A high power density energy harvesting device for marine unmanned equipment

Abstract

The application relates to the technical field of wave energy collection and ocean wave energy collection, and discloses a high-power-density energy collection device for ocean unmanned equipment, which comprises a coil fixing device, a central pendulum body and a swing track, the swing track is fixedly arranged on a cabin body or a base of the ocean unmanned equipment, the central pendulum body is movably connected to the track, an electromagnetic conversion unit is arranged in the central pendulum body and comprises a pure iron core, a magnet and a coil, the magnet is arranged on the pure iron core, the coil is fixed by a coil positioning plate of the coil fixing device and arranged in the middle of the magnet, and the two ends of the coil fixing device are mounted on the swing track. The structure that the rolling track cooperates with the central pendulum body is adopted, the problems of wasted movement space and insufficient energy capture are overcome, and the dual requirements of built-in demand in a narrow and closed space and matching with low-frequency excitation of waves are met.

Description

Technical Field

[0001] This invention relates to the field of wave energy harvesting and ocean wave energy harvesting technology, specifically to a high power density energy harvesting device for marine unmanned equipment. Background Technology

[0002] With the continuous growth of marine resource development and maritime activities, various types of unmanned marine equipment (such as unmanned surface vessels, unmanned buoys, marine observation nodes, and surface / underwater robots) are widely used in marine environmental monitoring, target detection, communication relay, and emergency rescue. These devices typically need to operate continuously for extended periods in unmanned or inaccessible sea areas, placing higher demands on their sensors, communication modules, and control systems for a stable and reliable energy supply. Traditional methods relying on disposable batteries or single solar power sources are limited by battery capacity, solar radiation conditions, and factors such as sea surface winds and obstructions, making it difficult to reliably meet the energy needs of unmanned marine equipment under long-term, continuous, and complex sea conditions. Furthermore, the costs of frequent maintenance and power supply replacements are high.

[0003] Ocean waves, as a widely available renewable environmental energy source, possess high energy density and exhibit diurnal continuity, thus wave vibration energy harvesting technology has received widespread attention in recent years. Among existing wave energy harvesting methods, large floating pontoon or oscillating water column devices, while capable of outputting significant power in nearshore or fixed platforms, suffer from large overall structural volume, complex mechanical construction, high cost, and stringent requirements for installation environment and sea conditions, making them unsuitable for direct integration into the hull or cabin of small marine unmanned equipment. Research on vibration energy harvesting for small devices has proposed various micro / miniature vibration energy harvesters based on piezoelectric, electromagnetic, and capacitive mechanisms. These devices have relatively simple structures and are easily miniaturized, but their individual output power is generally low, making them more suitable for low-power applications at the milliwatt level or below. They remain significantly insufficient for marine unmanned platforms requiring medium or even higher power levels.

[0004] In the field of electromagnetic pendulum vibration energy harvesting, existing devices often employ pendulum structures with relatively long pendulum rods to adapt to the low-frequency marine environment. By increasing the pendulum length, the natural frequency of the system is lowered to match the low-frequency excitation characteristics of ocean waves, thereby achieving relatively stable energy output under typical sea conditions. However, when such long pendulum structures are arranged in a closed chamber, issues such as limited effective travel and difficulty in participating in energy conversion in certain areas can arise.

[0005] Furthermore, existing electromagnetic vibration energy harvesters also have limitations in terms of magnetic circuit design and winding topology. Some devices have relatively simple permanent magnet arrangements and coil layouts, with magnetic circuits often being partially open or unoptimized. Magnetic flux is dispersed in the air gap, resulting in high air gap magnetic reluctance and low effective flux change rate and electromagnetic conversion efficiency. In terms of coil design, the winding topology has not been systematically reconstructed in conjunction with the spatial magnetic field distribution, leading to insufficient capture of usable magnetic flux per unit volume and difficulty in further improving power density. These problems are particularly prominent in marine unmanned equipment with limited volume and mass that requires medium to high power output: on the one hand, the device must be able to be arranged in a small, enclosed space and adapted to low-frequency wave excitation; on the other hand, it must achieve high electromagnetic power output under limited volume and mass conditions.

[0006] Therefore, there is an urgent need for an electromagnetic vibration energy harvesting device that can be deployed in a small, enclosed space, adapt to low-frequency excitation of ocean waves, and has both high power density and high electromagnetic conversion efficiency. This would solve the problems of low space utilization and insufficient energy capture of traditional pendulum structures, as well as the limited efficiency and power density of traditional electromagnetic conversion units, and better meet the urgent need of marine unmanned equipment for long-term, reliable, and autonomous power supply. Summary of the Invention

[0007] To address the technical problems of existing technologies, such as low utilization of movement space, insufficient energy capture, and limited efficiency and power density of traditional electromagnetic conversion units, this invention proposes a high-power-density energy harvesting device for marine unmanned equipment. The technical solution is as follows:

[0008] It includes: a coil fixing device, a central pendulum body, and a swing track. The swing track is fixedly installed on the hull or base of the marine unmanned equipment. The central pendulum body is movably connected to the track. An electromagnetic conversion unit is installed inside the central pendulum body. The electromagnetic conversion unit includes a pure iron core, a magnet, and a coil. The magnet is installed on the pure iron core. The coil is fixed by the coil positioning plate of the coil fixing device and is located in the middle of the magnet. The two ends of the coil fixing device are installed on the swing track.

[0009] Furthermore, the magnet of the electromagnetic conversion unit is a permanent magnet, which is fixed to the pure iron core by a threaded connection. The pure iron core is rounded and has threaded holes machined.

[0010] Furthermore, multiple sets of electromagnetic conversion units are connected in series within the central pendulum body. The magnetic poles of the magnets in each set of electromagnetic conversion units are in the same direction, while the magnetic poles of the magnets in adjacent sets of electromagnetic conversion units are in opposite directions. Each electromagnetic conversion unit is positioned and isolated by an upper isolation positioning block and a lower isolation positioning block.

[0011] Furthermore, the coils in the multiple sets of electromagnetic conversion units are connected in series, with the ends connected, and a coil winding topology is adopted.

[0012] Furthermore, the central pendulum body is provided with a fixed side plate, which is installed on both sides of multiple sets of electromagnetic conversion units for fixation, and its bottom is movably connected to the swing track by a rolling bearing.

[0013] Furthermore, the rolling bearing includes a bullseye bearing, a zirconia bearing, and a support shaft.

[0014] Furthermore, the shape of the swing track includes a ring, an arc, or a composite spatial curve structure.

[0015] Furthermore, the device is equipped with multiple central pendulum bodies, which are connected in parallel or series to form an array arrangement.

[0016] Furthermore, the coil fixing device integrates an energy management module, including a rectifier circuit, a filter circuit, a DC-DC converter circuit, and an energy storage unit.

[0017] Beneficial effects

[0018] This invention overcomes the problems of wasted motion space and insufficient energy capture in traditional pendulum structures by eliminating the pendulum rod of traditional pendulum energy harvesters and adopting a structure that combines a rolling track with a central pendulum body. It meets the dual requirements of being built into a confined space and matching low-frequency wave excitation. Through optimized magnetic circuit design and winding configuration, it achieves directional concentration of magnetic field lines and minimizes air gap magnetic reluctance. The proposed rolling track pendulum structure has excellent spatial adaptability and motion flexibility. The combination of bullseye bearings and zirconia bearings achieves low-friction, high-reliability rolling motion, maintaining stable energy output performance, especially in complex sea conditions and long-term unmanned environments. This invention can be integrated with the hull structure of marine unmanned equipment. Through modular design, multiple energy harvesting units can be flexibly configured. Combined with efficient energy management circuitry, it provides enormous application potential for achieving autonomous power supply and long-term continuous operation of marine unmanned equipment. Attached Figure Description

[0019] Figure 1 A schematic diagram of the overall structure of a high-power-density energy harvesting device for marine unmanned equipment;

[0020] Figure 2 This is a schematic diagram of the electromagnetic conversion unit in the central pendulum.

[0021] Figure 3 This is a schematic diagram of the axial side view of the electromagnetic conversion unit in the central pendulum.

[0022] Figure 4This is a cross-sectional view of the central pendulum.

[0023] Figure 5 This is a schematic diagram of the rolling bearing arrangement of the device of the present invention;

[0024] Figure 6 This is a flowchart of the finite element analysis process for the device of the present invention;

[0025] Figure 7 This is a schematic diagram of the magnetic flux density mode finite element simulation of the device of the present invention.

[0026] The meanings of the labels in the attached figures are as follows: 1-coil fixing device, 2-central pendulum body, 3-swing track, 4-pure iron core, 5-magnet, 6-coil, 7-fixed side plate, 8-upper isolation positioning block, 9-lower isolation positioning block, 10-coil positioning plate, 11-bullseye bearing, 12-zirconia bearing, 13-support shaft. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, the high power density energy harvesting device for marine unmanned equipment of the present invention includes a coil fixing device 1, a central pendulum body 2, and a swing track 3. The swing track 3 is fixedly installed on the cabin or base of the marine unmanned equipment, and the central pendulum body 2 is movably connected to the track. The two ends of the coil fixing device 1 are installed on the swing track 3.

[0029] The central pendulum 2 can roll and swing along the swing track 3 in a plane, and an electromagnetic conversion unit is installed inside it, such as... Figure 2 and Figure 3 As shown, it includes a pure iron core 4, a magnet 5, and a coil 6. The magnet 5 consists of two permanent magnets with the same magnetic direction, which are fixed to the upper and lower pure iron cores 4 respectively and are fixed by threaded connection. The pure iron core 4 needs to be rounded and threaded holes are machined to optimize the magnetic conductivity and facilitate assembly.

[0030] like Figure 4As shown, the central pendulum 2 contains an electromagnetic conversion unit consisting of six sets of magnets 5, pure iron cores 4, and coils 6. In each set of electromagnetic conversion units, the magnetic poles of the upper and lower magnets 5 are in the same direction, while the magnetic poles of the magnets 5 in adjacent sets of electromagnetic conversion units are in opposite directions. This spatial arrangement of permanent magnets achieves directional concentration of magnetic field lines within the effective cutting area, making the magnetic flux distribution more concentrated, significantly reducing air gap magnetic resistance, and improving magnetic circuit utilization. The coils 6 are connected in series end-to-end and fixed by coil positioning plates 10. This reconfiguration design of the coil winding topology achieves a larger effective magnetic flux change rate and output voltage within a limited space, significantly improving electromagnetic conversion efficiency and power density. The pure iron cores 4 are positioned and isolated by upper and lower isolation positioning blocks 8 and 9, with a total of five isolation positioning blocks. These isolation positioning blocks not only serve a positioning function but also optimize the magnetic circuit structure, reduce magnetic flux leakage, and further improve electromagnetic conversion efficiency. The six sets of electromagnetic conversion units are fixed by threaded connections through two side plates 7.

[0031] like Figure 5 As shown, the central pendulum 2 is connected to the swing track 3 by a bullseye bearing 11, a zirconia bearing 12, and a support shaft 13 via a threaded connection, and they roll together. The design of the bullseye bearing 11 and the zirconia bearing 12 can effectively reduce rolling resistance and improve energy conversion efficiency, while also having good corrosion resistance to meet the long-term operation requirements of the marine environment.

[0032] When the device is subjected to lateral excitation, the coil fixing device 1 and the swing track 3 remain relatively stationary, and the central pendulum 2 rolls along the swing track 3. Due to the gravity and inertia characteristics of the central pendulum 2, it will generate a large restoring torque after being excited, causing the central pendulum 2 to roll back and forth relative to the swing track 3, thereby generating relative motion between the magnet 5 and the coil 6. The coil 6 cuts the magnetic lines of force to generate an induced electromotive force, realizing the collection and conversion of vibration energy.

[0033] Furthermore, by optimizing the total mass and geometric parameters of the central pendulum 2 and the radius of curvature of the swing track 3, the present invention can match the equivalent natural frequency of the device under typical sea conditions with the low-frequency excitation of ocean waves. Under the premise of ensuring a compact structure and enclosed installation, it can achieve high power density vibration energy harvesting. On this basis, the swing track 3 of the present invention can be a ring, bow-shaped or composite spatial curve structure to adapt to wave excitation in different directions and achieve multi-degree-of-freedom equivalent response. The central pendulum 2 can be configured in multiples to form an array arrangement, which can be connected in parallel or series to further improve the total output power and directional adaptability.

[0034] To achieve high power output in the energy harvester, this invention requires parameter co-optimization of the core magneto-electric coupling components. Given the strongly coupled nonlinear electromagnetic field problem caused by the distribution of the magnet-coil array on a circular arc surface, traditional analytical methods struggle to accurately solve its transient response characteristics. Therefore, the finite element method (FEM), capable of handling complex geometry and multiphysics coupling, is employed. Based on the multiphysics simulation platform COMSOL Multiphysics, its parametric scanning and optimization modules automatically explore the design space. Finally, a three-dimensional electromagnetic characteristic simulation analysis of the designed high-power-density energy harvesting device is performed, such as... Figure 6 As shown, the technical process includes: model building, setting boundary conditions and parameters, mesh generation, analysis and solution, convergence judgment, correction and iteration.

[0035] To intuitively evaluate the electromagnetic characteristics of the energy harvesting device, this invention first imports a 3D model of the energy harvesting device drawn in Solidworks into COMSOL Multiphysics. Material properties are configured for pure iron DT4, air, coils, and magnets. Next, the solution boundary region is drawn, the current excitation direction is set, the parameter analysis steps are defined, and then meshing is performed. A transient simulation of the static magnetic field is then conducted to obtain the magnetic field cross-sectional distribution, such as... Figure 7 As shown.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-power-density energy harvesting device for marine unmanned equipment, characterized in that, include: The device includes a coil fixing device (1), a central pendulum (2), and a swing track (3). The swing track (3) is fixedly installed on the hull or base of the marine unmanned equipment. The central pendulum (2) is movably connected to the track. An electromagnetic conversion unit is installed inside the central pendulum (2). The electromagnetic conversion unit includes a pure iron core (4), a magnet (5), and a coil (6). The magnet (5) is installed on the pure iron core (4). The coil (6) is fixed by the coil positioning plate (10) of the coil fixing device (1) and is installed in the middle of the magnet (5). The two ends of the coil (6) fixing device (1) are installed on the swing track (3).

2. The high power density energy harvesting device for marine unmanned equipment as described in claim 1, characterized in that: The magnet (5) of the electromagnetic conversion unit is a permanent magnet, which is fixed to the pure iron core (4) by a threaded connection. The pure iron core (4) is rounded and has threaded holes.

3. The high power density energy harvesting device for marine unmanned equipment as described in claim 1, characterized in that: Multiple sets of electromagnetic conversion units are connected in series inside the central pendulum (2). The magnetic poles of the magnets (5) in each set of electromagnetic conversion units are in the same direction. The magnetic poles of the magnets (5) in two adjacent sets of electromagnetic conversion units are in opposite directions. Each electromagnetic conversion unit is positioned and isolated by the upper isolation positioning block (8) and the lower isolation positioning block (9).

4. The high power density energy harvesting device for marine unmanned equipment as described in claim 3, characterized in that: The coils (6) in the multiple electromagnetic conversion units are connected in series, with the coil winding topology.

5. The high power density energy harvesting device for marine unmanned equipment as described in claim 3, characterized in that: The central pendulum (2) is provided with a fixed side plate (7), which is installed on both sides of multiple electromagnetic conversion units for fixation. Its bottom is movably connected to the swing track (3) by a rolling bearing.

6. The high power density energy harvesting device for marine unmanned equipment as described in claim 5, characterized in that: The rolling bearing includes a bullseye bearing (11), a zirconia bearing (12), and a support shaft (13).

7. The high power density energy harvesting device for marine unmanned equipment as described in claim 1, characterized in that: The shape of the swing track (3) includes a ring, an arc or a composite spatial curve structure.

8. The high power density energy harvesting device for marine unmanned equipment as described in claim 1, characterized in that: The device is equipped with multiple central pendulum bodies (2), which are connected in parallel or series to form an array arrangement.

9. The high power density energy harvesting device for marine unmanned equipment as described in claim 1, characterized in that: The coil fixing device (1) integrates an energy management module, including a rectifier circuit, a filter circuit, a DC-DC converter circuit, and an energy storage unit.

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