RU186414U1 - Suspension assembly of wires and lightning protection cables on an intermediate support of an overhead power line - Google Patents

Abstract

The utility model relates to the construction of overhead power lines (OHL) and can find application in the design and manufacture of steel lattice intermediate supports for OHL of 500 kV.

The technical result of the utility model is to provide lightning protection and the possibility of melting ice on lightning cables for overhead lines with increased interfacial insulation distances (relative to their normalized minimum values) without increasing the metal consumption of the support compared to the prototype.

A traverse (2) for a single-tier insulating suspension of three-phase wires (3) and two cable resistances are horizontally mounted on the Y-shaped rack (1) of the overhead line support. Each cable rack consists of a first element (4) mounted on a traverse (2), and a second element (5), cantilever mounted on the first element (4) for an insulating suspension of a lightning protection cable (6). Elements (4) of each cable-resistance are made with a slope (angle α) towards the external phase wire (3). The slope is sufficient to ensure a normalized angle of lightning protection with respect to the phase wire (3) and to ensure the insulation distance normalized for melting ice ice of the lightning protection cable (6) to the grounded parts of the support.

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Description

Technical field

The utility model relates to the construction of overhead power lines (OHL) and can find application in the design and manufacture of steel lattice intermediate supports for OHL of 500 kV.

State of the art

Known for the suspension of wires and lightning protection cables used in the intermediate support for 500 kV overhead lines, containing a traverse for a single-tier insulating suspension of three-phase wires and two cable racks, each of which has a first element mounted on the specified traverse and a second element cantilevered on the first element designed for insulating suspension of a ground wire [Makarov E.F. Handbook of Electric Networks 0.4-35 kV and 110-1150 kV, Volume 2, 2003, Fig. 2.10.21 (c)].

This site is selected as a prototype.

The first cable-resistant element in the prototype assembly is mounted on the traverse perpendicular to it and provides vertical displacement of the lightning protection cable suspended on the second element.

Lightning protection cables are suspended on a cable rack so as to provide:

- the angle of lightning protection for external phase conductors normalized by the current edition of the "Rules for the Installation of Electrical Installations" (ПУЭ-7);

- the possibility of melting ice due to compliance with the insulating distances (to the grounded parts of the support), normalized by PUE-7 for the voltage used when melting ice formation on a lightning protection cable.

Both of these requirements are provided by the corresponding suspension height of each lightning protection cable and its horizontal displacement towards the external phase wire.

When optimizing the length of spans on overhead lines using modern types of wires, there is a need to increase interfacial insulation distances compared to their minimum values, normalized by PUE-7. At the same time, to fulfill the above requirements of PUE-7, which provide both lightning protection and the ability to use supports in climatic regions with intense icing, the prototype cable resistance must have an increased height of the first element and / or an increased length of the second (cantilever) element.

In any of these cases, a corresponding increase in the metal consumption of the support in which the inventive assembly is used is required. An increase in the length (extension) of the cantilever element requires the strengthening of the first cable-resistant element (i.e., an increase in its strength with a corresponding increase in metal consumption), and an increase in the height of the first element leads to a significant increase in the load on the support column and a corresponding increase in its metal consumption. The increase in load is mainly due to the increase in bending moment from horizontal wind effects on a suspended lightning protection cable, especially if there are ice formations on it.

Utility Model Disclosure

The technical result of the utility model in relation to the prototype is to provide lightning protection and the possibility of melting ice on lightning cables for overhead lines with increased interfacial insulation distances (with respect to their normalized minimum values) without the need to increase the metal consumption of the support in which the claimed unit is used, compared to the support, using the prototype node.

The subject of a utility model is a node for the suspension of wires and lightning protection cables on an intermediate support of an overhead power transmission line, containing a cross-arm for a single-tier insulating suspension of three-phase wires and two cable-stands, consisting of two elements each, with the first element mounted on the specified cross-arm and the second element cantilevered to the first element and is intended for an insulating suspension of a lightning-protective cable, characterized in that the first elements of each cable-resistance are made with an inclination to the side under Eski outer phase conductor, is sufficient to ensure relative thereto normalized lightning protection angle and normalized to ensure insulating distances ice melting grounding wire to earthed parts of the support.

This allows you to get the above technical result.

Utility Model Implementation

The figure shows a diagram of an intermediate support made using the proposed site.

The diagram shows a Y-shaped rack 1, on which the yoke 2 is horizontally mounted for a single-tier insulating suspension of three-phase wires 3. On the yoke 2 are fixed two wire ropes consisting of two elements each. The first element 4 is mounted on the traverse 2, and the second element 5 is cantilevered on the first element 4. The second element 5 of each cable is designed to isolate the lightning protection cable 6 with an offset to the side of the nearest external phase wire 3.

Each element 4 is made with an inclination towards the suspension of the nearest external phase wire. The slope of element 4 can be characterized, for example, by the angle a between the median of element 4 and the vertical. For a given length of the cantilever element 5 (not exceeding the length of the cantilever element of the cable-resistant prototype), the inclination of the first element 4 (i.e., angle a) is selected sufficient to provide a lightning protection angle (25 °) as normalized for a given class with respect to the external phase wire, and the insulation distance of the lightning protection cable 6 to the grounded parts of the support normalized for the ice melting voltage (the closest of which is traverse 2 and cable-resistant of elements 4,5).

Thus, the use of the inventive assembly, in which the first elements 4 of the cable stands are made with a slope (angle α) in the direction of the external phase wire suspension, allows to provide lightning protection and the possibility of melting ice on lightning cables of overhead lines with increased interfacial insulation distances without increasing both the height of element 4, so and the length of element 5, i.e. without the need to increase the intensity of the support.

Claims (1)

Suspension assembly of wires and lightning protection cables on an intermediate support of an overhead power transmission line, comprising a cross-arm for a single-tier insulating suspension of three-phase wires and two cable-resistance, consisting of two elements each, while the first element is mounted on the specified cross-beam, and the second element is cantilevered on the first element and is intended for an insulating suspension of a lightning protection cable, characterized in that the first elements of each cable resistant are made with an inclination towards the suspension of the external phase wire, accurate to ensure the normal angle of lightning protection with respect to it and to ensure the insulation distance of the lightning protection cable normalized for melting ice to the grounded parts of the support.

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