 and the right oil bladder 16 converges at the two-position four-way solenoid directional valve 11, and then flows into the inner oil tank 12 after passing through the buoyancy adjustment unit. In other words, the hydraulic oil from the left oil bladder 1 and the right oil bladder 16 converges at the two-position four-way solenoid directional valve 11 and then sequentially passes through the first filter 9, the first gear pump 8, the first overflow valve 7, the first bidirectional flow meter 6, and the first one-way valve 10 before flowing into the inner oil tank 12. As the volume of the left oil bladder 1 and the right oil bladder 16 decreases, the buoyancy decreases, and the oil bladder-type buoyancy adjustment device begins to submerge. Second stage: The depth sensor equipped with the oil bladder buoyancy adjustment device monitors the depth data of the oil bladder buoyancy adjustment device in real time. When the depth data is close to the set depth, the opening of the left electric ball valve 13a and the right electric ball valve 13b decreases, the flow rate of hydraulic oil flowing out of the left oil bladder 1 and the right oil bladder 16 decreases, the rate at which the volume of the left oil bladder 1 and the right oil bladder 16 decreases slows down, the rate at which the buoyancy decreases slows down, and the oil bladder buoyancy adjustment device gradually reaches the set depth by relying on inertia. Third stage: The depth sensor equipped with the oil bladder buoyancy adjustment device monitors the depth data of the oil bladder buoyancy adjustment device in real time. When the difference between the depth data and the set depth is within the tolerance range and is maintained for a set period of time, the left electric ball valve 13a and the right electric ball valve 13b are closed, the buoyancy adjustment unit no longer performs adjustment action, and the oil bladder buoyancy adjustment device maintains the current depth state. Preferably, the depth sensor can be replaced by the second pressure sensor 2 and the third pressure sensor 14, wherein the second pressure sensor 2 and the third pressure sensor 14 are used to monitor the pressure values ​​of the left oil bladder 1 and the right oil bladder 16 in real time, respectively. The oil bladder buoyancy adjustment device is equipped with a main control system, i.e., a control system. The main control system calculates the water depth where the oil bladder buoyancy adjustment device is located based on the pressure value and in combination with seawater density, gravitational acceleration, and atmospheric pressure. The calculation formula is as follows:

[0038] in, The pressure exerted on the oil bladder. This refers to the local atmospheric pressure. The density of the local seawater, For local gravitational acceleration, The depth at which the oil-filled buoyancy regulating device is located.

[0039] Preferably, during the descent process, if the attitude sensor of the oil bladder buoyancy adjustment device detects a pitch angle deviation in real time, and the pitch angle reaches a set threshold, the main control system can control the opening degree of the left electric ball valve 13a and the right electric ball valve 13b corresponding to the left oil bladder 1 and the right oil bladder 16 based on the difference between the current calculated depth and the set depth, and in combination with the pitch angle deviation, so as to achieve precise adjustment of the oil filling and discharging volume of the oil bladder, thereby achieving the purpose of the device diving to the set depth and maintaining the expected pitch attitude.

[0040] II. For details regarding long working hours, please refer to... Figure 8 : Phase 1: The depth sensor installed in the oil bladder buoyancy adjustment device is used to monitor the depth data of the oil bladder buoyancy adjustment device in real time. When the difference between the depth data and the set depth is within the set tolerance range and remains for a period of time, that is, when the oil bladder buoyancy adjustment device is in a stable working state, the oil bladder buoyancy adjustment device enters the steady-state operation stage. The main control system switches the buoyancy adjustment unit to the energy-saving standby mode. At this time, the first gear pump 8 stops working to reduce the energy consumption and mechanical wear caused by the continuous operation of the motor of the first gear pump 8. At the same time, the left electric ball valve 13a and the right electric ball valve 13b remain closed. The three-position four-way solenoid directional valve 20 of the emergency attitude adjustment unit remains in the neutral position. The three-position four-way solenoid directional valve 20, together with the left electric ball valve 13a and the right electric ball valve 13b, maintains pressure on the left oil bladder 1 and the right oil bladder 16.

[0041] Second stage: As the oil bladder buoyancy adjustment device operates underwater for a long time, due to factors such as temperature difference changes, thermal expansion and contraction of materials, and minor leakage, the hydraulic oil inside the left oil bladder 1 and the right oil bladder 16 may slowly leak, causing the buoyancy to gradually decrease, thereby increasing the diving depth of the oil bladder buoyancy adjustment device, or even deviating from its set operating water depth.

[0042] At this time, when the second pressure sensor 2 and the third pressure sensor 14 detect that the pressure of the left oil bladder 1 and the right oil bladder 16 is lower than the set threshold, the pressure relay 5 resets, the valve cores of the left electric ball valve 13a and the right electric ball valve 13b automatically open to an opening degree of 0% to 10%, the two-position four-way solenoid directional valve 11 automatically switches to the preset position of the oil injection channel, and at the same time, the accumulator 3 releases the hydraulic oil stored inside. After passing through the two-position four-way solenoid directional valve 11, the hydraulic oil is divided into two streams: one stream flows through the left electric ball valve 13a and the left first pipeline 15a to inject into the left oil bladder 1, and the other stream flows through the right electric ball valve 13b and the right first pipeline 15b to inject into the right oil bladder 16. During the replenishment process of the left oil bladder 1 and the right oil bladder 16, the second pressure sensor 2 and the third pressure sensor 14 continuously monitor the pressure of the left oil bladder 1 and the right oil bladder 16. When the second pressure sensor 2 and the third pressure sensor 14 detect that the pressure of the left oil bladder 1 and the right oil bladder 16 has reached the set threshold, the left electric ball valve 13a and the right electric ball valve 13b are closed. The oil bladder buoyancy regulating device then re-enters the first stage of its long-term operation.

[0043] This control logic ensures that stable pressure and buoyancy can be maintained in the left oil bladder 1 and the right oil bladder 16 without the need for frequent starting of the first gear pump 8, thereby reducing the motor start-stop frequency of the first gear pump 8, extending its service life, and reducing overall energy consumption. Preferably, the accumulator 3 is disposed between the two-position four-way solenoid directional valve 11 and the first one-way valve 10 to prevent the hydraulic oil output by the accumulator 3 from flowing back to the first gear pump 8 and to avoid damage to the first gear pump 8.

[0044] Preferably, a first filter 9 is provided at the inlet of the first gear pump 8. The first filter 9 is used to filter the hydraulic oil before it enters the pump body of the first gear pump 8 to remove impurity particles and prevent foreign objects from entering the pump chamber and causing wear or blockage.

[0045] III. The charging process of accumulator 3, see [link / details]. Figure 9 : When the first pressure sensor 4 detects that the hydraulic oil pressure in the inlet circuit of the accumulator 3 is lower than the set threshold, the main control system determines that there is an insufficient pressure state, thus triggering the charging process start condition. The left electric ball valve 13a and the right electric ball valve 13b close, cutting off the hydraulic oil passages related to the left oil bladder 1 and the right oil bladder 16, preventing high-pressure oil from accidentally flowing into the left oil bladder 1 and the right oil bladder 16 during the charging process, and ensuring that the charging path of the accumulator 3 is independent. Subsequently, the two-position four-way solenoid directional valve 11 switches to the oil injection state, and the first gear pump 8 starts running. The hydraulic oil output at a constant flow rate and pressure is set at a set speed by the frequency converter driver of the first gear pump 8 to ensure that the oil injection pressure rises steadily and avoids damage to the main control system or the structure of the accumulator 3 caused by instantaneous impact. The hydraulic oil output by the first gear pump 8 passes through the first relief valve 7, the first bidirectional flow meter 6, and the first one-way valve 10 in sequence before entering the pipeline of the accumulator 3. The first one-way valve 10 prevents hydraulic oil backflow and has good sealing and responsiveness. The main control system uses the first pressure sensor 4, located on the charging path of the accumulator 3, to collect real-time data on the rise in hydraulic oil pressure in the inlet circuit of the accumulator 3. When the internal hydraulic pressure of the accumulator 3 reaches the set upper limit, it is considered that charging is complete, and the main control system immediately issues a pump stop signal, shutting down the first gear pump 8. The main control system then returns to standby mode. Preferably, the opening pressure of the first overflow valve 7 is set to 1.1 times the rated charging pressure of the accumulator 3, so as to ensure that it remains closed before the main control system reaches the expected pressure, so that high-pressure oil is stably injected into the accumulator 3.

[0046] Preferably, the accumulator 3 has a gas-liquid isolation structure with a pre-filled nitrogen chamber inside. When hydraulic oil is injected from the bottom port, it pushes the diaphragm upward and compresses the gas chamber to achieve kinetic energy storage.

[0047] Preferably, the first bidirectional flow meter 6 is disposed between the first overflow valve 7 and the first one-way valve 10, and is used to monitor the flow rate of hydraulic oil in and out during the charging process in real time. By monitoring the flow rate through the first bidirectional flow meter 6, and measuring the pressure of the hydraulic oil through the second pressure sensor 2 and the third pressure sensor 14, the charging process of the oil is ensured to be stable, and overcharging or undercharging is avoided.

[0048] IV. Normal Posture Adjustment Process: When the attitude sensor detects a pitch angle deviation in the oil-filled buoyancy adjustment device in real time, and the pitch angle reaches a first set threshold, the first gear pump 8 starts. The variable frequency drive of the first gear pump 8 is set to output hydraulic oil at a constant flow rate and pressure at the target speed. Simultaneously, the two-position four-way solenoid valve 11 switches to the oil filling state, allowing the hydraulic oil to be guided from the inner oil tank 12 to the left oil bladder 1 and the right oil bladder 16 via the buoyancy adjustment unit. Based on this, the main control system performs attitude correction calculations according to the current attitude angle, device center of gravity distribution, and weight parameters, calculates the buoyancy distribution requirements, and then executes the following two stages sequentially: Phase 1: When the bladder-type buoyancy adjustment device exhibits a pitch deviation, the main control system determines the direction based on the real-time attitude angle signal. If the bladder-type buoyancy adjustment device tilts to the left, the left electric ball valve 13a is opened to a set opening degree, while the right electric ball valve 13b remains closed. If the bladder-type buoyancy adjustment device tilts to the right, the right electric ball valve 13b is opened to a set opening degree, while the left electric ball valve 13a remains closed. Both the left and right electric ball valves 13a and 13b operate in a continuously adjustable manner, ensuring that the first gear pump 8 injects hydraulic oil from the inner oil tank 12 only into the bladder on the tilting side, while the volume of the other bladder remains unchanged. This enhances buoyancy on that side, generating a restoring torque that causes the bladder-type buoyancy adjustment device to complete the pitch attitude directional adjustment and return to center.

[0049] The second stage: To prevent the increase in the total volume of the oil bladder caused by the first stage of oil filling during normal attitude adjustment, which would lead to an increase in the overall buoyancy of the oil bladder-type buoyancy adjustment device, the attitude sensor of the main control system detects that the pitch angle has returned to the set error and then enters the oil discharge balance stage. During the oil discharge balance stage, the main control system controls both the left electric ball valve 13a and the right electric ball valve 13b to open to the set opening degree, and simultaneously switches the two-position four-way solenoid directional valve 11 to the oil discharge circuit, so that the left oil bladder 1 and the right oil bladder 16 respectively discharge a portion of hydraulic oil into the inner oil tank 12 through the buoyancy adjustment unit. The oil discharge process is adjusted in conjunction with the real-time feedback from the second pressure sensor 2 at the inlet of the left oil bladder 1, the third pressure sensor 14 at the inlet of the right oil bladder 16, and the first bidirectional flow meter 6, to ensure that the volume of the left oil bladder 1 and the right oil bladder 16 is reduced without changing the attitude, achieving a stable return of the system's total buoyancy and avoiding the oil bladder-type buoyancy adjustment device from floating due to the accumulation of inertial buoyancy.

[0050] Preferably, during the first stage of adjustment in the normal attitude adjustment process, the main control system cycles through attitude error judgment every 50 milliseconds. Once it is detected that the deflection angle of the oil bladder buoyancy adjustment device has recovered to within a certain range, the current oil bladder state is maintained unchanged, and a "first stage attitude adjustment completed" command is issued, the first gear pump 8 is turned off, and the two-position four-way electromagnetic reversing valve 11 is switched to oil discharge mode.

[0051] Preferably, the main control system determines the opening degree of the left electric ball valve 13a and the right electric ball valve 13b based on pressure, flow rate, and attitude. That is, after returning to center, it first quickly closes the opening degree to 90%, and then slowly adjusts it to complete closure to prevent over-adjustment caused by inertial flow.

[0052] V. Emergency posture adjustment process, see [link / reference] Figure 7 : When the bladder-type buoyancy adjustment device experiences severe disturbance during underwater operation, causing its attitude sensor to detect a pitch angle deviation exceeding a second preset threshold, an independently configured emergency attitude adjustment unit is activated. The main control system determines, based on real-time angle signals collected by the attitude sensor, that rapid attitude realignment adjustment via dual-bladder hydraulic convection is required. At this time, the three-position four-way solenoid valve 20 switches to either the oil filling or draining position depending on the pitch state of the bladder-type buoyancy adjustment device, establishing a hydraulic passage between the left bladder 1 and the right bladder 16. Simultaneously, the left electric ball valve 13a and the right electric ball valve 13b remain closed to ensure a closed and stable fluid flow path for the emergency attitude adjustment unit, preventing fluid diversion or disturbance. The main control system starts the second gear pump 18, which operates at rated speed to output stable hydraulic oil pressure.

[0053] If the main control system determines that the bladder-type buoyancy adjustment device is tilted to the left, hydraulic oil flows out from the right bladder 16 through the right second pipe 17b, and is introduced into the left second pipe 17a through the three-position four-way solenoid valve 20 and injected into the left bladder 1. Conversely, if the system determines that the device is tilted to the right, hydraulic oil flows from the left bladder 1 through the left second pipe 17a into the right bladder 16. Through the above structure, directional hydraulic convection is formed between the left bladder 1 and the right bladder 16, causing the volume of the bladder on the tilted side to gradually increase and the buoyancy to increase, while the volume of the bladder on the other side decreases and the buoyancy to decrease accordingly. This generates a restoring torque in a short time, quickly pulling the bladder-type buoyancy adjustment device from a severely tilted state back to an approximately horizontal position.

[0054] Preferably, during emergency posture adjustment, both the left electric ball valve 13a and the right electric ball valve 13b remain closed, ensuring that the left oil bladder 1 and the right oil bladder 16 form a passage with the emergency posture adjustment unit.

[0055] Preferably, to prevent back pressure interference, the second one-way valve 21 installed at the outlet of the second gear pump 18 in the emergency attitude adjustment unit ensures that the liquid can only flow in one direction and avoids impact backflow.

[0056] Preferably, to avoid excessive buoyancy transfer caused by continuous hydraulic convection during attitude adjustment, which could lead to reverse overshoot or over-adjustment of the oil bladder buoyancy adjustment device, the main control system collects the pitch angle change trend in real time during convection. This data, combined with pressure data from the second pressure sensor 2 and the third pressure sensor 14 located at the inlets of the left and right oil bladders 1 and 16, and flow data from the second bidirectional flowmeter 22, enables closed-loop monitoring of attitude, flow, and pressure. When the main control system detects that the pitch angle has returned to the set attitude tolerance range and the oil pressure difference has stabilized and remained stable for a set period, it shuts off the second gear pump 18 and switches the three-position four-way solenoid valve 20 to the neutral position, disconnecting the hydraulic passage of the emergency attitude adjustment unit and maintaining the set buoyancy state.

[0057] Preferably, the main control system can be configured with buffer control logic to implement delayed slow-closing control on the three-position four-way solenoid directional valve 20 before cutting off the hydraulic passage, or to release residual pressure in the hydraulic passage by setting a bypass pressure stabilizing circuit, thereby avoiding slight attitude bounce or decreased stability of the oil bladder buoyancy adjustment device caused by inertial flow. This rapid convection attitude adjustment mechanism can achieve buoyancy redistribution without relying on external oil injection, improving pitch adjustment response speed and control accuracy under severe attitude deviation scenarios.

[0058] In comparison, the emergency attitude adjustment unit provided in this embodiment is suitable for scenarios such as large wave impacts, sudden changes in water flow, or failure of the buoyancy adjustment unit when the oil bladder buoyancy adjustment device encounters such situations. It has advantages such as short response time, large adjustment range, and independent control path, which improves the self-stabilization capability and operational reliability of the oil bladder buoyancy adjustment device in high-risk environments.

[0059] VI. Ascent process, see [link / reference] Figure 6 : The depth sensor installed in the bladder-type buoyancy adjustment device monitors the depth data of the device in real time. When the collected depth data is greater than the set depth, the two-position four-way solenoid valve 11 switches to the oil filling state. The left electric ball valve 13a and the right electric ball valve 13b open according to a set ratio, generally with an initial opening of 60%, forming an oil filling passage from the inner oil tank 12, the first gear pump 8 to the left oil bladder 1 via the left electric ball valve 13a, and to the right oil bladder 16 via the right electric ball valve 13b. The first gear pump 8 starts and runs at a set speed, outputting a stable hydraulic pressure. The hydraulic oil enters the first gear pump 8 after being purified by the first filter 9 from the inner oil tank 12, and then enters the first check valve 10. Subsequently, it is injected into the corresponding left oil bladder 1 and right oil bladder 16 via the left electric ball valve 13a and the right electric ball valve 13b, respectively. As hydraulic oil is injected, the volume of the left oil bladder 1 and the right oil bladder 16 gradually increases, and the buoyancy of the oil bladder increases synchronously with the volume change.

[0060] The depth sensor equipped with the oil bladder buoyancy adjustment device monitors the depth data of the oil bladder buoyancy adjustment device in real time. When the depth data is close to the set depth, the opening of the left electric ball valve 13a and the right electric ball valve 13b decreases, the flow rate of hydraulic oil injected into the left oil bladder 1 and the right oil bladder 16 decreases, the rate at which the volume of the left oil bladder 1 and the right oil bladder 16 decreases slows down, the rate at which the buoyancy decreases slows down, and the oil bladder buoyancy adjustment device gradually reaches the set depth by relying on inertia. The depth sensor equipped with the oil bladder buoyancy adjustment device monitors the depth data of the oil bladder buoyancy adjustment device in real time. When the difference between the depth data and the set depth is within the set range and is maintained for a set period of time, the left electric ball valve 13a and the right electric ball valve 13b are closed, the buoyancy adjustment unit no longer performs adjustment action, and the oil bladder buoyancy adjustment device maintains the current state. Preferably, the left electric ball valve 13a and the right electric ball valve 13b need to be opened at the same initial opening during the buoyancy process. The first bidirectional flow meter 6 continuously monitors the oil injection rate and provides feedback in conjunction with the second pressure sensor 2 and the third pressure sensor 14. If the injection speed on one side is slower than that on the other side, the main control system will automatically fine-tune the opening of the corresponding left electric ball valve 13a and the right electric ball valve 13b to achieve compensation, ensuring that the buoyancy increases evenly on both sides and preventing the attitude of the oil bladder buoyancy adjustment device from pitching or deflecting during the buoyancy process.

[0061] The innovation of this invention lies in the collaborative construction of a closed-loop control system using a bidirectional flow meter, an adjustable electric ball valve, and a pressure sensor. This system dynamically adjusts the liquid volume within the oil bladder from both flow and pressure dimensions, achieving real-time and precise control of buoyancy. This mechanism not only improves attitude stability and depth response accuracy during ascent and descent but also provides real-time feedback adjustments based on ocean current disturbances, ensuring precise positioning and efficient energy capture for the unit in complex sea conditions.

[0062] The innovation of this invention lies in the construction of a dual-loop attitude control mechanism, consisting of primary attitude adjustment and emergency attitude adjustment, which improves dynamic response and safety assurance capabilities. The two adjustment mechanisms work together during system operation, achieving both high-precision attitude maintenance under normal conditions and rapid emergency response capabilities in unforeseen circumstances, thereby enhancing the adaptability and reliability of the entire system in complex sea conditions.

[0063] The innovation of this invention lies in the active energy management mechanism achieved through the coordinated operation of the accumulator 3 and the pressure relay 5 during the buoyancy adjustment process. This design reduces the energy consumption of the buoyancy adjustment system during long-term underwater operation, while also reducing the operating frequency of the first gear pump 8 and the motor, thereby lowering the equipment failure rate and maintenance costs, and fundamentally improving the overall system's energy efficiency, reliability, and continuous underwater operation capability.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of this technical solution. Those skilled in the art should understand that this technical solution is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this technical solution. Various changes and modifications can be made to this technical solution without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed technical solution. The scope of protection of this technical solution is defined by the appended claims and their equivalents.

[0065] It should be noted that the structures, proportions, and sizes depicted in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the content disclosed herein. They are not intended to limit the implementation of this technical solution and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this technical solution, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms used in this specification, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity and not intended to limit the scope of implementation of this technical solution. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the technical solution's implementation.

[0066] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0067] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

Claims

1. A bladder-type buoyancy adjustment device for ocean current power generator sets, characterized in that, include: The outer shell, the left oil bladder (1) and the right oil bladder (16) located on opposite sides of the outer shell, the main attitude adjustment unit, the buoyancy adjustment unit and the inner oil tank (12) located inside the outer shell. The left oil bladder (1) is connected to the left first pipeline (15a), and the right oil bladder (16) is connected to the right first pipeline (15b). The left first pipeline (15a) and the right first pipeline (15b) are both connected to the inner oil tank (12) through the main attitude adjustment unit and the buoyancy adjustment unit. The main attitude adjustment unit includes a left electric ball valve (13a) and a right electric ball valve (13b). Both the left electric ball valve (13a) and the right electric ball valve (13b) are located inside the outer casing. The left electric ball valve (13a) is connected to the left oil bladder (1) through the left first pipeline (15a), and the right electric ball valve (13b) is connected to the right oil bladder (16) through the right first pipeline (15b). Both the left electric ball valve (13a) and the right electric ball valve (13b) are connected to the inner oil tank (12). The buoyancy adjustment unit includes a first filter (9), a first gear pump (8), a first overflow valve (7), a first bidirectional flow meter (6), a first check valve (10), and a two-position four-way solenoid valve (11) connected in sequence. One end of the first filter (9) is connected to the inner oil tank (12) through the two-position four-way solenoid valve (11). The two-position four-way solenoid valve (11) is connected to the left oil bladder (1) through the left electric ball valve (13a) and the left first pipeline (15a), and is connected to the right oil bladder (16) through the right electric ball valve (13b) and the right first pipeline (15b).

2. The oil-filled buoyancy regulating device for an ocean current power generator set according to claim 1, characterized in that, Also includes: The emergency posture adjustment unit includes a second filter (19), a second gear pump (18), a second check valve (21), a second bidirectional flow meter (22), and a three-position four-way solenoid valve (20) connected in sequence. The left oil bladder (1) is connected to one end of the second bidirectional flow meter (22) through the left second pipeline (17a) and the three-position four-way solenoid valve (20). The right oil bladder (16) is connected to one end of the second filter (19) through the right second pipeline (17b) and the three-position four-way solenoid valve (20).

3. The oil-filled buoyancy regulating device for an ocean current power generator set according to claim 2, characterized in that, Also includes: An accumulator (3) is located between the first one-way valve (10) and the two-position four-way solenoid directional valve (11) and is connected to a pressure relay (5).

4. The oil-filled buoyancy regulating device for an ocean current power generator set according to claim 3, characterized in that: A second pressure sensor (2) is installed on the left first pipeline (15a), and a third pressure sensor (14) is installed on the right first pipeline (15b).

5. A bladder-type buoyancy adjustment device for an ocean current power generator set according to any one of claims 2-4, characterized in that: A first pressure sensor (4) is provided between the two-position four-way solenoid directional valve (11) and the pressure relay (5).

6. A bladder-type buoyancy regulating device for an ocean current power generator set according to any one of claims 1-4, characterized in that: Both the left electric ball valve (13a) and the right electric ball valve (13b) are electrically controlled ball valves with a movable ball as the valve core. The opening degree of the left electric ball valve (13a) and the right electric ball valve (13b) can be adjusted independently.

7. A bladder-type buoyancy regulating device for an ocean current power generator set according to any one of claims 1-4, characterized in that: When the pitch angle of the bladder-type buoyancy adjustment device reaches the first set threshold, if the bladder-type buoyancy adjustment device tilts to the left, the left electric ball valve (13a) opens and the right electric ball valve (13b) remains closed; if the bladder-type buoyancy adjustment device tilts to the right, the right electric ball valve (13b) opens and the left electric ball valve (13a) remains closed, so that the hydraulic oil in the inner oil tank (12) is injected only into the bladder on one side of the tilt direction, and the volume of the bladder on the other side remains unchanged. Then the left electric ball valve (13a) and the right electric ball valve (13b) open, and the two-position four-way solenoid directional valve (11) is switched to the oil discharge circuit, so that the left oil bladder (1) and the right oil bladder (16) respectively discharge part of the hydraulic oil to the inner oil tank (12) through the buoyancy adjustment unit.

8. The oil-filled buoyancy regulating device for an ocean current power generator set according to claim 2, characterized in that: When the pitch angle deviation of the oil bladder buoyancy adjustment device exceeds the second set threshold, both the left electric ball valve (13a) and the right electric ball valve (13b) remain closed, the three-position four-way solenoid directional valve (20) switches to the corresponding oil filling position or oil draining position, and the second gear pump (18) drives the hydraulic oil to transfer between the left oil bladder (1) and the right oil bladder (16) through the emergency attitude adjustment unit.

9. A bladder-type buoyancy adjustment device for an ocean current power generator set according to claim 4, characterized in that: When the second pressure sensor (2) and the third pressure sensor (14) detect that the pressure of the left oil bladder (1) and the right oil bladder (16) is lower than the set threshold, the left electric ball valve (13a) and the right electric ball valve (13b) open to the set opening degree, the two-position four-way solenoid directional valve (11) switches to the preset position of the oil injection channel, the accumulator (3) releases hydraulic oil and flows into the left oil bladder (1) through the left first pipeline (15a) and into the right oil bladder (16) through the right first pipeline (15b). When the first pressure sensor (4) detects that the oil inlet pressure of the accumulator (3) is lower than the set threshold, the left electric ball valve (13a) and the right electric ball valve (13b) are closed, the first gear pump (8) is started and the hydraulic oil in the inner oil tank (12) is transported to the accumulator (3) through the buoyancy adjustment unit.

10. A bladder-type buoyancy regulating device for an ocean current power generator set according to any one of claims 1, 2, 3, 4, 8, or 9, characterized in that: During the upward movement of the oil bladder type buoyancy adjustment device, as the two-position four-way solenoid valve (11) of the buoyancy adjustment unit switches to the oil injection state, the hydraulic oil output by the first gear pump (8) is injected into the left oil bladder (1) and the right oil bladder (16) through the buoyancy adjustment unit. During the sinking process of the oil bladder type buoyancy adjustment device, the two-position four-way solenoid valve (11) of the buoyancy adjustment unit is switched to the oil discharge state, and the hydraulic oil in the left oil bladder (1) and the right oil bladder (16) flows back to the inner oil tank (12) through the buoyancy adjustment unit.

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