Electromagnetic and Frictional Composite Energy Harvester

Abstract

The present invention discloses an electromagnetic and friction composite energy harvester, comprising: at least one energy harvesting mechanism; the energy harvesting mechanism includes a housing and at least one power generation mechanism; the housing includes an outer housing and an inner housing, and a receiving cavity is formed between the outer housing and the inner housing, and at least one power generation mechanism is arranged in the receiving cavity; the power generation mechanism includes an arc-shaped mass and at least one power generation component, the power generation component includes a coil, a folding spring and a magnet, the coil is arranged on the outer side wall of the inner housing, one end of the folding spring is connected to the inner side wall of the outer housing, at least one first friction material and at least one second friction material are arranged on the folding spring, the magnet faces the coil, the other end of the folding spring and the magnet can both move along with the arc-shaped mass, the contact and separation of the first friction material and the second friction material realize friction power generation, and the magnetic induction lines of the magnet cut the coil to realize electromagnetic power generation. The present invention realizes composite, multi-directional, multi-frequency and wide-band energy harvesting.

Description

Technical Field

[0001] The present invention relates to the technical field of energy harvesting, and particularly to an electromagnetic and triboelectric hybrid energy harvester. Background Art

[0002] Power transmission cables are the arteries of the power system, and their operating status directly affects the safety of the power system. Research scholars at home and abroad have devoted a great deal of effort to monitoring the operating status parameters of high-voltage cables. However, the power supply technology problem of these monitoring terminal devices has become a bottleneck restricting the development of this field. The monitoring terminal devices cannot be powered by traditional mains electricity because they are exposed to the outdoors for a long time.

[0003] At present, the main power supply methods for high-voltage cable condition monitoring terminal devices are solar cell power supply and battery power supply. Solar power generation technology is relatively mature, but it has high installation costs, difficult maintenance, and its performance is easily affected by natural conditions such as day and night, seasons, and geographical latitude. Although batteries have stable power supply performance and low prices, they have short battery life, frequent daily maintenance, and excessive additional costs. Research has also been conducted on the energy generated by cable vibration and magnetic fields at home and abroad. The energy conversion mechanisms used in related devices mainly include three forms: piezoelectric, electromagnetic, and nano-triboelectric. Piezoelectric energy conversion is achieved through the direct piezoelectric effect of piezoelectric materials. An external force causes strain in the piezoelectric material, resulting in a shift of charges inside the material, and opposite charges accumulate on the upper and lower surfaces, thus forming a potential difference to achieve power generation. The electromagnetic energy conversion mechanism is based on Faraday's law of electromagnetic induction. When there is a relative displacement between a magnet and a coil, the magnetic flux inside the coil will change, and an induced electromotive force can be generated at both ends of the coil at this time. The working principle of the nano-triboelectric energy conversion mechanism is that when an electron-rich material comes into contact with, separates from, or collides with an electron-losing material, the charges on the material surface transfer from the electron-losing material to the electron-rich material, and a current is generated through one of the materials passing through a metal electrode, thus achieving power generation.

[0004] Regarding the vibration energy and alternating magnetic field energy of transmission cables, existing energy harvesting devices have the problem of a single energy conversion mechanism, resulting in low conversion efficiency and difficult power storage. For example, the output characteristics of the electromagnetic energy conversion mechanism are low voltage and high current, while the output characteristics of the triboelectric energy conversion mechanism are high voltage and low current. In addition, the cable has a wide range of motion frequencies due to vibration and magnetic fields in the actual environment, while traditional energy harvesting devices have a single operating frequency and cannot achieve multi-directional and wide-band energy capture, resulting in low output power and difficulty in meeting the power requirements of cable condition monitoring terminal devices. In addition to the vibration energy generated by environmental factors, the cable itself will also generate magnetic field energy due to power transmission. Currently, the energy harvesting devices have not achieved synchronous composite harvesting of the two types of energy. Therefore, there is an urgent need to propose a high-density vibration energy harvester with a composite of multiple energy conversion mechanisms and broadband characteristics, which can be an important supplement to the existing technology. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an electromagnetic and triboelectric composite energy harvester.

[0006] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0007] An electromagnetic and triboelectric composite energy harvester, comprising:

[0008] At least one energy harvesting mechanism;

[0009] The energy harvesting mechanism includes a housing and at least one power generation mechanism;

[0010] The housing includes an outer housing and an inner housing, and a receiving cavity is formed between the outer housing and the inner housing, and the at least one power generation mechanism is disposed in the receiving cavity;

[0011] The power generation mechanism includes an arc-shaped mass block and at least one power generation component. The power generation component includes a coil, a folding spring, and a magnet. The coil is disposed on the outer sidewall of the inner housing of the housing. One end of the folding spring is connected to the inner sidewall of the outer housing. At least one first friction material and at least one second friction material are provided on the folding spring. The magnet faces the coil. The other end of the folding spring and the magnet can both move along with the arc-shaped mass block. The first friction material and the second friction material come into contact and separate to achieve triboelectric power generation, and the magnetic induction lines of the magnet cut the coil to achieve electromagnetic power generation.

[0012] As a further improvement of the present invention, the power generation mechanism further includes a sandwich shell, the outer sidewall of the sandwich shell is attached to the inner sidewall of the outer housing, and one end of the folding spring is connected to the inner sidewall of the sandwich shell.

[0013] As a further improvement of the present invention, the sandwich shell is arc-shaped.

[0014] As a further improvement of the present invention, the other end of the folding spring is connected to the magnet, and the magnet is connected to the outer side wall of the arc-shaped mass block.

[0015] As a further improvement of the present invention, at least one end of the outside of the housing is connected to at least one end of the inside of the housing by side plates.

[0016] As a further improvement of the present invention, both the outside and the inside of the housing are arc-shaped.

[0017] As a further improvement of the present invention, at least one support plate is provided at the edge of the outside of the housing, and mounting holes are provided on the support plate.

[0018] As a further improvement of the present invention, the power generation mechanism includes an arc-shaped mass block and two power generation components, and an included angle is formed between the axes of the two power generation components.

[0019] As a further improvement of the present invention, the energy harvesting mechanism includes a housing and at least two power generation mechanisms. The at least two power generation mechanisms are distributed along the axial direction of the housing, and the thickness of the folding springs and / or the sizes of the arc-shaped mass blocks of the at least two power generation mechanisms are different.

[0020] As a further improvement of the present invention, the folding spring includes a plurality of folding plates integrally folded, and the first friction material and the second friction material are respectively arranged on the opposite plate surfaces of two adjacent folding plates.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) When the cable vibrates under the influence of factors such as wind force, the arc-shaped mass block shakes, which can drive the folding spring and the magnet to move together. The folding spring is made of polyimide material, and a copper film and a polytetrafluoroethylene film are respectively attached to the folding spring. During the compression and stretching of the folding spring, nano-friction power generation is realized, and at the same time, magnetic induction lines cut the coil to realize electromagnetic power generation, thus constituting an electromagnetic-nano-friction composite energy conversion mechanism coupling to improve the output power of the energy harvester.

[0023] (2) By adjusting the thickness of the folding spring and the size of the arc-shaped mass block, the energy harvester can maintain high-efficiency energy capture under different frequency excitations. Each power generation mechanism uses a double folding spring and an array layout, which can realize multi-directional, multi-frequency, and wide-band energy harvesting.

[0024] (3) The power transmission cable will vibrate under the influence of environmental factors. The energy harvester can efficiently collect vibration energy through the internal folding spring and arc-shaped mass block. During the power transmission process, the power transmission cable will generate alternating magnetic field energy. The magnet can respond to the excitation of the alternating magnetic field and move relative to the coil to effectively collect magnetic field energy, realizing the multi-energy complementarity of vibration energy and electromagnetic field energy and achieving the high-power output of the energy harvester.

[0025] (4) By capturing environmental energy, the present invention converts the collected energy into electrical energy and supplies it to the cable condition monitoring terminal device, realizing the fully self-powered operation of the monitoring terminal device, which has important value for solving the power supply endurance bottleneck problem of the cable condition monitoring terminal device. This power supply technology can assist the cable condition monitoring terminal device to achieve long-term maintenance-free operation, greatly extend the equipment maintenance and recycling cycle, save labor costs, realize the all-weather effective perception of the cable operation state, provide technical support for the real-time perception and active early warning of the monitoring system, promote the intelligent upgrade of the equipment, improve the safety guarantee ability of the power grid, and promote the networking construction of the power grid monitoring equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 Structural schematic diagram of the energy collection mechanism of the preferred embodiment of the present invention;

[0028] Figure 2 Structural schematic diagram of the coil arranged inside the housing of the preferred embodiment of the present invention;

[0029] Figure 3 Structural schematic diagram of the power generation component and the sandwich housing of the preferred embodiment of the present invention;

[0030] Figure 4 Structural schematic diagram of the array arrangement of the low-frequency power generation mechanism, medium-frequency power generation mechanism, and high-frequency power generation mechanism of the preferred embodiment of the present invention;

[0031] Figure 5 Structural schematic diagram of the folding spring of the preferred embodiment of the present invention;

[0032] Figure 6 Structural schematic diagram of the energy harvester installed on the cable of the present invention;

[0033] Figure 7Structural schematic diagram of two energy harvesting mechanisms of the present invention before assembly;

[0034] Figure 8 Internal side view of the energy harvester of the preferred embodiment of the present invention installed on a cable;

[0035] In the figure: 1. Energy harvesting mechanism, 10. Housing, 101. Outer part of the housing, 102. Inner part of the housing, 103. Accommodation cavity, 104. Side plate, 105. Support plate, 106. Mounting hole, 201. Arc-shaped mass, 202. Coil, 203. Folding spring, 204. Magnet, 206. First friction material, 207. Second friction material, 210. Sandwich shell, 211. Folding plate, 21. Low-frequency power generation mechanism, 22. Medium-frequency power generation mechanism, 23. High-frequency power generation mechanism, 2. Cable. Specific embodiments

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Please refer to Figures 1 - 3 、 Figure 5 、 Figure 8 The embodiments of the present application disclose an electromagnetic and friction composite energy harvester, including:

[0038] At least one energy harvesting mechanism 1;

[0039] The energy harvesting mechanism 1 includes a housing 10 and at least one power generation mechanism;

[0040] The housing 10 includes an outer part 101 of the housing and an inner part 102 of the housing. An accommodation cavity 103 is formed between the outer part 101 of the housing and the inner part 102 of the housing, and at least one power generation mechanism is arranged in the accommodation cavity 103;

[0041] The power generation mechanism includes an arc-shaped mass 201 and at least one power generation component. The power generation component includes a coil 202, a folding spring 203, and a magnet 204. The coil 202 is arranged on the outer sidewall of the inner part 102 of the housing. One end of the folding spring 203 is connected to the inner sidewall of the outer part 101 of the housing. At least one first friction material 206 and at least one second friction material 207 are arranged on the folding spring 203. The magnet 204 faces the coil 202. The other end of the folding spring 203 and the magnet 204 can both move following the arc-shaped mass 201. The contact and separation of the first friction material 206 and the second friction material 207 realize friction power generation, and the magnetic induction lines of the magnet 204 cut the coil 202 to realize electromagnetic power generation.

[0042] When the energy collector vibrates under the influence of external factors, the arc-shaped mass 201 sways due to inertial force, and the folding spring 203 in the accommodation cavity 103 will be compressed and stretched accordingly. Since the electronegativities of the first friction material 206 and the second friction material 207 are different, during the compression and stretching process, the first friction material 206 and the second friction material 207 generate contact and separation movements to realize nano-friction power generation. At the same time, the magnet 204 will move together with the arc-shaped mass 201, and the magnetic induction lines of the magnet 204 cut the coil 202 to realize electromagnetic power generation.

[0043] To facilitate the installation of the power generation mechanism 20 in the housing 10, preferably, the power generation mechanism further includes an interlayer shell 210. The outer sidewall of the interlayer shell 210 is attached to the inner sidewall of the outer part 101 of the housing. One end of the folding spring 203 is connected to the inner sidewall of the interlayer shell 210. Preferably, the interlayer shell 210 is arc-shaped to facilitate a stable connection with one end of the folding spring 203.

[0044] In this embodiment, the other end of the folding spring 203 is connected to the magnet 204, and the magnet 204 is connected to the outer sidewall of the arc-shaped mass 201. It can be understood that the folding spring 203 and the magnet 204 can also be respectively arranged on the outer sidewall and the inner sidewall of the arc-shaped mass 201.

[0045] To facilitate the strength and stability of the connection between the outer part 101 of the housing and the inner part 102 of the housing, preferably, at least one end of the outer part 101 of the housing and at least one end of the inner part 102 of the housing are connected with side plates 104.

[0046] Preferably, both the outer shell 101 and the inner shell 102 are arc-shaped, which is convenient for installation on the cable, and they are evenly distributed along the cable, improving the smoothness of vibration and facilitating the stable realization of power generation at various frequencies subsequently. At the same time, the sandwich shell 210 is arc-shaped. Due to the limitation of the space of the accommodation cavity 103 formed between the outer shell 101 and the inner shell 102, one end of the folding spring 203 can be connected to the inner side wall of the sandwich shell 210 outside the accommodation cavity 103 first, which is convenient and fast. Since both the sandwich shell 210 and the outer shell 101 are arc-shaped, the outer diameter of the sandwich shell 210 is the same as the inner diameter of the outer shell 101, and the sandwich shell 210 and the outer shell 101 are in a mating shape, so that the sandwich shell 210 can be more quickly attached and fixed to the inner side wall of the outer shell 101, improving work efficiency.

[0047] To facilitate limiting the energy collector on the cable, preferably, at least one support plate 105 is provided at the edge of the outer shell 101, and an installation hole 106 is provided on the support plate 105.

[0048] In this embodiment, the power generation mechanism 20 includes an arc-shaped mass 201 and two power generation components, and an angle is formed between the axes of the two power generation components. Each power generation mechanism 20 pulls the arc-shaped mass 201 through two folding springs 203, improving the stability of the shaking of the arc-shaped mass 201, thereby improving the stability of the movement of the magnet 204 and the stability of the compression and stretching of the folding spring 203, improving the power generation performance. At the same time, an angle is formed between the axes of the two power generation components, facilitating the collection of energy in different directions. Preferably, the angle between the axes of the two power generation components is 90°, but it is not limited to 90° and can be adjusted as needed.

[0049] The energy collection mechanism 1 includes a housing 10 and at least two power generation mechanisms. The at least two power generation mechanisms are distributed along the axial direction of the housing 10, and the thickness of the folding spring 203 and / or the size of the arc-shaped mass 201 of the at least two power generation mechanisms are different. By adjusting the thickness of the folding spring 203 and / or the size of the arc-shaped mass 201, different characteristic frequencies can be achieved for each power generation mechanism. Under the external excitation of different frequencies, wide-band energy capture can be realized. At the same time, the folding spring 203, the magnet 204, and the coil 202 are all symmetrically arranged on the circumference, and at least two power generation mechanisms are arranged in an array, better realizing the efficient energy collection of different frequencies and different directions of the cable.

[0050] In this embodiment, the folding spring 203 includes a plurality of folding plates 211 integrally folded, and the first friction material 206 and the second friction material 207 are respectively arranged on the opposite plate surfaces of two adjacent folding plates 211. The thickness of the folding spring 203 refers to the thickness of the folding plates 211.

[0051] Taking the installation of this energy collector on the cable 2 as an example, the embodiments of the present invention will be further described. Please refer toFigures 6 - 8 , the energy harvester includes two energy harvesting mechanisms 1. When the two energy harvesting mechanisms 1 are assembled on the cable 2, the inner part 102 of the housing of the two energy harvesting mechanisms 1 wraps around the cable 2. The support plates 105 on the housings 10 of the two energy harvesting mechanisms 1 are butted, and are locked by bolts or screws passing through the two mounting holes 106 and cooperating with nuts, or locked by pins, so as to firmly fix the energy harvester on the cable 2. In order to better achieve multi-directional wide-band energy capture, the angle between the axes of the two coils 202 is 90°, the angle between the axes of the two folding springs 203 is 90°, and the angle between the axes of the two magnets 204 is 90°. As Figure 4 shown, three power generation mechanisms are provided, namely a low-frequency power generation mechanism 21, a medium-frequency power generation mechanism 22, and a high-frequency power generation mechanism 23. Among them, the thickness of the folding spring 203 of the low-frequency power generation mechanism 21 is 0.5 mm, and the sector angle of the arc-shaped mass block 201 is 180°. The thickness of the folding spring 203 of the medium-frequency power generation mechanism 22 is 0.75 mm, and the sector angle of the arc-shaped mass block 201 is 150°. The thickness of the folding spring 203 of the high-frequency power generation mechanism 23 is 1 mm, and the sector angle of the arc-shaped mass block 201 is 120°. The folding spring 203 is set to be folded from polyimide material, which has good wear resistance and is easy to bend, but is not limited to polyimide material, and can also be made of metal or plastic. The first friction material 206 is a copper film, and the second friction material 207 is a polytetrafluoroethylene film. It can be understood that the material of the folding spring 203, the thickness of the folding plate 211, and the number of folding plates 211 can all be adjusted as needed to improve the nano-friction power generation performance.

[0052] When the energy harvester is installed on the outdoor high-voltage cable 2 and the cable 2 is stationary during use, the folding spring 203 is in a free hanging state under the influence of the arc-shaped mass 201. When the cable 2 vibrates due to external natural forces, the arc-shaped mass 201 drives the folding spring 203 to compress and stretch under the action of inertia force. During this process, the polytetrafluoroethylene film and the copper film on the folding spring 203 produce contact-separation movement, realizing nano-friction power generation. The magnet 204 moves together with the arc-shaped mass 201, and at the same time, the folding spring 203 pulls the magnet 204 to make the magnet 204 move along its own axis, and the magnetic induction lines cut the coil 202 fixed inside the housing 102, realizing electromagnetic power generation, thus realizing nano-friction-electromagnetic hybrid power generation. The cable 2 will also generate an alternating magnetic field during power transmission. The magnet 204 is also affected by the magnetic field and moves. The folding spring 203 restricts the movement direction of the magnet 204 to keep the magnet 204 moving along its own axis, and the magnetic induction lines cut the coil 202 fixed inside the housing 102, realizing electromagnetic power generation. The energy harvester of the embodiment of the present invention collects the alternating magnetic field energy in the high-voltage cable 2 when there is no wind, and collects the vibration energy and the alternating magnetic field energy at the same time when there is wind, realizing the multi-energy complementarity of the vibration energy and the magnetic field energy of the cable 2.

[0053] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0054] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electromagnetic and friction composite energy harvester, characterized in that, Comprising: At least one energy harvesting mechanism; The energy harvesting mechanism includes a housing and at least one power generation mechanism; The housing includes an outer housing and an inner housing, and an accommodation cavity is formed between the outer housing and the inner housing, and the at least one power generation mechanism is arranged in the accommodation cavity; The power generation mechanism includes an arc-shaped mass and at least one power generation component. The power generation component includes a coil, a folding spring and a magnet. The coil is arranged on the outer side wall of the inner housing. One end of the folding spring is connected to the inner side wall of the outer housing. At least one first friction material and at least one second friction material are arranged on the folding spring. The magnet faces the coil. The other end of the folding spring and the magnet can both move along with the arc-shaped mass. The contact and separation of the first friction material and the second friction material realize friction power generation, and the magnetic induction lines of the magnet cut the coil to realize electromagnetic power generation.

2. The electromagnetic and frictional composite energy harvester according to claim 1, wherein The power generation mechanism further includes a sandwich shell, the outer side wall of the sandwich shell is attached to the inner side wall of the outer housing, and one end of the folding spring is connected to the inner side wall of the sandwich shell.

3. The electromagnetic and friction hybrid energy harvester according to claim 2, wherein, The sandwich shell is arc-shaped.

4. The electromagnetic and friction composite energy harvester according to claim 1, characterized in that, The other end of the folding spring is connected to the magnet, and the magnet is connected to the outer side wall of the arc-shaped mass.

5. The electromagnetic and friction composite energy harvester according to claim 1, characterized in that At least one end of the outer housing is connected to at least one end of the inner housing by side plates.

6. The electromagnetic and friction hybrid energy harvester according to claim 1, wherein, Both the outer housing and the inner housing are arc-shaped.

7. The electromagnetic and friction composite energy harvester according to claim 1, wherein At least one support plate is arranged at the edge of the outer housing, and mounting holes are arranged on the support plate.

8. The electromagnetic and friction composite energy harvester according to claim 1, characterized in that The power generation mechanism includes an arc-shaped mass and two power generation components, and an included angle is formed between the axes of the two power generation components.

9. The electromagnetic and friction hybrid energy harvester according to claim 1 or 8, characterized in that, The energy harvesting mechanism includes a housing and at least two power generation mechanisms. The at least two power generation mechanisms are distributed along the axial direction of the housing, and the thickness of the folding springs and / or the sizes of the arc-shaped masses of the at least two power generation mechanisms are different.

10. The electromagnetic and friction composite energy harvester according to claim 1, characterized in that, The folding spring includes a plurality of folding plates integrally folded, and the first friction material and the second friction material are respectively arranged on the opposite plate surfaces of two adjacent folding plates.

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