RU2667945C1 - Two-chain intermediate support and overhead line with such support - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the construction of overhead lines (OL) of power transmission and can find application in the design and manufacture of steel intermediate supports for double-circuit overhead lines. Two-chain intermediate support of an overhead line, containing a rack on which two-console crossheads for suspension of phase conductors and a cable support for suspending a lightning-proof cable are located above these traverses. Rope-proof is made V-shaped with the possibility of an isolated suspension of the lightning protection cable between its inclined consoles at a height sufficient to provide a normalized angle of lightning protection of the phase conductors of both circuits, and at insulation distances from rope-resistant, normalized for the melting point of ice on a lightning protection cable. Dual-circuit overhead transmission line is also described.

EFFECT: lightning protection of a double-circuit overhead line by a single ground wire with the possibility of melting ice on it.

3 cl, 2 dwg

Description

Technical field

The invention relates to the construction of overhead power lines (VL) and can find application in the design and manufacture of steel intermediate supports for double-circuit VL.

State of the art

It is known that for double-circuit OHLs of the 35-330 kV class, single-column intermediate supports are used with a three-tier suspension of phase wires of two OHL chains on two-beam traverses and a suspension in the fourth tier of two lightning protection cables (lightning cables) on a two-wire cable rack mounted on a support column (“Unified steel supports of 220 and 330 kV overhead lines ”, series 3.407-100, All-Union State Design and Research and Research Institute“ Energetsetproekt ”, Moscow, 1973 [1]).

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

- the lightning protection angle normalized by the current edition of the “Rules for the Installation of Electrical Installations” (ПУЭ-7) for all phase wires of both circuits;

- 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.

The first of these requirements is provided by the corresponding height of the suspension of lightning cables, the second - by the corresponding value of the departure of the console of the cable-resistant.

The need to use two lightning protection cables to fulfill these requirements is a disadvantage of the known single-column intermediate supports for double-circuit overhead lines (double-circuit supports).

From [1] two-chain anchor supports are known (for example, type U220-2) with a cable-resistant designed to suspend a single lightning cable that fulfills both of the above requirements. According to this decision, the span sections of the ground wire are attached to the cable rack on the axis of symmetry of the support with the help of insulating suspensions and are connected by an insulated cable. The disadvantage of this solution is the increased cost of lightning protection of overhead lines due to the use of insulating loops and greater installation costs.

As a prototype, the support is selected according to patent RU122109. According to the general structural scheme, including lightning protection with two cables, this support is similar to a unified steel intermediate support for double-circuit 220 kV overhead lines of type P220-2t [1].

The prototype is a two-chain intermediate VL support containing a rack on which two-beam traverses are mounted for suspension of six phase wires of two power transmission circuits and a two-wire cable rack is located above the said traverses.

In order to ensure the fulfillment of the above requirements (both lightning protection and the possibility of using the support in climatic regions with intense icing), the prototype wire-resistant is made of a vertical rack element and two horizontal consoles designed for insulated suspension of two lightning protection cables.

It is theoretically possible to design a two-chain single-column intermediate support with one ground wire, asymmetrically (relative to the axis of the support) suspended on a cantilever cable, and which fulfills both of these requirements (Fig. 1).

высота тросостойки. Это приводит к существенному возрастанию нагрузки на стойку опоры и соответствующему увеличению её металлоемкости. Возрастание нагрузки обусловлено главным образом ростом изгибающего момента от горизонтальных ветровых воздействий на

подвешенный грозотрос, особенно, при наличии на нем гололедных образований.However, in practice, such a solution is not applied, since in such a design an increased mark of fastening of the ground wire is necessary and, accordingly,

cable resistant height. This 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 ground wire, especially if there are ice formations on it.

Disclosure of invention

The technical result of the invention with respect to the prototype is lightning protection of a double-circuit overhead line with one lightning cable with the possibility of melting ice on it, i.e. ensuring the above technical requirements using one ground wire instead of two.

At the same time, the suspension height of the ground wire on the intermediate support is preserved and there is no need to increase its metal consumption compared to the prototype.

The subject of the invention is a double-circuit intermediate VL support, comprising a rack, on which two-console traverses for suspension of phase wires are fixed and a two-wire cable support for suspension of a lightning protection cable, placed above said traverses, characterized in that the cable resistance is made V-shaped with the possibility of an isolated suspension of a lightning protection cable between it inclined consoles at a height sufficient to ensure a normalized angle of lightning protection of the phase conductors of both circuits, and at insulating distances x from trosostoyki normalized voltage for melting ice on the ground wire.

This allows you to get the above technical result.

The development of the invention provides for the installation of spacers between the inclined consoles of a V-shaped cable rack.

The subject of the invention is also a double-circuit overhead power transmission line in which at least one intermediate support is made as described above.

The implementation of the invention

The scheme of the proposed double-chain intermediate support with a V-shaped cable-resistant is shown in FIG. 2.

The support diagram shows a rack 1, on which two-console traverses 2 (lower), 3 (middle) and 4 (upper) are fixed in three tiers for insulating suspension of six phase wires of a double-circuit overhead line. Above the upper traverse 4 on the rack 1, a V-shaped double-conductor cable rack 5 is fixed. On the inclined consoles 6 and 7 of the cable rack 5, with the help of insulating suspensions 8 and 9, a lightning protection cable 10 is fixed.

To increase the strength of the cable 5 between the inclined consoles 6 and 7, a spacer 11 can be installed.

The lengths of the consoles 6 and 7 and the angle between them are selected so that the distances from the ground wire 10 to the consoles 6 and 7 are equal to or greater than the insulation distances to the grounded parts of the support, normalized for the used ice melting voltage on the ground wire. The suspension height of the ground wire 10 provides for any of the six phase wires an angle of lightning protection, the maximum value of which (30 °) is normalized by PUE-7.

Thus, the use of a V-shaped wire-rack in the intermediate double-circuit overhead support of the overhead line made it possible to suspend the ground wire 10 symmetrically with respect to both chains of the double-circuit overhead line at a height (mark) that practically does not exceed the suspension height of two lightning protection cables on known double-circuit intermediate supports of the same voltage class and, therefore, thereby, without increasing the total metal consumption of the support, provide lightning protection of a double-circuit overhead line with one lightning cable with the possibility of melting ice on it.

Claims (3)

1. A double-chain intermediate support of an overhead line, comprising a rack on which two-console traverses for suspension of phase wires are fixed and a cable rack for suspension of a lightning protection cable placed above said traverses, characterized in that the wire resistance is made V-shaped with the possibility of an isolated suspension of a lightning protection cable between its inclined consoles at a height sufficient to ensure a normalized angle of lightning protection of the phase conductors of both circuits, and at insulating distances from the cable-rack, normalized for the voltage of melting ice on a lightning protection cable. 2. A support according to claim 1, characterized in that a spacer is installed between the inclined consoles of the cable. 3. A double-circuit overhead power line, in which at least one intermediate support is made according to claim 1 or 2.

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