Flexible starting type ocean current energy power generation device suitable for low-flow-speed environment

Abstract

The technical scheme belongs to the technical field of new energy power generation, and particularly relates to a flexible starting type ocean current energy power generation device suitable for a low-flow-speed environment, which comprises a shell, a main transmission shaft, an impeller, a planar magnetic coupling module, a ball screw module and a permanent magnet synchronous generator, the front end of the main transmission shaft extends out of the shell and is connected with the impeller; the rear end of the main transmission shaft is connected with the impeller end plane magnetic coupling; the permanent magnet synchronous generator is installed on the ball screw module and connected with the motor end plane magnetic coupling. The permanent magnet synchronous generator and the motor end plane magnetic coupling are driven by the ball screw module to be close to or far away from the impeller end plane magnetic coupling, flexible joint and separation of the magnetic coupling are achieved, and therefore stable starting of the generator is completed in the low-flow-speed environment, and the impeller is matched with the permanent magnet synchronous generator to convert ocean current energy into electric energy. The device has the advantages of low starting flow velocity, flexible starting and the like, and is suitable for development and utilization of low-speed ocean current energy.

Description

Technical Field

[0001] This technical solution relates to the field of new energy power generation technology, specifically a flexible start-up type ocean current energy power generation device suitable for low flow velocity environments. Background Technology

[0002] my country boasts a vast territorial waters and abundant marine resources, with a mainland coastline exceeding 18,000 kilometers. The surrounding seas are rich in ocean current energy resources with development potential. While the current velocities in nearshore areas such as the East China Sea and South China Sea remain relatively stable, they are generally between 0.2 m / s and 1.0 m / s, below the medium-to-high velocity threshold (above 1.5 m / s) required for current ocean current power generation devices. This situation limits the widespread application of ocean current energy in my country.

[0003] Current ocean current power generation devices are designed for startup at medium to high current velocities and are suitable for environments with strong ocean currents or tidal currents. These devices typically require large torque and high impeller speeds to drive the generator, resulting in either failure to start up or reduced operating efficiency after startup when the current velocity is below 1.0 m / s, making it difficult to meet actual power generation needs.

[0004] In addition, existing ocean current power generation devices use traditional rigid couplings as transmission connection components. Under the influence of complex marine environments (such as seawater corrosion, water flow impact, and silt abrasion), these rigid couplings are prone to problems such as sealing performance failure and accelerated component wear rate. This not only increases the maintenance cost of ocean current power generation devices, but also affects the long-term stability and reliability of ocean current power generation devices.

[0005] Existing ocean current power generation devices generally suffer from technical bottlenecks such as high required flow velocities for startup and high rigidity of the system transmission structure. Developing ocean current power generation devices with low-flow-velocity flexible startup, enabling low-flow-velocity operation of ocean current power generation devices, is of great significance for "on-site energy extraction and ocean energy utilization". Summary of the Invention

[0006] To address the aforementioned problems of existing ocean current power generation devices, this invention proposes a flexible-start ocean current power generation device suitable for low-flow-velocity environments. By using a ball screw module to drive the spacing of a planar magnetic coupling module, flexible adjustment of the magnetic coupling state is achieved, thereby enabling flexible start-up and power generation of the power generation device in low-flow-velocity environments.

[0007] The purpose of this technical solution is achieved as follows: A flexible-start ocean current power generation device suitable for low-flow-velocity environments includes: Housing, main drive shaft, impeller, planar magnetic coupling module, ball screw module, permanent magnet synchronous generator; The housing contains the main drive shaft, the planar magnetic coupling module, the ball screw module, and the permanent magnet synchronous generator. The front end of the main drive shaft extends out of the housing and is connected to the impeller, and the rear end of the main drive shaft is connected to the impeller end planar magnetic coupling of the planar magnetic coupling module. The permanent magnet synchronous generator is mounted on the ball screw module, and the permanent magnet synchronous generator is connected to the motor end planar magnetic coupling of the planar magnetic coupling module. The ball screw module drives the permanent magnet synchronous generator and the motor end planar magnetic coupling to move closer to or further away from the impeller end planar magnetic coupling.

[0008] Preferably, a flow guide is provided on the outer side of the housing. The outer side of the flow guide is cylindrical. The inner sides of the front and rear ends of the flow guide are both funnel-shaped. The inner side of the middle part of the flow guide is connected to the outer wall of the housing by a number of cylindrical connecting rods.

[0009] Preferably, the planar magnetic coupling module includes: an impeller-end planar magnetic coupling, an isolation plate, and a motor-end planar magnetic coupling; The impeller end planar magnetic coupling is connected to the rear end of the main drive shaft; The motor end planar magnetic coupling is connected to the permanent magnet synchronous generator; The isolation plate is located between the impeller end planar magnetic coupling and the motor end planar magnetic coupling, and the edge of the isolation plate is sealed to the inner wall of the housing.

[0010] Preferably, the isolation plate has a disc structure with a constant thickness, and the edge of the isolation plate is fixedly connected to the inner wall of the shell by waterproof adhesive.

[0011] Preferably, the ball screw module includes: a servo motor, a linear guide, a screw, a slider, and a motor mounting bracket; the ball screw module is used to drive the motor end planar magnetic coupling to move axially along the main drive shaft, so as to adjust the axial distance between the motor end planar magnetic coupling and the impeller end planar magnetic coupling, thereby realizing flexible engagement and disengagement of the two under different working conditions, thus achieving flexible start-up under low flow rate conditions.

[0012] A linear guide rail is installed inside the housing. A slider is slidably mounted on the upper end of the linear guide rail. A motor mounting bracket is mounted on the slider. A permanent magnet synchronous generator is mounted on the motor mounting bracket. A lead screw is rotatably mounted on the upper end of the linear guide rail. The lead screw and the slider are connected by ball bearings. A servo motor is mounted on the end of the linear guide rail, and the drive end of the servo motor is connected to the lead screw.

[0013] Preferably, the housing contains a control module and a battery. The control module is used to control the start and stop of the ball screw module, and the battery is used to store the electricity generated by the permanent magnet synchronous generator and to supply power to the ball screw module.

[0014] Preferably, the front end of the main drive shaft is connected to the impeller via a keyway and a flat key. The front end of the housing is provided with a bearing end cover; the middle part of the main drive shaft is provided with a shaft shoulder, and a bearing is sleeved on the main drive shaft, with the two ends of the bearing abutting against the bearing end cover and the shaft shoulder respectively; The rear end of the main drive shaft is connected to the impeller end planar magnetic coupling.

[0015] Preferably, the front end of the housing is connected to the bearing end cover, and the rear end of the housing is connected to the base cover plate. The housing has several compartments. The first compartment is used to accommodate the bearing, the second compartment is used to accommodate the impeller end planar magnetic coupling, and the third compartment is used to accommodate the motor end planar magnetic coupling, the ball screw module, the battery, and the control module. The inner wall of the third compartment is a non-circular structure, and one side of the third compartment is a flat surface for installing the ball screw module.

[0016] Preferably, when the ocean current velocity is low, the impeller end planar magnetic coupling and the motor end planar magnetic coupling maintain a set distance, so that no torque is transmitted between the impeller end planar magnetic coupling and the motor end planar magnetic coupling; When the impeller speed reaches the first set speed threshold, the ball screw module drives the motor end planar magnetic coupling to move towards the impeller end planar magnetic coupling. The distance between the motor end planar magnetic coupling and the impeller end planar magnetic coupling gradually decreases, and the impeller end planar magnetic coupling causes the torque and speed of the motor end planar magnetic coupling to gradually increase. When the impeller speed reaches the second set speed threshold, the ball screw module stops working, and the servo motor of the ball screw module is in a self-locking state.

[0017] The key and beneficial technical effects of this technical solution compared to existing technologies are: 1. This technical solution has low flow rate start-up capability: The ball screw module and the planar magnetic coupling work together. When the ocean current velocity is low, the planar magnetic coupling at the impeller end and the planar magnetic coupling at the motor end are in a separated state, and the impeller rotates under no-load, which effectively reduces the starting resistance and enables the ocean current power generation device to start the impeller in a low flow rate (flow velocity below 1.5m / s) environment.

[0018] 2. This technical solution has a flexible coupling function: when the impeller speed gradually increases to the set threshold, the ball screw module drives the motor end planar magnetic coupling to approach the impeller end planar magnetic coupling to complete the flexible engagement process, thereby gradually transmitting torque to the permanent magnet synchronous generator, realizing the impeller driving the permanent magnet synchronous generator to work, and thus realizing the smooth start-up and operation of the ocean current power generation device, that is, the flexible start-up of the permanent magnet synchronous generator.

[0019] 3. This technical solution has excellent sealing performance: It adopts a non-contact impeller-end planar magnetic coupling, a motor-end planar magnetic coupling, and an isolation plate structure between them, achieving complete non-mechanical contact between the impeller-end planar magnetic coupling and the motor-end planar magnetic coupling during transmission. This avoids the sealing problems caused by the rotating shaft penetrating the shell in traditional rigid coupling structures. The isolation plate, as a physical isolation layer between the impeller-end planar magnetic coupling and the motor-end planar magnetic coupling, is made of non-magnetic and corrosion-resistant materials and is fixedly connected to the inner wall of the shell with waterproof adhesive to form an integrated sealing structure, preventing seawater from penetrating and corroding the permanent magnet synchronous generator, control module, and battery inside the shell.

[0020] 4. This technical solution has energy-saving characteristics: It adopts a servo motor to drive the ball screw structure, which only operates during the engagement and disengagement of the magnetic coupling. The overall driving process has a short duration, small load, and low power requirements. In comparison, the energy output of the ocean current power generation device in a normal power generation under low flow conditions is higher than the energy required for the servo motor to work. The ocean current power generation device has a high overall energy utilization rate, good energy-saving characteristics and engineering applicability, and is suitable for efficient energy acquisition in low ocean flow environments. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the ocean current energy generation device of the present invention; Figure 2 This is a schematic diagram of the structure of the ocean current energy generation device of the present invention; Figure 3 This is a partial structural schematic diagram of the ocean current energy generation device of the present invention during no-load startup. Figure 4 This is a partial structural schematic diagram of the ocean current energy power generation device of the present invention during the power generation process; Reference numerals: 1. Impeller; 2. Flat key; 3. Main drive shaft; 4. Bearing end cover; 5. Bearing; 6. Housing; 7. Impeller end planar magnetic coupling; 8. Isolation plate; 9. Motor end planar magnetic coupling; 10. Motor mounting bracket; 11. Permanent magnet synchronous generator; 12. Speed ​​encoder; 13. Slider; 14. Lead screw; 15. Linear guide rail; 16. Servo motor; 17. Control module; 18. Battery; 19. Base cover plate; 20. Cylindrical connecting rod; 21. Draft shield. Detailed Implementation

[0022] The specific implementation of this technical solution will be further described in detail below with reference to the accompanying drawings.

[0023] This invention provides a flexible-start ocean current energy generation device suitable for low-flow-velocity environments. This device can achieve rapid response, startup, and stable power output even under low ocean current velocities (below 1.0 m / s). The device employs a magnetic coupling to gradually transmit torque to a permanent magnet synchronous generator via a non-contact transmission method, enabling smooth and efficient startup. This effectively reduces the mechanical resistance and starting torque requirements present in traditional rigid couplings, thereby improving the startup performance and energy conversion efficiency of the ocean current energy generation device under low-flow-velocity conditions.

[0024] like Figures 1-4 As shown, this embodiment provides a flexible start-up type ocean current energy generation device suitable for low flow velocity environments, including: a flow guide 21, a housing 6, an impeller 1, a main drive shaft 3, a planar magnetic coupling module, a permanent magnet synchronous generator 11, a ball screw module, a control module 17, and a battery 18. The housing 6 houses the main drive shaft 3, the planar magnetic coupling module, the ball screw module, and the permanent magnet synchronous generator 11. The front end of the main drive shaft 3 extends out of the housing 6 and is connected to the impeller 1. The rear end of the main drive shaft 3 is connected to the impeller end planar magnetic coupling 7 of the planar magnetic coupling module. The permanent magnet synchronous generator 11 is mounted on the ball screw module and is connected to the motor end planar magnetic coupling 9 of the planar magnetic coupling module. The ball screw module drives the permanent magnet synchronous generator 11 and the motor end planar magnetic coupling 9 to move closer to or further away from the impeller end planar magnetic coupling 7.

[0025] A flow guide 21 is provided on the outer side of the shell 6. The outer side of the flow guide 21 is a cylindrical structure. The inner sides of the front and rear ends of the flow guide 21 are funnel-shaped. The inner side of the flow guide 21 is connected to the shell 6 by three circumferentially evenly distributed cylindrical connecting rods 20. The funnel shape of the front end of the flow guide 21 can effectively converge and guide the ocean current into the middle of the flow guide 21, which can reduce the start-up flow velocity of the ocean current power generation device and improve the capture efficiency of low-speed ocean currents.

[0026] The impeller 1 is located outside the housing 6 and is used to directly contact the external ocean current and convert the kinetic energy of the ocean current into mechanical energy.

[0027] One end of the main drive shaft 3 with a keyway is connected to the impeller 1, and the other end is located inside the housing 6 and connected to the impeller end planar magnetic coupling 7.

[0028] The planar magnetic coupling module includes an impeller-end planar magnetic coupling 7, an isolation plate 8, and a motor-end planar magnetic coupling 9. The planar magnetic coupling module is used to realize a non-contact transmission connection between the impeller 1 and the permanent magnet synchronous generator 11. Its main function is to ensure effective torque transmission while maintaining good system sealing and structural independence. The impeller end planar magnetic coupling 7 is connected to the rear end of the main drive shaft 3; the isolation plate 8 is located between the impeller end planar magnetic coupling 7 and the motor end planar magnetic coupling 9, and the edge of the isolation plate 8 is sealed to the inner wall of the housing 6; the motor end planar magnetic coupling 9 is connected to the permanent magnet synchronous generator 11.

[0029] The ball screw module includes a servo motor 16, a linear guide rail 15, a screw 14, a slider 13, and a motor mounting bracket 10. The ball screw module is used to drive the motor end planar magnetic coupling 9 to move axially along the main drive shaft 3, so as to adjust the axial distance between the motor end planar magnetic coupling 9 and the impeller end planar magnetic coupling 7, thereby realizing flexible engagement and disengagement of the two under different working conditions, thus achieving flexible start-up under low flow rate conditions.

[0030] The linear guide rail 15 is installed inside the housing 6 by hexagonal head bolts. The slider 13 is slidably mounted on the upper end of the linear guide rail 15. The motor mounting bracket 10 is fixed on the slider 13 by hexagonal head bolts. The permanent magnet synchronous generator 11 is mounted on the motor mounting bracket 10 by hexagonal head bolts. The lead screw 14 is rotatably mounted on the upper end of the linear guide rail 15. The lead screw 14 and the slider 13 are connected by ball bearings. The servo motor 16 is mounted on the end of the linear guide rail 15 through a motor flange, and the drive end of the servo motor 16 is connected to the lead screw 14.

[0031] The motor end planar magnetic coupling 9 and the permanent magnet synchronous generator 11 can be equipped with an elastic coupling or a rigid coupling according to actual usage requirements, to compensate for axial or radial deviations and buffer impact loads.

[0032] The servo motor 16 has a self-locking function, which can maintain the set position when it stops running, preventing the lead screw 14 from rotating due to external force and causing the position of the planar magnetic coupling 9 at the motor end to shift. The servo motor 16 also has the ability to continuously supply power to maintain torque control, that is, during operation, even if there is ocean current disturbance or load change, its control module 17 can still continuously supply power to the servo motor 16 to maintain the locked state of the motor shaft and slider 13 of the servo motor 16, thereby improving the system's response capability and anti-interference performance in low-speed, high-precision linkage processes.

[0033] The ball screw module is a high-precision preloaded ball screw pair, which can be equipped with an automatic backlash compensation structure to improve the stability and repeatability of the positioning response.

[0034] The housing 6 is equipped with a control module 17 and a storage battery 18. The control module 17 is used for centralized control and status management of various subsystems of the ocean current power generation device, including real-time monitoring and command scheduling of the servo motor 16, the planar magnetic coupling, the permanent magnet synchronous generator 11, the charging and discharging of the battery 18, and the speed encoder 12.

[0035] The control module 17 receives the rotational speed signal of the impeller 1 and controls the start-up, shutdown, and running direction of the servo motor 16 based on real-time detection results. When the rotational speed of the impeller 1 is lower than a set threshold, the servo motor 16 remains stationary, maintaining a set interval between the motor end planar magnetic coupling 9 and the impeller end planar magnetic coupling 7. When the rotational speed of the impeller 1 reaches the set threshold, the control module 17 drives the servo motor 16 to rotate the lead screw 14, thereby pushing the slider 13 and the motor end planar magnetic coupling 9 to move closer to the impeller end planar magnetic coupling 7 along the axial direction of the main drive shaft 3, realizing the flexible engagement of the magnetic coupling module. The above control method realizes the automatic flexible start-up and start-stop adjustment of the ocean current power generation device at low flow rates.

[0036] The battery 18 is used to store the electrical energy output by the permanent magnet synchronous generator 11 and to provide continuous and stable power support for the control module 17 and the servo motor 16. The main drive shaft has a keyway at the front end of the impeller 1, which is connected to the impeller 1 through the cooperation of the keyway and the flat key 2. The front end of the housing 6 is provided with a bearing end cover 4 by a hexagonal head bolt. The main drive shaft 3 has a shoulder in the middle. A bearing 5 is respectively fitted at both ends of the middle part of the main drive shaft 3. The bearing 5 is a rolling bearing or a ceramic bearing. The two ends of the bearing 5 located at the front end of the middle part of the main drive shaft 3 abut against the bearing end cover 4 and the front end of the shoulder, respectively. The bearing end cover 4 and the bearing 5 limit the axial movement of the main drive shaft 3, restricting the main drive shaft 3 from moving away from the motor end plane magnetic coupling 9. The isolation plate 8 abuts against the rear end of the impeller end plane magnetic coupling 7 to restrict the movement towards the motor end plane magnetic coupling 9. The rear end of the main drive shaft 3 is connected to the impeller end plane magnetic coupling 7.

[0037] To further enhance the axial fixation capability of the connection, threaded holes are provided on the contact surfaces of the main drive shaft 3 and the impeller 1, and axial clamping and fixing are performed by screws, which effectively prevents loosening or slippage caused by vibration or impact during operation, thereby improving the operational stability and safety of the main drive shaft 3 and the impeller 1.

[0038] The impeller-end planar magnetic coupling 7 and the motor-end planar magnetic coupling 9 are respectively provided with a plurality of N-pole permanent magnets and S-pole permanent magnets evenly arranged along the circumference. The impeller-end planar magnetic coupling 7 and the motor-end planar magnetic coupling 9 are arranged coaxially and separated from each other by the isolation plate 8. The thickness of the isolation plate 8 is constant, so that the impeller-end planar magnetic coupling 7 and the motor-end planar magnetic coupling 9 maintain a fixed distance. The isolation plate 8 is a disc structure, and its edge is fixedly connected to the inner wall of the housing 6 by waterproof adhesive.

[0039] The isolation plate 8 is made of a non-magnetic material, such as stainless steel, aluminum alloy, glass, or plastic, to ensure effective magnetic force transmission and prevent magnetic field interference. In this invention, the isolation plate 8 must not use magnetically conductive or highly conductive metals such as iron or copper plates to avoid magnetic flux leakage or eddy current losses, ensuring stable operation and efficient transmission performance of the planar magnetic coupling.

[0040] The impeller end planar magnetic coupling 7 is connected to the main drive shaft 3 by insertion and is pressed together on the side wall of the insertion point by screws; the motor end planar magnetic coupling 9 is connected to the motor shaft of the permanent magnet synchronous generator 11 by insertion and is pressed together on the side wall of the insertion point by screws.

[0041] The base cover plate 19 and the housing 6 are connected by threads, which improves the reliability of the connection while ensuring the overall sealing performance of the structure. The connection method is compact and easy to disassemble and maintain.

[0042] The housing 6 has three compartments inside. The first compartment is used to accommodate two bearings 5 ​​and the middle part of the main drive shaft 3. The second compartment is used to accommodate the impeller end planar magnetic coupling 7 and the rear end of the main drive shaft 3. The third compartment is used to accommodate the motor end planar magnetic coupling 9, the ball screw module, the battery 18, and the control module 17. The inner wall of the third compartment is a non-circular structure, and one side of the inner wall of the third compartment is a plane for installing the linear guide rail 15 in the ball screw module.

[0043] The motor mounting bracket 10 is fixedly connected to the front end of the permanent magnet synchronous generator 11, the rear end of the permanent magnet synchronous generator 11 is fixedly connected to the speed encoder 12, and the motor shaft of the permanent magnet synchronous generator 11 is fixedly connected to the motor end planar magnetic coupling 9.

[0044] The flexible start-up type ocean current energy generation device suitable for low flow velocity environments provided in this embodiment operates as follows: Phase 1 (Impeller 1 No-load Start-up): When the ocean current velocity reaches the low-speed start-up threshold, i.e., when the ocean current velocity reaches the first start-up velocity, due to the cylindrical structure on the outer side of the guide shroud 21 and the funnel-shaped front and rear ends on the inner side, the ocean current is effectively converged and guided when passing through the guide shroud 21, and the ocean current velocity is increased. The impeller 1 rotates under the push of the ocean current. In this phase, the impeller end planar magnetic coupling 7 and the motor end planar magnetic coupling 9 maintain a set distance, so that no magnetic coupling relationship is established between them, resulting in torque not being transmitted to the permanent magnet synchronous generator 11, and the ocean current energy generation device is in a no-load state. Since the impeller 1 is not connected to the permanent magnet synchronous generator 11, the impeller 1 only operates under low start-up resistance. The main resistance when the impeller 1 rotates comes from the friction between the main drive shaft 3 and the bearing 5, so the required start-up velocity is low and the energy loss during the start-up process is small.

[0045] Phase Two (Weak Coupling Generation Phase of Planar Magnetic Coupling Module): When the ocean current velocity reaches the weak coupling operation threshold but not the stable generation threshold, that is, when the ocean current velocity reaches the second starting velocity but not the third starting velocity (i.e., the impeller 1 speed reaches the first set speed threshold), the servo motor 16 starts working, driving the slider 13 in the ball screw module, the motor fixing frame 10, the permanent magnet synchronous generator 11, the speed encoder 12, and the motor end planar magnetic coupling 9 to move slowly along the screw 14 towards the impeller end planar magnetic coupling 7. The distance between the motor-end planar magnetic coupling 9 and the impeller-end planar magnetic coupling 7 gradually decreases, and the magnetic field coupling between them gradually increases. During this process, the torque and speed transmitted between the motor-end planar magnetic coupling 9 and the impeller-end planar magnetic coupling 7 gradually increase as the distance between them decreases, thereby achieving effective driving of the motor-end planar magnetic coupling 9 and the motor shaft of the permanent magnet synchronous generator 11, realizing flexible start-up, ensuring that the impeller 1 rotates normally and is not disturbed, while realizing stable power generation output of the permanent magnet synchronous generator 11.

[0046] Phase Three (Stable Power Generation Process of Permanent Magnet Synchronous Generator 11): When the ocean current velocity reaches the stable power generation threshold, that is, when the ocean current velocity reaches the third starting velocity (i.e., when the impeller 1 speed reaches the second set speed threshold), the ocean current energy power generation device enters the stable power generation stage. At this time, the impeller end planar magnetic coupling 7 and the motor end planar magnetic coupling 9 are engaged to form a stable power transmission connection. At this time, the ball screw module stops moving after completing the predetermined stroke and is in a stationary state. The servo motor 16 enters a self-locking state, keeping the current position of the slider 13 and the motor fixing frame 10 from displacement, thereby ensuring that the power generation device maintains a stable mechanical structure configuration and power transmission path throughout the entire power generation process.

[0047] Phase Four (Permanent Magnet Synchronous Generator 11 Stops Power Generation): When the ocean current velocity is lower than the stable power generation threshold, or when the ocean current velocity is lower than the third start-up velocity, and the minimum torque input required by the permanent magnet synchronous generator 11 cannot be maintained, the control module 17 issues a cut-out command, triggering the decoupling operation of the impeller-end planar magnetic coupling 7 and the motor-end planar magnetic coupling 9. Specifically, after receiving the control signal, the servo motor 16 releases its self-locking state and drives the lead screw 14 to rotate in the reverse direction, causing the slider 13, the motor mounting bracket 10, the permanent magnet synchronous generator 11, the speed encoder 12, and the motor-end planar magnetic coupling 9 to move as a whole away from the impeller-end planar magnetic coupling 7 along the axial direction of the lead screw 14. As the movement progresses, the distance between the motor-end planar magnetic coupling 9 and the impeller-end planar magnetic coupling 7 gradually increases, and the magnetic field coupling strength between them weakens accordingly, eventually disengaging and cutting off the torque transmission path. At this time, the permanent magnet synchronous generator 11 stops generating electricity, and the entire ocean current power generation device enters an unloaded operation state. The ball screw module stops moving after completing the predetermined stroke. The servo motor 16 then enters a self-locking state, keeping the position of the motor end planar magnetic coupling 9 unchanged.

[0048] Preferably, the energy consumed by the ball screw module is less than the energy collected in stages two and three. The energy calculation formula for the ball screw module is as follows:

[0049] in, It is the torque of the servo motor 16. It is the angular velocity of servo motor 16; This refers to the continuous working time of the ball screw module. The ball screw module has high transmission efficiency and very low energy consumption. The formula for calculating the energy of the ball screw module can be used to quantitatively analyze the drive energy consumption of the ball screw module during the flexible engagement process between the impeller-end planar magnetic coupling 7 and the motor-end planar magnetic coupling 9, providing a reference for system power matching and efficiency optimization.

[0050] Preferably, under low flow velocity conditions, the energy output of the impeller 1 driving the permanent magnet synchronous generator 11 is calculated using the following formula:

[0051] in, It is the energy output by the permanent magnet synchronous generator 11. This is the power of the permanent magnet synchronous generator 11. This is the start time of power generation for the permanent magnet synchronous generator 11. It is the power generation end time of the permanent magnet synchronous generator 11.

[0052] The innovation of this invention lies in the use of a ball screw module and a planar magnetic coupling to work together. When the ocean current velocity is low, the planar magnetic coupling 7 at the impeller end and the planar magnetic coupling 9 at the motor end are in a separated state, and the impeller 1 rotates under no-load, which effectively reduces the starting resistance and enables the ocean current power generation device to start the impeller 1 at low flow rates.

[0053] The two formulas described above can be used to calculate the drive energy consumption of the ball screw module and the output energy of the permanent magnet synchronous generator, providing an analytical basis for further evaluating the energy conversion efficiency and system matching characteristics of the power generation device under low flow conditions. The innovation of this invention lies in the fact that as the impeller 1's rotational speed gradually increases to a set threshold, the servo motor 16 drives the ball screw module to push the motor-end planar magnetic coupling 9 closer to the impeller-end planar magnetic coupling 7, completing a flexible engagement process. This gradually transmits torque to the permanent magnet synchronous generator 11, achieving a smooth and efficient start-up of the ocean current power generation device.

[0054] The innovation of this invention lies in its structure, which uses a servo motor 16 to drive the lead screw 14 to rotate, thereby moving the motor mounting bracket 10. This structure operates only briefly during the engagement and disengagement phases of the planar magnetic coupling module, resulting in a short overall drive duration, low load, and extremely low energy requirements. In contrast, the energy output of a single normal power generation cycle under low-current conditions is higher than the energy required for the ball screw module to drive the system. The overall energy utilization rate is high, exhibiting excellent energy-saving characteristics and engineering applicability, making it suitable for efficient energy harvesting in low-current marine environments.

[0055] The fairing 21 adopts a three-section design, including a contraction section, a straight section, and an expansion section. The curves of the contraction and expansion sections adopt Vickers curves with good hydrodynamic performance. The impeller 1 and the guide shield 21 are made of fiberglass. This type of material has the characteristics of light weight, high strength and excellent corrosion resistance. It is suitable for long-term marine operation environment and has good corrosion resistance and sealing performance.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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 flexible-start ocean current energy generation device suitable for low-flow-velocity environments, characterized in that, include: Housing (6), main drive shaft (3), impeller (1), planar magnetic coupling module, ball screw module, permanent magnet synchronous generator (11); The housing (6) contains the main drive shaft (3), the planar magnetic coupling module, the ball screw module and the permanent magnet synchronous generator (11). The front end of the main drive shaft (3) extends out of the housing (6) and is connected to the impeller (1), and the rear end of the main drive shaft (3) is connected to the impeller end planar magnetic coupling (7) of the planar magnetic coupling module. The permanent magnet synchronous generator (11) is mounted on the ball screw module, and the permanent magnet synchronous generator (11) is connected to the motor end planar magnetic coupling (9) of the planar magnetic coupling module; The permanent magnet synchronous generator (11) and the motor end planar magnetic coupling (9) are driven by the ball screw module to approach or move away from the impeller end planar magnetic coupling (7).

2. The flexible start-up type ocean current power generation device suitable for low-flow-velocity environments according to claim 1, characterized in that: The outer side of the housing (6) is provided with a flow guide (21). The outer side of the flow guide (21) is a cylindrical structure. The inner side of the front end and the inner side of the rear end of the flow guide (21) are both flared. The inner side of the middle part of the flow guide (21) is connected to the outer side wall of the housing (6) by a number of cylindrical connecting rods (20).

3. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1 or 2, characterized in that: The planar magnetic coupling module includes: an impeller-end planar magnetic coupling (7), an isolation plate (8), and a motor-end planar magnetic coupling (9); the impeller-end planar magnetic coupling (7) is connected to the rear end of the main drive shaft (3); the motor-end planar magnetic coupling (9) is connected to the permanent magnet synchronous generator (11); the isolation plate (8) is located between the impeller-end planar magnetic coupling (7) and the motor-end planar magnetic coupling (9), and the edge of the isolation plate (8) is sealed to the inner wall of the housing (6).

4. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 3, characterized in that: The isolation plate (8) is a disc structure with a constant thickness, and the edge of the isolation plate (8) is fixedly connected to the inner wall of the shell (6) by waterproof adhesive.

5. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1, 2, or 4, characterized in that: The ball screw module includes: a servo motor (16), a linear guide (15), a screw (14), a slider (13), and a motor mounting bracket (10); the linear guide (15) is installed inside the housing (6), the slider (13) is slidably disposed on the upper end of the linear guide (15), the motor mounting bracket (10) is mounted on the slider (13), the permanent magnet synchronous generator (11) is mounted on the motor mounting bracket (10), the screw (14) is rotatably disposed on the upper end of the linear guide (15), the screw (14) and the slider (13) are connected by balls, the servo motor (16) is installed at the end of the linear guide (15), and the drive end of the servo motor (16) is connected to the screw (14); the ball screw module is used to drive the motor end planar magnetic coupling (9) to move axially along the main drive shaft (3).

6. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1, 2, or 4, characterized in that: The housing (6) is equipped with a control module (17) and a battery (18). The control module (17) is used to control the start and stop of the ball screw module, and the battery (18) is used to store the electricity generated by the permanent magnet synchronous generator (11) and to supply power to the ball screw module.

7. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1, 2, or 4, characterized in that: The front end of the main drive shaft (3) is connected to the impeller (1) through a keyway and a flat key (2); the front end of the housing (6) is provided with a bearing end cover (4); the middle part of the main drive shaft (3) is provided with a shaft shoulder, and a bearing (5) is sleeved on the main drive shaft (3), with the two ends of the bearing (5) abutting against the bearing end cover (4) and the shaft shoulder respectively; the rear end of the main drive shaft (3) is connected to the impeller end planar magnetic coupling (7).

8. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1, 2, or 4, characterized in that: The front end of the housing (6) is connected to the bearing end cover (4), and the rear end of the housing (6) is connected to the base cover plate (19). The housing (6) has several compartments inside. The first compartment is used to accommodate the bearing (5), the second compartment is used to accommodate the impeller end planar magnetic coupling (7), and the third compartment is used to accommodate the motor end planar magnetic coupling (9), the ball screw module, the battery (18), and the control module (17). The inner wall of the third compartment is a non-circular structure, and one side of the third compartment is a plane for installing the ball screw module.

9. A flexible-start ocean current power generation device suitable for low-flow-velocity environments according to claim 1, 2, or 4, characterized in that: When the ocean current velocity is low, the impeller end planar magnetic coupling (7) and the motor end planar magnetic coupling (9) maintain a set distance, so that no torque is transmitted between the impeller end planar magnetic coupling (7) and the motor end planar magnetic coupling (9); When the impeller (1) reaches the first set speed threshold, the ball screw module drives the motor end planar magnetic coupling (9) to move towards the impeller end planar magnetic coupling (7). The distance between the motor end planar magnetic coupling (9) and the impeller end planar magnetic coupling (7) gradually decreases, and the impeller end planar magnetic coupling (7) causes the torque and speed of the motor end planar magnetic coupling (9) to gradually increase. When the impeller (1) reaches the second set speed threshold, the ball screw module stops working and the servo motor (16) of the ball screw module is in a self-locking state.

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