Overload self-tuning magnetic field energy collector

Abstract

The invention discloses an overload self-tuning magnetic field energy collector which comprises a packaging shell, a frame, bias magnets, an energy taking coil, a rotating device and a mechanical tuning device, the frame is installed in the packaging shell and serves as a framework to wind the energy taking coil, the bias magnets are arranged in grooves in the two sides of the packaging shell, the rotating device is arranged in the grooves, and the mechanical tuning device is arranged in the packaging shell. A rotating device is mounted in the frame; the mechanical tuning device is arranged on the outer side of the packaging shell, and a tuning magnet is arranged above the mechanical tuning device. According to the overload self-tuning magnetic field energy collector, a permanent magnet material is utilized, a magnetism gathering ring in a traditional current transformer is not needed, space magnetic field energy taking can be achieved, and installation and maintenance are more convenient; and due to the overload self-tuning design, the function of automatically adjusting the resonant frequency in the working process of the system can be realized, the damage to the bearing is reduced, the damage to the system caused by high-current impact can be avoided, and the working bandwidth of the system is effectively increased.

Description

Technical Field

[0001] The invention belongs to the technical field of space magnetic field energy capture, and in particular relates to an overload self-tuning magnetic field energy collector. Background Art

[0002] With the increasing popularity of the Internet of Things, wireless sensor networks have received more and more attention in power grid monitoring systems, but the power supply problem has always restricted the application and development of sensors. Traditional wireless sensor nodes are mainly powered by batteries, but the battery capacity is limited and difficult to replace and maintain, making it difficult to achieve normal deployment of large-scale sensor networks. In power application scenarios, stray magnetic fields with a frequency of 50Hz (<1mT or <10Oe) are widely distributed around transmission / distribution lines, providing a reliable energy source for wireless sensor nodes in smart grids.

[0003] The magnetic-mechanical-electric vibration energy harvester based on the cantilever beam structure is a new type of device commonly used to capture power frequency magnetic field energy. The magnetic-mechanical-electric vibration energy harvester has a simple structure, high output energy density, and high electromechanical conversion efficiency, but the working frequency band is narrow and the dynamic range is small, which makes it difficult to meet the mW-level power supply requirements. The magnetic field energy harvesting technology based on the principle of electromagnetic induction is currently the mainstream in the field of power sensing. According to the different deployment methods, there are two types: invasive and non-invasive: invasive energy harvesting is similar to conventional current transformers, with good coupling effect and high energy harvesting power, but poor operability and high subsequent maintenance costs. When installed on transmission lines on a large scale, it will bring additional mechanical stress to the transmission lines and cause line aging; non-invasive energy harvesting does not destroy the structure of the original system during installation, has good operability and low maintenance costs, but this method has low energy harvesting coupling coefficient and power, making it difficult to achieve stable power supply for wireless sensor nodes, and when the source current is too large, the closed magnetic ring structure will also cause problems such as core saturation and core overheating damage.

[0004] In 2017, researchers proposed a nonlinear resonant high-power industrial frequency magnetic energy harvester that can harvest up to 13.5mW of power in a 2.4Oe (RMS) industrial frequency AC magnetic field. However, the output Q value of this structure is high, which causes great damage to the bearings during operation. When the excitation magnetic field is too strong, the permanent magnet can easily rotate too much and cannot swing normally. In reality, when lightning, line short circuits, etc. cause transient current surges to exceed the rated value, the energy harvester itself and the electronic devices connected to its output port will also suffer catastrophic failures and damage due to the rapidly changing voltage / current.

[0005] Considering the limitations of existing energy harvesting technology, there is an urgent need for a high-power space energy harvesting technology and an overload self-tuning method to solve the problems of narrow working bandwidth of energy harvesters and easy damage of components under large current shocks. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the present invention proposes an overload self-tuning magnetic field energy collector.

[0007] The present invention adopts the following technical solution.

[0008] The present invention discloses an overload self-tuning magnetic field energy collector, comprising a packaging shell, a frame, a bias magnet, a rotating device and a mechanical tuning device, wherein grooves are arranged on both sides of the packaging shell, the frame is installed in the packaging shell, the bias magnet is arranged in the grooves on both sides of the packaging shell, and the rotating device is installed in the frame;

[0009] The rotating device comprises a permanent magnet and a guide rod, the permanent magnet is provided with a guide rod, and the guide rod abuts against the mechanical tuning device;

[0010] The mechanical tuning device includes a tuning magnet, which changes the size of the bias magnetic field applied to the rotating device by changing the number of bias magnets in the packaging shell. The mechanical tuning device changes the size of the bias magnetic field applied to the rotating device by changing the distance between the tuning magnet and the bias magnet, and is used for overload self-tuning of the system.

[0011] Preferably, the guide rod is fixed on the surface of the permanent magnet along the radial direction of the bottom circle of the permanent magnet.

[0012] Preferably, an energy extraction coil is wound around the outer periphery of the frame, and the energy extraction coil is wound around the frame using a surface-insulated copper wire.

[0013] Preferably, the rotating device further comprises a rotating shaft, the rotating shaft is longitudinally installed in the frame, and a permanent magnet is fixed on the outer periphery of the rotating shaft.

[0014] Preferably, the mechanical tuning device further comprises: a baffle and a crank;

[0015] The baffle is provided with a limiting groove, the crank is rotatably connected to one side of the baffle, and a cross bar is provided at one end of the crank, the cross bar is inserted into the limiting groove, and the other end of the crank is fixed with a tuning magnet.

[0016] Preferably, the crank includes a fixedly connected sleeve, a first arm and a second arm, the first arm and the second arm are located on both sides of the sleeve, the sleeve is rotatably connected to one side of the baffle, the end of the first arm can be slidably inserted into the limit groove, and the end of the second arm is fixed with the tuning magnet.

[0017] Preferably, the mechanical tuning device further comprises: a tuning magnet base, wherein the tuning magnet base is arranged below the tuning magnet and is used to fix the tuning magnet, and the tuning magnet interacts with the bias magnet to change the magnitude of the bias magnetic field applied to the rotating device.

[0018] Preferably, the mechanical tuning device also includes: a tube and a sliding device, the sliding device is slidably arranged in the tube in a horizontal direction, the tube is arranged on the packaging shell, one end of the sliding device abuts against the guide rod, and the other end abuts against the crank, the rotating device drives the sliding device to move through the guide rod, and the sliding device drives the position adjustment of the tuning magnet through the crank.

[0019] Preferably, a through hole is provided at the bottom of the packaging shell, and the through hole is used to cooperate with a fastener for fixing the magnetic field energy collector.

[0020] Preferably, the mechanical tuning device further comprises a slider, a through hole is arranged inside the slider, and one end of the sliding device passes through the through hole of the slider and abuts against the guide rod.

[0021] Preferably, the permanent magnet in the rotating device is in any one of a cylindrical, rectangular or polygonal shape.

[0022] The beneficial effect of the present invention is that, compared with the prior art,

[0023] (1) The overload self-tuning design of the magnetic field energy collector described in the present invention is provided with a permanent magnet, a rotating device and a mechanical tuning device. When the energy collector works at its resonant frequency of 50Hz, the nonlinear state is extremely strong under the impact of large current. In this state, the swing amplitude of the permanent magnet will increase with the increase of current. The permanent magnet drives the rotating device to interact with the mechanical tuning device, and the distance between the rotating device and the mechanical tuning device is changed to achieve the change of the resonant frequency of the energy collector, so that the energy collector returns to a state with a smaller swing amplitude in a non-resonant state, thereby achieving the purpose of overload self-tuning and protecting the overall structure; at the same time, due to the effect of gravity, the mechanical tuning device will return to the initial state in a clockwise circular motion after approaching the rotating device for a certain distance;

[0024] It utilizes the mechanical resonance of permanent magnetic materials under the action of torque to achieve energy conversion. It does not require the magnetic focusing ring in the traditional current transformer, can realize energy extraction from the spatial magnetic field, is more convenient for installation and maintenance, and can realize the function of automatically adjusting the resonance frequency of the system during operation, which not only reduces damage to the bearings, but also avoids damage to the system caused by large current shocks.

[0025] (2) The overload self-tuning method of the magnetic field energy harvester described in the present invention can suppress the nonlinear behavior of the system when it operates at the resonant frequency and can effectively increase the operating bandwidth of the system.

[0026] (3) The permanent magnetic material used in the overload self-tuning magnetic field energy harvester of the present invention has a high magnetization intensity and can generate sufficient driving force to achieve resonance under the excitation of a considerable volume and current. Near a 1A current-carrying conductor, the open circuit voltage of the energy harvesting device reaches 15V, and the matching load power reaches 1mW.

[0027] (4) The resonant frequency of the overload self-tuning magnetic field energy harvester described in the present invention can be adjusted by the position and size of the bias magnet, and resonance at 50 Hz can be easily achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0029] Figure 1 It is a schematic diagram of the overall structure of an overload self-tuning magnetic field energy collector according to the present invention;

[0030] Figure 2 It is a schematic diagram of the internal structure of an overload self-tuning magnetic field energy collector according to the present invention;

[0031] Figure 3 It is a schematic diagram of the overall structure of an overload self-tuning magnetic field energy collector using a rectangular permanent magnet according to the present invention;

[0032] Figure 4 It is a schematic diagram of the overall structure of an overload self-tuning magnetic field energy collector using a hexagonal permanent magnet according to the present invention;

[0033] Figure 5 It is a schematic diagram of the overall structure of an overload self-tuning magnetic field energy collector using a permanent magnet in the form of a combination of a polygon and a cylinder according to the present invention;

[0034] Figure 6 It is a schematic diagram of the overall structure of an overload self-tuning magnetic field energy collector with a crank angle of 90° according to the present invention;

[0035] Figure 7 The output effect comparison of the overload self-tuning magnetic field energy collector of the present invention and whether the overload self-tuning method is used;

[0036] Figure 8 It is a frequency sweep curve of an overload self-tuning magnetic field energy collector according to the present invention using an overload self-tuning method;

[0037] Fig. 9 It is a relationship diagram of the actual output voltage and energy extraction power and load next to the 1A wire of the present invention;

[0038] Fig.10 It is a schematic diagram of the principle of an overload self-tuning magnetic field energy collector according to the present invention, and is a top view of the energy collector;

[0039] Fig.11It is a front view of a principle schematic diagram of an overload self-tuning magnetic field energy collector according to the present invention;

[0040] In the figure: 1-power-carrying wire; 2-packaging shell; 3-frame; 4-bias magnet; 5-permanent magnet; 6-bearing No. 1; 7-rotating shaft; 8-energy extraction coil; 9-crank; 10-limiting groove; 11-horizontal rod; 12-slider; 13-guide rod; 14-tuning magnet base; 15-baffle; 16-cylinder; 17-through hole; 18-tuning magnet; 19-bearing No. 2. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0042] like Figure 1-2 As shown, the present invention provides an overload self-tuning magnetic field energy collector, including a packaging shell 2, a frame 3, a bias magnet 4, an energy extraction coil 8, a rotating device and a mechanical tuning device.

[0043] Among them, the packaging shell 2 is a rectangular box with grooves on both sides, the frame 3 is installed in the packaging shell 2, the frame 3 is used as a skeleton to wind the energy extraction coil 8, the bias magnet 4 is placed in the grooves on both sides of the packaging shell 2, and a rotating device is installed in the frame 3. The bias magnetic field applied to the rotating device can be changed by changing the number of bias magnets 4. The mechanical tuning device achieves the system overload self-tuning effect by changing the distance between the tuning magnet 18 and the bias magnet 4, that is, changing the size of the bias magnetic field applied to the rotating device.

[0044] The rotating device comprises a permanent magnet 5, a rotating shaft 7 and a guide rod 13. The rotating shaft 7 is longitudinally installed in the frame, the permanent magnet 5 is fixed on the outer periphery of the rotating shaft 7, and the guide rod 13 is fixed on the permanent magnet 5;

[0045] Specifically, the rotating device consists of a permanent magnet 5, two No. 1 bearings 6, a rotating shaft 7 and a guide rod 13, wherein the permanent magnet 5 is a cylindrical NbFeB material magnetized in the radial direction, and a through hole is set in the center of the cylinder; the rotating shaft 7 is fixed to the frame 3 through the No. 1 bearing 6, and is set in the through hole of the cylindrical permanent magnet 5 for tight fit; the guide rod 13 is fixed on the surface of the permanent magnet 5, along the radius of the bottom circle of the permanent magnet 5.

[0046] The frame 3 is used to install the No. 1 bearing 6 and serves as the skeleton of the energy extraction coil 8 .

[0047] In a preferred but non-limiting embodiment of the present invention, the energy harvesting coil 8 is tightly wound around the frame using surface-insulated copper wire, and the energy harvesting coil 8 can generate a signal output when the magnetic field in the environment excites the permanent magnet to resonate.

[0048] A groove for placing the bias magnet 4 is reserved on the packaging shell 2, and a mechanical tuning device is set up at one end, which includes a crank 9, a horizontal rod 11, a slider 12, a tuning magnet base 14, a baffle 15, a cylinder 16 and a tuning magnet 18; the horizontal rod 11 passes through the cylinder 16, and the slider 12 is fixedly pasted at one end close to the guide rod, the crank 9 is installed on the baffle 15, and a limiting groove 10 is set on the baffle 15, and the crank 9 is provided with two rods, one end of the lower rod passes through the limiting groove 10, and one end of the upper rod is fixed with a bias magnet base 14, and the bias magnet 4 is fixed on the bias magnet base.

[0049] Specifically, the mechanical tuning device is composed of a baffle 15, a tuning magnet base 14, a crank 9, a barrel 16, a tuning magnet 18, a No. 2 bearing 19, a horizontal rod 11 and a slider 12;

[0050] Among them, a limiting groove 10 is provided on the baffle 15, the No. 2 bearing 19 is installed on the baffle 15, the crank 9 is sleeved on the outer wheel of the No. 2 bearing 19 and the lower cross bar is inserted into the limiting groove 10, the No. 2 bearing 19 fixes the crank 9 outside, the tuning magnet base 14 on the upper cross bar is pasted with a tuning magnet 18, the horizontal rod 11 and the slider 12 constitute a sliding device, which is horizontally penetrated in the cylinder 16 on the packaging shell 2, one end of the sliding device abuts against the guide rod 13, and the other end abuts against the crank 9, the rotating device drives the sliding device to move through the guide rod 13, and the sliding device drives the position adjustment of the tuning magnet 18 through the crank 9.

[0051] More specifically, the crank 9 includes a fixedly connected sleeve, a first arm and a second arm, the first arm and the second arm are located on both sides of the sleeve, the sleeve is rotatably connected to one side of the baffle, the end of the first arm can be slidably inserted into the limiting groove 10, and the end of the second arm is fixed to the tuning magnet 10.

[0052] A through hole is provided inside the slider 12 , and one end of the sliding device passes through the through hole of the slider 12 and abuts against the guide rod 13 .

[0053] In a preferred but non-limiting embodiment of the present invention, the permanent magnet is radially magnetized, the bias magnetic field and the tuning magnetic field are provided by cylindrical or rectangular magnets, and both the bias magnet and the tuning magnet are magnetized along the thickness direction.

[0054] Further preferably, the permanent magnet, the bias magnet and the tuning magnet are all made of permanent magnetic materials, and the material is one of NdFeB, SmCo, AlNiCo and permanent ferrite.

[0055] The energy collector further comprises a through hole 17 for cooperating with a fastener for fixing the magnetic field energy collector.

[0056] In a preferred but non-limiting embodiment of the present invention, the No. 1 bearing 6 and the No. 2 bearing 19 may include one of the commonly used zirconia ceramics, plastics, bearing steel, stainless steel and low-carbon steel, and may also include other materials that are not easily magnetized, such as copper, aluminum, silver, etc.

[0057] The packaging shell, frame, rotating shaft, guide rod, slider, horizontal rod and crank are made by 3D printing technology or machined with aluminum alloy.

[0058] The resonant frequency of the overload self-tuning method of the overload self-tuning magnetic field energy collector described in the present invention is positively correlated with the applied bias magnetic field. When the energy collector works at its resonant frequency of 50Hz, the nonlinear state is extremely strong under large current impact. In this state, the swing amplitude of the permanent magnet will increase with the increase of current. After exceeding a certain angle, the guide rod 13 fixedly bonded to the permanent magnet 5 will collide with the slider 12 during the swinging process, applying a horizontal thrust to the slider 12, so that the slider 12 moves to the right together with the horizontal rod 11 fixedly connected to it. The horizontal rod 11 transmits force to the crank 9 during the movement. After the crank 9 is subjected to the force, it rotates counterclockwise. At the same time, the tuning magnet 18 at the upper end of the crank 9 is close to the rotating device of the energy collector, changing The size of the bias magnetic field of the energy collector has changed, that is, the resonant frequency of the energy collector has changed. At this time, the energy collector returns to a state with a smaller swing amplitude in a non-resonant state, so as to achieve the purpose of overload self-tuning and protection of the overall structure; at the same time, due to the effect of gravity, the tuning magnet 18 will return to the initial state in a clockwise circular motion after approaching the rotating device for a certain distance. During this process, the crank 9 exerts a clockwise circular motion on the horizontal rod 11 to the left, so that the horizontal rod 11 and the slider 12 fixed to it move horizontally to the left together, returning to the initial state before the guide rod 13 collides with the slider 12. As the slider 12, crank 9, etc. return to the initial position, the resonant frequency of the energy collector also returns to 50Hz. When faced with a persistent high current or a large current shock again, the mechanical tuning device of the energy collector will repeat the above process.

[0059] like Figure 3-5 As shown, in a preferred but non-limiting embodiment of the present invention, the permanent magnet 5 in the rotating device can be in the shape of a cylinder, a cuboid, a polygon, or a combination of the three, and is placed at the center of the rotating shaft 7.

[0060] The bias magnet 4 placed on the packaging shell 2 introduces a constrained magnetic torque to the energy collector, so that the permanent magnet 5 is always in a balanced position when there is no excitation magnetic field.

[0061] like Figure 6 As shown, the angle of the upper limit groove 10 on the baffle 15 and the included angle on the crank 9 can be changed according to specific conditions and requirements.

[0062] Embodiment 1:

[0063] The energy taking coil 8 is tightly wound with copper enameled wire with a diameter of 200 μm, with multiple layers and 500 turns.

[0064] The material of the permanent magnet 5 is the strongest grade of NdFeB magnet N52 available. The permanent magnet 5 is cylindrical with a through hole in the middle. The overall dimensions are: bottom diameter 14mm, height 19mm, and the diameter of the bottom center through hole is 7.1mm.

[0065] The materials of bearing No. 1 6 and bearing No. 2 19 are both made of zirconia ceramics, with an outer diameter of 10 mm, an inner diameter of 5 mm, and a height of 4 mm. The energy-taking coil 8 wound on the frame 3 is fixed with 502 glue.

[0066] The angle between the two rods on the crank 9 is 150°, and the initial position is as follows Figure 1 shown.

[0067] Taking the vertical symmetry axis of the baffle 15 as the 0° reference line, the angle of the limiting groove 10 is from -27° to 27°.

[0068] The packaging shell 2, the frame 3, the rotating shaft 7, the guide rod 13, the slider 12, the horizontal rod 11 and the crank 9 are manufactured by 3D printing technology or machined from aluminum alloy.

[0069] Figure 7 The output effect comparison between this embodiment and whether the overload self-tuning method is used is shown. It can be seen that the proposed overload self-tuning method has an obvious inhibitory effect on the nonlinear behavior of the energy harvester and can work stably under strong magnetic field excitation.

[0070] Figure 8 This is a frequency sweep curve measured by the overload self-tuning method in this embodiment, which illustrates that the mechanical tuning mechanism proposed in the present invention can effectively increase the working bandwidth of the system.

[0071] Fig. 9 1 is a graph showing the relationship between the output voltage and the energy extraction power of this embodiment at the 1A wire and the load. It can be seen from the graph that the peak-to-peak value of the open-circuit voltage is close to 10V; under a pure resistive load of 10kΩ, the optimal output power reaches 1.2mW.

[0072] The overload self-tuning magnetic field energy collector described in the present invention does not require the magnetic focusing ring in the traditional current transformer, and can realize space magnetic field energy extraction, which is more convenient for installation and maintenance; secondly, the residual magnetization intensity of the swinging permanent magnet material used is high, and under the excitation of a small current, it can generate sufficient driving force to achieve resonance, thereby reducing the starting current threshold of the traditional current transformer; in addition, the mechanical tuning mechanism of the energy collector can timely change the applied bias magnetic field when the excitation is overloaded, thereby realizing the self-tuning function.

[0073] In order to further improve the output power of the overload self-tuning magnetic field energy collector, multiple permanent magnet magnetic field energy collectors can be connected in parallel and arranged in a straight line around the wire. In order to solve the problem that the permanent magnet swings too much when the current is large, which easily leads to structural damage, the designed overload self-tuning method can automatically reduce the resonant frequency of the energy collector when the permanent magnet swings beyond a certain range. In addition, considering the working state of the energy collector and the errors in processing and installation, the overload self-tuning magnetic field energy collector will produce vertical vibrations, affecting the final energy extraction efficiency.

[0074] like Fig.11 As shown, the working principle of the overload self-tuning method of the overload self-tuning magnetic field energy harvester is: when the energy harvester is working, a DC bias magnetic field needs to be applied to it to provide a constrained magnetic torque on the permanent magnet so that the permanent magnet 5 is kept in a balanced position, such as Fig.10 At the horizontal dotted line position shown, when the energy collector is placed around the current-carrying conductor 1, the AC magnetic field generated around the current-carrying conductor 1 will apply an AC magnetic torque to the energy collector, and the torque mode excitation will be applied to the magnetic moment of the permanent magnet 5, causing the permanent magnet 5 to swing left and right around its equilibrium position. The equilibrium magnetization direction of the permanent magnet 5 in the energy collector is parallel to the plane of the energy collection coil 8, so that the relative movement between the permanent magnet 5 and the energy collection coil 8 is greater, and the cylindrical permanent magnet 5 makes the oscillating magnetic field stronger and more uniform. This design greatly improves the coupling effect between the coil and the oscillating magnetic field, and realizes the function of obtaining high output power at the output port of the coil.

[0075] As the coupling effect between the coil and the oscillating magnetic field in the energy collector increases, a large current shock will cause the permanent magnet 5 to swing too much, resulting in a sudden change in the output voltage / current of the energy harvesting device, and catastrophic failure and damage to the energy harvester itself and the electronic devices at its output port. To solve this problem, a mechanical tuning structure is added to the original framework. When the swing amplitude of the permanent magnet 5 exceeds a certain range, the tuning structure can automatically reduce the resonant frequency of the energy collector, that is, overload self-tuning, and this tuning method can also effectively increase the working bandwidth of the energy harvesting device.

[0076] The design idea of ​​the overload self-tuning method is as follows: According to existing research, the resonant frequency of the energy collector is positively correlated with the applied bias magnetic field. When the energy collector operates at a frequency of 50 Hz, the nonlinear state is extremely strong under large current impact. In this state, the swing amplitude of the permanent magnet exceeds a certain range and triggers the tuning mechanism to work. The tuning mechanism reduces the resonant frequency of the energy collector by reducing the size of the bias magnetic field, so that it returns to the state where the permanent magnet 5 swings with a smaller amplitude when it is non-resonant, thereby achieving the purpose of protecting the overall structure.

[0077] The present invention also provides a method for preparing an overload self-tuning magnetic field energy collector, comprising the following steps:

[0078] Step 1: Mechanical design: 3D print the packaging shell 2, frame 3, shaft 7, guide rod 13, slider 12, horizontal rod 11 and crank 9;

[0079] Step 2: Assemble the rotating device: Pass the rotating shaft 7 through the through hole in the center of the permanent magnet 5, connect the two ends of the rotating shaft 7 with the No. 1 bearing 6, and stick the guide rod 13 on the permanent magnet 5 to form a rotating device;

[0080] In a preferred but non-limiting embodiment of the present invention, step 2 specifically comprises:

[0081] Step 2.1: Pass the rotating shaft 7 through the through hole in the center of the rotating magnet, so that the permanent magnet 5 is located at its center, and use 502 or double-sided tape to tightly connect them;

[0082] Step 2.2: Assemble the rotating device consisting of the rotating shaft 7, the permanent magnet 5 and the No. 1 bearing 6, so that the rotating shaft 7 and the permanent magnet 5, and the rotating shaft 7 and the No. 1 bearing 6 are tightly connected;

[0083] Step 2.3: Use 502 glue to stick the guide rod 13 to the appropriate position on the permanent magnet 5.

[0084] Step 3: Assemble the mechanical tuning device: pass the horizontal rod 11 through the cylinder 16 and glue it together with the slider 12, connect the baffle 15 with the second bearing 19, connect the second bearing 19 with the crank 9, insert one end of the crank 9 into the limiting groove of the baffle 15, and glue and fix the tuning magnet 18 on the tuning magnet base 14 of the crank 9;

[0085] In a preferred but non-limiting embodiment of the present invention, step 3 specifically comprises:

[0086] Step 3.1: Pass the horizontal rod 11 through the cylinder 16 and fix it to the slider 12;

[0087] Step 3.2: Assemble the baffle 15, the second bearing 19 and the crank 9, so that the baffle 15 and the second bearing 19, the second bearing 19 and the crank 9 are tightly connected, and one end of the crank 9 is inserted into the limiting groove of the baffle 15;

[0088] Step 3.3: Paste and fix the tuning magnet 18 on the tuning magnet base 14 of the crank 9.

[0089] Step 4: Assemble the energy collector: install and fix the rotating device in the frame 3, set the mechanical tuning device on one side of the rotating device, evenly wind the energy harvesting coil 8 on the frame 3, install the packaging shell 2 outside the frame 3 with the energy harvesting coil 8 wound around it, place the bias magnet 4 on both sides of the packaging shell 2, and finally fix the entire device through the through hole 17 to form a magnetic field energy collector.

[0090] The beneficial effect of the present invention is that, compared with the prior art,

[0091] (1) The present invention discloses an overload self-tuning magnetic field energy collector, which is provided with a permanent magnet, a rotating device and a mechanical tuning device. When the energy collector operates at its resonant frequency of 50 Hz, the nonlinear state is extremely strong under the impact of a large current. In this state, the swing amplitude of the permanent magnet increases with the increase of the current. The permanent magnet drives the rotating device to interact with the mechanical tuning device, and changes the distance between the rotating device and the mechanical tuning device to achieve the change of the resonant frequency of the energy collector, so that the energy collector returns to a state with a smaller swing amplitude in a non-resonant state, thereby achieving the purpose of overload self-tuning and protecting the overall structure; at the same time, due to the effect of gravity, the mechanical tuning device will return to the initial state in a clockwise circular motion after approaching the rotating device for a certain distance;

[0092] It utilizes the mechanical resonance of permanent magnetic materials under the action of torque to achieve energy conversion. It does not require the magnetic focusing ring in the traditional current transformer, can realize energy extraction from the spatial magnetic field, is more convenient for installation and maintenance, and can realize the function of automatically adjusting the resonance frequency of the system during operation, which not only reduces damage to the bearings, but also avoids damage to the system caused by large current shocks.

[0093] (2) The overload self-tuning method of the magnetic field energy harvester described in the present invention can suppress the nonlinear behavior of the system when it operates at the resonant frequency and can effectively increase the operating bandwidth of the system.

[0094] (3) The permanent magnetic material used in the overload self-tuning magnetic field energy harvester of the present invention has a high magnetization intensity and can generate sufficient driving force to achieve resonance under the excitation of a considerable volume and current. Near a 1A current-carrying conductor, the open circuit voltage of the energy harvesting device reaches 15V, and the matching load power reaches 1mW.

[0095] (4) The resonant frequency of the overload self-tuning magnetic field energy harvester described in the present invention can be adjusted by the position and size of the bias magnet, and resonance at 50 Hz can be easily achieved.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An overload self-tuning magnetic field energy harvester, characterized in that: The invention comprises a packaging shell (2), a frame (3), a bias magnet (4), a rotating device and a mechanical tuning device, wherein grooves are arranged on both sides of the packaging shell (2), the frame (3) is installed in the packaging shell (2), the bias magnet (4) is arranged in the grooves on both sides of the packaging shell (2), and the rotating device is installed in the frame (3); The rotating device comprises a permanent magnet (5) and a guide rod (13), the permanent magnet (5) is provided with a guide rod (13), and the guide rod (13) abuts against the mechanical tuning device; The mechanical tuning device comprises a tuning magnet (18), and the magnitude of the bias magnetic field applied to the rotating device is changed by changing the number of bias magnets (4) in the packaging shell (2). The mechanical tuning device changes the magnitude of the bias magnetic field applied to the rotating device by changing the distance between the tuning magnet (18) and the bias magnet (4), and is used for overload self-tuning of the system.

2. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The guide rod (13) is fixed on the surface of the permanent magnet (5) along the radial direction of the bottom circle of the permanent magnet (5).

3. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: An energy extraction coil (8) is wound around the outer periphery of the frame (3), and the energy extraction coil (8) is wound around the frame using a surface-insulated copper wire.

4. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The rotating device also includes a rotating shaft (7), the rotating shaft (7) is longitudinally installed in the frame (3), and a permanent magnet (5) is fixed on the outer periphery of the rotating shaft (7).

5. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The mechanical tuning device further comprises: a baffle (15) and a crank (9); The baffle (15) is provided with a limiting groove (10), the crank (9) is rotatably connected to one side of the baffle (15), and a cross bar is provided at one end of the crank (9), and the cross bar is inserted into the limiting groove (10); the other end of the crank (9) is fixed with a tuning magnet (18).

6. The overload self-tuning magnetic field energy harvester according to claim 5, characterized in that: The crank (9) comprises a fixedly connected sleeve, a first arm and a second arm, wherein the first arm and the second arm are located on both sides of the sleeve, the sleeve is rotatably connected to one side of the baffle, the end of the first arm can be slidably inserted into the limiting groove (10), and the end of the second arm is fixed with a tuning magnet (18).

7. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The mechanical tuning device further comprises: a tuning magnet base (14), wherein the tuning magnet base (14) is arranged below the tuning magnet (18) and is used to fix the tuning magnet (18), wherein the tuning magnet (18) interacts with the bias magnet (4) to change the magnitude of the bias magnetic field applied to the rotating device.

8. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The mechanical tuning device further comprises: a cylinder (16) and a sliding device, wherein the sliding device is slidably arranged in the cylinder (16) in a horizontal direction, the cylinder (16) is arranged on the packaging shell (2), one end of the sliding device abuts against the guide rod (13), and the other end abuts against the crank (9), the rotating device drives the sliding device to move through the guide rod (13), and the sliding device drives the position adjustment of the tuning magnet (18) through the crank (9).

9. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: A through hole (17) is provided at the bottom of the packaging shell (2), and the through hole (17) is used to cooperate with a fastener for fixing the magnetic field energy collector.

10. The overload self-tuning magnetic field energy harvester according to claim 8, characterized in that: The mechanical tuning device also includes a slider (12), a through hole is provided inside the slider (12), and one end of the sliding device passes through the through hole of the slider (12) and abuts against the guide rod (13).

11. The overload self-tuning magnetic field energy harvester according to claim 1, characterized in that: The shape of the permanent magnet (5) in the rotating device is any one of a cylindrical shape, a rectangular parallelepiped shape and a polygonal shape.

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