Built-in double-body type wave power generation device

Abstract

The invention discloses a built-in double-body type wave energy power generation device, belongs to the technical field of wave energy power generation, and aims at solving the problems that an existing device is difficult to deploy, low in reliability and poor in control precision. The device comprises a sealed cabin shell, a slotless cylindrical permanent magnet linear generator, an auxiliary spring, a main control circuit, an energy storage module and a sensing system. The cabin body is a vertical equal-cross-sectional-area cylinder, serves as an external floater and is fully sealed; the axial length of the primary slotless iron core outside the generator, the axial length of the secondary slotless iron core inside the generator and the axial length of the primary slotless iron core are optimized through a formula to reduce end force. The auxiliary springs are two groups of pressure springs with different rigidities, and are matched with the cross split type rotor end cover and the guide rod, so that the motion dead zone of the rotor is reduced; the sensing system comprises a grating ruler and an acceleration sensor, and the main control circuit controls and counteracts electromagnetic force and stores electricity. The device generates power through relative movement of the cabin body and the rotor, is easy to maintain and migrate, adapts to multiple ocean scenes, and can efficiently capture wave energy.

Description

Technical Field

[0001] This invention relates to the field of wave energy power generation technology, and in particular to a built-in dual-body wave energy power generation device. Background Technology

[0002] Wave energy, as a renewable energy source with abundant reserves, high energy density, and strong predictability, has attracted widespread attention globally. Direct-drive wave energy generation devices, especially point-suction devices, have become a research hotspot due to their simple structure, high conversion efficiency, and suitability for my country's marine conditions. Their core principle is to utilize wave-driven buoys (movers) to generate relative linear motion with a fixed stator, directly converting mechanical energy into electrical energy through a linear generator.

[0003] However, existing direct-drive wave energy generation technologies still have significant drawbacks: A built-in twin-hull wave energy generation device: 1. Current direct-drive wave energy generation devices are generally single-unit, meaning the generator stator is fixed to the shore or seabed, and waves drive a float connected to the mover to generate electricity. Single-unit devices not only damage the marine ecological environment during installation and deployment but also present construction difficulties. Furthermore, the energy capture system of single-unit wave energy generation devices involves technical issues such as dynamic sealing, and reliability decreases with increasing operating time.

[0004] 2. Currently, existing direct-drive wave energy generation devices often do not employ control measures for energy capture motion. Therefore, previous designs for linear generators generally focused on maximizing generator output power, with reducing positioning forces and improving generator stability as secondary objectives. However, with the introduction of wave capture control theory, the interference of positioning forces significantly impacts control accuracy and wave force prediction. After introducing optimal control methods for wave power generation, the performance of linear generators designed using previous methods cannot meet the control requirements of wave power generation.

[0005] Therefore, there is an urgent need for a wave energy power generation device that is easy to deploy, highly reliable, can effectively suppress internal disturbances, and provides a basis for advanced control algorithms. Summary of the Invention

[0006] The purpose of this invention is to provide a built-in dual-body wave energy generation device that solves deployment challenges and improves reliability through a fully sealed built-in structure; significantly reduces positioning force through slotless motor design and structural optimization, creating conditions for implementing precise wave energy control strategies; and increases effective stroke through innovative internal mechanical structure design, improving space utilization and energy capture efficiency.

[0007] To achieve the above objectives, the present invention provides a built-in dual-body wave energy generation device comprising: a sealed outer shell, a built-in slotless cylindrical permanent magnet linear generator, an auxiliary spring, a main control circuit and an energy storage module, and a sensing and guidance system.

[0008] The cabin shell is a vertical hollow cylinder structure with equal cross-sectional area, and its two ends are sealed by cabin covers and are pulled tightly by long pull rods and lifting lugs to form a whole. The equal cross-sectional design makes the hydrostatic restoring force and displacement linearly related, simplifying the system dynamics model and control difficulty.

[0009] Preferably, the slotless cylindrical permanent magnet linear generator adopts an outer primary and inner secondary structure layout, forming an integer slot matching of 18 slots and 6 poles.

[0010] The secondary part (fixed to the cabin shell): includes a secondary core, a permanent magnet ring, and an end mounting seat. The secondary core is fixed between the two end mounting seats. The permanent magnet ring is spliced by multiple (preferably 8) magnetic tiles and is fixed to the secondary core by steel ribs. The adjacent magnetic rings are magnetized in opposite directions, forming a Halbach array or similar structure to enhance the magnetic field. The magnetic ring is equipped with a spacer ring on both sides for adjusting the installation size.

[0011] The primary part (internal mover): includes a primary core, a winding coil, and a winding frame. The winding coil is pre-wound on the winding frame made of non-magnetic material (such as nylon), and then the whole is inserted into the primary core. The primary core is equipped with a primary washer at both ends for limiting and leading out three-phase wires. The mover is closed by the mover end cover installed in a cross shape at both ends, and the linear bearing is installed on the mover end cover. Rubber pads are also installed on the outside of the mover end cover as a buffer.

[0012] Preferably, the auxiliary spring includes two sets of compression springs and four spring guide rods. The four spring guide rods are parallelly arranged between the two end mounting seats, forming the motion guide track of the entire mover. The two sets of compression springs have different free lengths and stiffness coefficients and are symmetrically sleeved on the spring guide rods. Specifically, the upper end of the lower spring is in contact with the lower end surface of the upper mover end cover, and the lower end of the upper spring is in contact with the upper end surface of the lower mover end cover. This arrangement ensures that the two sets of springs are always in compression state in the working state, providing a nonlinear restoring force together and greatly reducing the motion dead zone caused by the limit compression length of the spring.

[0013] Preferably, the main control circuit and energy storage module are installed on the end mounting seat, used to rectify and stabilize the alternating current generated by the generator and store it in the battery, and execute the wave energy capture control algorithm to actively control the motion state of the device by adjusting the load or back electromotive force of the generator.

[0014] Preferably, the sensing and guiding system comprises a grating ruler and an acceleration sensor. The ruler body is fixed by a vertical plate, and the reading head is installed on the mover by a fixed block, for accurately measuring the relative displacement and speed between the mover and the stator. The acceleration sensor is installed on the mover, for measuring the acceleration of the movement. The sensor signals are fed back to the main control module, to provide data basis for realizing optimal control.

[0015] Preferably, the axial length of the primary core is designed to be optimized, to minimize the end force. The optimization amount satisfies the formula: , and the value of which is determined by the formula ; wherein, is the pole pitch, is an integer, n is the harmonic number, and are the Fourier decomposition coefficients of the end force of the motor, to minimize the end force. Through the optimization, the main harmonic component Fn of the end force can be theoretically zero, so as to significantly suppress the thrust fluctuation.

[0016] Therefore, the built-in double-body wave energy power generation device has the following beneficial effects: 1. The device can drive the linear generator to capture wave energy through the relative movement of the sealed cabin and the internal mover, all components are built-in in the sealed cabin, the cost is low, the reliability is high, and the maintenance or migration is easy, which can meet the differentiated power demand of offshore islands, ships, marine instruments, offshore drilling or mining operation platforms, marine energy or communication relay stations, etc.

[0017] 2. The internal structure of the device adopts the design scheme that the upper and lower end covers of the mover are cross-distributed and guided by the guide shaft, which reduces the dead space of the mover movement caused by the limit compression length of the spring, increases the movement stroke of the primary mover of the motor, and improves the overall space utilization.

[0018] 3. The two groups of unequal length and unequal stiffness springs used in the device expand the adjustable spring stiffness range, can coordinate the adjustment of the free length and stiffness of the two groups of springs, and obtain the spring stiffness designed according to the dynamics analysis.

[0019] 4. The cabin of the direct-drive wave power generation device is a vertical long and narrow hollow cylindrical structure, and the equal cross-sectional area design makes the hydrostatic restoring force of the wave power generation device and the floater displacement in a linear relationship, which reduces the difficulty of wave energy capture control.

[0020] 5. The cylindrical linear generator used in the application adopts a toothless structure, theoretically completely solves the fluctuation problem caused by the tooth slot force, and in weakening the edge force, adopts the way of optimizing the length of the primary iron core structure. The positioning force is greatly reduced, the influence of the thrust fluctuation on the motion stability is weakened, and the influence of the internal disturbance on the control accuracy of the control system is weakened.

[0021] The technical solutions of the application are further described in detail below through the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Overall cross-section of the wave energy power generation device carrying the toothless cylindrical linear generator; Figure 2 Overall structure diagram of the wave energy power generation device carrying the toothless cylindrical linear generator; Figure 3 Internal structure diagram of the wave energy power generation device carrying the toothless cylindrical linear generator; Figure 4 Internal structure cross-sectional view of the toothless cylindrical linear generator carried by the wave energy power generation device, including the distribution of the secondary permanent magnet array of the generator; REFERENCE NUMERALS 1 - spacer ring, 2 - main control circuit and energy storage module, 3 - cover plate, 4 - long pull rod, 5 - hatch cover, 6 - long spacer sleeve, 7 - permanent magnet ring, 8 - acceleration sensor, 9 - linear bearing, 10 - primary washer, 11 - cabin body shell, 12 - rotor end cover, 13 - auxiliary spring, 14 - end tension plate, 15 - secondary iron core, 16 - lifting lug, 17 - end mounting seat, 18 - steel rib, 19 - grating ruler, 20 - grating ruler fixed stand, 21 - winding coil, 22 - winding frame, 23 - primary iron core, 24 - spring guide rod, 25 - grating ruler reading head fixed block, 26 - rotor sleeve, 27 - rubber pad. DETAILED DESCRIPTION

[0023] The technical solutions of the application are further described in detail below through the drawings and examples.

[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Example like Figures 1-4 As shown, the present invention provides a built-in dual-body wave energy generation device, including: an external float, a built-in slotless cylindrical permanent magnet linear generator, an auxiliary spring, a main control circuit and an energy storage module, and a sensing and guidance system.

[0026] The external float includes a sealed hull shell 11, a hatch cover 5, a cover plate 3, and a lifting lug 16. The hatch cover 5 and the lifting lug 16 are equipped with a static sealing ring when assembled. The cylindrical permanent magnet linear generator is an 18-slot, 6-pole integer-slot motor. Its primary section includes a winding coil 21, a winding frame 22, a primary core 23, a mover sleeve 26, a mover end cover 12, a primary washer 10, and a linear bearing 9. The secondary section includes a secondary core 15, a permanent magnet ring 7, steel ribs 18, a spacer ring 1, and an end mounting base 17. The winding coil 21 is wound within the winding frame 22 and its surface is insulated. The winding frame 22 is made of a non-magnetic material and is compatible with the slotless primary core 23. The primary core 23 is installed... In the mover sleeve 26, the winding coil 21 is fitted into the primary iron core 23, the primary washer 10 is installed at both ends of the primary iron core 23, the mover end cap 12 is cross-shaped and installed on both sides of the mover sleeve 26, and the linear bearing 9 is installed in the mounting hole of the mover end cap 12; the secondary iron core 15 is inserted into the central circular groove of the end mounting seat 17, and the permanent magnet ring 7 is composed of eight magnetic tiles and is installed in the groove formed by the steel rib 18 and the secondary iron core 15, forming a permanent magnet array of adjacent magnet rings with different magnetization directions; the spacer ring 1 is installed on both sides of the permanent magnet array. The auxiliary springs 13 are in contact with the upper and lower sets of the mover end cover 12 respectively. The lower spring is in contact with the lower end face of the upper end cover of the mover, and the upper spring is in contact with the upper end face of the lower end cover of the mover. The two sets of springs 13 have different free lengths and stiffnesses. Also included are spring guide rod 24, end tension plate 14 and long spacer sleeve 6, the spring guide rod 24 is inserted into end mounting seat 17 and end inserted into end tension plate 14, the spring 13 is sleeved into spring guide rod 24, the long spacer sleeve 6 is inserted into spring guide rod 24 and is axially positioned to end mounting seat 17; The main control circuit and energy storage module are installed on end mounting seat 17, used for rectifying and stabilizing the alternating current generated by the generator, storing to the storage battery, and executing the wave energy capture control algorithm, and actively controlling the motion state of the device by adjusting the load or back electromotive force of the generator. The sensing and guiding system includes acceleration sensor 8 and grating ruler 19. The ruler body of grating ruler 19 is fixed by a stand, and the reading head is installed on the mover through a fixing block, used for accurately measuring the relative displacement and speed between the mover and the stator. Acceleration sensor 8 is installed on the mover, used for measuring the motion acceleration thereof. These sensor signals are fed back to the main control module, providing a data basis for realizing optimal control. Grating ruler 19 is equipped with grating ruler fixing stand 20 and grating ruler reading head fixing block 25, grating ruler fixing stand 20 is used for fixing grating ruler 19, and grating ruler reading head fixing block 25 is used for fixing the grating ruler reading head.

[0027] The cylindrical permanent magnet linear generator designed in the application adopts an integer slot form, and finally forms an 18-slot 6-pole motor.

[0028] The stator part of the cylindrical permanent magnet linear generator, secondary core 15 is inserted into the center circular groove of end mounting seat 17, permanent magnet magnetic ring 7 is spliced by eight magnetic tiles, installed in the groove composed of steel rib 18 and secondary core 15, and after assembly, a magnetic ring permanent magnet array with different adjacent magnetization directions is formed, in addition, the grinded spacer ring 1 is installed on both sides of the permanent magnet array to adjust the overall installation size.

[0029] The mover part of the cylindrical permanent magnet linear generator, winding coil 21 is wound in nylon winding frame 22, and the surface is insulated. Primary core 23 is installed in mover sleeve 26, and the treated coil is sleeved into primary core 23, and primary washer 10 is installed at both ends respectively and three-phase output wires are led out from the slotted parts. Two mover end covers 12 are cross-installed on both sides of mover sleeve 26, limiting the internal coil, and linear bearing 9 is installed in the mover end cover 12 mounting hole, to ensure that the motor mover part moves along spring guide rod 24. Rubber pad 27 is installed on the outside of mover end cover 12, which plays a role of buffering and preventing impact during the operation of the generator.

[0030] As to other components of the linear generator, four spring guide rods 24 are inserted into the end mounting seats 17 of the secondary iron core 15, and the ends of the spring guide rods 24 are slightly elongated and inserted into the end tension plates 14. Two springs 13 are symmetrically sleeved on the spring guide rods 24, and the generator mover provided with the linear bearings 9 is sleeved on the spring guide rods 24. After the assembly is completed, the other end mounting seat 17 is inserted into the secondary iron core 15 and the four spring guide rods 24 at the same time until the inner end face of the positioning hole of the end mounting seat 17 is coincident with the upper end face of the secondary iron core 15. Four long spacer sleeves 6 are inserted into the guide rods 24 to complete the axial positioning of the end mounting seat 17, and finally the end tension plate 14 is installed. The main control circuit board and the energy storage module 2 are installed on the upper end face of the end mounting seat 17. The long pull rod 4 is inserted into the hollow guide rod 24, one side is installed with the hatch cover 5, and after being sleeved on the cabin body shell 11, the other side is installed with the hatch cover 5. Eight lifting lugs 16 and the long pull rod 4 are used to assemble and tension the whole device. The static sealing ring is provided when the generator device hatch cover 5 and the lifting lug 16 are assembled. Finally, the cover plates 3 are installed at both ends of the cabin body to complete the installation of the overall device.

[0031] In terms of material selection of the wave power generation device, the magnetic ring 7 is made of high-grade neodymium iron boron material, the secondary iron core 15 is made of No. 10 steel, and the primary iron core 23 is made of silicon steel material, which is processed by using a wire cutting process. The guide rod 24 is plated with chromium light shaft to ensure strength and surface smoothness. In terms of material selection of the remaining structure, on the one hand, it is necessary to avoid affecting the electromagnetic performance of the motor, and on the other hand, it is necessary to consider the convenience and safety angle of installation. In principle, it is necessary to avoid selecting magnetic materials. For parts with high precision requirements, aluminum alloy can be selected. For parts with auxiliary positioning function, resin, nylon and other materials can be selected. For parts with little effect on the overall electromagnetic performance, stainless steel material can also be selected.

[0032] In the internal generator guide design, four guide columns are adopted. The primary mover uses cross-shaped upper and lower mover end covers 12 to be installed with two groups of spring guide rods 24 through linear bearings 9. The auxiliary spring 13 of the generator mover adopts two groups of compression springs with different stiffness and lengths. Each group of compression springs has the same stiffness and length, and two compression springs in each group are symmetrically installed. The bottom spring is in contact with the lower end face of the upper end cover 12, and the top spring is in contact with the upper end face of the lower end cover 12. The space of the dead zone of the mover movement caused by the limit compression length of the spring is increased. In the working process, the two groups of springs are always in a compressed state, and the assembly work between the spring and the primary motor and the end mounting seat 17 is omitted. By dynamically analyzing the overall system, the spring stiffness is designed, and the ratio of the stiffness and length of the two groups of springs is adjusted to obtain the spring parameters that meet the dynamic analysis design.

[0033] The mounted cylinder type linear generator in the application adopts slotless permanent magnet linear generator in the motor structure form to weaken the influence of internal disturbance of the motor on wave power control, and uses the winding frame made of non-magnetic material to perform classified grouping winding.

[0034] The positioning force of the permanent magnet linear generator mainly includes two parts of end force and slot force, and since the slotless structure is adopted in the application, theoretically, there is no slot force, and the main fluctuation source is the end force. The end force is generated due to the opening of the stator core, and after the motor starts to move, the magnetic resistance of the magnetic circuit at the end tooth exists instantaneous mutation phenomenon, so there is a periodic thrust fluctuation on the motor.

[0035] For the end force, ; Among them, , is the axial length of the primary core, is an integer, is the pole pitch. The end force is written in the form of Fourier expansion as follows: ; Among them, and are the Fourier decomposition coefficients of the linear motor under single-end stress.

[0036] For any finite length of the primary core, the end force can be written as: ; Among them, can be written as: ; Trying to reduce the end force by changing the length of the primary core should satisfy the following formula: ; Further, the length variation of the primary core of the linear generator in the application is: .

[0037] The built-in double-body type wave energy power generation device provided by the application has the working process as follows: The wave energy power generation device in the application is in working state, the cabin shell drives the linear generator secondary part to perform heaving motion under the action of vertical wave exciting force, under the hysteresis action of the auxiliary spring 13 in the cabin, the primary coil and the secondary permanent magnet of the motor produce reciprocating relative motion, the coil cuts the magnetic induction line to produce electric energy, the alternating current is converted into direct current and stored in the battery after rectification control by the main control circuit board and the energy storage module 2. In the whole power generation process, the energy is directly converted from mechanical energy to electric energy by the linear generator, avoiding the energy loss caused by multi-stage energy conversion.

[0038] In the above power generation process, the back electromagnetic force control of the linear generator can be realized by the main control circuit board, and the device is equipped with motion information acquisition sensors such as grating rulers and acceleration sensors, which provides the possibility for wave information acquisition and wave energy related control algorithm to realize efficient capture of wave energy.

[0039] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application and not to limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the technical solutions of the application can still be modified or replaced by the same, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the application.

Claims

1. An in-line catamaran wave energy generator, characterised in that, The application relates to a sealed cabin shell which constitutes the outer float of the device, a slotless cylindrical permanent magnet linear generator whose secondary part is fixed inside the cabin shell, a primary part which is suspended inside the secondary part as a mover through a guide mechanism so that the primary part and the cabin shell can produce axial relative movement, a main control circuit and energy storage module for controlling the power generation process and storing electric energy, and the power generation device directly drives the linear generator to generate electricity through the relative movement between the cabin shell and the internal mover. The guide mechanism comprises at least two parallel spring guide rods and linear bearings; the linear bearings are installed on the end cover of the mover part of the generator and are sleeved on the spring guide rods; the two ends of the spring guide rods are fixedly connected to the end mounting seat which is fixed to the secondary part. At least one set of auxiliary springs is further included; the auxiliary springs are sleeved on the spring guide rods, and the two ends of the auxiliary springs respectively act on the end mounting seat and the mover end cover to provide restoring force for the mover. The auxiliary springs comprise two groups of compression springs with different stiffness coefficients and / or different free lengths; the lower end of the first group of springs is in contact with the upper end face of the lower mover end cover, and the upper end of the second group of springs is in contact with the lower end face of the upper mover end cover. The mover end cover is a split end cover with a cross structure and is matched with different groups of the spring guide rods and linear bearings.

2. The built-in two-body wave energy generator according to claim 1, characterized in that, The primary part of the slotless cylindrical permanent magnet linear generator comprises a slotless primary core and a winding coil which is pre-wound on a non-magnetic material winding frame; the winding frame and the winding coil are integrally sleeved on the primary core.

3. The built-in two-body wave energy generator according to claim 1, characterized in that, The cabin shell is a vertical cylindrical structure with equal cross-sectional areas.

4. The built-in two-body wave energy generator according to claim, characterized in that, A sensor for monitoring the motion state of the mover is further included; the sensor comprises a grating ruler for measuring relative displacement and an acceleration sensor for measuring acceleration.

5. The built-in two-body wave energy generator according to claim, characterized in that, The whole device is a fully-sealed structure and is fixed through long pull rods and lifting lugs.

6. The built-in two-body wave energy generator according to claim, characterized in that, ​ 7. The built-in two-body wave energy generator according to claim, characterized in that, axial length of the primary core optimized amount satisfies the formula: , and the value of is determined by the formula calculation; wherein, is the pole pitch, is an integer, n is the harmonic number, and are Fourier decomposition coefficients of the motor single end force to minimize the end force.

8. The built-in two-body wave energy generator according to claim, characterized in that, ​ 9. The built-in two-body wave energy generator according to claim, characterized in that, ​ 10. The internal two-body wave energy power plant according to any of claims 1-9, characterized in that, ​

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