CN205388922U - Composite covering has series gap metal oxide lightning arrester for 420kV alternating current transmission line - Google Patents

Abstract

The utility model discloses a 420kV AC transmission line composite jacket with metal oxide lightning arresters with series gaps, including a series gap group connected with a number of series-connected lightning arrester bodies, the series gap group includes a plurality of support insulators connected in series with gaps , both ends of the series gap group are equipped with electrodes, one of which is connected to the high-voltage end of the terminal arrester body, and the other electrode is connected to the transmission line conductor, so that the discharge voltage of the device at 50% of the standard lightning impact is not greater than 1831kV, and appears on the arrester body It can withstand the power frequency voltage of not less than 267kV for 1min under the specified raining conditions when it fails, and it can withstand the power frequency voltage of not less than 340kV for 1min under the specified raining conditions when there is no abnormality. The structure of this device It is compact and simple, small in size, easy to install, wide in gap adjustment range, reasonable in technical parameters, and has good application prospects.

Description

Metal Oxide Surge Arrester with Series Gap in Composite Jacket for 420kV AC Transmission Line

【Technical field】

The utility model belongs to the field of overvoltage protection devices for power equipment in an AC transmission system, and in particular relates to a metal oxide lightning arrester with series gaps in a compound jacket for a 420kV AC transmission line.

【Background technique】

In engineering, methods such as reducing grounding resistance, erecting double lightning protection lines, and reducing the protection angle of lightning arrester lines are usually used to limit lightning overvoltage and reduce lightning tripping rate. However, in the mountainous line section where the lightning activity is strong and it is difficult to reduce the grounding resistance, the above methods cannot fundamentally solve the problem of lightning tripping.

At present, there is no test data on metal oxide surge arresters with series gaps and insulation coordination for composite jackets for 420kV AC transmission lines at home and abroad, and the test and design are difficult.

This requires the concept of miniaturization to be applied in metal oxide surge arresters with composite jackets with series gaps for 420kV AC transmission lines, and design miniaturized metal oxide surge arresters with composite jackets with series gaps for 420kV AC transmission lines to reduce installation difficulty; It is necessary to determine the body size and gap distance of metal oxide surge arresters with series gaps in composite jackets for 420kV AC transmission lines.

【Content of utility model】

The purpose of this utility model is to overcome the above-mentioned deficiencies, and provide a metal oxide lightning arrester with a series gap in a compound jacket for a 420kV AC transmission line. application prospects.

In order to achieve the above-mentioned purpose, the utility model includes a series gap group, which is connected with a number of series-connected arrester bodies. The series gap group includes a number of support insulators connected in series with gaps. Both ends of the series gap group are provided with electrodes, one of which is The electrode is connected to the high-voltage end of the arrester body at the end, and the other electrode is connected to the transmission line wire; the arrester body includes an arrester jacket, a resistor is arranged inside the arrester jacket, and a connecting structure is arranged at both ends of the arrester jacket.

The dry arc distance of the arrester jacket is greater than or equal to 2790mm.

The series gap group is 1100mm-1300mm.

The electrodes are connected to the high-voltage end of the arrester body or the wires of the power transmission line through metal tubes or metal rods, and the diameter of the metal tubes or metal rods is greater than or equal to 50mm.

There are three arrester bodies, and the total length of the three arrester bodies and the series gap group is 5529 mm to 5729 mm.

Compared with the prior art, the utility model connects several arrester bodies through the series gap group, and the series gap group is provided with a number of support insulators connected in series, so that the discharge voltage of the device at 50% of the standard lightning impact is not greater than 1831kV. When a fault occurs, it can withstand a power frequency voltage of not less than 267kV for 1min under the specified raining conditions, and it can withstand a power frequency voltage of not less than 340kV for 1min under the specified raining conditions when there is no abnormality. The structure is compact and simple, the volume is small, the installation is convenient, the gap adjustment range is large, the technical parameters are reasonable, and it has a good application prospect.

Further, the dry arc distance of the utility model is greater than or equal to 2790mm, so that the arrester body can withstand a lightning impulse voltage of 1550kV not lower than 1.3 times its actual protection level, and can withstand not less than 1550kV under specified rain conditions. 340kV power frequency voltage for 1min.

Furthermore, the resistor sheet of the present invention can pass the long-duration impulse current test of no less than 1200A and pass the 4/10μs high-current impulse withstand test with an amplitude of 100kA for three consecutive times.

【Description of drawings】

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

【detailed description】

Below in conjunction with accompanying drawing, the utility model is further described.

Referring to Fig. 1, the utility model comprises a series gap group 1, on which a number of series-connected arrester bodies 2 are connected, the series gap group 1 includes a number of support insulators 3 with gaps connected in series, and both ends of the series gap group 1 are provided with There are electrodes 4, one of which is connected to the high-voltage end of the arrester body 2 at the end, and the other electrode is connected to the transmission line wire; the arrester body 2 includes an arrester jacket 5, which is provided with a resistor inside, and the two ends of the arrester jacket 5 are provided with connecting Structure 6, wherein the dry arc distance of the arrester jacket 5 is greater than or equal to 2790 mm, the series gap group 1 is 1100 mm to 1300 mm, and the distance of 1200 mm is preferred, and the electrodes are connected to the high voltage end of the arrester body 2 or the wires of the transmission line through metal pipes or metal rods , the diameter of the metal pipe or metal rod is greater than or equal to 50mm.

Preferably, there are three arrester bodies 2, and the total length of the three arrester bodies 2 and the series gap group 1 is 5529mm-5729mm.

The creepage distance of this device is not less than 10500mm, the reference voltage is not less than 490kV under the rated voltage of 360kVrms DC for 1ms, the nominal discharge current is 20kA, the residual voltage is not greater than 850kV under 20kA lightning impulse current, and the residual voltage is not greater than 918kA under 20kA steep slope impulse current .

Claims (5)

1. A compound jacket for 420kV AC transmission lines has a series gap metal oxide arrester, characterized in that: it comprises a series gap group (1), and the series gap group (1) is connected with some series-connected surge arrester bodies (2), connected in series The gap group (1) includes a number of support insulators (3) connected in series with gaps, electrodes (4) are arranged at both ends of the series gap group (1), one of the electrodes is connected to the high-voltage end of the terminal arrester body (2), and the other The electrodes are connected to the wires of the transmission line; the arrester body (2) includes an arrester jacket (5), the arrester jacket (5) is provided with a resistance plate inside, and the two ends of the arrester jacket (5) are provided with connection structures (6). 2. The compound jacket for 420kV AC transmission line according to claim 1 with a series gap metal oxide arrester, characterized in that: the dry arc distance of the arrester jacket (5) is greater than or equal to 2790mm. 3. A metal oxide surge arrester with a series gap in a composite jacket for a 420kV AC transmission line according to claim 1, characterized in that: the series gap group (1) is 1100mm-1300mm. 4. A kind of 420kV AC transmission line according to claim 1. The metal oxide surge arrester with a series gap in the compound jacket is characterized in that: the electrodes are connected to the high voltage end of the arrester body (2) or the power transmission terminal through a metal tube or a metal rod. The diameter of line conductors, metal pipes or metal rods is greater than or equal to 50mm. 5. A compound jacket for a 420kV AC transmission line according to claim 1 has a series gap metal oxide arrester, characterized in that: the arrester body (2) is provided with three, and the three arrester bodies (2) are connected with the series gap metal oxide arrester. The total length of the gap group (1) is 5529mm-5729mm.