CN203166445U - Device using coupling ground line to reduce lightning trip-out rate of transmission line - Google Patents

Abstract

The utility model discloses a device using a coupling ground line to reduce the lightning trip-out rate of a transmission line. The device comprises the coupling ground line (1). The coupling ground line (1) is arranged below a cross arm of a lower conductor (5). A line clip (2) is arranged on the coupling ground line (1). The coupling ground line (1) is connected with a main material (3) through the line clip (2). Two ends of the coupling ground line (1) are sheathed with anti-vibration whips (4). The installation distance of each anti-vibration whip (4) is 150 mm from the rear end of a preformed armor rod of the line clip (2). According to the utility model, by using the effects of shunt and coupling of the coupling ground line, the lightning overvoltage is reduced, and the lightning trip-out rate of the line is reduced.

Description

A device for reducing the lightning tripping rate of transmission lines by using coupled ground wires

technical field

The utility model relates to a device for reducing the lightning strike tripping rate of a power transmission line by using a coupling ground wire. the

Background technique

In recent years, due to the increasing lightning activity, the accidents caused by lightning strikes on the line are increasing, which poses a serious threat to the safe operation of the line and seriously affects the power supply reliability of the transmission line. However, Xinghua is located in a water network area, and some lines have inconvenient traffic. Accident inspections and emergency repairs not only waste huge manpower and material resources, but also increase the labor intensity of operation and maintenance personnel. Therefore, the lightning protection of lines has become an operation and maintenance task. top priority. At present, the lightning protection measures of the transmission line itself mainly rely on the overhead ground wire erected on the top of the tower. The operation and maintenance work is mainly to detect and modify the grounding resistance of the tower. Due to the singleness of the lightning protection measures, it cannot meet the lightning protection requirements. In 2009, Xinghua Company tripped 8 times at 110kV, all of which were caused by lightning strikes, of which 110kV Guzi line tripped twice. The line is located in an area prone to lightning strikes, and most of the surrounding areas are open areas. The iron tower is the tallest building in the surrounding area and is vulnerable to lightning strikes. The line is of standardized design, and the entire line is GJ-50 lightning protection line. The protection angle meets the design requirements and the grounding resistance measurement results Both are less than the design specified value, but they still trip frequently, seriously affecting the safe and stable operation of the line. As the intensity of lightning strikes is increasing and the lightning current exceeds the lightning resistance level of the tower, the insulator string of the tower will flashover, causing the line to trip. This is the main cause of the line trip; The lightning resistance level of the power transmission line with the lightning conductor at the voltage level is as follows. It can be seen that the lightning protection of the lightning conductor is relatively safe, that is, a part of the lightning is allowed to cause the line insulation flashover, so reducing this probability and improving the lightning resistance level are the main reasons. the

Contents of the invention

The utility model provides a device for reducing the lightning strike trip rate of a transmission line by using a coupled ground wire, which utilizes the shunting and coupling functions of the coupled ground wire to reduce the lightning strike overvoltage and reduce the lightning strike trip rate of the line. the

The utility model adopts the following technical solutions: a device for reducing the lightning tripping rate of transmission lines by using the coupling ground wire, which includes a coupling ground wire, the coupling ground wire is arranged under the cross arm of the lower conductor, and a wire clamp is arranged on the coupling ground wire. The coupling ground wire is connected to the main material through the clamp, and the two ends of the coupling ground wire are covered with anti-vibration whips. The installation distance of the anti-vibration whip is 150 mm from the end of the pre-twisted wire of the clamp. the

The coupling ground wire is GJ-35 galvanized steel strand, its maximum service stress is 261.3Mpa, its annual average stress is 294Mpa, and its safety factor is 4.5. The anti-vibration whip is SVD-5050103 anti-vibration whip. The installation distance of the anti-vibration whip is 150 mm outward from the end of the pre-twisted wire of the clamp. The installation position of the coupling ground wire: the linear tower is installed on the main material 4.0m below the cross arm of the lower conductor, and the tension tower is installed on the main material 2.0m below the cross arm of the lower conductor. The clamps are suspension clamps or tension clamps. the

The utility model has the following beneficial effects: the effect of the coupling ground wire of the utility model is:

(1) Increase the coupling coefficient between the lightning conductor and the conductor, thereby reducing the counterattack voltage and induced voltage components of the voltage at both ends of the insulator string;

(2) Increase the lightning current shunted to adjacent towers when lightning strikes the top of the tower. the

For towers with lightning conductors, the maximum voltage on the insulation is:

Uj＝Utd(ha/ht-k)+Ug(1-hg/hc-k0) 

As the coupling coefficients k and k0 increase, the maximum voltage on the insulation decreases. the

(where Utd is the maximum voltage at the top of the tower; Ug is the maximum induced overvoltage on the conductor; K is the coupling coefficient between the conductor and the lightning conductor considering the lightning conductor corona; K0 is the geometric coupling coefficient between the conductor and the lightning conductor ; ha horizontal single-to-ground height, ht tower height, hg lightning conductor height, hc average conductor height). the

(3) Improve the reliability of power supply for equipment: the utility model erecting coupling ground wire can not only improve the lightning resistance level of the transmission line, reduce the lightning tripping rate, but also ensure the reliable power supply of the transmission line. It saves money and reduces the labor intensity of the operation and maintenance personnel, so that the line operation and inspection personnel can devote more energy to the routine operation and maintenance of the line. the

(4) Improve economic benefits: With the application of "coupled ground wire" in line lightning protection, the lightning trip rate is greatly reduced, reducing the power loss due to less power supply on the line, and saving the huge manpower and labor caused by fault inspection and emergency repair. Wealth and material consumption. the

(5) Prediction of social benefits: The reduction of lightning tripping faults improves the reliability of power grid operation and reduces power outages due to faults, which has significant social benefits. the

Description of drawings

Fig. 1 is the structural representation of the utility model

Detailed ways

In Fig. 1, the utility model provides a kind of device that utilizes the coupling ground wire to reduce the lightning strike tripping rate of the transmission line, it includes the coupling ground wire 1, the coupling ground wire 1 is arranged under the cross arm of the lower conductor 5, and the coupling ground wire 1 There is a wire clamp 2 on the top, the wire clamp 2 is a suspension wire clamp or a strain-resistant wire clamp, the coupling ground wire 1 is connected to the main material 3 through the wire clamp 2, and the two ends of the coupling ground wire 1 are covered with anti-vibration whips 4 to prevent vibration The installation distance of the whip 4 is 150 mm from the end of the pre-twisted wire of the clamp 2. The coupling ground wire 1 is a GJ-35 galvanized steel strand with a maximum service stress of 261.3Mpa and an annual average stress of 294Mpa. The safety factor is 4.5, the anti-vibration whip 4 is SVD-5050103 anti-vibration whip, the installation distance of the anti-vibration whip 4 is 150 mm from the end of the pre-twisted wire of the wire clamp, the installation position of the coupling ground wire 1: straight tower Installed on the main material at 4.0m below the cross arm of the lower conductor, and the tension tower is installed on the main material at 2.0m below the cross arm of the lower conductor. the

Claims (5)

1. device that utilizes coupling ground wire to reduce the transmission line lightning stroke trip-out rate, it is characterized in that it comprises coupling ground wire (1), coupling ground wire (1) is arranged on the below of lower wire (5) cross-arm, be provided with wire clamp (2) at coupling ground wire (1), coupling ground wire (1) is connected with main material (3) by wire clamp (2), be with spiral vibration rod (4) at the two ends of coupling ground wire (1), spiral vibration rod (4) mounting distance is terminal outside 150 mm of the preformed armor rods of wire clamp (2).

2. the device that utilizes coupling ground wire to reduce the transmission line lightning stroke trip-out rate according to claim 1, it is characterized in that described coupling ground wire (1) is the GJ-35 galvanized strand wires, its maximum applied stress is 261.3Mpa, and annual stress is 294Mpa, coefficient of safety 4.5.

3. the device that utilizes coupling ground wire to reduce the transmission line lightning stroke trip-out rate according to claim 1 is characterized in that described spiral vibration rod (4) is the SVD-5050103 spiral vibration rod.

4. the device that utilizes coupling ground wire to reduce the transmission line lightning stroke trip-out rate according to claim 1, it is characterized in that described coupling ground wire (1) installation site: tangent tower is installed on the main material at 4.0m place under the lower wire cross-arm, and strain tower is installed on the main material at 2.0m place under the lower wire cross-arm.

5. the device that utilizes coupling ground wire to reduce the transmission line lightning stroke trip-out rate according to claim 1 is characterized in that described wire clamp (2) is suspension clamp or strain clamp.

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