Wireless Power Transmission Coupling Mechanism on High-Voltage Line Insulator and Manufacturing Method

Abstract

Wireless power transmission coupling mechanism on high-voltage line insulators and manufacturing method thereof. The main body of the mechanism includes a transmitting end and a receiving end; both the transmitting end and the receiving end include a spiral circular coil and a magnetic core; wherein, the magnetic core is composed of uniformly distributed support frames and magnetic core rings with the same spacing, and the height of each is the same as the height of the coil; the inner side of the smallest magnetic core ring is fixed on the insulator fitting, and the outer side of the largest magnetic core ring is closely attached to the inner wall of the coil; the optimal number of support frames and magnetic core rings is selected according to the simulation results; it is verified that the addition of this coupling mechanism will not damage the insulation performance of the high-voltage transmission line. The invention is applied to a wireless power transmission system for spanning the insulator distance on a high-voltage line, the coils can be fixed at both ends of the insulator, and at the same time, the mutual inductance of the coils is significantly increased, effectively improving the transmission performance of the system.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless power transmission, and in particular relates to a wireless power transmission coupling mechanism on a high-voltage line insulator and a manufacturing method thereof. Background Art

[0002] With the continuous advancement of science and technology, the continuous reform of the power system, and the strong support of the state for the development of the power grid, the construction of high-voltage transmission lines of various levels has been continuously promoted and developed. However, they are usually directly exposed in the wild, with a wide distribution range, complex and changeable environment, and are extremely vulnerable to damage. Therefore, it is necessary to build an intelligent operation and inspection system and install a variety of sensors on power towers, such as ice monitoring, line dancing and wind deviation monitoring, lightning monitoring, tower tilt monitoring, etc. All-round and multi-functional real-time monitoring of the working status of the transmission line and its surrounding environment can be carried out to quickly and accurately judge the safety hazards of power equipment, give early warning of potential risks, and reduce the losses caused by equipment failures.

[0003] Traditional power supply methods for power monitoring equipment on high-voltage poles and towers, such as lithium batteries and new energy power generation, have the disadvantages of cumbersome battery replacement and great influence of environmental factors on power supply stability. They are increasingly unable to meet the development trend of rapid capacity expansion of intelligent online monitoring nodes. Compared with traditional wire-type power transmission, wireless power transmission technology is a new power transmission technology in the power field. Magnetic coupling resonant wireless power transmission technology is a relatively special method in the field of wireless power transmission. It converts traditional electric energy into a resonant alternating electromagnetic field through an energy transmitting resonator, and transmits electric energy to a receiving resonator through air. Magnetic coupling resonant wireless power transmission technology is used in the field of charging with medium and long-distance high-power requirements such as wireless charging of electric vehicles due to its wide transmission distance and high power level of energy transmission. Therefore, in order to solve the problem of stable and uninterrupted power supply, stable electric energy can be directly obtained from the high-voltage transmission line, and the monitoring equipment can be powered across the insulation distance through magnetic coupling wireless transmission.

[0004] Prior Art 1 (CN114123535A) "Wireless Power Transmission Coupling Mechanism for On-line Monitoring Equipment on UHV Transmission Lines". The main body of the mechanism includes a transmitting end and a receiving end. The transmitting end includes a first coil, a second coil connected in series, and a transmitting end magnetic core. The receiving end includes a receiving coil and a receiving end magnetic core. By optimizing the internal structure of the transmitting end, this invention improves the uniformity of the magnetic flux density distribution, thereby significantly increasing the utilization rate of the magnetic core of the wireless power transmission coupling mechanism, making it more suitable for long-distance and high-current wireless power transmission. The deficiency of the prior art document 1 is that it does not design a fixing mechanism that is convenient to install on high-voltage lines or towers, and the size of the wound coil has limitations. The magnetic core block used in this mechanism is a rectangular ferrite strip, and the coil is a flat solenoid, resulting in an asymmetric distribution of the spatial magnetic field, uneven distribution of the magnetic induction intensity, and easy leakage of the magnetic field at a distance from the magnetic core, causing a decrease in the coupling coefficient of wireless power transmission. At the same time, the comb-shaped magnetic chip is prone to snow and dust accumulation, making maintenance and repair more difficult. This application can be directly installed and fixed at both ends of the insulator without considering how to stabilize the coil position in the air, and this mechanism can be applied to different coil sizes on towers of different voltage levels. In addition, the magnetic core structure surrounded by the coil on the inner side of this application is centrosymmetrically distributed, and the ring-shaped structure can increase the self-coupling area magnetic resistance, effectively confine the magnetic field in the energy transmission area, enhance the magnetic field coupling in the energy transmission area, and ensure the stability of wireless power transmission. This structure adopts a hollow design to avoid water, snow, and dirt accumulation, making it more suitable for wireless power transmission in high-voltage environments. Summary of the Invention

[0005] To solve the deficiencies in the prior art, the purpose of the present invention is to provide a wireless power transmission coupling mechanism and manufacturing method on high-voltage line insulators, which are applied to a wireless power transmission system for the distance across insulators on high-voltage lines, can fix the coils at both ends of the insulators, and at the same time, the mutual inductance of the coils is significantly increased, effectively improving the transmission performance of the system.

[0006] The present invention adopts the following technical solutions:

[0007] A wireless power transmission coupling mechanism on a high-voltage line insulator, the mechanism includes a transmitting end and a receiving end; the transmitting end includes a transmitting coil and a transmitting end magnetic core, and the receiving end includes a receiving coil and a receiving end magnetic core, wherein,

[0008] Both the transmitting coil and the receiving coil are circular coils wound in a spiral manner;

[0009] Both the transmitting end magnetic core and the receiving end magnetic core include a support frame and magnetic core rings that are concentric but have different radii. The transmitting end support frame and the receiving end support frame are evenly distributed radially, connecting the innermost to the outermost magnetic core rings. The support frame and the magnetic core rings are integrally formed. The transmitting end support frame is perpendicularly connected to the transmitting end magnetic core ring, and the receiving end support frame is perpendicularly connected to the receiving end magnetic core ring;

[0010] Preferably, the support frame and the magnetic core ring are made of the same material, which is made of ferrite material.

[0011] Preferably, the inner side of the innermost magnetic core ring is welded to the insulator fitting, and the outermost magnetic core ring is bonded to the inner wall of the coil.

[0012] Both the transmitting end magnetic core ring and the receiving end magnetic core ring take the cross-section center of the insulator fitting as the center of the ring, and the distance between adjacent magnetic core rings is equal, showing an equidistant distribution.

[0013] Preferably, the heights of the transmitting end magnetic core, the receiving end magnetic core, the transmitting coil and the receiving coil are the same.

[0014] Preferably, the number of the transmitting end support frames and the receiving end support frames is 6 each.

[0015] Preferably, the number of the transmitting end magnetic core rings and the receiving end magnetic core rings is 4 each.

[0016] Preferably, the heights of the magnetic core ring and the support frame are both 0.1 m.

[0017] Preferably, the diameter of the transmitting coil is 0.5 m, and the diameter of the receiving coil is 0.6 m.

[0018] A manufacturing method of a wireless power transmission coupling mechanism on a high-voltage line insulator includes the following steps.

[0019] Step 1: Determine the coil structure according to the voltage level of the high-voltage line.

[0020] Step 2: Further determine the wire diameter, the number of turns of the coil and the coil size through electromagnetic simulation, and determine the model and the number of strands of the Litz wire.

[0021] Step 3: Manufacture two magnetic cores, wind the transmitting coil and the receiving coil respectively along the outermost magnetic core ring, and fix the innermost magnetic core ring at the fittings at both ends of the insulator.

[0022] Step 4: After the system works, the electric energy at the high-voltage end is converted and then transmitted to the receiving coil at the low-voltage end in a wireless transmission manner across the insulation distance through the transmitting coil to supply power to the detection equipment located on the pole tower.

[0023] The beneficial effects of the present invention are as follows. Compared with the prior art,

[0024] 1) The present invention uses the magnetic core and the support frame as the brackets. The material properties and design structures of the magnetic core and the support frame are relatively firm, which can fix the coils on both sides of the insulator and have little influence on the insulation performance and power quality of the high-voltage transmission line.

[0025] 2) The magnetic core structure surrounded by the coil inside the present invention is centrosymmetrically distributed. The ring-shaped structure can increase the magnetic resistance of the autotransformer region, effectively confine the magnetic field in the energy transfer region, enhance the magnetic field coupling in the energy transfer region, and ensure the stability of wireless power transmission. This structure adopts a hollow design to avoid water accumulation, snow accumulation, and dirt accumulation, and is more suitable for wireless power transmission in high-voltage environments;

[0026] 3) The present invention can increase the mutual inductance value between the transmitting coil and the receiving coil, further improve the transmission performance, and is applicable to long-distance wireless power transmission systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of the wireless power transmission coupling mechanism on the high-voltage line insulator of the present invention;

[0028] Figure 2 is the model and simulation results of various magnetic core structures designed by the present invention;

[0029] Figure 3 is the model and simulation results of different numbers of magnetic cores designed by the present invention;

[0030] Figure 4 is the mutual inductance difference curve of different numbers of magnetic cores designed by the present invention;

[0031] Figure 5 is the contour map of the electric field strength distribution around the insulator and coil in the preferred embodiment of the present invention;

[0032] Figure 6 is the electric field strength curve at the edge of the insulator petticoat in the preferred embodiment of the present invention;

[0033] Figure 1 The reference numerals in are explained as follows:

[0034] 1 - Transmitting coil; 2 - Transmitting end support frame; 3 - Transmitting end magnetic core ring; 4 - Receiving end support frame; 5 - Receiving coil; 6 - Receiving end magnetic core ring. SPECIFIC EMBODIMENTS

[0035] The present application will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present application.

[0036] Embodiment 1.

[0037] As Figure 1 , the wireless power transmission coupling mechanism on the high-voltage line insulator includes: a transmitting end and a receiving end; the transmitting end includes a transmitting coil 1 and a transmitting end magnetic core, and the receiving end includes a receiving coil 5 and a receiving end magnetic core, wherein,

[0038] The transmitting coil 1 and the receiving coil 5 are both circular coils wound in a spiral manner;

[0039] The transmitting core and the receiving core both include a support frame and magnetic core rings that are concentric but have different radii. The transmitting support frame 2 and the receiving support frame 4 are evenly distributed radially, connecting the innermost to the outermost magnetic core rings. The support frame and the magnetic core rings are integrally formed. The transmitting support frame 2 and the transmitting magnetic core ring 3 are perpendicularly connected, and the receiving support frame 4 and the receiving magnetic core ring 6 are perpendicularly connected;

[0040] The inner side of the innermost magnetic core ring is fixedly sleeved on the insulator fitting, and the outer side of the outermost magnetic core ring is closely attached to the inner wall of the circular coil. The magnetic core serves as a support to fix the coil at both ends of the insulator. Among them, the transmitting end is fixed to the high-voltage end of the insulator, and the receiving end is fixed to the low-voltage end of the insulator.

[0041] Preferably in this embodiment, the inner side of the innermost magnetic core ring is welded to the insulator fitting, and the outermost magnetic core ring is bonded to the inner wall of the coil.

[0042] Preferably in this embodiment, the support frame and the magnetic core rings are made of the same material, which is made of a ferrite material that can enhance magnetic field coupling.

[0043] The transmitting support frame 2 and the receiving support frame 4 are evenly distributed radially, connecting the innermost to the outermost magnetic core rings.

[0044] The transmitting magnetic core ring 3 and the receiving magnetic core ring 6 take the cross-section center of the insulator fitting as the center of the ring, and the distance between adjacent magnetic core rings is equal, showing an equidistant distribution.

[0045] The height of the transmitting core, the receiving core, the transmitting coil 1 and the receiving coil 5 is the same.

[0046] The thickness and height of the support frame and the magnetic core rings are both the same.

[0047] Embodiment 2.

[0048] This embodiment is for a wireless power transmission system across a 500 kV insulator distance. The transmission distance L between the fittings at both ends of the composite insulator is 4.01 m. Taking the transmitting coil diameter d = 0.5 m, the receiving coil diameter D = 0.6 m, and the height h of the coil and the core as 0.1 m as an example, an analysis and demonstration are carried out.

[0049] As Figure 2, five different styles of magnetic core structures for fixing coils are designed, including a solid columnar magnetic core, a disc-shaped magnetic core with upper and lower hollow parts, a cover-shaped magnetic core with a hollow bottom, and an annular mesh magnetic core when the number M of support frames is 6 and 12 respectively. Through finite element calculation, the inductances of the receiving coil and the transmitting coil, the mutual inductance and the coupling coefficient between the two coils are obtained at this time, and the volume of the magnetic core is calculated. It is found through analysis that the larger the volume of the magnetic core, the higher the mutual inductance of the coils, but it also means an increase in the weight and manufacturing cost of the magnetic core. Therefore, the ratio of mutual inductance to volume is taken as the reference object, and it is found through calculation that this ratio is relatively the largest in the annular mesh magnetic core structure with M = 6, indicating that the mutual inductance of the coils is relatively high at this time, and the volume of the magnetic core is relatively small, and the hollow design is not conducive to water accumulation, snow accumulation and dirt accumulation, which is suitable for application in the wireless power transmission system across high-voltage insulators.

[0050] As Figure 3 , for the annular mesh magnetic core structure with M = 6, a model is built under the condition that the number 2 ≤ N ≤ 11 of annular magnetic cores. Through finite element calculation, the inductances of the receiving coil and the transmitting coil, the mutual inductance and the coupling coefficient between the two coils are obtained at this time. At this time, the volume of the magnetic core increases approximately proportionally with the number N of annular magnetic cores. Therefore, the differential curves of the mutual inductance of the coils at each N value are calculated as Figure 4 shown. The differential of N rings refers to the difference between the mutual inductance value at N rings and the mutual inductance value at (N - 1) rings. It can be obtained from the curve that with the increase of the number N of rings, the mutual inductance is also increasing continuously. Among them, the mutual inductance differential is the largest when N = 4, indicating that under the condition that the increase value of the magnetic core volume is approximately the same, the mutual inductance increases at the fastest speed at this time, and the weight and manufacturing cost of the magnetic core are relatively low. Considering all aspects, it is suitable for application in engineering. If the requirement for the wireless transmission performance of the system is relatively high, the number of annular magnetic cores 5 ≤ N ≤ 7 can be selected according to the actual situation, and the mutual inductance differential in this range is also relatively large.

[0051] In this embodiment, N = 4 is preferably selected. At this time, the mutual inductance of the coil is 7.0769 μH, which is increased by 49.85% compared with the case without a magnetic core structure (4.7228 μH), indicating that this coupling mechanism can greatly improve the transmission performance of the system. In this invention, it is also necessary to consider whether the addition of the wireless power transmission system will affect the insulation performance of the insulators of the 500 kV transmission line and damage the safe operation of the high-voltage transmission line. According to the finite element calculation results, the contour map of the electric field strength distribution of the system cross-section is obtained, as Figure 5 shown. The electric field strength at the fittings at both ends of the insulator is relatively high, and the middle part is relatively uniform, and the change trend is stable. The highest value of the electric field strength of the system is about 6.23×10 6 V / m, which is much smaller than the breakdown field strength of the silicone rubber umbrella skirt of the insulator. At the same time, the electric field strength curve at the outer edge of the large umbrella skirt of the insulator is simulated, as Figure 6 shown. The change trend of the electric field strength reflected by this curve is the same as that of the cloud Figure 1 diagram, and the electric field strength at the curve is less than the air breakdown field strength (3×106 (V / m), so the addition of this coupling mechanism will not damage the insulation performance of high-voltage transmission lines and can be safely applied in actual scenarios.

[0052] Embodiment 3.

[0053] A method for manufacturing a wireless power transmission coupling mechanism on a high-voltage line insulator, comprising the following steps:

[0054] Step 1: Determine the coil structure according to the voltage level of the high-voltage line;

[0055] Step 2: Further determine the wire diameter, number of coil turns, and coil size through electromagnetic simulation, and determine the type and number of strands of Litz wire;

[0056] Step 3: Manufacture two magnetic core structures, wind the transmitting coil and the receiving coil respectively along the outermost magnetic core ring, and fix the innermost magnetic core ring at the fittings at both ends of the insulator;

[0057] Step 4: After the system works, the electric energy at the high-voltage end is converted and then transmitted to the receiving coil at the low-voltage end in a wireless transmission manner across the insulation distance through the transmitting coil to supply power to the detection equipment located on the pole tower.

[0058] The beneficial effects of the present invention are as follows. Compared with the prior art,

[0059] 1) The present invention uses the magnetic core and the support frame as the support. The material properties and design structures of the magnetic core and the support frame are relatively firm, which can fix the coils on both sides of the insulator and have little impact on the insulation performance and power quality of high-voltage transmission lines;

[0060] 2) The magnetic core structure surrounded by the coils on the inner side of the present invention is centrosymmetrically distributed. The ring-shaped structure can increase the magnetic resistance of the self-coupling region, effectively confine the magnetic field in the energy transmission region, enhance the magnetic field coupling in the energy transmission region, and ensure the stability of wireless power transmission. This structure adopts a hollow design to avoid water accumulation, snow accumulation, and dirt accumulation, and is more suitable for wireless power transmission in high-voltage environments;

[0061] 3) The present invention can increase the mutual inductance value between the transmitting coil and the receiving coil, further improve the transmission performance, and is applicable to long-distance wireless power transmission systems.

[0062] The applicant of the present invention has made detailed explanations and descriptions of the embodiments of the present invention in combination with the accompanying drawings of the specification. However, those skilled in the art should understand that the above embodiments are only the preferred implementation schemes of the present invention. The detailed explanations are only to help readers better understand the spirit of the present invention, rather than a limitation on the protection scope of the present invention. On the contrary, any improvement or modification based on the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. Wireless power transfer coupling mechanism on high-voltage line insulators, the mechanism comprising: Transmitter and receiver; the transmitter includes a transmitting coil (1) and a transmitter magnetic core, and the receiver includes a receiving coil (5) and a receiver magnetic core, characterized in that Both the transmitting coil (1) and the receiving coil (5) are circular coils wound in a spiral manner; Both the transmitter magnetic core and the receiver magnetic core include a support frame and magnetic core rings that are concentric but have different radii. The transmitter support frame (2) and the receiver support frame (4) are evenly distributed radially. The support frame and the magnetic core rings are integrally formed. The transmitter support frame (2) and the transmitter magnetic core ring (3) are perpendicularly connected, and the receiver support frame (4) and the receiver magnetic core ring (6) are perpendicularly connected; The inner side of the innermost magnetic core ring is welded to the insulator fitting, and the outermost magnetic core ring is adhered to the inner wall of the coil.

2. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 1, characterized in that Both the transmitter magnetic core and the receiver magnetic core are made of ferrite materials.

3. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 2, characterized in that Both the transmitter magnetic core ring (3) and the receiver magnetic core ring (6) take the cross-section center of the insulator fitting as the center of the ring, and the distance between adjacent magnetic core rings is equal, showing an equidistant distribution.

4. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 3, characterized in that The heights of the transmitter magnetic core, the receiver magnetic core, the transmitting coil (1), and the receiving coil (5) are the same.

5. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 1, characterized in that The number of both the transmitter support frame (2) and the receiver support frame (4) is 6.

6. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 1, characterized in that The number of both the transmitter magnetic core ring (3) and the receiver magnetic core ring (6) is 4.

7. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 1, characterized in that The heights of both the magnetic core ring and the support frame are 0.1 m.

8. The wireless power transmission coupling mechanism on a high-voltage line insulator according to claim 1, characterized in that The diameter of the transmitting coil (1) is 0.5 m, and the diameter of the receiving coil (5) is 0.6 m.

9. Method for manufacturing a wireless power transmission coupling mechanism on a high-voltage line insulator, implemented by using the wireless power transmission coupling mechanism on a high-voltage line insulator according to any one of claims 1 to 8, characterized in that The manufacturing method includes the following steps Step 1, determine the coil structure according to the voltage level of the high-voltage line; Step 2, through electromagnetic simulation, determine the wire diameter, the number of turns of the coil, and the coil size, and determine the type and number of strands of the Litz wire; Step 3, manufacture two magnetic cores, wind the transmitting coil and the receiving coil respectively along the outermost magnetic core ring, and fix the innermost magnetic core ring at the fittings at both ends of the insulator; Step 4, after the system works, the electric energy at the high-voltage end is converted and then transmitted to the receiving coil at the low-voltage end in a wireless transmission manner across the insulation distance through the transmitting coil to supply power to the detection equipment located on the pole tower.

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