CN201975524U - Arrangement structure for lightning protection grounding device of power tower - Google Patents

Abstract

The utility model discloses an arrangement structure for a lightning protection grounding device of a power tower, which comprises a grounding leg (1) of a tower. A grounding wire (2) is connected with the grounding leg (1) and is laid in a trench. The grounding wire (2) is connected with a vertical grounding body (3) perpendicular to the ground. As the vertical grounding body perpendicular to the ground is connected to the grounding wire, the electric conductivity of the grounding leg near the tower is increased. The vertically arranged vertical grounding body can enable lightning stroke currents to spread deeper underground, so as to effectively use the advantage of strong electric conductivity of deep soil. The node connecting the grounding wire and the vertical grounding body is connected with branches of the grounding wire, and the branches of the grounding wire in the innermost ring are connected mutually into a ring shape, which can further increase the electric conductivity near the grounding leg of the tower, thereby ensuring the lightning protection effect.

Description

Arrangement structure of lightning protection and grounding device for power tower

technical field

The utility model relates to an arrangement structure of a lightning protection and grounding device for a power tower, belonging to the technical field of lightning protection and grounding.

Background technique

Among all the equipment in the power grid, the probability of failure of power transmission equipment due to lightning strikes accounts for 60%-80%, so lightning protection and grounding devices occupy an important position in the power industry. The lightning protection of existing power towers is to connect the grounding wires to the four grounding legs of the tower respectively. The arrangement of this lightning protection grounding device can meet the lightning protection requirements in the early stage of laying, but as time goes by, all The conductivity of the laid lightning protection grounding device will change with the geological soil conditions of the geographical location, making it unable to reach the conductivity. For example, in rocky areas or karst areas, the former is due to the high resistivity caused by silicon content. If it is too low, the latter will affect the resistivity due to rock faults in geology, and the resistivity will also be affected by the moisture content in the soil in the soil layer. Due to the above reasons, when a strong current flows through the base of the tower, there will be a phenomenon that the lightning current is too late to discharge, causing the line to trip. Therefore, the layout structure of the lightning protection grounding device that can only meet the current detection is too simple and modular , there is a great risk.

Contents of the invention

The technical problem to be solved by the utility model is to provide an arrangement structure of lightning protection and grounding devices for power towers that can ensure the lightning protection performance of power towers and improve the safe operation of power equipment, which can overcome the shortcomings of the prior art.

The technical scheme of the utility model: it includes the grounding leg of the tower rod, the grounding leg is connected with a grounding wire, the grounding wire is laid in the trench, and the grounding wire is connected with a vertical grounding body perpendicular to the ground.

A branch of the grounding line is connected to the node where the grounding line is connected to the vertical grounding body.

The included angle between the branch of the connecting wire closest to the grounding leg and the extending direction of the grounding wire is 90°-120°, and the included angle between the other connecting wire branches and the extending direction of the grounding wire is 120°-135°.

The ground wire branches closest to the ground leg are connected to each other in a ring shape.

The distance between vertical grounding bodies connected to the same grounding wire shall not be less than 5m.

The distance between the grounding branch line and the grounding leg shall not be less than 5m.

The anti-corrosion layer is coated on the grounding wire, the vertical grounding body and the branch of the grounding wire.

Compared with the prior art, the utility model connects the vertical grounding body perpendicular to the ground on the grounding line, which can increase the conductivity near the grounding legs of the tower, and the vertically arranged vertical grounding body can make the lightning strike current travel deeper underground , can effectively take advantage of the strong conductivity of deep soil. Grounding wire branches are connected to the node where the grounding wire is connected to the vertical grounding body, and the innermost ring of grounding wire branches are connected to each other in a ring shape, which can further expand the conductivity of the grounding foot attachment of the tower pole and ensure the lightning protection effect . After the applicant measured the grounding resistance of the transformed tower, it was found that the original resistivity was 1.5-3 times that of the improved resistivity, and the fluctuation range after the transformation was also within the scope of the national safety standard, effectively solving the problem of leakage Tripping phenomenon caused by lack of urgency. Simultaneously, the utility model can also be widely used in the transformation of old pole towers, and has good popularization value.

Instructions attached

Fig. 1 is the structural representation of the utility model.

Detailed ways

Example: Transformation of existing towers

1. Before construction, investigate the geological environment near the tower, and carry out grounding retesting.

(1) The retest result is corrected by the seasonal coefficient (1.3-1.6), and if it exceeds the set value, modification is required: (2) The retest result exceeds I7Ω (not weighted with the seasonal coefficient), regardless of whether it is within the design value range. renovation;

(3) If the grounding resistance of the tower leg is not large in the retest, first check whether there is a breakpoint and connect the breakpoint;

2. Arrangement of lightning protection and grounding devices for power towers

(1) Installation of ground wire 2

The four grounding legs 1 of the tower are connected with the externally projected grounding wire 2, the grounding wire 2 is made of φl0 round steel, and the buried depth is not less than 0.6m: when the grounding wire of the existing tower is reconstructed, the diameter of the existing grounding wire is less than φl0. replace.

(2) Installation of vertical grounding body 3

Install a vertical grounding body 3 on the grounding line 2. The vertical grounding body 3 is made of hot-dip galvanized angle steel of ∠50×50×5. The distance between the vertical grounding body 3 on the grounding line 2 is not less than 5m, and the length is 0.6-1.2 m, depending on the geological conditions, the connection between the vertical grounding body 3 and the grounding wire 2 requires double-sided welding, and the overlapping length is not less than 100mm.

(3) Installation of wiring branch 4

Starting from the newly added vertical grounding body 3 (that is, the node where the grounding line 2 is connected to the vertical grounding body 3), lay the grounding line branch 4 on both sides of the grounding line 2, and the grounding line branch 4 closest to the grounding leg 1 and The angle between the extending directions of the grounding wire 2 is 90°-120°, and the grounding wire branch 4 closest to the grounding leg 1 is connected to each other in a ring shape, but it must be ensured that the distance between the formed grounding ring and the grounding leg 1 of the tower is not less than 5m, and the angle between the branch 4 of the other connecting wires and the extending direction of the grounding wire 2 is 120°-135°.

(4) Backfilling of ground trenches

If there are soil and rocks at the bottom of the ground trench after excavation, fine soil must be spread during laying, with a thickness of not less than 0.1m. After laying, it must be backfilled with fine soil, with a depth of not less than 0.4m. Only after compaction can it be backfilled with soil of other materials.

(5) Anti-corrosion treatment of lightning protection and grounding device

The anti-corrosion treatment includes the treatment of the grounding down conductor, the exposed part of the grounding wire 2, the connection part between the grounding wire 2 and the vertical grounding body 4, the connection part between the grounding module and the grounding wire 2, and the grounding part of the grounding wire 2.

Requirements for anti-corrosion treatment: use asphalt paint or anti-corrosion paint for treatment, and must be painted more than twice.

Claims (7)

1. the arrangement of an electric force pole tower lightning protection device, it comprises the ground connection leg (1) of tower bar, on ground connection leg (1), be connected with earth connection (2), earth connection (2) is laid in the trench, it is characterized in that: be connected with the vertical junction terrain (3) perpendicular to ground on earth connection (2).

2. the arrangement of electric force pole tower lightning protection device according to claim 1 is characterized in that: be connected with earth connection branch (4) on earth connection (2) and node that vertical junction terrain (3) is connected.

3. the arrangement of electric force pole tower lightning protection device according to claim 1 is characterized in that: and the nearest branch of connecting wires (4) of ground connection leg (1) and the angle between earth connection (2) bearing of trend are that angle between 90 °-120 °, all the other branches of connecting wires (4) and earth connection (2) bearing of trend is at 120 °-135 °.

4. the arrangement of electric force pole tower lightning protection device according to claim 3 is characterized in that: the earth connection branch (4) nearest apart from ground connection leg (1) is connected to ring-type.

5. the arrangement of electric force pole tower lightning protection device according to claim 2 is characterized in that: the distance that is connected between the vertical junction terrain (3) on the same earth connection (2) is not less than 5m.

6. the arrangement of electric force pole tower lightning protection device according to claim 4 is characterized in that: ground connection branch line (4) is not less than 5m apart from the distance of ground connection leg (1).

7. the arrangement of electric force pole tower lightning protection device according to claim 1 and 2 is characterized in that: be coated with anticorrosive coat in earth connection (2), vertical junction terrain (3) and the branch of connecting wires (4).

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