500kV indoor GIS double-layer outgoing line structure with lightning arrester arranged at high position and method

Abstract

The invention discloses a 500kV indoor GIS (Gas Insulated Switchgear) double-layer outgoing line structure and method with lightning arresters arranged at high positions, which comprises an upper-layer framework, a lower-layer framework, a second three-phase lightning arrester arranged on the upper-layer framework, a first three-phase lightning arrester arranged on the lower-layer framework, a second three-phase lightning arrester arranged on the lower-layer framework, a second three-phase lightning arrester arranged on the lower-layer framework, and a third three-phase lightning arrester arranged on the lower-layer framework, the three-phase wire outlet loop is connected with a three-phase wire outlet loop on the upper- The three-phase wires are arranged on the upper-layer framework and the lower-layer framework, the three-phase wires on the upper-layer framework and the three-phase wires on the lower-layer framework are the same, and the phase distances between the three-phase wires are equal. Under the condition of the same outgoing line interval, the double number of outgoing line loops is achieved, the occupied area and the investment amount can be reduced for a new project, and the project requirements of multiple outgoing line loops can be met for an extension project on the basis of the limited reserved outgoing line interval. And the high-position arrangement of the lightning arrester is the same as the width of a conventional 500kV outgoing line framework, so that the improvement on a road is avoided, and the influence on existing facilities is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer substation outgoing line structures, and in particular relates to a 500kV indoor GIS double-layer outgoing line structure and method with a lightning arrester arranged at a high position. Background Art

[0002] In 2022, my country's electricity demand will grow steadily, with total electricity consumption reaching 8.6 trillion kWh, a year-on-year increase of 3.6%. The electricity consumption structure will continue to be optimized, maintaining the trend of shifting from secondary industry to tertiary industry and residents' daily life. In the next three years, the national electricity demand will continue to grow rigidly, and it is estimated that in 2025, the total electricity consumption will reach 9.8 trillion to 10.2 trillion kWh. This will increase the number and scale of substations to meet the needs of power conversion.

[0003] However, when GIS adopts an overhead line-out method, the width of the line-out structure needs to meet the phase-to-phase distance and the distance relative to the ground of the lines, resulting in the traditional "single-column" GIS line-out solution occupying a much longer length than the GIS equipment itself, which increases the overall area and construction cost of the substation.

[0004] On the one hand, due to the restrictions of external conditions such as urban land use planning and outgoing line corridors, the difficulty of substation site selection is increasing. On the other hand, the continuous expansion of the outgoing line scale of substations has put forward higher requirements for substation expansion projects.

[0005] At present, the GIS double-layer overhead line structure is used in many projects. This solution arranges the lightning arresters and voltage transformers of the two outgoing lines on both sides of the GIS respectively.

[0006] The arrester and voltage transformer of the lower outgoing line are placed on the outgoing line side of the GIS, and the outgoing line is completed through the outgoing line side frame. The arrester and voltage transformer of the upper outgoing line loop are arranged on the incoming line side of the GIS, connected to the suspended insulator string of the incoming line side frame through soft wires, and then connected to the line conductor through the crossover wire between the incoming line side frame and the outgoing line side frame, forming a complete upper outgoing line loop. Although this double-layer outgoing line scheme can meet the scale of realizing two outgoing lines within the interval of one frame, the scheme has a large construction workload and substation construction cost due to the setting of the incoming line side frame and crossover wire. Summary of the invention

[0007] The purpose of the present invention is to provide a 500kV indoor GIS double-layer outgoing line structure and method with a high-position lightning arrester, so as to solve the technical defects of the prior art in that the construction workload and substation construction cost are large due to the setting of an incoming line side frame and a cross-line.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: In the first aspect, a 500kV indoor GIS double-layer outgoing line structure with a high-position lightning arrester is provided, comprising: The upper frame and the lower frame are installed on the 500kV outgoing line side of the substation, and there is a distance between the upper frame and the lower frame; Three-phase conductors are arranged on the upper frame and the lower frame, the three-phase conductors on the upper frame and the lower frame are the same, and the phase spacing between the three-phase conductors is equal; The first three-phase lightning arrester and the first GIS voltage transformer are arranged on the ground and connected to the three-phase conductor outgoing line loop on the lower frame; The second three-phase lightning arrester is arranged on the beam of the lower frame and is connected to the three-phase conductor outgoing line loop on the upper frame.

[0009] Furthermore, the height between the second three-phase lightning arrester and the ground is 23m~25m.

[0010] Furthermore, the upper structure is 12m to 14m higher than the lower structure.

[0011] Furthermore, the upper frame and the lower frame are arranged on the same frame.

[0012] Furthermore, the three-phase conductors include three-phase conductors A, B and C, and the phase spacing between the three-phase conductors A, B and C on the upper frame is 6m to 8m; The phase spacing between the A, B and C three-phase conductors on the lower frame is also 6m~8m.

[0013] Furthermore, the first three-phase lightning arrester is installed on the ground in a straight line.

[0014] Furthermore, suspension insulators and supporting insulators are installed on the lower frame beams, and suspension insulators are also installed on the cantilever arms of the upper frame; wherein, the upper outgoing wires of the upper frame are connected through the suspension insulators and supporting insulators on the lower frame beams and the suspension insulators installed on the cantilever arms of the upper frame.

[0015] Furthermore, the upper frame and the lower frame have different structures.

[0016] Furthermore, a lightning protection line is provided on the upper structure.

[0017] In a second aspect, a method for using a 500kV indoor GIS double-layer outgoing line structure with a high-position lightning arrester is provided, wherein the method is performed using the double-layer outgoing line structure as described above, and comprises: Preset the installation position of the frame and install the frame; An upper frame and a lower frame are sequentially installed on the frame, and the distance between the upper frame and the lower frame is 12m~14m.

[0018] Install three-phase conductors on the upper and lower frames, and make the phase spacing between the conductors of each phase equal; The three lightning arresters of the upper outgoing line circuit of the upper structure are installed on the beams of the lower structure, and the three-phase lightning arresters of the upper and lower outgoing line circuits of the lower structure are installed on the ground, and the three-phase lightning arresters of the upper structure are placed 23m~25m away from the ground.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Compared with the conventional GIS outgoing line structure, the outgoing line structure with high-position lightning arrester can achieve the goal of completing two outgoing lines in one outgoing line interval without increasing the incoming line frame and cross-line. This can not only reduce the length of GIS main busbar and branch busbar in the newly built substation, and realize the compact layout of the distribution device. It can also meet the needs of multiple outgoing lines under the conditions of limited interval and floor space in the substation expansion project, reducing the construction workload and substation construction cost.

[0020] 2. Under the condition of the same outgoing line interval, the number of outgoing line circuits can be doubled, which can reduce the floor space and investment amount for new construction projects, and meet the engineering requirements of multiple outgoing line circuits based on the limited reserved outgoing line interval for expansion projects. The "high-position arrangement of lightning arresters" is the same as the width of the conventional 500kV outgoing line frame, avoiding the improvement of roads, reducing the impact on existing facilities, and realizing the convenience of substation operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is the existing 500kV GIS conventional outgoing line layout diagram; Figure 2 This is the cross-sectional diagram of the conventional outgoing line of the existing 500kV GIS; Figure 3 The plane layout of the 500kV GIS equilateral triangle outgoing line in the existing 500kV indoor GIS double-layer outgoing line structure with high-position lightning arresters; Figure 4The cross-sectional view of the 500kV GIS regular triangle outgoing line in the existing 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement; Figure 5 A plan view of a 500kV GIS double-layer outgoing line arrangement with a high-positioned lightning arrester in a 500kV indoor GIS double-layer outgoing line structure with a lightning arrester high-positioned provided by the present invention; Figure 6 A cross-sectional view of a 500kV GIS double-layer outgoing line structure with a high-position arrangement of a lightning arrester provided by the present invention; Figure 7 The present invention provides a flow chart of the method for using a 500kV indoor GIS double-layer outgoing line structure with a high-position lightning arrester. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0027] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0028] When GIS adopts an overhead line-out method, the width of the line-out structure needs to meet the phase-to-phase distance and the distance relative to the ground. As a result, the length of the traditional "single-column" GIS line-out solution is much longer than the length of the GIS equipment itself, which increases the overall area and construction cost of the substation.

[0029] On the one hand, due to the restrictions of external conditions such as urban land use planning and outgoing line corridors, the difficulty of substation site selection is increasing. On the other hand, the continuous expansion of the outgoing line scale of substations has put forward higher requirements for substation expansion projects.

[0030] At present, the GIS double-layer overhead line structure is used in many projects. This solution arranges the lightning arresters and voltage transformers of the two outgoing lines on both sides of the GIS respectively.

[0031] The arrester and voltage transformer of the lower outgoing line are placed on the outgoing line side of the GIS, and the outgoing line is completed through the outgoing line side frame. The arrester and voltage transformer of the upper outgoing line loop are arranged on the incoming line side of the GIS, connected to the suspended insulator string of the incoming line side frame through soft wires, and then connected to the line conductor through the crossover wire between the incoming line side frame and the outgoing line side frame, forming a complete upper outgoing line loop. Although this double-layer outgoing line scheme can meet the scale of realizing two outgoing lines within the interval of one frame, the scheme has a large construction workload and substation construction cost due to the setting of the incoming line side frame and crossover wire.

[0032] In order to solve the above technical defects, the inventor provides a 500kV indoor GIS double-layer outgoing line structure and method with a high-position lightning arrester.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 3-Figure 6 As shown, in the first aspect of the embodiment of the present invention, a 500kV indoor GIS double-layer outgoing line structure with a high-position lightning arrester is provided, the structure includes an upper frame and a lower frame, the upper frame and the lower frame are installed on the 500kV outgoing line side of the substation, the upper frame and the lower frame are arranged on the same frame, and the upper frame and the lower frame are arranged at an interval, the upper frame is 12m~14m higher than the lower frame, specifically 13m; three-phase conductors, including A, B and C three-phase conductors, A, B and C three-phase conductors are arranged on the upper frame and the lower frame, the three-phase conductors on the upper frame and the lower frame are the same, The phase spacing between the conductors of each phase is equal. Specifically, the phase spacing between the three-phase conductors A, B and C on the upper frame is 6m~8m, specifically 7m, and the phase spacing between the three-phase conductors A, B and C on the lower frame is also 6m~8m, specifically 7m; the first three-phase lightning arrester and the first GIS voltage transformer are arranged on the ground and connected to the outgoing line circuit of the three-phase conductor on the lower frame. The first three-phase lightning arrester is installed on the ground in a straight line; the second three-phase lightning arrester is arranged on the beam of the lower frame and connected to the outgoing line circuit of the three-phase conductor on the upper frame, and the height between the second three-phase lightning arrester and the ground is 23m~25m. Suspension insulators and supporting insulators are installed on the beams of the lower frame, and suspension insulators are also installed on the cantilever of the upper frame; wherein, the upper outgoing line of the upper frame is completed through the suspension insulators on the beams of the lower frame, the supporting insulators and the suspension insulators installed on the cantilever of the upper frame. Furthermore, the upper frame and the lower frame have the same structure, and a lightning conductor is also provided on the upper frame.

[0034] like Figure 1-Figure 2 As shown in the figure, it can be seen that the previous project planned to have 8 500kV outgoing lines to the west, 6 outgoing line intervals have been built, and two outgoing line intervals are reserved. The three-phase lightning arrester and voltage transformer on the outgoing line side are arranged on the ground and connected to the GIS bushing outgoing line through soft wires. The line conductor hanging point is 24m above the ground, the lightning arrester is 32m above the ground, and the lightning rod is 38m above the ground. The current expansion project needs to have four outgoing lines in the two reserved intervals. Since there is a branch busbar on the GIS incoming line side, the frame cannot be arranged, resulting in the inability to implement the traditional double-layer outgoing line solution. The conventional outgoing line method cannot meet the current expansion needs of this project.

[0035] In order to reasonably arrange the 500kV outgoing line interval, a "equilateral triangle" double-layer outgoing line scheme was first proposed. The "equilateral triangle" double-layer outgoing line scheme fully combines the characteristics of GIS equipment connection and flexible layout. By raising the B-phase outgoing line, the outgoing line interval width is compressed, and the three-phase conductors of the outgoing line are arranged in an equilateral triangle. The two outgoing lines share a gate-type frame. It meets the outgoing line requirements of this project, while reducing the length of the GIL branch pipeline and saving project investment.

[0036] There are two aspects to consider when determining the interval width. One aspect is to consider the electrical distance of the upper overhead flexible conductor. First, when the flexible conductor is at the center of the span and the maximum phase-to-phase swing occurs (considering the asynchronous swing), the phase-to-phase conductor should not discharge.

[0037] Secondly, in the gate-type frame of the incoming and outgoing lines, when the side phase jumper experiences the maximum swing, the frame should not be discharged. On the other hand, considering the electrical equipment installed on the ground in the circuit, firstly, the phase-to-phase distance of the electrical equipment should meet the requirements of the minimum electrical distance between phases and the electrical distance when transporting equipment between phases. Secondly, the side phase electrical equipment arranged under and near the gate-type frame should not discharge the structure. At the same time, the requirements for the maintenance distance of the side phase electrical equipment of two adjacent circuits should also be considered. Since the "equilateral triangle" distribution device only optimizes the outgoing line frame and uses GIS equipment, it is only necessary to consider the electrical distance between the down conductor and the outgoing conductor of the outgoing line. like Figure 3 and Figure 4 As shown in the figure, the three-phase voltage transformer of the outgoing line circuit adopts GIS voltage transformer, and the three-phase lightning arrester is staggered on the ground. The A and C phases are connected through the lower frame, and the B phase is connected through the suspension insulator on the lower frame beam, the support insulator and the suspension insulator installed on the upper frame cantilever. The three-phase outgoing line is in the shape of an "equilateral triangle" in space. Figure 3 and Figure 4 It can be seen that in the absence of a surge arrester, the phase-to-phase distance between A and C is 7 meters, which is the same as the conventional 500kV GIS outgoing line structure; the conductor spacing between adjacent different circuits is 7 meters, which meets the requirement of a 5.8-meter distance for power outages and maintenance at different times. At the same time, considering the swings in different periods, the requirements can be met by empirical calculations of the swings in different periods.

[0038] Through the calculation of the windage swing of the down conductor, it can be known that this distance meets the electrical distance requirements under the main working conditions. By raising the B phase by 13 meters, it can meet the phase-to-phase electrical distance requirements and the needs of line cross wiring.

[0039] In summary, the "equilateral triangle" outgoing line scheme can meet the engineering requirements of four outgoing lines in two intervals. However, the "equilateral triangle" outgoing line scheme has two 500kV lines per frame, and the width needs to be increased to 33 meters, which exceeds the reserved space and requires local road diversion. For this reason, the "high-position lightning arrester arrangement" scheme is proposed to increase the outgoing line circuit based on the original reserved interval.

[0040] For conventional 500kV GIS outgoing lines, the structure and principle of the 500kV "high-position lightning arrester" double-layer outgoing line solution is to make full use of the spatial distance of the frame to meet the requirements of the safety distance between different phases of equipment. Figure 5 and Figure 6As shown, the three-phase voltage transformer of the outgoing line circuit adopts GIS voltage transformer, the three-phase lightning arrester of the lower outgoing line is installed on the ground in a "straight" shape, and the three-phase lightning arrester of the upper outgoing line is installed on the beam of the lower frame. The upper outgoing line is completed through the suspension insulator on the lower frame beam, the support insulator and the suspension insulator installed on the upper frame cantilever. As can be seen from the figure, in the absence of a wave arrester, the phase-to-phase distance between the A, B, and C outgoing lines from the lower frame to the interconnection transformer is 7 meters, which is the same as the conventional 500kV GIS outgoing line frame; the phase-to-phase distance between the A, B, and C outgoing lines from the upper frame to the reserved outgoing lines is also 7 meters. The upper frame is 13 meters higher than the lower frame, making full use of the space distance to achieve the requirement of two 500kV lines in one bay, so that the "high-position lightning arrester arrangement" double-layer outgoing line scheme fully utilizes the space distance. Each frame is 26 meters wide, the same as the conventional 500kV outgoing line frame, avoiding the improvement of the road. Compared with the conventional GIS outgoing line structure, the outgoing line structure with high-position lightning arrester arrangement can achieve the goal of completing the scale of two outgoing lines in one outgoing line interval without increasing the incoming line frame and cross-line. This can not only reduce the length of the GIS main bus and branch bus in the newly built substation, and realize the compact layout of the distribution device. It can also meet the needs of multiple outgoing lines under the conditions of limited intervals and floor space in the substation expansion project, reducing the construction workload and substation construction costs.

[0041] In a second aspect, an embodiment of the present invention provides a method for using a 500kV indoor GIS double-layer outlet structure with a lightning arrester arranged at a high position, wherein the method is performed using the double-layer outlet structure as described above, such as Figure 7 As shown, including: S101, preset a truss frame installation position, and install the truss frame; illustratively, install the truss frame on one side of the high resistance, and make the truss frame axially perpendicular to the ground.

[0042] S102. Install an upper frame and a lower frame on the frame in sequence, and make the distance between the upper frame and the lower frame be 12m~14m; exemplarily, install the upper frame and the lower frame on the frame from top to bottom, the structures of the upper frame and the lower frame are the same, and during the installation process, make the distance between the upper frame and the lower frame be 13m, so as to form a double-layer outgoing line structure; then set the first three-phase lightning arrester and the first GIS voltage transformer on the ground, and connect them to the three-phase conductor outgoing line loop on the lower frame, and the first three-phase lightning arrester is installed on the ground in a straight line; the second three-phase lightning arrester is set on the beam of the lower frame, and connected to the three-phase conductor outgoing line loop on the upper frame, and the second GIS voltage transformer is set on the ground, and the height between the second three-phase lightning arrester and the ground is 23m~25m.

[0043] S103, installing three-phase conductors on the upper frame and the lower frame, and making the phase spacing between the phase conductors equal; illustratively, the three-phase conductors include A, B and C three-phase conductors, and the A, B and C three-phase conductors are arranged on the upper frame and the lower frame. The three-phase conductors on the upper frame and the lower frame are the same, and the phase spacing between the phase conductors is equal. Specifically, the phase spacing of the A, B and C three-phase conductors on the upper frame is 7m, and the phase spacing of the A, B and C three-phase conductors on the lower frame is also 7m.

[0044] S104, install the three lightning arresters of the upper outgoing line circuit of the upper frame on the beam of the lower frame, install the three-phase lightning arresters of the upper and lower outgoing line circuits of the lower frame on the ground, and make the second three-phase lightning arrester of the upper frame be located on the lower frame, 23m~25m from the ground. Exemplarily, compared with the conventional GIS outgoing line structure, the high-position outgoing line structure of the GIS lightning arrester can achieve the goal of completing the scale of two outgoing lines in one outgoing line interval without increasing the incoming line frame and cross-line. This can reduce the length of the GIS main busbar and branch busbar in the newly built substation and realize the compact layout of the distribution device. It can also meet the demand for multiple outgoing lines under the conditions of limited intervals and floor space in the substation expansion project, reducing the construction workload and substation construction costs.

[0045] 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 its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester, characterized in that: include: The upper frame and the lower frame are installed on the 500kV outgoing line side of the substation, and there is a distance between the upper frame and the lower frame; Three-phase conductors are arranged on the upper frame and the lower frame, the three-phase conductors on the upper frame and the lower frame are the same, and the phase spacing between the three-phase conductors is equal; The first three-phase lightning arrester and the first GIS voltage transformer are arranged on the ground and connected to the three-phase conductor outgoing line loop on the lower frame; The second three-phase lightning arrester is arranged on the beam of the lower frame and is connected to the three-phase conductor outgoing line loop on the upper frame.

2. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The height between the second three-phase lightning arrester and the ground is 23m~25m.

3. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The upper structure is 12m to 14m higher than the lower structure.

4. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The upper frame and the lower frame are arranged on the same frame.

5. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The three-phase conductors include A, B and C three-phase conductors, and the phase spacing between the A, B and C three-phase conductors on the upper frame is 6m to 8m; The phase spacing between the A, B and C three-phase conductors on the lower frame is also 6m~8m.

6. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The first three-phase lightning arrester is installed on the ground in a straight line shape.

7. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: Suspension insulators and supporting insulators are installed on the lower frame beams, and suspension insulators are also installed on the cantilever of the upper frame; wherein, the upper layer outgoing wires of the upper frame are completed through the suspension insulators and supporting insulators on the lower frame beams and the suspension insulators installed on the cantilever of the upper frame.

8. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: The upper frame and the lower frame have different structures.

9. The 500kV indoor GIS double-layer outgoing line structure with high-position lightning arrester arrangement according to claim 1 is characterized in that: A lightning protection line is also arranged on the upper structure.

10. A method for using a 500kV indoor GIS double-layer outgoing line structure with a high-position lightning arrester, characterized in that: The method is carried out using the double-layer outlet structure according to any one of claims 1 to 9, comprising: Preset the installation position of the frame and install the frame; An upper frame and a lower frame are sequentially installed on the frame, and the distance between the upper frame and the lower frame is 12m-14m; Install three-phase conductors on the upper and lower frames, and make the phase spacing between the conductors of each phase equal; The three lightning arresters of the upper outgoing line circuit of the upper structure are installed on the beams of the lower structure, and the three-phase lightning arresters of the upper and lower outgoing line circuits of the lower structure are installed on the ground, and the three-phase lightning arresters of the upper structure are placed 23m~25m away from the ground.

Images