RU2636657C1 - GROUNDING DEVICE FOR OVERHEAD ELECTRIC LINES WITH ISOLATED WIRES UP TO 1 kV - Google Patents

Abstract

FIELD: electricity.SUBSTANCE: grounding device is a bridge in the form of flexible grounding conductor (1) made of metal rope, one end of which is attached by clips (2) to the attachable grounding lead (4) on the tower body (3), the middle part to its metal ware using interface nodes and the second end to an isolated neutral conductor of the self-supporting isolated wire (5) through piercing clamp (6).EFFECT: optimum protection against extra voltages of overhead electric lines.5 cl, 2 dwg

Description

The invention relates to the field of electric power, in particular to grounding devices of overhead power lines with insulated wires with voltage up to 1 kV.

On overhead power lines with insulated wires, grounding of the neutral (neutral) conductor, for example, self-supporting insulated wires, as well as metal structures of reinforced concrete supports (traverses, brackets, hooks and so on) must be re-ground in order to protect the conductive wires of the wires and the line itself.

A grounding device for supporting overhead power transmission lines is known, comprising an annular grounding electrode buried in the ground and a vertical electrode connected to it, characterized in that the grounding electrode is in the form of a cylindrical helical spiral with a varying number of turns in depth inversely proportional to the resistivity of the soil layers in the pit, and with a diameter of turns equal to the diameter of the pit drilled in the ground to install the support of the overhead power line, while the ground electrode is equipped with a clamp that controls the magnitude of the step between the turns and fixes their position when backfilling the foundation pit with earth [1].

This well-known grounding device, in terms of its functional purpose and design, is simply not suitable for re-grounding a zero (neutral) core, self-supporting insulated wires, and also metal structures of reinforced concrete supports of overhead power transmission lines with insulated wires and can be considered as a variant of a grounding device used on open electric power facilities of other varieties.

A grounding device in electrical networks with an insulated neutral is also known, consisting of a metal conductor connecting the non-conductive parts of the electrical installation and grounding conductors, characterized in that one of the contacts of an additional gas-guided spark gap is connected to the specified metal conductor, connected to the non-conductive parts of the electrical installation, the second contact of which connected to grounding [2].

This grounding device is designed and adapted to operate exclusively in electrical networks with insulated neutral, that is, re-grounding the zero (neutral) core of self-supporting insulated wires to provide overvoltage protection of overhead lines with insulated wires using such a device using a gas-directed arrester will be difficult and even simple impractical both from an electric and constructive point of view.

The applicant set himself the task of developing and mass-producing a device designed to re-ground zero (neutral) conductors of self-supporting insulated wires, as well as metal structures of reinforced concrete supports of overhead power lines with insulated wires up to 1 kV, simple in design and effective in terms of optimal surge protection of overhead power lines of this class. This positive technical result was achieved due to the combination of essential structural features of the proposed grounding device of overhead power lines with insulated wires up to 1 kV, presented in the following claims: "grounding device of overhead power lines with insulated wires up to 1 kV, which is made of a metal rope a shunt made in the form of a flexible grounding conductor of length L connected at one end by means of the presses to the grounding descent fixed to the support post, with the middle part using at least one interface to the metal structures of the line support post and the second end to the insulated zero core of the self-supporting insulated wire by means of a piercing clip without tension, which excludes the possibility of pulling out the flexible grounding conductor of the shunt from the above clamps and interface nodes in case of oscillations of the line wires and providing re-grounding of the zero core of the self-supporting insulated wire and Talloconstructs of the line support strut, while the aforementioned interface node is structurally combined with a shunt or a separate part is included in the grounding device, connecting to the shunt as necessary, and when using a self-supporting insulated wire with an uninsulated zero core, the shunt is connected directly to it; the length L of the shunt is 300 ÷ 2500 mm; the interface is made in the form of a “flag” in the form of a flat plate fixed on a flexible grounding conductor of the shunt and having a shank with a bolt hole on one side that clamps it on the anchor brackets of the reinforced concrete struts of the line supports; the diameter of the metal cable of the shunt is selected in the range of 4 ÷ 20 mm; the shunt is connected to the grounding descent of the reinforced concrete rack of the line support by means of die clamps. "

The invention is illustrated by drawings, where in FIG. 1 shows an example of a structural embodiment of the elements of the grounding device on an intermediate branch reinforced concrete rack of an overhead power line support with insulated wires up to 1 kV, according to the present invention; in FIG. 2 - the design of the shunt in the form of a flexible grounding conductor with the nodes of the device attached to it in FIG. one.

The proposed grounding device of overhead power lines with insulated wires up to 1 kV is a shunt in the form of a flexible grounding conductor 1, made of a metal rope, for example, a galvanized steel cable, the diameter of which is selected in the range of 4 ÷ 20 mm. To carry out re-grounding of the zero (neutral) core of a self-supporting insulated wire, the shunt 1 at one end is connected, for example, with die clips 2 to the grounding (upper) descent 4 fixed to the reinforced concrete support 3 of the support 4, with the middle part to its metal structures (traverses, brackets, hooks and other metal elements) with the help of interface units and the second end to the insulated zero core of the self-supporting insulated wire 5 by means of a piercing clamp 6. When using self-supporting its insulated wire 5 with an uninsulated zero core shunt 1 is connected to it directly. In this case, the connection of the shunt 1 is carried out without tension, eliminating the possibility of tearing out the flexible grounding conductor of the shunt 1 from the interface nodes during oscillations of the line wires. The interface can be structurally combined with a shunt 1 or a separate part to be a part of the grounding device and attached to the shunt 1 as necessary.

The interface is made in the form of a "flag" in the form of a flat plate 7, mounted on a flexible grounding conductor of the shunt 1 and having on one side a shank 8 with a hole 9 for the bolt 10 of the clamp 11, rigidly fixing the flag, for example, on the anchor bracket 12 of the reinforced concrete rack 3 line supports.

The invention is implemented as follows.

In accordance with the requirements of the "Rules for Electrical Installations" on pylons of insulated aerial power lines with voltage up to 0.4 kV, grounding of the zero (neutral) core of self-supporting insulated wires must be carried out, and the metal elements of the poles must be electrically connected to the upper grounding slopes of the poles. To ensure such connections in the claimed technical solution, a shunt is used in the form of a flexible grounding conductor 1 and clamps 11, for example, of a bolt type. In particular, the bracket 12 on the rack 3 of the supports of overhead isolated power lines is connected to the upper grounding descent 4 of the reinforced concrete rack 3 of the support using a flexible grounding conductor 1 by clamping a “flag” secured to it with a bolt 10 of the clamp 11 mounted on the bracket 12 of the intermediate support for suspension of a self-supporting insulated wire 5. The flexible grounding conductor 1 itself, as previously indicated, is connected to the upper grounding descent 4 of the reinforced concrete rack 3 supports using spot clamps in 2 (Fig. 1).

The proposed device, designed to re-ground zero (neutral) conductors of self-supporting insulated wires, as well as metal structures of reinforced concrete supports of overhead power lines with insulated wires of up to 1 kV, is quite simple in design and effective in terms of optimal protection against overvoltage of overhead power lines of this class. LLC “MZVA” carried out serial production of the claimed grounding devices of overhead power lines with insulated wires up to 1 kV.

Information sources

[1] Description of the invention to patent No. 2288529 "Grounding device for supports of overhead power lines", H01R 4/66, claimed 18.04.2005, published 11.27.2006.

[2] Description of the invention to patent No. 2081490 "Grounding device in electrical networks with insulated neutral", H01R 4/66, claimed on 08.29.1994, published on 10.06.1997.

[3] Description of the invention to copyright certificate No. 504267 “Earthing switch”, H01R 3/06, claimed 04.11.74, published 02.25.76. Bulletin No. 7.

[4] Description of the invention to copyright certificate No. 985867 “Grounding device”, H01R 4/66, Н02В 1/16, claimed 13.11.80, published 12.30.88. Bulletin No. 48.

[5] Description of the invention to copyright certificate No. 1363352 "Grounding device", H01R 4/66, claimed 03/26/1986, published 12/30/1987.

[6] Description of the invention to copyright certificate No. 1432638 “Earthing switch”, H01R 4/66, Н02В 1/16, filed on 12.30.86, published on 10.23.88. Bulletin No. 39.

[7] Description of the invention to patent No. 2109378 "Section of the electric network", H01R 4/66, Н02В 1/16, filed April 13, 1993, published April 20, 1998.

[8] Description of the invention to patent No. 2074465 "Zotovaya short circuit for overhead power transmission line supports", H01R 4/66, claimed 09.02.1994, published 11.27.1997.

[9] Description of the invention to copyright certificate No. 412646 "Grounding device for equalizing electric potential", H01R 3/06, claimed 30.10.72, published 01.25.74. Bulletin No. 3.

[10] Description of the invention to patent No. 21151585 “Electricity network section”, H01R 4/66, Н02В 1/16, claimed on 04/13/1993, published on 05/20/1998.

[11] Japanese Patent No. 20033217702 "Grounding Device", H01R 4/66, published July 31, 2003.

[12]. Japanese Patent No. 11144778 "Grounding Device", H01R 4/66, published 05/28/1999.

Claims (5)

1. The grounding device of overhead power lines with insulated wires up to 1 kV, which is a shunt made of a metal cable, made in the form of a flexible grounding conductor of length L, connected at one end to the grounding descent fixed to the support column, with the middle part using at least at least one interface node to the metal structures of the line support strut and the second end to the insulated zero core of the self-supporting insulated wire by means of a piercing clamp without tension, eliminating the possibility of pulling out the flexible grounding conductor of the shunt from the above clamps and interface nodes when the wires of the line vibrate and providing re-grounding of the zero core of the self-supporting insulated wire and metal structures of the line support strut. 2. The device according to p. 1, in which the length L of the shunt is 300 ÷ 2500 mm 3. The device according to claim 1, in which the interface is made in the form of a “flag” in the form of a flat plate fixed on a flexible grounding conductor of the shunt and having on one side a shank with a hole for the bolt clamping it on the anchor brackets of the reinforced concrete struts of the line supports. 4. The device according to claim 1, in which the diameter of the metal cable of the shunt is selected in the range of 4 ÷ 20 mm. 5. The device according to claim 1, in which the shunt is connected to the grounding descent of the reinforced concrete strut of the line support by means of die clamps.

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