CN101232163B - Protection method and device for gap lightning protection - Google Patents

Abstract

The invention relates to a gap lightning protection protection method and a device thereof, which belong to the technical field of lightning protection of power system distribution lines. The arc starting metal rod and the grounding arc starting metal rod with the arc starting distance are installed on an insulator, and the insulator Installed on the grounding end of the arc-resistant insulator, so that the grounding arc-starting metal rod is electrically connected to the grounding end of the arc-resistant insulator; an arc-starting insulated soft wire electrically connects the puncture clamp installed on the overhead insulated wire with the arc-starting metal rod, When lightning strikes, the lightning overvoltage on the overhead insulated wire breaks down the arc-starting distance and causes an arc, which causes the continuous-flow power-frequency arc to move to the arc-starting metal rod for burning. The invention has the advantages of low cost of manufacture and use, simple structure, no change of the positions of the arc-resistant insulator and the piercing wire clip on the original circuit, high temperature during discharge will not affect the arc-resistant insulator and the piercing wire clip, and reliable arc starting.

Description

Protection method and device for gap lightning protection

technical field

The invention relates to a gap lightning protection protection method and a device thereof for preventing overhead insulated cables from being broken by lightning, and belongs to the technical field of lightning protection of distribution lines in electric power systems.

Background technique

Power systems such as 10kV or 20kV distribution overhead lines mostly use insulated overhead wires. In order to prevent lightning from breaking overhead insulated wires, as disclosed in CN1238864C "Puncture Clamp Insulator for Preventing Lightning Breakage of Overhead Insulated Wires", arc-resistant insulators, puncture wire clamps, and arc-resistant insulators and puncture wire clamps are used. The insulated flexible wires between the piercing wire clips are installed on the overhead insulated wires to pierce the insulation layer of the insulated wires so that the piercing wire clips are electrically connected to the wires. One end of the insulated flexible wires is installed on the piercing wire clips, and the other end is connected to the arc-resistant insulator The high-voltage electrode end of the arc-resistant insulator is electrically connected so that the potential of the arc-resistant insulator and the puncture clamp are the same. When the lightning discharges at high voltage, the arc root of the continuous power-frequency short-circuit current arc is fixed on the high-voltage electrode of the arc-resistant insulator and burns to protect the overhead insulation. The wires are free from blown. However, this kind of structure leads the high-voltage arc to the arc-resistant insulator, so that the arc root of the continuous-flow power-frequency arc burns on the high-voltage electrode of the arc-resistant insulator, which may easily cause damage to the arc-resistant insulator and affect the reliability of the line work. The "arc-resistant puncture fittings used to prevent lightning breakage of overhead insulated wires" disclosed by CN1481057A adopts puncture wire clips, grounding arc-starting electrodes, arc-resistant electrodes and insulating covers, and the puncture wire clips pierce the insulation layer of insulated wires to The puncture clamp is electrically connected to the wire, the arc-resistant electrode is electrically connected to the puncture clamp, the insulating cover is fixed on the outside of the puncture clamp for insulation and arc limitation, and the ground arc electrode is installed on the ground terminal of the line insulator for electrical connection, so that lightning When it happens, discharge occurs between the puncture wire clip and the grounded arc-starting electrode, so that the continuous-flow power-frequency arc moves to the arc-resistant electrode for burning, and protects the overhead insulated wire from being burned. The arc-resistant puncture fitting of this structure discharges through the discharge distance between the grounded arc-starting electrode and the arc-resistant electrode when lightning strikes, because the arc-resistant electrode is installed on the puncture clamp, and the grounded arc-starting electrode is installed on the line insulator On the one hand, the installation and construction are all high-altitude operations. Since the arc striking distance between the arc-resistant electrode on the piercing wire clip and the grounding arc striking electrode on the line insulator cannot be guaranteed, especially in lightning weather and wind and rain, the overhead insulated wire will shake. However, changing the arc striking distance reduces the reliability of lightning protection. On the other hand, since the arc-resistant electrode is installed on the puncture wire clamp, the continuous-flow power-frequency arc is burnt on the arc-resistant electrode during a lightning strike, and the current intensity of the lightning strike can reach tens of thousands of amperes, and the temperature can reach 20,000 degrees Celsius. The arc-resistant electrode is close to the overhead insulated wire, and the local high temperature will affect the insulation layer of the overhead insulated wire around the piercing wire clip and the piercing wire clip.

Contents of the invention

The purpose of the present invention is to provide a low-cost, simple structure, does not change the position of the arc-resistant insulator and the piercing line clamp on the original line, the high temperature during discharge will not affect the arc-resistant insulator and the piercing line clamp, and the arc is reliable A protection method and device for gap lightning protection.

In order to achieve the above-mentioned technical solution, the present invention is: a protection method for gap lightning protection, which is characterized in that: the arc-starting metal rod with the arc-starting distance and the grounding arc-starting metal rod are installed on an insulator, and the insulator is installed on the arc-resistant The grounding end of the insulator is used to electrically connect the grounding arc-starting metal rod to the grounding end of the arc-resistant insulator; an arc-starting insulated flexible wire is electrically connected to the puncture clamp installed on the overhead insulated wire and the arc-starting metal rod. The lightning overvoltage on the insulated wire breaks down the arc-starting distance and causes an arc, which moves the freewheeling power-frequency arc to the arc-starting metal rod for burning.

The gap lightning protection device of the present invention includes an arc-resistant insulator, a piercing wire clip and an arc-starting insulated flexible wire, and the piercing wire clip penetrates the insulation layer of the overhead insulated wire and is connected to the conductor inside it, and is characterized in that: The high-voltage end of the arc-resistant insulator is electrically connected to the overhead insulated wire, and the grounding end of the arc-resistant insulator is connected to an insulator. It is electrically connected with the grounding end of the arc-resistant insulator, and the two ends of the arc-starting insulated soft wire are respectively electrically connected with the arc-starting metal rod and the piercing wire clamp.

In the present invention, an insulator is connected to the grounding end of the arc-resistant insulator. The insulator has an arc-starting metal rod and a grounding arc-starting metal rod. The grounding arc-starting metal rod is electrically connected to the grounding end of the arc-resistant insulator. The arc insulated flexible conductor is connected to the arc strike metal rod, so when lightning strikes, the lightning arc energy can be transferred from the overhead insulated conductor to the arc strike metal rod through the puncture clamp and the arc strike insulated flexible conductor in a very short time. The arc is caused by piercing the arc spacing, and the grounding terminal of the arc-resistant insulator is connected to the ground, so as to protect the overhead insulated conductor and the arc-resistant insulator from damage. The invention installs the arc-starting metal rod and the grounding arc-starting metal rod on the insulator, and the insulator mainly bears its own weight, so the endurance requirement is much lower than that of conventional arc-resistant insulators, which not only reduces the manufacturing cost, but also does not damage the circuit insulation. Since the insulator, the arc-starting metal rod and the grounding arc-starting metal rod are connected into one structure, the present invention has a simple structure, no omissions during construction and installation, and can improve construction efficiency. Even if it is damaged by high temperature, it only needs to be removed and replaced, and the use cost is low. Because the present invention does not change the installation position of the arc-resistant insulator and the piercing wire clamp on the original overhead insulated line, only the insulator is installed on the grounding end of the lower part of the arc-resistant insulator, and the arc-starting insulated flexible conductor is connected to the piercing wire clip and the arc-starting wire. On the metal rod, it is very convenient for the online transformation of the lightning protection of the existing overhead insulated lines, and has good usability and economy. In the present invention, the arc-starting insulated flexible wire is connected with the arc-starting metal rod and the puncture wire clip, not only the arc-starting metal rod is moved to the lower part of the arc-resistant insulator, but also the distance between the discharge burning point and the puncture wire clip and the overhead insulating wire is increased, The high temperature will not affect the puncture clamp and the overhead insulated wire, and when the overhead insulated wire is shaken by external force, the insulated arc starting soft wire that plays the role of connection will not be restrained, so that the puncture part of the wire in the puncture clamp will not be affected. damage, to ensure the reliability of lightning protection. The arc starting distance of the present invention is determined by the arc starting distance between the arc starting metal rod installed on the insulator and the grounding arc starting metal rod, and the reliability of the arc starting is guaranteed because it will not be affected by other external forces.

Description of drawings

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a structural schematic diagram of the present invention.

Among them: 1-overhead insulated wire, 2-arc-resistant insulator, 3-horizontal sheet, 4-grounding arc metal rod, 5-insulator, 6-arc metal rod, 7-arc insulated flexible wire, 8-puncture wire folder.

Detailed ways

The protection method of the gap lightning protection of the present invention installs the arc-starting metal rod 6 with the arc-starting distance A and the grounding arc-starting metal rod 4 on an insulator 5, and the insulator 5 is installed on the grounding end of the arc-resistant insulator 2, so that the grounding lead The arc metal rod 4 is electrically connected to the ground terminal of the arc-resistant insulator 2 . An arc-starting insulated flexible conductor 7 electrically connects the piercing wire clip 8 installed on the overhead insulated wire 1 with the arc-starting metal rod 6, so that the two are at the same potential. 8 and the arc-starting insulated flexible conductor 7 to the arc-starting metal rod 6, and the lightning strike overvoltage on the overhead insulated wire breaks down the arc-starting distance A to cause an arc, so that the freewheeling power-frequency arc moves to the arc-starting metal rod 6 for burning, and The ground terminal of the arc-resistant insulator 2 is led to the earth, and the lightning arc energy is transferred from the overhead insulated wire in a very short time, thereby protecting the overhead insulated wire from damage.

As shown in Figure 1, the gap lightning protection device of the present invention includes an arc-resistant insulator 2, a piercing wire clip 8 and an arc-strike insulated flexible wire 7, and the piercing wire clip 8 is installed on the overhead insulated wire 1, and penetrates the overhead insulation The insulating layer of the conductor 1 connects the puncture clamp 8 to the conductor of the overhead insulated conductor 1, the high voltage end of the arc-resistant insulator 2 is electrically connected to the overhead insulated conductor 1, and the grounding end of the arc-resistant insulator 2 is connected to the insulator 5, which is 5 is connected to the grounding end of the arc-resistant insulator 2 through the horizontal sheet 3 and fasteners. In order to reduce the volume of the insulator 5, the outer edge of the insulator 5 is provided with 3 to 6 sheds to increase the creepage distance. The arc-starting metal rod 6 and the grounding arc-starting metal rod 4 are respectively installed, and are located in the opposite direction of the overhead insulated conductor 1. The grounding arc-starting metal rod 4 is electrically connected to the grounding end of the arc-resistant insulator 2, which can make the insulator 5 conduct electricity. The metal is connected to the grounding insulated metal rod 4, and the two ends of the arc-starting insulated flexible wire 7 are electrically connected to the arc-starting metal rod 6 and the puncture clamp 8 respectively, so that the overvoltage during lightning strikes is transmitted from the overhead insulated wire 1 through the arc-starting insulated soft wire. The wire 7 is led to the arc-starting metal rod 6. There is an arc-starting distance A between the arc-starting metal rod 6 and the grounding arc-starting metal rod 4. The arc-starting distance A is between 100 and 250 mm. The distance A triggers the arc, so that the continuous flow power frequency arc moves to the arc-starting metal rod 6 for burning, and connects to the ground through the grounding end of the arc-resistant insulator 2, so as to protect the overhead insulated conductor 1, the arc-resistant insulator 2 and the puncture clamp 8 from being damaged. damage.

The present invention effectively controls the arc striking distance A for different voltage levels, the arc striking metal rod 6 installed on the insulator 5 can be adjusted axially along the insulator 5, the connecting part of the arc striking metal rod 6 is provided with a via hole, and The connecting part of the insulator 5 is provided with threads, and the locking nut connects the arc striking metal rod 6 to the insulator 5 , and an adjusting gasket is arranged between the insulator 5 and the arc striking metal rod 6 . In the present invention, the grounding arc starting metal rod 4 installed on the insulator 5 can also be adjusted axially along the insulator 5. Similarly, the connecting part of the grounding arc starting metal rod 4 is provided with a via hole, and the connecting part of the insulator 5 is provided with a screw thread for locking. The nut connects the grounding arc starting metal rod 4 to the insulator 5 , and an adjusting gasket is arranged between the insulator 5 and the grounding arc starting metal rod 4 .

Claims (6)

1. A protection method for gap lightning protection, characterized in that: the arc-starting metal rod with the arc-starting distance and the grounding arc-starting metal rod are installed on an insulator, and the insulator is installed on the grounding end of the arc-resistant insulator, so that the grounding lead The arc metal rod is electrically connected to the grounding end of the arc-resistant insulator; an arc-starting insulated soft wire electrically connects the puncture clamp installed on the overhead insulated wire with the arc-starting metal rod. When a lightning strike occurs, the lightning overvoltage on the overhead insulated wire will The arc is caused by piercing the arc spacing, so that the continuous flow power frequency arc moves to the arc metal rod for burning. 2. A gap lightning protection device, comprising an arc-resistant insulator (2), a piercing wire clip (8) and an arc-strike insulated flexible wire (7), and the piercing wire clip (8) penetrates the insulation of the overhead insulated wire (1) Layer and connected with the conductor inside, it is characterized in that: the high-voltage end of the arc-resistant insulator (2) is electrically connected with the overhead insulated wire (1), and the grounding end of the arc-resistant insulator (2) is connected with an insulator (5) , the insulator (5) is respectively equipped with an arc striking metal rod (6) and a grounding arc striking metal rod (4) with an arc striking distance A, and the grounding end of the grounding arc striking metal rod (4) and the arc resistant insulator (2) Electrically connected, the two ends of the arc-starting insulated soft conductor (7) are electrically connected with the arc-starting metal rod (6) and the piercing wire clamp (8) respectively. 3. The gap lightning protection device according to claim 2, characterized in that the insulator (5) is connected to the grounding end of the arc-resistant insulator (2) through a horizontal sheet (3) and fasteners. 4. The gap lightning protection device according to claim 2 or 3, characterized in that 3 to 6 sheds are provided on the outer edge of the insulator (5) to increase the creepage distance. 5. The gap lightning protection device according to claim 2, characterized in that the arc-starting metal rod (6) installed on the insulator (5) can be adjusted axially along the insulator (5). 6. The gap lightning protection device according to claim 2, characterized in that the grounded arc-starting metal rod (4) installed on the insulator (5) can be adjusted axially along the insulator (5).

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