CN201348907Y - Lightning protector of 10kV line - Google Patents

Abstract

The utility model discloses a 10kV line lightning protector, which relates to lightning protection equipment. It consists of interconnected insulators and wires, and is equipped with arc-starting electrodes, zinc oxide arresters and supporting crossarms. The arc-starting electrodes are fixed on the high-voltage end of the zinc oxide arrester, forming a discharge gap between the wires and the zinc oxide arrester to provide lightning flashover The channel, the low-voltage end of the zinc oxide arrester is fixed on the right end of the supporting cross-arm to prevent lightning overvoltage and cut off the continuous flow of power frequency, and the left end of the supporting cross-arm is fixed on the steel foot at the lower end of the insulator. The utility model is suitable for preventing lightning breakage and tripping of 10kV overhead power distribution lines, and has practicability and economy.

Description

10kV Line SPD

Technical field:

The utility model relates to a lightning protection device, in particular to a 10kV line lightning protector, in particular to a lightning arrester for preventing lightning breakage and tripping of a 10kV overhead power distribution line.

Background technique:

The insulation level of 10kV distribution lines is low, and lightning flashovers are prone to occur, and then power frequency arcs are formed to burn the wires. Overhead distribution lines use insulated conductors, which have obvious advantages compared with cables, with less investment and quicker construction. However, the problem of lightning disconnection is serious, and there have been many lightning disconnection accidents of insulated conductors across the country. According to the on-site operation, 10kV bare conductors also have relatively high-frequency lightning strike disconnection accidents or lightning tripping accidents, and even 35kV bare conductors have also experienced lightning strike disconnection accidents. The main reason for disconnection is that the arc is built on the lightning flashover channel to form a power frequency continuous current. The temperature of the arc root is very high, and the wire can be blown in a short time. Even if it is a bare wire, if the current passing through it is large, It is also possible to blow the wire.

The current lightning protection measures include installation of overhead ground wires, piercing anti-arc fittings, lightning protection post insulators and zinc oxide arresters, etc. However, according to feedback from field practice, there are various problems that need to be improved.

Utility model content:

In order to overcome the defects of the prior art, the purpose of this utility model is to provide a relatively suitable lightning protection measure, that is, to provide a 10kV line lightning protector, which can effectively prevent lightning strikes and disconnection accidents, and at the same time reduce the lightning tripping of the line. rate and improve the reliability of power supply.

The utility model solves the technical problem and adopts the following technical solutions:

A 10kV line lightning arrester, including interconnected insulators and wires, is provided with an arc-starting electrode, a zinc oxide arrester and a supporting cross-arm; the arc-starting electrode is fixed at the high-voltage end of the zinc oxide arrester, and forms a A discharge gap; the low-voltage end of the zinc oxide arrester is fixed on the right end of the supporting cross-arm; the left end of the supporting cross-arm is fixed on the steel foot at the lower end of the insulator.

The arc starting electrode is a U-shaped metal structure including an arc starting surface and a fixing screw hole from top to bottom.

The zinc oxide surge arrester consists of a high-voltage end screw, a fixed nut, a compression nut, a composite casing, a plurality of series-connected zinc oxide valve plates, a lower composite casing, a lower compression nut, a lower fixed nut, and a low-pressure end screw connected in sequence from top to bottom. .

The supporting cross arm is a kind of bent metal support sheet, the left end is provided with an open screw hole connected with the steel foot at the lower end of the insulator, and the right end is provided with a closed screw hole connected with the low-voltage end screw of the arrester.

Compared with the prior art, the beneficial effects of the utility model are reflected in:

1. The utility model includes arc starting electrodes, zinc oxide lightning arresters and supporting cross-arms, etc. Its special feature is that an air gap is formed between the wire and the arrester through the arcing electrode, and the low-voltage end of the arrester is naturally grounded, without adding additional grounding resistance, reducing construction intensity and effectively solving the problem of wire disconnection caused by lightning strikes.

2. The arc starting electrode is installed at the high voltage end of the zinc oxide arrester, and an air gap is formed between the wire and the zinc oxide arrester. There will not be too much change to ensure the stability of the discharge; the air gap in series makes the arrester not affected by power frequency voltage and operating overvoltage at ordinary times, which increases the service life of the arrester; under the action of lightning overvoltage, the arrester can effectively Action to limit the amplitude of lightning overvoltage and cut off power frequency continuous flow to prevent insulator flashover accidents; install the arrester in parallel on the side of the insulator through the support cross arm, and reasonably design the support cross arm to form an appropriate series gap between the arrester and the wire. An effective discharge channel can be formed through the series gap, ensuring that the zinc oxide arrester can escape the operating overvoltage and operate effectively under the lightning overvoltage.

According to the above, when the 10kV overhead distribution line is struck by lightning, it can break through the discharge gap provided by the arc-triggering electrode, make the zinc oxide arrester operate, limit the lightning overvoltage below the flashover voltage of the insulator, and then pass through the zinc oxide The surge arrester cuts off the power frequency freewheeling, which can prevent tripping and wire disconnection accidents caused by lightning flashover.

The utility model also has the following positive effects:

1. It meets the performance requirements of zinc oxide arresters and fittings stipulated in the national standard, and the discharge residual voltage is much lower than the flashover voltage of insulators.

2. The jacket of zinc oxide arrester is made of synthetic jacket silicone rubber, which has good insulation performance and antifouling performance.

3. The design is simple, the construction and installation are convenient, the pure air gap is used, the system does not bear the system voltage, and the zinc oxide arrester has a long service life.

4. With good action characteristics, the arc starting electrode can provide multiple power frequency arc ablation, and the performance is reliable.

5. It is suitable for 10kV overhead distribution lines, including insulated lines and bare wire lines to prevent lightning tripping and disconnection accidents.

Description of drawings:

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

Fig. 2 is a schematic diagram of the structure of the arc starting electrode.

Fig. 3 is a structural schematic diagram of a zinc oxide arrester.

Fig. 4 is a top view of the structure supporting the cross arm.

Labels in the figure: 1 arc striking electrode, 1.1 arc striking surface, 1.2 fixing screw hole, 2 zinc oxide arrester, 2.1 high voltage end screw, 2.2 fixing nut, 2.3 compression nut, 2.4 composite casing, 2.5 zinc oxide valve plate, 2.6 low voltage End screw, 2.7 lower compound jacket, 2.8 lower compression nut, 2.9 lower fixed nut, 3 support cross arms, 3.1 open screw holes, 3.2 closed screw holes, 4 insulators, 5 wires.

The utility model will be further described below through specific embodiments in conjunction with the accompanying drawings.

The specific implementation, non-limiting examples are as follows:

Embodiment: As shown in Figure 1, the utility model includes interconnected insulators 4 and conductors 5, and is provided with an arc starting electrode 1, a zinc oxide arrester 2 and a supporting cross arm 3;

The arc striking electrode 1 is fixed on the high-voltage end of the zinc oxide arrester 2, and a discharge gap is formed between the wire 5 and the zinc oxide arrester 2 to provide a lightning flashover channel;

The low-voltage end of the zinc oxide arrester 2 is fixed on the right end of the supporting cross-arm 3 to prevent lightning overvoltage and cut off power frequency continuous flow;

The left end of support cross arm 3 is fixed on the steel foot of insulator 4 lower ends.

As shown in Fig. 2, the arc starting electrode 1 is a U-shaped metal structure including an arc starting surface 1.1 and a fixing screw hole 1.2 from top to bottom. The fixing screw hole 1.2 can fix the arc striking electrode 1 on the high voltage end screw 2.1 of the zinc oxide arrester 2, tighten the nut hole, and install the arc striking electrode 1 firmly; when installing on the line, place the wire 5 on the arc striking electrode 1 On the arc striking surface 1.1, a discharge gap between the wire 5 and the zinc oxide arrester 2 is formed.

As shown in Figure 3, the zinc oxide arrester 2 includes a high-voltage end screw 2.1, a fixed nut 2.2, a compression nut 2.3, a composite jacket 2.4, a plurality of series-connected zinc oxide valve pieces 2.5, a lower composite jacket 2.7, Lower compression nut 2.8, lower fixing nut 2.9 and low pressure end screw rod 2.6.

The upper and lower composite jackets 2.4 and 2.7 provide the outer insulation of the zinc oxide arrester 2 to ensure sufficient insulation strength;

Multiple series-connected zinc oxide valve slices 2.5 are placed in the center of the zinc oxide arrester 2, which can limit lightning overvoltage and cut off power frequency freewheeling.

In addition, the zinc oxide arrester 2 can be selected as a finished arrester that meets the two standards of JB/T 8952-2005 "Composite Metal Oxide Arrester for AC Systems" and GB11032-2000 "Gapless Metal Oxide Arrester for AC".

As shown in Figure 4, the support cross arm 3 is a bent metal support piece, the left end is provided with an open screw hole 3.1 connected to the steel foot at the lower end of the insulator, and the right end is provided with a closed screw hole 3.2 connected with the low-voltage end screw of the arrester .

The open screw hole 3.1 is installed on the steel foot of the insulator 4, the low-voltage end screw rod 2.6 of the zinc oxide arrester 2 is installed in the closed screw hole 3.2 of the support cross arm 3, and the lower compression nut 2.8 is tightened.

In this way, the zinc oxide arrester 2 is connected in parallel on the side of the insulator 4 to prevent disconnection due to lightning.

Working principle of the utility model:

The lightning overvoltage amplitude of 10kV overhead distribution lines is high and the discharge time is short, while the insulation level of 10kV distribution lines is low. Lightning overvoltage can cause flashover of insulator 4 and form power frequency freewheeling burning on the lightning flashover channel. Broken wire.

When the power grid is in normal operation, because the arc striking electrode 1 forms a discharge gap between the wire and the zinc oxide arrester 2 to isolate the power frequency voltage, the zinc oxide arrester 2 hardly bears the voltage, and at the same time, a reasonable gap is designed to make the zinc oxide arrester 2 in It does not operate when the overvoltage is exceeded, which increases the service life of the zinc oxide arrester 2; under the action of lightning overvoltage generated by direct lightning or induced lightning, the air gap is broken down, and the zinc oxide arrester 2 body presents low impedance, which discharges the lightning current. Put it into the ground; after the lightning strike, the power frequency voltage is loaded on the body of the zinc oxide arrester 2, the resistance of the zinc oxide arrester 2 body increases instantly, the passing current, that is, the arc current, is suppressed at a lower value, and the air gap arc voltage drop increases , the insulation of the air gap is quickly restored, the arc is naturally extinguished in a very short time, and the power frequency freewheeling is completely blocked.

Claims (4)

1. A 10kV line lightning arrester, comprising interconnected insulators (4) and wires (5), is characterized in that, It is provided with an arc striking electrode (1), a zinc oxide arrester (2) and a supporting cross arm (3); The arc striking electrode (1) is fixed on the high voltage end of the zinc oxide arrester (2), forming a discharge gap between the wire (5) and the zinc oxide arrester (2); The low voltage end of the zinc oxide arrester (2) is fixed on the right end of the supporting cross arm (3); The left end of support cross arm (3) is fixed on the steel foot of insulator (4) lower end. 2. A 10kV line lightning protector according to claim 1, characterized in that the arc starting electrode (1) is a U-shaped arc starting surface (1.1) and fixing screw holes (1.2) from top to bottom. shape metal structure. 3. A 10kV line lightning arrester according to claim 1, characterized in that the zinc oxide arrester (2) comprises a high-voltage end screw (2.1), a fixing nut (2.2), a compression Nut (2.3), composite casing (2.4), multiple series-connected zinc oxide valve pieces (2.5), lower composite casing (2.7), lower compression nut (2.8), lower fixing nut (2.9) and low pressure end screw rod (2.6 ). 4. A 10kV line lightning protector according to claim 1, characterized in that the supporting cross arm (3) is a bent metal support piece, and the left end is provided with an open screw connected to the steel foot at the lower end of the insulator. Hole (3.1), the right end is provided with a closed screw hole (3.2) connected with the low-voltage end screw of the arrester.

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