A self-powered intelligent spacer based on dancing energy harvesting

Abstract

A self-powered intelligent spacer based on galloping energy harvesting. The vibration energy harvester is embedded inside the double pendulum anti-galloping device and is responsible for converting the mechanical energy generated by galloping into electrical energy. The energy management circuit, through a matching circuit, boosts the output power and then rectifies and steps up the voltage to store the energy in the energy storage element for use by the force monitoring system and the data interconnection terminal. The stress module of the intelligent monitoring system deposits the dielectric printing substrate, capacitive flexible strain electrodes, and the protective layer at the connection between the connecting rod and the body frame through aerosol printing. The force condition at the center of the connecting rod is converted into an electrical signal and transmitted to the data interconnection module. The data interconnection module realizes the interconnection and communication between each spacer and between the spacer and the intelligent power grid terminal through a low-power communication chip. The data is uploaded to the cloud platform through the intelligent power grid terminal, realizing the cloud monitoring of the line status. The present invention adopts an integrated intelligent manufacturing technology, with a high degree of integration, a high strain coefficient of the strain gauge, low hysteresis, and high stability.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent power grid monitoring technology, and particularly relates to the field of conductor galloping monitoring technology. Specifically, it is a self-powered intelligent spacer based on galloping energy harvesting. Background Art

[0002] The stability of power transmission plays a crucial role in the development of modern intelligent power grids. Under special meteorological conditions such as strong winds and icing, high-voltage overhead transmission lines will generate a low-frequency and large-amplitude galloping phenomenon. This phenomenon will cause fatigue broken strands of the line and damage to fittings, seriously affecting the power supply safety. Traditional spacers only suppress the galloping phenomenon and do not have the function of intelligent monitoring.

[0003] To achieve a smart power grid, it is necessary to rely on stable, high-quality, and reliable information sensing technology and low-voltage DC drive chips. The traditional power supply methods for transmission line sensors mainly include solar power supply, battery power supply, and mutual inductance power extraction. However, these power extraction methods have problems such as being greatly affected by environmental factors, the need for frequent maintenance and replacement of batteries, and high costs.

[0004] At the same time, for existing line galloping monitoring technologies, the first type relies on cameras at both ends of high-voltage towers, which is greatly affected by weather and difficult to function under bad weather. At the same time, it lacks the ability to detect minor equipment failures such as damage to the single-strand connecting rod of the spacer. The second type of discrete galloping sensors can achieve all-weather and all-round automatic monitoring. However, they are generally installed independently on single-strand conductors, which will cause damage to the conductors, increase additional costs and line burdens, and cannot monitor spacer damage. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in high-voltage power extraction and spacer intelligent monitoring technologies in the prior art. The present invention proposes a self-powered intelligent spacer based on galloping energy harvesting, which can monitor the stress condition of the spacer without additional power supply, and then reflect the galloping condition of the line. At the same time, it has a double-pendulum anti-galloping hammer. The design of the slow-star-shaped slow-damping energy collection device plays a certain role in anti-galloping. The capacitive strain gauge can collect data quickly and accurately, and the application of aerosol technology makes it more conformable to the surface of the main frame, with high durability. Data interconnection and relay transmission can also be achieved between spacers, reducing the data transmission distance, reducing the transmission energy consumption, and ensuring the reliability of line galloping data.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A self-powered intelligent spacer dampener based on galloping energy harvesting, comprising a pair of cantilevered magnetostrictive composite material vibration energy harvesters, a double pendulum anti-galloping device, a main circuit, a flexible RF antenna, a spacer dampener body, a slow star-shaped slow damping energy collection device, a stress sensor, a connecting rod, a crab-claw bionic wire clamp, a connecting bracket, a vibration monitoring sensor, and a star-shaped slow damping energy collection device. The two cantilevered magnetostrictive composite material vibration energy harvesters are respectively embedded in the cavities of the two connecting rods of the double pendulum anti-galloping device, and are rectified, boosted, and stored through the energy management system of the main circuit. The spacer dampener body is connected to the double pendulum anti-galloping device through a connecting bracket. The stress sensor and the vibration monitoring sensor are located on the surface of the end of the double pendulum anti-galloping device, are encoded through the data processing part of the main circuit, and communicate data through the flexible RF antenna. The main circuit and the flexible RF antenna are located on the connecting bracket. Each node of the spacer dampener body has a slow star-shaped slow damping energy collection device and is connected to the crab-claw bionic wire clamp through a connecting rod. The star-shaped slow damping energy collection device is arranged at the center of the spacer dampener body and is connected to each node of the spacer dampener body.

[0008] As a further improvement of the present invention, the cantilevered magnetostrictive composite material vibration energy harvester comprises a pendulum weight, an alloy thin sheet, a pick-up coil, a pre-magnetized permanent magnet, and a connecting screw. The cantilevered magnetostrictive composite material vibration energy harvester is embedded in the cavity of the corresponding connecting rod of the double pendulum anti-galloping device through the connecting screws at both ends. There is a pendulum weight in the shell at the end of the double pendulum anti-galloping device. One end of the alloy thin sheet is fixed to the connecting screw in a cantilever manner, and the other end corresponds to the pendulum weight. There is a pre-magnetized permanent magnet at each end of the alloy thin sheet. There is a pick-up coil in the cavity of the connecting rod of the double pendulum anti-galloping device, and the alloy thin sheet is inside the pick-up coil.

[0009] As a further improvement of the present invention, the star-shaped slow damping energy collection device comprises a spherical metal ball in the middle, a connecting bearing, a connecting rod, a piston pin, and a piston outer wall. The spherical metal ball is pre-opened with a bearing groove. The bearing groove is embedded with the connecting bearing and is connected to the piston sheath through a connecting rod. The piston sheath is inserted into the piston outer wall, and the end of the piston outer wall is connected to each node of the spacer dampener body.

[0010] As a further improvement of the present invention, the cantilevered magnetostrictive composite material vibration energy harvester is a magnetostrictive material.

[0011] As a further improvement of the present invention, the material of the double pendulum anti-galloping device is aluminum alloy, the connecting rod part is a hollow structure, and a groove for embedding a copper coil is reserved on its inner wall. It is fixed to the connecting bracket through bolts.

[0012] As a further improvement of the present invention, the main circuit includes an energy management circuit, a strain gauge voltage acquisition circuit, and a radio frequency communication circuit. The energy management circuit includes an impedance matching circuit, a rectifying and filtering circuit, a boosting circuit, and a supercapacitor energy storage. The strain gauge voltage acquisition circuit includes a filtering circuit and the A / D conversion part of the main control chip. The radio frequency communication circuit includes a matching circuit and the radio frequency communication part of the main control chip.

[0013] As a further improvement of the present invention, the connecting rod is fixed by a bolt with damping. Based on the traditional structure, the structural optimization is carried out, and weight reduction and wind resistance reduction designs are carried out. The use of metal intelligent manufacturing technology makes it possible to design complex structures. While being lighter in weight, the overall strength of the frame is also ensured.

[0014] As a further improvement of the present invention, the stress sensor uses a capacitive strain gauge manufactured by aerosol printing technology. An anti-corrosion, durable and insulating material is used as the protective layer, and a dielectric material is used as the printing substrate. The aerosol jet conductive material prints electrodes with a width of micron level. The capacitive strain gauge used in the present invention uses an anti-corrosion, durable and insulating material as the protective layer, and a dielectric material (such as polyimide, polyethylene terephthalate) is used as the printing substrate. The aerosol jet conductive material (nano silver) prints electrodes with a width of micron level.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages:

[0016] 1. The dancing energy harvesting type stress monitoring interconnected spacer damper makes up for the deficiency in the damage monitoring of the spacer damper body and indirectly reflects the dancing condition of the line. Compared with the existing line dancing monitoring devices, it is integrated on the spacer damper, reducing the line burden, and can realize the simultaneous monitoring of multiple strands of lines.

[0017] 2. The dancing energy harvesting type stress monitoring interconnected spacer damper uses a magnetostrictive material vibration energy harvester to collect the low-frequency mechanical energy generated by the line dancing, and replaces chemical batteries and solar energy to provide persistent and stable electrical energy for the wireless sensor network nodes, solving the problem of power supply for high-voltage lines.

[0018] 3. The capacitive strain gauge used in the dancing energy harvesting type stress monitoring interconnected spacer damper is prepared by aerosol printing, realizing fine vibration sensing in a small area. The strain coefficient and response speed are better than those of traditional strain gauges, the structure is more stable, and the service life is longer.

[0019] 4. Multiple dancing energy harvesting stress monitoring interconnected spacer dampers have the functions of joint networking and relay communication, avoiding power loss in long-distance signal transmission. Line data will be packaged and sent to the smart grid terminals of the high-voltage towers at both ends of the line in the form of data packets, and uploaded to the cloud together, reducing the possibility of misoperation.

[0020] 5. The new type of crab-claw bionic structure high-voltage wire clamp is simpler to operate at high altitudes. At the same time, the stress distribution is more uniform, increasing the reliability of the wire clamp. The irregular structure forms turbulence, reducing the wind resistance at the wire clamp.

[0021] 6. The dancing energy harvesting stress monitoring interconnected spacer adopts intelligent manufacturing technology. While ensuring the structural strength, weight reduction and wind resistance reduction designs are carried out. The combination of the mechanical structure and the circuit structure is more stable, improving the durability of the equipment. At the same time, it has a double pendulum anti-dancing hammer and a damping shock absorption device, having a certain anti-dancing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a main structure diagram of a self-powered intelligent spacer damper based on motion energy harvesting. Among them, 1 - cantilever type magnetostrictive composite material vibration energy harvester, 2 - double pendulum anti-dancing device, 3 - main circuit, 4 - flexible radio frequency antenna, 5 - spacer damper main body, 6 - star-shaped slow damping energy collection device, 7 - stress sensor, 8 - connecting rod, 9 - crab-claw bionic wire clamp, 10 - connecting bracket, 11 - vibration monitoring sensor, 12 - star-shaped slow damping energy collection device;

[0023] Figure 2 It is a schematic diagram of the structure of the vibration energy harvester; among them, 13 - pendulum weight, 14 - alloy sheet, 15 - pickup coil, 16 - pre-magnetized permanent magnet, 17 - connecting screw;

[0024] Figure 3 It is a star-shaped slow damping energy collection device, 18 - connecting bearing, 19 - connecting rod, 20 - piston pin, 21 - piston outer wall;

[0025] Figure 4 It is a design diagram of the energy collection circuit of the vibration energy harvester;

[0026] Figure 5 It is a design diagram of the structure of the stress sensor;

[0027] Figure 6 It is a design diagram of the main circuit;

[0028] Figure 7 It is a schematic diagram of the relay of the spacer damper and the interconnection communication with the smart grid. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments:

[0030] The self-powered intelligent spacer damper body provided by the present invention is as follows Figure 1 shown, including a pair of cantilevered magnetostrictive composite material vibration energy harvesters 1, a double pendulum anti-vibration damper 2, a main circuit 3, a flexible RF antenna 4, a spacer damper body 5, a slow star-shaped slow damping energy harvesting device 6, a stress sensor 7, a connecting rod 8, a crab claw bionic clamp 9, a connecting bracket 10, a vibration monitoring sensor 11 and a star-shaped slow damping energy harvesting device 12. The two cantilevered magnetostrictive composite material vibration energy harvesters 1 are respectively embedded in the cavities of the two connecting rods of the double pendulum anti-vibration damper 2, and are rectified, boosted and stored through the energy management system of the main circuit 3. The spacer damper body 5 is connected to the double pendulum anti-vibration damper 2 through the connecting bracket 10. The stress sensor 7 and the vibration monitoring sensor 11 are located on the surface of the end of the double pendulum anti-vibration damper 2, are encoded through the data processing part of the main circuit 3, and perform data communication through the flexible RF antenna 4. The main circuit 3 and the flexible RF antenna 4 are located on the connecting bracket 10. Each node of the spacer damper body 5 is provided with a slow star-shaped slow damping energy harvesting device 6 and is connected to the crab claw bionic clamp 9 through the connecting rod 8. The star-shaped slow damping energy harvesting device 12 is arranged at the center of the spacer damper body 5, and the star-shaped slow damping energy harvesting device 12 is connected to each node of the spacer damper body 5.

[0031] This application adopts magnesium alloy additive manufacturing technology. Through hydrodynamic simulation in terms of structure, the overall wind resistance is reduced. At the same time, according to force field simulation, the structure is weight-reduced, ensuring the structural strength while reducing the mass.

[0032] The vibration energy harvester is as follows Figure 2 shown. The alloy thin sheet 14 is used as the core material for vibration power generation and is fixed in a cantilevered manner. The alloy thin sheet is fixed on the spacer damper frame through the connecting screw 17 and is pre-magnetized through the pre-magnetized permanent magnets 16 at both ends of the thin sheet. The electromechanical coupling mainly satisfies the Jiles-Atherton model. The relationship between the magnetization intensity of the Fe-Ga alloy thin sheet and the stress change rate is as the formula;

[0033]

[0034] M rev = c(M an - M irr )

[0035] M = M rev + M irr

[0036] where M is the average magnetization intensity, σ is the internal stress received by the thin sheet, E m is the Young's elastic modulus of GMM, c is the irreversible loss coefficient, ξ is the unit volume energy coupling parameter of the material, M an is the magnetization intensity without magnetic hysteresis, Mirr is the irreversible magnetization intensity, M rev is the reversible magnetization intensity.

[0037] Through the pre-magnetization of the permanent magnet, the alloy sheet 14 just enters the magnetic domain deflection stage, enhancing the inverse magnetostrictive effect. Through the pre-magnetization of the permanent magnet, there is no need to use an energized coil to generate a magnetic field, reducing energy consumption and also shrinking the volume. The pickup coil 15 embedded inside the double pendulum anti-vibration device has an inner diameter close to that of the sheet in order to reduce the air gap. According to Faraday's electromagnetic induction effect, the induced electromotive force generated by the pickup coil 15 around the Fe-Ga alloy sheet 14 is as follows:

[0038]

[0039] The collector of the cantilever magnetostrictive composite vibration energy harvester 1 outputs alternating current. Affected by the environment, its output voltage has randomness and instability and cannot supply the main circuit to work normally. A corresponding matching circuit needs to be designed, including a rectifier filter, a DC-DC boost, and an energy storage circuit. The magnetostrictive circuit is inductive as a whole. In order to make the load obtain the maximum power and meet the bandwidth requirements at the same time, the maximum output power matching in dynamic impedance matching is used, and a matching capacitor C is connected in series to make it meet the resonance relationship.

[0040] The design flow chart of the star slow-damping energy harvesting device is as Figure 3 shown. When the line shakes, the star slow-damping energy harvesting device 12 at the center of the spacer and the spacer frame move relative to each other, thus driving the piston sheath 20 and the pre-magnetized permanent magnet 16 on it to move. The pre-magnetized permanent magnet 16 cuts the coil inside the outer wall 21 of the piston to generate an induced electromotive force. In order to provide a suitable voltage and current for the electronic load and improve the energy conversion efficiency, this set of energy harvesting system has a supporting energy management circuit and is incorporated into the final energy storage circuit. The star slow-damping energy harvesting device 12 is a spherical metal ball with a pre-opened bearing groove. A connecting bearing 18 is embedded at the pre-opened groove and is connected to the piston sheath 20 through a connecting rod 19.

[0041] The design flow chart of the energy harvesting circuit of the vibration energy harvester is as Figure 4 shown. In order to make the load obtain the maximum power, the load impedance and the internal impedance must satisfy the conjugate relationship. The cantilever magnetostrictive composite vibration energy harvester 1 is inductive as a whole. After power matching calculation, a matching resistor is connected in series. Since the output voltage of the cantilever magnetostrictive composite vibration energy harvester 1 is low, a voltage multiplier rectifier circuit is selected to process the output electrical signal of the magnetostrictive energy harvesting unit, and a CRC filter circuit is connected at the back end to eliminate the ripple. According to the rated voltage of the main control chip, an appropriate DC-DC chip is selected. A super capacitor is selected for the energy storage circuit.

[0042] The structural design of the stress sensor is as Figure 5As shown, a single-layer capacitive strain gauge design is adopted, which is deposited on the surface of the spacer frame by aerosol printing and then laser sintered after printing.

[0043] An electrode plate with N electrodes on one side, the length of each electrode is called L, and the width of the electrode is W. The gap between two adjacent electrodes is 2a, and the electrodes on both sides are surrounded by a uniform dielectric with a dielectric constant of ε r , a thickness of d. The electrode length L should be much greater than the electrode width W, and the electrode half-gap a should be much smaller than the electrode width W. The electrolyte thickness d should be less than the field penetration depth T, and the formula for the field penetration depth is:

[0044]

[0045] The effective width W of the electrode eff Satisfies the following equation:

[0046]

[0047] The calculation formula for the capacitance C of the single-layer capacitive strain gauge is as follows:

[0048]

[0049] The main circuit is as Figure 6 shown. The voltage signal collected by the strain gauge is filtered and then converted from analog to digital through the A / D conversion part of the main control function chip. The corresponding digital quantity is obtained through the stress-voltage fitting function conversion program based on experiments. After being encoded by the radio frequency part of the main control chip, the data is sent through the flexible radio frequency antenna 4 for communication. To ensure communication efficiency, the radio frequency antenna also needs to be equipped with corresponding matching and filtering circuits.

[0050] The schematic diagram of the interconnection communication networking between the spacer relay and the smart grid is as Figure 7 shown. After encoding the stress data by the main chip, the data is transmitted to the spacer of the smart grid terminal of the adjacent iron tower through the relay chip. The data includes a check bit, a start bit, a spacer position number, stress data, and an end bit. After merging the data into a data packet, it continues to be transmitted to the adjacent end. What the smart grid terminal of the iron tower collects is the data packet of half a line, which can conduct an overall judgment on the line condition, avoiding false alarms of the line caused by the stress detection failure of a single spacer. At the same time, the form of relay transmission reduces the energy loss and the data processing pressure of the information acquisition section. The two-way transmission supports the information collection end to send a data request to the spacer.

[0051] Working principle: According to the line requirements and the meteorological conditions at the usage location, the mechanical structure design and the aerodynamic design of the outer surface of the spacer are carried out through simulation. Based on the required transmission distance, the type of communication protocol, and the digital-to-analog conversion accuracy, an appropriate main control chip is selected. Based on the spacer model obtained from the structural design, the position with the maximum stress is selected as the printing position. An appropriate strain gauge design is selected according to the requirements of response speed and sampling accuracy. The stress-voltage curve is obtained through experiments, and the curve is fitted with a function and written into the main program. The vibration monitoring sensor 11 is placed at the location where voltage monitoring is required. According to the power requirements of the main control chip, an appropriate vibration energy harvester and energy collection circuit are designed. The main program should also include relays and communication protocols.

[0052] The above are only the preferred embodiments of the present invention, and do not limit the present invention in any other form. Any modification or equivalent change made according to the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A self-powered intelligent spacer based on galloping energy harvesting, characterized in that It includes a pair of cantilevered magnetostrictive composite vibration energy harvesters (1), a double pendulum anti-vibration device (2), a main circuit (3), a flexible RF antenna (4), a spacer bar body (5), a slow star-shaped slow damping energy harvesting device (6), a stress sensor (7), a connecting rod (8), a crab-claw bionic clamp (9), a connecting bracket (10), a vibration monitoring sensor (11) and a star-shaped slow damping energy harvesting device (12). The two cantilevered magnetostrictive composite vibration energy harvesters (1) are respectively embedded in the cavities of the two connecting rods of the double pendulum anti-vibration device (2), and are rectified, boosted and stored through the energy management system of the main circuit (3). The spacer bar body (5) is connected to the double pendulum anti-vibration device (2) through the connecting bracket (10). The stress sensor (7) and the vibration monitoring sensor (11) are located on the surface of the end of the double pendulum anti-vibration device (2), are encoded through the data processing part of the main circuit (3), and perform data communication through the flexible RF antenna (4). The main circuit (3) and the flexible RF antenna (4) are located on the connecting bracket (10). Each node of the spacer bar body (5) has a slow star-shaped slow damping energy harvesting device (6) and is connected to the crab-claw bionic clamp (9) through the connecting rod (8). A star-shaped slow damping energy harvesting device (12) is arranged at the center of the spacer bar body (5). The star-shaped slow damping energy harvesting device (12) is connected to each node of the spacer bar body (5). The star-shaped slow damping energy harvesting device (12) includes a spherical metal ball in the middle, a connecting bearing (18), a connecting rod (19), a piston pin (20) and a piston outer wall (21). The spherical metal ball is pre-opened with a bearing groove. The bearing groove is embedded with the connecting bearing (18) and is connected to the piston pin (20) through the connecting rod (19). The piston pin (20) is inserted into the piston outer wall (21). The end of the piston outer wall (21) is connected to each node of the spacer bar body (5).

2. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, wherein: The cantilevered magnetostrictive composite vibration energy harvester (1) includes a pendulum weight (13), an alloy thin sheet (14), a pick-up coil (15), a pre-magnetized permanent magnet (16) and a connecting screw (17). The cantilevered magnetostrictive composite vibration energy harvester (1) is embedded in the cavity of the corresponding connecting rod of the double pendulum anti-vibration device (2) through the connecting screws (17) at both ends. There is a pendulum weight (13) in the shell at the end of the double pendulum anti-vibration device (2). One end of the alloy thin sheet (14) is fixed to the connecting screw (17) in a cantilever manner. The other end of the alloy thin sheet (14) corresponds to the pendulum weight (13). There is a pre-magnetized permanent magnet (16) at each end of the alloy thin sheet (14). There is a pick-up coil (15) in the cavity of the connecting rod of the double pendulum anti-vibration device (2). The alloy thin sheet (14) is inside the pick-up coil (15).

3. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, wherein: The cantilevered magnetostrictive composite vibration energy harvester (1) is a magnetostrictive material.

4. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, characterized in that: The material of the double pendulum anti-vibration device (2) is aluminum alloy, and the connecting rod part is a hollow structure with a groove reserved on its inner wall for embedding a copper coil. The double pendulum anti-vibration device (2) is fixed to the connecting bracket (10) by bolts.

5. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, wherein: The main circuit (3) includes an energy management circuit, a strain gauge voltage acquisition circuit, and a radio frequency communication circuit. The energy management circuit includes an impedance matching circuit, a rectifier filter circuit, a boost circuit, and supercapacitor energy storage. The strain gauge voltage acquisition circuit includes a filter circuit and the A / D conversion part of the main control chip. The radio frequency communication circuit includes a matching circuit and the radio frequency communication part of the main control chip.

6. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, characterized in that: The connecting rod (8) is fixed by a bolt with damping.

7. The self-powered intelligent spacer based on galloping energy harvesting according to claim 1, wherein: The stress sensor (7) is a capacitive strain gauge manufactured using aerosol printing technology, with an anti-corrosion and durable insulating material as the protective layer, a dielectric material as the printing substrate, and an aerosol jet conductive material used to print electrodes with a width in the micron range.

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