RU51276U1 - POWER CABLE - Google Patents

Abstract

The utility model relates to the field of electrical engineering, namely to power cables with plastic insulation such as VVG, AVVG.

The cable contains polymer-coated sector conductive conductors, a grounding conductor, twisted into a core, a belt insulation, a protective polymer sheath. On top of the belt insulation, the cable additionally contains an inner polymer sheath, on which a grounding conductor is applied in the form of a coil from individual conductors.

The conductors in the midwire may be rectangular or part of the conductors may be steel or at least one of the conductors is covered with insulation.

The midwire of conductors is made by wave twisting and additionally has a fastening element made in the form of a winding with mylar ribbon or thread.

The insulation and / or shell is made of a flame retardant polymer material. The cable has a smaller diameter, greater flexibility, does not have electromagnetic interference to neighboring electrical installations.

Description

The utility model relates to the field of electrical engineering, namely, to the construction of power cables with plastic insulation, intended for the transmission and distribution of electrical energy in stationary AC or DC networks at a nominal voltage of 0.66; one; 3 and 6 kV.

Known five-core power cable type VVG, AVVG with insulated sector conductive conductors and a grounding conductor, twisted into a core, which is covered with belt insulation. Insulation and sheath made of PVC compound or polyethylene. (Power cables with plastic insulation. GOST 16442-80).

The disadvantage of the cable is an oversized diameter in relation to the useful cross section of the cores. This drawback is due to the peculiarity of the twisting of five veins, as well as with the use of round, but not sector, veins. The manufacture of a five-core cable with sector wires, of which one or two wires of a substantially smaller cross section is technically difficult.

In addition, the cable is not protected from electromagnetic effects on surrounding electrical installations.

The basis of this utility model is the task of creating a power cable that, thanks to the introduction of new structural elements, the new implementation of the elements and their new mutual arrangement, would have minimum overall dimensions, increased noise immunity, flexibility and mechanical stability.

The problem is solved in that the power cable, including coated with polymer insulation sector conductive conductors, a grounding conductor, twisted into a core, a belt insulation, a protective polymer sheath, according to a utility model, on top of the core additionally contains an inner polymer sheath, on which a grounding core is made, made in in the form of coils from individual conductors.

The conductors in the midwire can be made rectangular.

Part of the conductors in the midwife can be made in the form of reinforcing elements, for example, of steel wires.

In the midwire, at least one of the conductors may be insulated. A twisting of individual conductors can be performed by wave twisting.

The fastening element can be made in the form of a winding tape made of polyethylene terephthalate.

The insulation and / or shell may be made of a flame retardant polymeric material.

The advantage of the proposed power cable is that, thanks to the new implementation of the grounding core in the form of a coil from separate wires, the introduction of new elements - the inner polymer shell and the fastening element, the cable diameter is reduced by 15-20% compared with the prototype and, therefore, the consumption of materials is reduced , its flexibility increases. Having twisted the wires of the grounding wire acts as a shield, therefore, the cable is protected from electromagnetic influence on neighboring equipment or electrical installations. The cable is protected against unauthorized connection. The use of reinforcing elements in the field allows air suspension of the cable without a supporting cable.

In addition, the use of wave twisting will reduce the ohmic resistance of the grounding core, since with normal twisting, the twist of the wires is 3-4%, and with wave twisting it is 0.5-0.7%, therefore, aluminum consumption also decreases by the same amount to the grounding conductor.

In addition, the laboriousness of manufacturing the cable is reduced, since for twisting the conductors with ordinary twisting, it is necessary to use a twisting machine and coils for it, and with wave twisting, the process of applying the outer conductor is combined with the application of the sheath. Placement of insulated conductors in a layer allows them to be used in control automation circuits.

The proposed cable is schematically shown in cross section in drawings 1-3. Figure 1 shows a cable with a grounding conductor in the form of a coil of individual conductors. Figure 2 shows a cable with a grounding conductor having reinforcing elements. Figure 3 is given a cable with a grounding conductor, having insulated conductors in the area. In the figures: 1 - sector conductive core, 2 - insulation, 3 - belt insulation, 4 - inner polymer sheath, 5 - conductors of the grounding conductor, 6 - fastening

conductive element, 7 — protective polymer sheath, 8 — reinforcing elements, 9 — insulated conductors.

The power cable contains coated on the extruder with polymer insulation 2 sector conductive conductors 1, grounding core 5, which are twisted into a core on a winding machine having a wrapper for applying belt insulation 3, a protective polymer sheath 7, which is also imposed on the extruder.

The cable on top of the belt insulation 3 additionally contains an extruded inner polymer sheath, 4 on which a grounding conductor is applied, made in the form of a coil of separate conductors 5. Laying of a coil of separate conductors 5 is carried out on any armored machine designed for applying wire armor, or on any torsional a machine with enough recoil coils.

If necessary, the cable may have an inter-core filling, for example, in the form of cordels of insulation material 2, which are superimposed together with the cores on a twisting machine.

The conductors 5 in the coil can be made rectangular and superimposed on the scroll coil machine, increasing the fill factor in the scroll to 100%, which reduces the diameter of the cable.

Part of the conductors 5 (four conductors are shown in FIG. 2) in the midwire can be made in the form of reinforcing elements 8, for example, of steel wires, which allows cable suspension between current collectors without a cable.

In a midwire of individual conductors 5, at least one of the conductors 9 can be coated with insulation applied to the extruder (two insulated conductors 9 are shown in FIG. 3), which makes it possible to use them in control circuits.

The coil of the individual conductors 5 can be made by wave twisting, combined with the application of a protective polymer sheath 7, while for applying the coil of wires 5, a device for wave twisting with fixed detectors for coils with aluminum and steel wire is used. The wires are passed through the eyes (holes) of two sockets, spaced from each other at a distance of a twist step, and having a reverse rotation from the drive. Between the specified device and the press head for applying the sheath 7 is installed tape wrapper or thread wrapper for

fastening of the midwash with fastening elements 6 of tapes, for example of polyethylene terephthalate or of synthetic threads.

Insulation 2, insulation of conductors 9, or sheaths 4, 7 can be made of flame-retardant polymer material, for example, polyvinyl chloride plastic compound or polyethylene, which increases the fire resistance and reliability of the cable.

For cables of higher voltage (up to 6 kV), a semiconducting screen can be applied over the core to equalize the electric field, for example, from semiconducting polyvinyl chloride plastic compound or polyethylene.

Depending on the requirements of the operating conditions, the cable may have armor under a protective sheath, and, if necessary, other protective covers.

Claims (7)

1. Power cable, including polymer-coated sector conductive conductors, grounding conductor, twisted into a core, waist insulation, protective polymer sheath, characterized in that on top of the waist insulation additionally contains an inner polymer sheath, on which a grounding core is made in the form of a coil from individual conductors. 2. The cable according to claim 1, characterized in that a part of the conductors in the coil is made in the form of reinforcing elements, for example, of steel wires. 3. The cable according to claim 1, characterized in that in the coil, at least one of the conductors is coated with insulation. 4. The cable according to any one of claims 1 to 3, characterized in that the coil of the individual conductors is made by wave twisting. 5. The cable according to claim 4, characterized in that the winding of the individual conductors is additionally covered with a fastening element made in the form of a winding tape, for example, from polyethylene terephthalate. 6. The cable according to claim 1, characterized in that the conductors in the coil are made rectangular. 7. The cable according to claim 1, characterized in that the insulation and / or the sheath is made of a flame retardant polymer material.