CN103997007A - Protection device for preventing windage yaw flashover of power transmission line - Google Patents

Abstract

The invention discloses a wind deflection flashover protection device for a power transmission line, which comprises a wire, a fitting connected to the wire, an insulator for a power transmission line, a fitting protection device and two wire protection devices located on both sides of the fitting; the wire protection device is arranged on the wire The outer side of the metal fitting is connected to the metal fitting protection device, and the metal fitting protection device is installed on the outer side of the fitting and connected to the transmission line insulator. The invention aims at the most direct cause of wind flashover, which is the most direct cause of wind-bias flashover due to insufficient insulation distance caused by strong wind, which leads to air breakdown and discharge, and increases the electrical insulation strength between the wire and the tower. The invention effectively eliminates the problem of electric field distortion between the wire and the insulating sheath, and between the fittings and the insulating sheath box, and avoids the greatly reduced effect of preventing wind and partial flashover caused by excessive local field strength. The invention effectively prevents water from entering the insulating sheath and the insulating sheath box, reduces the probability of corona of wires and fittings, and eliminates the problem of electrochemical corrosion and aging of the device.

Description

A protection device against wind and deflection flashover for transmission lines

technical field

The invention relates to a wind deflection flashover protection device for power transmission lines, which belongs to the technical field of power transmission and transformation.

Background technique

In recent years, with the gradual increase of various disastrous weathers, especially the emergence of extremely bad micro-meteorology such as squall line winds, wind deflection flashover problems of transmission lines have occurred from time to time. Lines where wind deflection flashover occurs include single and double circuit towers; tower types include tension towers and straight towers, tension towers are mostly concentrated in the discharge of jumper wires to the tower frame, and straight towers are mostly concentrated in wires or fittings to the tower arm discharge. When a wind-bias flashover occurs, there are often strong winds and heavy rain or hail in the occurrence area; there are obvious arc burn marks at the discharge point of the tower, and the discharge path is clear; Leading to line outage, seriously affecting the reliability of power supply, causing great economic losses. In addition, according to statistics, wind deflection trips occur mostly in linear towers, and relatively few in tension towers.

The main causes of wind-bias flashover can be summarized as follows: The most direct cause of wind-bias flashover is that the insulation distance between the conductor and the tower is insufficient due to strong wind, which leads to air breakdown and discharge. Traditional insulators are made of conventional porcelain and glass. When the wind speed exceeds the design, the insulator strings are tilted toward the tower, which reduces the air gap distance between the wire and the tower. When the air gap distance cannot meet the minimum discharge voltage requirements, flashover will occur. In addition, the wind deflection check was not carried out after the composite insulators were used for line adjustment and climbing. Because the composite insulators are light in weight, even if the swing of the heavy hammer is large when the wind deflects, it will cause discharge.

At present, the technical measures to prevent wind deflection mainly adopt the following: 1. Adopt double-connected "V"-shaped string configuration: change the jumper string single-connected string to double-connected "V"-shaped string configuration to improve the insulator's ability to withstand strong winds. The method is suitable for new lines, but not for reconstruction of old lines; 2. Install a heavy hammer: install a heavy hammer at the lower end of the insulator, and limit the swing of the insulator by increasing the weight of the insulator to prevent wind-bias flashover. Although the use of heavy hammers to improve the wind deflection of insulator strings has certain effects, it cannot really control the wind deflection of insulator strings. 3. Install new windproof composite insulators: change the installation method of traditional products from "hinge type" to "cantilever type", from swing to hard support, and change the composite insulator from "dynamic" to "static". This method artificially fixes the position of the composite insulator. Under the action of strong wind, the composite insulator will be subjected to transverse shear force, which will accelerate the mechanical fatigue of the insulator mandrel under long-term action, resulting in a broken string accident.

Publication No. CN202978174U utility model patent case "Transmission line anti-wind and partial flashover device", the publication date is June 05, 2013. A transmission line anti-wind and partial flashover device is proposed. The external clamping of the suspension clamp is high-voltage insulation Covering cover, high-voltage insulation covering cover has a central hole, and the two ends of the central hole are respectively fixed with the left and right high-voltage resistant insulating sheaths of the transmission wire. A power transmission wire is passed through the central hole of the cover. The limitation of this method is that the insulating sheath in the device is directly exposed to the high field strength area formed by the wire burr, the tip, and the sharp corner area of the connecting fitting, which will accelerate the aging of the insulating material under long-term action; in addition, the device does not It can ensure the close fit between the conductor and the sheath, which will cause moisture to penetrate deeply and accelerate the electrochemical aging of the insulating material.

Contents of the invention

Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a wind deflection flashover protection device for transmission lines that can effectively reduce the probability of wind deflection flashover of transmission lines and has the function of protecting wires and fittings.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A power transmission line anti-wind flashover protection device of the present invention includes a wire, a metal fitting connected to the wire and a power transmission line insulator, and the invention also includes a metal fitting protection device and two wire protection devices located on both sides of the metal fitting; the wire protection device It is arranged on the outer side of the wire and connected with the metal fitting protection device, and the metal fitting protection device is installed on the outer side of the metal fitting and connected with the transmission line insulator.

The above-mentioned wire protection device includes a stress cone, a semi-conductive tape wrapped on the outside of the wire to eliminate the distortion of the electric field of the wire burr, an insulating sheath arranged outside the semi-conductive tape, and a water-blocking tape filled between the semi-conductive tape and the insulating sheath and a pressure equalizing ring installed at the outer end of the insulating sheath; the pressure equalizing ring is electrically connected to the semi-conductive strip through a stress cone.

The above-mentioned fitting protection device includes a stress cone, a water blocking strip, and an insulating sheath box installed between two insulating sheaths; the fitting is electrically connected to the semi-conductive strip through the stress cone to eliminate field strength distortion in the tip area of the fitting; The insulating sheath box and fittings are connected with the transmission line insulator through the water blocking tape.

The insulating sheath is seamlessly connected to the insulating sheath box through room temperature vulcanized silicone rubber.

The above-mentioned wires are single wires, double wires or multi-split wires.

The thickness of the above-mentioned semiconducting strip is 0.2-3.0mm.

The thickness of the water blocking strip is 0.5-2mm.

The above-mentioned insulating sheath has a thickness of 5-15mm and a length of 2-10m.

The thickness of the above-mentioned insulating sheath box is 5-15mm.

The invention aims at the most direct cause of wind deflection flashover, which is the most direct cause of wind deflection flashover, which is air breakdown and discharge due to insufficient insulation distance caused by strong wind between the wire and the tower, and increases the electrical insulation strength between the wire and the tower; the weight of the invented wind deflection protection device It is light, and can effectively avoid the mechanical strength problems of the tower caused by the aggravated weight and the wind deflection composite insulator. The invention effectively eliminates the problem of electric field distortion between the wire and the insulating sheath, and between the fittings and the insulating sheath box, and avoids the greatly reduced effect of wind deflection flashover caused by excessive local field strength. The invention effectively prevents water from entering the insulating sheath and the insulating sheath box, reduces the probability of corona of wires and fittings, and eliminates the problem of electrochemical corrosion and aging of the device.

Description of drawings

Fig. 1 is the structure schematic diagram of the transmission line anti-wind bias flashover protection device of the present invention;

Fig. 2 is the on-the-spot test figure of the transmission line single conductor wind deflection flashover protection device of the present invention;

Fig. 3 is the left view of Fig. 2;

Fig. 4 is the on-the-spot test figure of the transmission line four-split wire anti-wind bias flashover protection device of the present invention;

Fig. 5 is a left side view of Fig. 4 .

The labels in the figure are as follows:

1 is a voltage equalizing ring, 2 is a stress cone, 3 is an insulating sheath, 4 is a water blocking tape, 5 is a semi-conductive tape, 6 is a wire, 7 is a transmission line insulator, 8 is a fitting, and 9 is an insulating sheath box.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

Referring to Fig. 1 , the present invention proposes a wind-deflection flashover protection device for transmission lines, including a wire protection device and a fitting protection device.

Wherein, the wire protection device includes a semi-conductive strip 5 , a water blocking strip 4 , an insulating sheath 3 , a stress cone 2 and a pressure equalizing ring 1 .

Wherein, the metal fitting protection device includes a water blocking strip 4 , a stress cone 2 and an insulating sheath box 9 .

The wire protection device is wrapped on the outside of the wire 6 and connected to the metal fitting protection device, and the metal fitting protection device is wrapped on the outside of the metal fitting 8 and connected to the transmission line insulator 7 . The wire protection device is embedded in the metal protection device and is tightly and seamlessly connected by room temperature vulcanized silicone rubber.

In the wire protection device, the semi-conductive strip 5 is tightly wrapped on the outside of the wire 6 to eliminate the burr electric field distortion of the wire 6, and the thickness of the semi-conductive strip 5 is 0.2-3.0mm.

The water-blocking tape 4 is tightly packed between the semi-conductive tape 5 and the insulating sheath 3 to prevent natural rainfall such as rainwater from entering the wire protection device, and the thickness of the water-blocking tape 4 is 0.5-2mm.

The insulating sheath 3 is tightly wrapped on the outside of the water blocking belt 4 to enhance the electrical insulation level of the gap between the conductor 6 and the transmission line tower when wind deflection occurs. The insulating sheath 3 has a thickness of 5-15mm and a length of 2-10m.

In order to eliminate the electric field distortion between the wire 6 and the insulating sheath 3 at the end of the semiconducting strip 5, the equalizing ring 1 is installed on the outer end of the insulating sheath 3, and is electrically connected to the semiconducting strip 5 through the stress cone 2.

In the metal fitting protection device, the insulating sheath box 9 is wrapped on the outside of the fitting 8, and its thickness is 5-15mm. The stress cone 2 electrically connects the semi-conductive strip 5 and the fitting 8 to eliminate field strength distortion in the tip area of the fitting 8 and reduce the electrical breakdown probability of the insulating sheath box 9 .

The wire 6 adopted in the present invention can be single wire (referring to Fig. 2, Fig. 3), double wire or multi-split wire, and Fig. 4 and Fig. 5 are four split wires.

In this embodiment, the thickness of the insulating sheath 3 of the wire 6 is 10 mm, and the thickness of the insulating sheath box 9 of the fitting 8 is 10 mm. Both ends of the semi-conductive strip 5 are respectively connected to the equalizing ring 1 and the fitting 8 through the stress cone 2 to reduce electric field distortion.

The test found that: for 500kV conductors, after adopting the transmission line wind deflection flashover protection device of the present invention, the distance of air gap breakdown is 0.76-0.80m; The distance is 0.90-1.00m. Therefore, by adding the wind deflection flashover protection device of the present invention, the wind deflection flashover occurrence distance of 0.14-0.20m can be effectively improved.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (9)

1. A power transmission line anti-wind bias flashover protection device, comprising a lead (6), a fitting (8) connected to the lead (6) and a power transmission line insulator (7), is characterized in that, It also includes a metal fitting protection device and two wire protection devices located on both sides of the metal fitting (8); The wire protection device is arranged on the outside of the wire (6) and connected with the metal fitting protection device, and the metal fitting protection device is installed on the outside of the metal fitting (8) and connected with the power transmission line insulator (7). 2. The transmission line anti-wind flashover protection device according to claim 1, characterized in that, The wire protection device includes a stress cone (2), a semi-conductive tape (5) wrapped outside the wire (6) for eliminating burr electric field distortion of the wire (6), and an insulating sheath arranged outside the semi-conductive tape (5) (3), the water blocking strip (4) filled between the semi-conductive strip (5) and the insulating sheath (3) and the pressure equalizing ring (1) installed on the outer end of the insulating sheath (3); The pressure equalizing ring (1) is electrically connected to the semi-conductive strip (5) through a stress cone (2). 3. The transmission line anti-wind flashover protection device according to claim 2, characterized in that, The metal fitting protection device comprises a stress cone (2), a water blocking strip (4) and an insulating sheath box (9) installed between two insulating sheaths (3); The metal fitting (8) is electrically connected to the semi-conductive strip (5) through the stress cone (2), and is used to eliminate field strength distortion in the tip region of the metal fitting (8); Both the insulating sheath box (9) and the hardware (8) are connected to the power transmission line insulator (7) through the water blocking tape (4). 4. The transmission line anti-wind flashover protection device according to claim 3, characterized in that, The insulating sheath (3) is seamlessly connected to the insulating sheath box (9) through room temperature vulcanized silicone rubber. 5. The transmission line anti-wind flashover protection device according to any one of claims 1 to 4, characterized in that, The wires (6) are single wires, double wires or multi-split wires. 6. The transmission line anti-wind and flashover protection device according to any one of claims 1 to 4, characterized in that, The thickness of the semiconducting strip (5) is 0.2-3.0mm. 7. The transmission line anti-wind and flashover protection device according to any one of claims 1 to 4, characterized in that, The thickness of the water blocking strip (4) is 0.5-2mm. 8. The transmission line anti-wind and flashover protection device according to any one of claims 1 to 4, characterized in that, The insulating sheath (3) has a thickness of 5-15mm and a length of 2-10m. 9. The transmission line anti-wind and flashover protection device according to any one of claims 1 to 4, characterized in that, The thickness of the insulating sheath box (9) is 5-15mm.