A method for manufacturing an electromagnetic shielding device for shared pole tower equipment

Abstract

The present invention discloses an electromagnetic shielding device for shared pole tower equipment and a manufacturing method thereof, the device comprises an inner shielding shell, the inner cavity of the inner shielding shell is provided with pole tower shared equipment, grooves are provided on the left and right sides of the upper end of the inner shielding shell, a conductive rubber strip is provided inside the groove, the inner shielding shell is covered with an inner shielding upper cover, the conductive rubber strip is located below the inner shielding upper cover, the gap between the inner shielding shell and the inner shielding upper cover is coated with conductive glue to form an electric field shielding layer; an outer shielding shell is installed outside the inner shielding shell, and the outer shielding shell is covered with an outer shielding upper cover to form a magnetic path. The device of the present invention integrates magnetic field shielding and electric field shielding, can effectively perform electromagnetic field shielding according to the electromagnetic field characteristics of the surface of the shared pole tower equipment, has a simple manufacturing method, is easy to assemble, and has good environmental adaptability.

Description

Technical Field

[0001] The invention belongs to the field of high-voltage transmission lines, and in particular is an electromagnetic shielding device for shared pole tower equipment and a manufacturing method thereof. Background Art

[0002] In order to effectively avoid resource waste in power companies and improve resource utilization, in recent years, more and more optical cables, communication base stations, mobile antennas, sensors, cameras, environmental monitors and other equipment have shared towers with transmission lines. However, high-voltage transmission lines will generate electromagnetic fields in space, which will affect the normal operation of shared equipment. In 2020, Tang Bo et al. published a paper titled "Electromagnetic Interference and Protection of Shared Tower Base Station Antennas on Online Monitoring Equipment", which disclosed that shared towers integrate power and communication equipment. The newly added base station antennas are installed close to the original transmission line online monitoring equipment on the tower, which will inevitably cause electromagnetic interference to the online monitoring equipment. According to the electromagnetic compatibility standards of existing online monitoring equipment, the interference mechanism of base station antennas on online monitoring equipment is analyzed, and it is recommended to use 10V / m of radio frequency radiation immunity as the anti-interference design limit. Combined with the antenna principle, the mathematical representation of the base station antenna source is derived, and then a mathematical model for solving the scattering field of electrically large-sized metal scatterers at any point in space under the radiation of multiple base station antennas is proposed. The proposed mathematical model is solved by the PO-MoM hybrid algorithm and verified by an anechoic chamber experiment. The results show that the global maximum relative deviation of the mathematical model increases with the increase of frequency, and is 8.33% at 2600MHz. Taking the Shandong shared tower as an example, the variation law of the electric field intensity at the online monitoring equipment under three working conditions, namely, tower head type, antenna power, and antenna tilt, is analyzed. Based on this, it is recommended that the protection distance between the antenna and the online monitoring equipment be set to 4m.

[0003] The article was published in 2020 by Zhang Ying and others in the journal VIP. It is titled "Study on the Impact of Shared Tower Base Stations on the Surrounding Electromagnetic Environment". The article analyzes the antenna structure type of the transmission line shared tower communication base station, the selection of shared towers and the location of antennas. It predicts and calculates the electromagnetic environment impact of different types of shared tower base stations and different installation methods, and obtains the electromagnetic environment control distance for 4G and 5G base stations installed on shared towers. The relevant research results have a good reference value for the site selection of shared towers for transmission lines, the selection of antenna types, and the adjustment of parameters of co-built base stations.

[0004] In summary, currently, researchers mostly establish mathematical models to study the electromagnetic impact of transmission lines on other monitoring equipment, and use mathematical algorithms to predict and calculate the protective distance between antennas and online monitoring equipment. However, in the actual installation process, this is difficult to implement, requires a lot of work, and easily leads to waste of resources and space.

[0005] Therefore, it is necessary to design electromagnetic shielding for electromagnetically sensitive equipment. At present, the electromagnetic shielding method in the field of high-voltage transmission lines is mainly used for buildings near high-voltage transmission lines, and it is impossible to perform electromagnetic field shielding for the electromagnetic field characteristics of the surface of shared tower equipment. Summary of the invention

[0006] The object of the present invention is to provide an electromagnetic shielding device for shared pole tower equipment and a manufacturing method thereof, which integrates magnetic field shielding and electric field shielding, is easy to assemble, and has good environmental adaptability.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An electromagnetic shielding device for a shared pole tower device comprises an inner shielding shell, an inner cavity of the inner shielding shell is provided with a pole tower shared device, grooves are provided on the left and right sides of the upper end of the inner shielding shell, a conductive rubber strip is provided inside the groove, an inner shielding upper cover is covered on the inner shielding shell, the conductive rubber strip is located below the inner shielding upper cover, and a conductive glue is coated in a gap between the inner shielding shell and the inner shielding upper cover to form an electric field shielding layer;

[0009] An outer shielding shell is installed outside the inner shielding shell, and an outer shielding upper cover is closed on the outer shielding shell to form a magnetic path.

[0010] Furthermore, a platform and a boss are provided at the top opening of the inner shielding shell, the grooves are provided on the left and right sides of the platform, and a plurality of first screw holes are evenly provided on the platform;

[0011] The bottom surface of the inner shielding upper cover is in contact with the platform, a plurality of first countersunk holes are evenly formed on the inner shielding upper cover, and the inner shielding upper cover is fixedly connected to the inner shielding shell by first screws.

[0012] Furthermore, the conductive adhesive is coated in the gap between the inner shielding cover and the boss.

[0013] Furthermore, second screw holes are evenly formed on the side wall of the inner shielding shell;

[0014] A through hole is provided on the side wall of the outer shielding shell, and a second countersunk hole is provided on the outer shielding cover. The second screw passes through the second countersunk hole, the through hole and the second screw hole in sequence to fix the inner shielding shell and the outer shielding cover to the outer shielding shell.

[0015] Furthermore, the inner shielding shell and the inner shielding upper cover are both made of aluminum alloy.

[0016] Furthermore, the outer shielding upper cover and the outer shielding shell are both made of iron-nickel soft magnetic alloy.

[0017] Furthermore, the wall thickness of the inner shielding shell is greater than the wall thickness of the outer shielding shell.

[0018] Furthermore, the outer surfaces of the inner shielding shell and the outer shielding shell are both coated with anti-rust paint.

[0019] A method for manufacturing an electromagnetic shielding device for shared tower equipment comprises the following steps:

[0020] (1) First, the inner shielding shell is manufactured by mechanical processing or casting, and then the surface of the platform and the boss is finely processed, and then the inner surface of the boss and the groove is subjected to conductive anodizing treatment, and then the outer surface of the inner shielding shell is coated with anti-rust paint, and finally the second screw holes are evenly opened on the four side walls of the inner shielding shell and the first screw holes are evenly opened on the platform;

[0021] (2) First, the inner shielding cover is manufactured by machining or casting, and then the inner surface of the inner shielding cover in the area in contact with the platform is finely processed, and the remaining area is subjected to conductive anodizing treatment, and then anti-rust paint is applied to the outer surface of the inner shielding cover, and finally the first countersunk holes are evenly opened on the inner shielding cover;

[0022] (3) firstly weld the outer shielding shell side plate and the outer shielding shell bottom plate into the outer shielding shell by laser welding, then perform magnetic annealing treatment on the outer shielding shell to improve the magnetic shielding performance, then apply anti-rust paint on the outer surface of the outer shielding shell, and finally evenly open through holes on the upper part of the outer shielding shell side plate;

[0023] (4) Processing the outer shielding cover by the method of step (3), and evenly opening second countersunk holes on the side wall of the outer shielding cover;

[0024] (5) First, place the pole tower shared equipment in the inner cavity of the inner shielding shell, then place the conductive rubber strip in the groove, and then fix the inner shielding cover on the platform by means of the first screw and apply conductive glue in the gap formed by the two; then, put the outer shielding shell on the outside of the inner shielding shell, and at the same time, cover the outer shielding cover on the outer shielding shell, and finally, insert the second screw through the second countersunk hole, the through hole and the second screw hole in sequence to fix the outer shielding cover, the outer shielding shell and the inner shielding shell together.

[0025] The present invention has the following beneficial effects:

[0026] The pole tower shared equipment is placed in the inner cavity of the inner shielding shell. The inner shielding shell and the inner shielding cover form a well-sealed electric field shielding layer with the conductive rubber strip and the conductive glue to avoid gap leakage and improve the electric field shielding efficiency. At the same time, an outer shielding shell is provided on the outside of the inner shielding shell. The outer shielding shell and the outer shielding cover form a good magnetic path to improve the magnetic field shielding efficiency. It can be seen that the device of the present invention integrates magnetic field shielding and electric field shielding, and can effectively perform electromagnetic field shielding according to the electromagnetic field characteristics on the surface of the shared pole tower equipment. The manufacturing method is simple, the assembly is convenient, and the environmental adaptability is good.

[0027] Considering the lightness of the tower-sharing equipment shielding device, and the convenience of production and assembly, and the inner shielding shell is the supporting structure of the entire device, not only the wall thickness of the inner shielding shell is greater than the wall thickness of the outer shielding shell, but also the material of the inner shielding cover is aluminum alloy with low density and good conductivity. At the same time, the outer shielding shell and the outer shielding cover adopt a thin-walled overlap structure, and the second screw material is selected from an iron-nickel soft magnetic alloy with high density, high initial magnetic permeability and maximum magnetic permeability, which is light and has high magnetic field shielding efficiency.

[0028] The outer shielding shell and the outer shielding cover are formed by laser welding the bottom plate and the surrounding plates, and can effectively avoid gap leakage. After laser welding, magnetic annealing treatment is performed to improve its magnetic shielding performance. After magnetic annealing, anti-rust paint is applied on the outer surface of the shell to increase the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 : A schematic diagram of the cross-sectional structure of the present invention;

[0030] Figure 2 : A schematic structural diagram of the inner shielding shell of the present invention;

[0031] Figure 3 : A schematic structural diagram of the front side of the inner shielding cover of the present invention;

[0032] Figure 4 : A schematic diagram of the structure of the back side of the inner shielding cover of the present invention;

[0033] Figure 5 : A schematic diagram of the structure of the outer shielding shell of the present invention;

[0034] Figure 6 : A schematic diagram of the structure of the outer shielding cover of the present invention;

[0035] Figure 7 : The electric field distribution diagram of the shared tower equipment surface before shielding of the present invention;

[0036] Figure 8 : The surface electric field distribution diagram of the shared tower equipment after shielding of the present invention;

[0037] In the figure: 1. pole tower sharing equipment; 2. inner shielding shell; 21. boss; 22. groove; 23. platform; 3. inner shielding cover; 4. first screw; 41. first screw hole; 42. first countersunk hole; 5. conductive rubber strip; 6. conductive glue; 7. outer shielding shell; 71. outer shielding shell side plate; 72. outer shielding shell bottom plate; 8. outer shielding cover; 81. outer shielding cover side plate; 82. outer shielding cover top plate; 9. second screw; 91. second screw hole; 92. through hole; 93. second countersunk hole. DETAILED DESCRIPTION

[0038] The specific contents of the present invention are further explained in detail below in conjunction with the embodiments, but are not intended to limit the present invention.

[0039] Example 1

[0040] like Figure 1-Figure 6 As shown, an electromagnetic shielding device for sharing pole tower equipment comprises an inner shielding shell 2, an inner cavity of the inner shielding shell 2 is provided with a pole tower sharing equipment 1, grooves 22 are provided on the left and right sides of the upper end of the inner shielding shell 2, a conductive rubber strip 5 is provided inside the groove 22, a platform 23 and a boss 21 are provided at the top opening of the inner shielding shell 2, the groove 22 is provided on the left and right sides of the platform 23, a plurality of first screw holes 41 are evenly provided on the platform 23, an inner shielding upper cover 3 is covered on the inner shielding shell 2, and a conductive rubber strip 5 is provided inside the groove 22. The electric rubber strip 5 is located below the inner shielding cover 3, the bottom surface of the inner shielding cover 3 is in contact with the platform 23, a plurality of first countersunk holes 42 are evenly provided on the inner shielding cover 3, the inner shielding cover 3 is fixedly connected to the inner shielding shell 2 by the first screw 4, the gap between the inner shielding cover 3 and the boss 21 is coated with conductive glue 6, the inner shielding shell 2 and the inner shielding cover 3 form a well-sealed electric field shielding layer with the conductive rubber strip 5 and the conductive glue 6 to avoid gap leakage and improve the electric field shielding efficiency.

[0041] An outer shielding shell 7 is installed on the outside of the inner shielding shell 2, and an outer shielding upper cover 8 is covered on the outer shielding shell 7. The outer shielding shell 7 and the outer shielding upper cover 8 adopt a thin-wall overlap structure, a through hole 92 is opened on the side wall of the outer shielding shell 7, and the outer shielding upper cover 8 is opened with a second countersunk hole 93; second screw holes 91 are evenly opened on the side wall of the inner shielding shell 2, and the second screw 9 passes through the second countersunk hole 93, the through hole 92 and the second screw hole 91 in sequence to fix the inner shielding shell 2 and the outer shielding upper cover 8 with the outer shielding shell 7. The outer shielding shell 7 and the outer shielding upper cover 8 form a good magnetic path to improve the magnetic field shielding efficiency.

[0042] Preferably, the inner shielding shell 2 and the inner shielding upper cover 3 are both made of aluminum alloy, which not only has good conductivity but is also light.

[0043] Preferably, the outer shielding cover 8, the outer shielding shell 7 and the second screw 9 are all made of an iron-nickel soft magnetic alloy with high initial magnetic permeability and maximum magnetic permeability, forming a good magnetic path and improving the magnetic field shielding efficiency.

[0044] Preferably, the wall thickness of the inner shielding shell 2 is greater than the wall thickness of the outer shielding shell 7, so that the entire device is lighter and the inner shielding shell 2 has a good supporting effect.

[0045] Preferably, the outer surfaces of the inner shielding shell 2 and the outer shielding shell 7 are coated with anti-rust paint, which can increase the life of the device.

[0046] like Figure 7-Figure 8 As shown, this embodiment takes a 330kV double-circuit transmission tower as an example. The tower is 55m high. The tower shared equipment model is a cuboid with a size of 800mm×400mm×200mm. It is installed on the main material of the tower at a height of 20m and is 1m away from the main material of the tower. Ansys software is used to analyze the surface electromagnetic field of the shared tower equipment:

[0047] (1) Before the shielding device of the present invention is used, the maximum electric field strength of the shared tower equipment is 64041 V / m, and the maximum magnetic field strength is 52.614 μT.

[0048] (2) After being shielded by the device of the present invention, the maximum electric field strength of the shared tower equipment is 4.5305 V / m, and the electric field shielding effectiveness is 83 dB; the maximum magnetic field strength is 1.2754 μT, and the magnetic field shielding effectiveness is 32.88 dB.

[0049] Example 2

[0050] A method for manufacturing an electromagnetic shielding device for shared tower equipment comprises the following steps:

[0051] (1) First, the inner shielding shell 2 is manufactured by mechanical processing or casting, and then the surface of the platform 23 and the boss 21 is finely processed, and then the inner surface of the boss 21 and the groove 22 is subjected to conductive anodizing treatment, and then the outer surface of the inner shielding shell 2 is coated with anti-rust paint, and finally, the second screw holes 91 are evenly opened on the four side walls of the inner shielding shell 2 and the first screw holes 41 are evenly opened on the platform 23;

[0052] (2) First, the inner shielding cover 3 is manufactured by machining or casting, and then the inner surface of the inner shielding cover 3 in the area in contact with the platform 23 is finely processed, and the remaining area is subjected to conductive anodizing treatment, and then the outer surface of the inner shielding cover 3 is coated with anti-rust paint, and finally the first countersunk holes 42 are evenly opened in the inner shielding cover 3;

[0053] (3) First, the outer shielding shell side plate 71 and the outer shielding shell bottom plate 72 are welded into the outer shielding shell 7 by laser welding, and then the outer shielding shell 7 is subjected to magnetic annealing treatment to improve the magnetic shielding performance, and then the outer surface of the outer shielding shell 7 is coated with anti-rust paint, and finally through holes 92 are evenly opened on the upper part of the outer shielding shell side plate 71;

[0054] (4) Using the method in step 3, laser weld the outer shielding cover top plate 82 and the outer shielding cover side plate 81 to form the outer shielding cover 8, and evenly open second countersunk holes 93 on the side walls of the outer shielding cover 8;

[0055] (5) First, place the pole tower sharing device 1 in the inner cavity of the inner shielding shell 2, then place the conductive rubber strip 5 in the groove 22, and then fix the inner shielding cover 3 on the platform 23 by the first screw 4 and apply the conductive glue 6 in the gap formed by the boss 21 and the inner shielding cover 3; then put the outer shielding shell 7 on the outside of the inner shielding shell 2, and at the same time cover the outer shielding cover 8 on the outer shielding shell 7, and finally insert the second screw 9 through the second countersunk hole 93, the through hole 92 and the second screw hole 91 in turn to fix the outer shielding cover 8, the outer shielding shell 7 and the inner shielding shell 2.

[0056] The working principle of the present invention is as follows:

[0057] When in use, first place the pole tower sharing device 1 in the inner cavity of the inner shielding shell 2, then place the conductive rubber strip 5 in the groove 22, then fix the inner shielding cover 3 on the platform 23 by the first screw 4 and apply the conductive glue 6 in the gap formed by the boss 21 and the inner shielding cover 3, at this time, the inner shielding shell 2 and the inner shielding cover 3 form a well-sealed electric field shielding layer with the conductive rubber strip 5 and the conductive glue 6 to avoid gap leakage; then put the outer shielding shell 7 on the outside of the inner shielding shell 2, and cover the outer shielding cover 8 on the outer shielding shell 7, and finally pass the second screw 9 through the second countersunk hole 93, the through hole 92 and the second screw hole 91 in turn to fix the outer shielding cover 8, the outer shielding shell 7 and the inner shielding shell 2, and the outer shielding shell 7 and the outer shielding cover 8 form a good magnetic path to improve the magnetic field shielding efficiency. Thus, the device of the present invention integrates magnetic field shielding and electric field shielding, and can effectively perform electromagnetic field shielding according to the electromagnetic field characteristics of the surface of the shared pole tower equipment.

[0058] Comparing this embodiment with the prior art, the title of the article "Electromagnetic interference and protection of shared iron tower base station antennas on online monitoring equipment and protection" published in the journal CNKI VIP, author Tang Bo et al. in 2020; the title of the article "Study on the impact of shared iron tower base stations on the surrounding electromagnetic environment" published in the journal CNKI VIP, author Zhang Ying et al. in 2020, the electromagnetic shielding device integrates magnetic field shielding and electric field shielding. The inner shielding shell and the inner shielding cover are made of aluminum alloy with good conductive properties, and form a well-sealed electric field shielding layer with conductive rubber strips and conductive glue to avoid gap leakage and improve the electric field shielding efficiency; the outer shielding shell and the outer shielding cover adopt a thin-wall lap joint structure, and the material of the mounting screws are all iron-nickel soft magnetic alloys with high initial magnetic permeability and high maximum magnetic permeability, forming a good magnetic path and improving the magnetic field shielding efficiency. In addition, the device has a simple manufacturing method, convenient assembly, and good environmental adaptability.

[0059] At the same time, this embodiment can arbitrarily change the distance between the monitoring equipment and the transmission line, thereby reducing material waste and saving space.

Claims

1. A method for manufacturing an electromagnetic shielding device for a shared pole tower device, characterized in that: The steps include: (1) An inner shielding shell (2) is first manufactured by mechanical processing or casting, wherein a pole tower sharing device (1) is arranged in an inner cavity of the inner shielding shell (2), grooves (22) are provided on the left and right sides of the upper end of the inner shielding shell (2), and a conductive rubber strip (5) is arranged inside the groove (22), the inner shielding shell (2) is covered with an inner shielding upper cover (3), and the conductive rubber strip (5) is located below the inner shielding upper cover (3), and a conductive glue (6) is coated in a gap between the inner shielding shell (2) and the inner shielding upper cover (3) to form an electric field shielding layer, and an outer shielding shell (6) is installed outside the inner shielding shell (2) 7), the outer shielding shell (7) is covered with an outer shielding upper cover (8) to form a magnetic path, a platform (23) and a boss (21) are provided at the top opening of the inner shielding shell (2), and the groove (22) is opened on the left and right sides of the platform (23), and then the surface of the platform (23) and the boss (21) is finely processed, and then the inner surfaces of the boss (21) and the groove (22) are subjected to conductive anodizing treatment, and then the outer surface of the inner shielding shell (2) is coated with anti-rust paint, and finally, the second screw holes (91) are evenly opened on the four side walls of the inner shielding shell (2) and the first screw holes (41) are evenly opened on the platform (23); (2) First, the inner shielding cover (3) is manufactured by machining or casting, and then the inner surface of the inner shielding cover (3) is finely processed in the area where it contacts the platform (23), and the remaining area is subjected to conductive anodizing treatment, and then anti-rust paint is applied to the outer surface of the inner shielding cover (3), and finally, the first countersunk holes (42) are evenly opened in the inner shielding cover (3); (3) firstly, using laser welding to weld the outer shielding shell side plate (71) and the outer shielding shell bottom plate (72) into an outer shielding shell (7), then performing magnetic annealing treatment to improve the magnetic shielding performance, then applying anti-rust paint on the outer surface of the outer shielding shell (7), and finally evenly opening through holes (92) on the upper part of the outer shielding shell side plate (71); (4) Processing the outer shielding cover (8) by the method of step (3), and evenly opening second countersunk holes (93) on the side wall of the outer shielding cover (8); (5) First, place the pole tower sharing device (1) in the inner cavity of the inner shielding shell (2), then place the conductive rubber strip (5) in the groove (22), then fix the inner shielding cover (3) on the platform (23) by means of the first screw (4) and apply the conductive glue (6) in the gap formed by the boss (21) and the inner shielding cover (3); then, cover the outer shielding shell (7) on the outside of the inner shielding shell (2), and cover the outer shielding cover (8) on the outer shielding shell (7); finally, insert the second screw (9) through the second countersunk hole (93), the through hole (92) and the second screw hole (91) in sequence to fix the outer shielding cover (8), the outer shielding shell (7) and the inner shielding shell (2) together.

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