RU152230U1 - THREE-WAY POWER CABLE - Google Patents

Abstract

1. A three-core power cable, in which layers are sequentially laid on top of each conductive core, namely, a first conductive shield, insulation, a second conductive shield, a layer of conductive tape and a metal shield, said conductive wires with these layers are twisted into the core either directly or around the bundle extruded from a polymeric material, on top of the specified core, either a separation layer, an inner shell and an outer shell are sequentially applied, or will separate the inner layer, the inner shell, the armor and the outer shell, or the inner shell and the outer shell, or the inner shell, the armor and the outer shell, wherein said insulation is made of ethylene-propylene rubber with reinforcing hydrophobic filler, said first and second electrically conductive screens are made of ethylene-propylene rubber containing soot, and the mentioned armor is made of either galvanized steel tapes or galvanized steel wires. 2. The cable according to claim 1, wherein the separation layer is made of either creped or cable paper tape, or polypropylene tape, or a non-woven fabric tape, or a rubberized fabric tape. The cable according to claim 1, in which the conductive conductors are made in cross section in the form of sectors. The cable according to claim 1, in which the metal shield is made of either a plurality of copper wires or a plurality of copper wires, on top of which either a copper tape made in the form of a winding or a pile of copper wires made in the form of a winding or a metal screen is made as a set

Description

Technical field

The utility model relates to cable technology, namely, to the construction of three-core power cables with rubber insulation, designed for transmission and distribution of electrical energy in stationary installations for a rated alternating voltage of 6, 10, 15, 20, 30, 35 kV with a nominal frequency of 50 Hz for networks with grounded and isolated neutral.

State of the art

A known power cable for voltage of 20 and 35 kV, containing three copper or aluminum conductive cores, each of which is coated with impregnated paper insulation and a shield of electrically conductive paper, insulated cores are twisted into a core over which a belt insulation is applied, a lead or aluminum sheath and protective sheaths (GOST 18410-73 "Power cables with impregnated paper insulation", date of introduction - 01.01.75).

Signs of a known cable, coinciding with the features of the claimed utility model, are the presence of three conductive cores coated with insulation and a shield, in the execution of cores twisted into a core, in the presence of a sheath.

The reason that prevents obtaining a technical result in a known cable, which is provided by the claimed utility model, is the insulation and the screen made of cable paper.

The closest analogue (prototype) is a power cable with a voltage of 10 and 20 kV with three round or round copper or aluminum conductive conductors, each conductive core is extruded by an electrically conductive screen from an electrically conductive cross-linked polyethylene composition, the screen is extruded by insulation from the cross-linked polyethylene composition, on top of the insulation - a second screen of an electrically conductive cross-linked composition, on top of the electrically conductive extruded screen on each core is a layer of electrically conductive tapes, on top of the electrical a metal screen made of coiled copper wires fastened together with a copper tape, extruded over the core twisted from three shielded cores, filling the space between the cores of a highly filled polymer composition, depending on the design and purpose of the cable, an inner sheath of an extruded polymer composition can be applied, steel tape armor and sheath made of extruded polymer composition (IEC 60502-2: 2005 “Power cables with extruded insulation and fittings to them for a rated voltage of 6 kV (Um = 7.2 kV) to 30 kV (Um = 36 kV). " Part 2. Cables for rated voltage from 6 kV (Um = 7.2 kV) to 30 kV (Um = 36 kV)).

Signs of a known cable that coincide with the features of the claimed utility model consist of a cable with a voltage of 10 and 20 kV, with three metal conductors, each of which is superimposed with a first conductive layer, insulation, a second conductive layer, a layer of conductive tapes, a metal screen, insulated shielded cores are twisted into a core over which an inner sheath and an outer sheath are superimposed.

The reason that prevents obtaining a technical result in a known cable, which is provided by the claimed utility model, is the insulation of conductive conductors from cross-linked polyethylene.

Utility Model Disclosure

The problem, which the utility model is aimed at, is to increase the cable throughput, increase its reliability and simplify its laying.

The technical result, which determines the solution of this problem, lies in the possibility of cable operation in nominal mode with a core temperature of up to 105 ° C, in increasing the flexibility of insulation (compared to cables with XLPE insulation), as well as in creating the possibility of laying the cable at temperatures up to -40 ° C.

The specified technical result is achieved in that the cable contains three conductive wires, layers are sequentially laid on top of each conductive core, namely, a first conductive screen, insulation, a second conductive screen, a layer of conductive tape and a metal screen, said conductive wires with these layers are twisted into the core, either directly or around a bundle extruded from a polymer material, either a release layer is sequentially applied over the said core, the inner shell and the outer shell, or the separation layer, the inner shell, the armor and the outer shell, or the inner shell and the outer shell, or the inner shell, armor and the outer shell, wherein said insulation is made of ethylene-propylene rubber with reinforcing hydrophobic filler, the first and the second electrically conductive screens are made of ethylene-propylene rubber containing soot, and said armor is made of either galvanized steel tapes or galvanized steel wires.

The technical result is also achieved by the fact that the separation layer is made of either crepe or cable paper tape, or polypropylene tape, or a non-woven fabric tape, or a rubberized fabric tape.

The technical result is also achieved by the fact that the conductors are made in cross section in the form of sectors.

The technical result is also achieved by the fact that the metal screen is made of either a plurality of copper wires, or of a plurality of copper wires, on top of which either a copper tape made in the form of a winding, or a pile of copper wires made in the form of a winding, or a metal screen is made in in the form of many wires of aluminum or aluminum alloy, wrapped in tape made of aluminum or aluminum alloy.

The technical result is also achieved by the fact that the inner shell is made of either rubber or PVC compound with a frost resistance of -50 ° C to -60 ° C, or a low-flammability PVC compound with an oxygen index of at least 32, or a low fire hazard PVC compound with an oxygen index of at least 28, or from a halogen-free polymer composition with an oxygen index of at least 32.

The technical result is also achieved by the fact that the outer shell is made either of a halogen-free polymer composition with an oxygen index of at least 32, or of low-flammability PVC compound with an oxygen index of at least 32, or of PVC compound with a frost resistance of -50 ° C to -60 ° C, or from PVC compound of reduced fire hazard with an oxygen index of at least 35.

The features of the claimed utility model, distinctive from the prototype, are in the insulation of the core of ethylene propylene rubber with reinforcing hydrophobic filler and in the implementation of electrically conductive screens of ethylene propylene rubber containing soot.

Utility Model Implementation

The cable contains three conductive wires made of copper or aluminum wires. Moreover, each core can be made in a cross section of a round or sector shape, multi-wire. On top of each core is the first electrically conductive screen, which is made of electrically conductive rubber based on ethylene-propylene rubber containing highly conductive soot. On top of the first electrically conductive screen of each core is an insulation made of rubber based on ethylene-propylene rubber containing a reinforcing hydrophobic filler. Above said insulation is a second conductive screen, which is made of the same material as the first conductive screen. On top of the second electrically conductive screen of each core is a layer of electrically conductive tape, which is an electrically conductive paper or an electrically conductive polymer tape. On top of the conductive tape of each core is a metal shield made either in the form of a plurality of copper wires, on top of which either a copper tape made in the form of a winding, or a pile of copper wires made in the form of a winding, or in the form of a plurality of aluminum or aluminum alloy wires wrapped in tape made of aluminum or aluminum alloy.

Insulated and shielded conductors are twisted into a core. Between twisted veins, there may be a bundle made of extruded PVC compound or unvulcanized rubber compound, or non-burning rubber.

The cable may contain a separation layer made of crepe or cable paper tape, or polypropylene tape, or non-woven fabric tape, or rubberized fabric overlaid on twisted cores.

On top of the separation layer (or core of twisted cores) there is an inner shell with filling the inter-core space, which is made of either rubber or PVC compound with a frost resistance of -50 ° C to -60 ° C, or of a low-combustibility PVC compound with an oxygen index not less than 32, either from PVC compound of reduced fire hazard with an oxygen index of at least 28, or from a polymer composition that does not contain halogens with an oxygen index of at least 32.

The cable may contain armor located on top of the inner shell, while the armor is made of galvanized steel tapes.

On top of the inner shell (or on top of the armor) there is an outer shell made of a halogen-free polymer composition, or of low flammability PVC compound with an oxygen index of at least 32, or of PVC compound with a frost resistance of -50 ° C to -60 ° C, or from PVC compound of reduced fire hazard with an oxygen index of at least 35.

The manufacture of the cable consists in alternately applying the above layers in the appropriate order. In this case, the first screen is applied to each core by extrusion, and its (screen) purpose is to evenly distribute the electric field at the boundary of the conductive core and the insulation layer. Then, insulation is applied to each core, which serves as the main electrical insulating element and is designed to withstand the effects of an electric field. Then impose a second electrically conductive screen, which serves to evenly distribute the tension between the insulation and the metal screen. A layer of an electrically conductive tape is applied over the second electrically conductive screen, which serves to align the electric field in the cable. Then impose a metal screen, the main purpose of which is protection against electromagnetic interference, as well as the removal of short circuit currents. After that, the cores are twisted into a core, on top of which a separating layer made of crepe or cable paper, or polypropylene tape, or non-woven fabric tape, or rubberized fabric can be located, which serves to prevent the material of the inner sheath from flowing between the wires of the metal screen. On top of the separation layer (or over the core of twisted veins) impose an inner shell. Armor can then be applied to protect against significant tensile forces. After that impose the outer shell.

The cable design has been successfully tested in the production environment. The use of insulation from ethylene-propylene rubber (rubber based on ethylene-propylene rubber containing a reinforcing hydrophobic filler) with high electrical and thermal resistance, as well as the use of the first and second electrically conductive layers of ethylene-propylene rubber (rubber based on ethylene-propylene rubber) with the content of highly conductive soot, can withstand the current load is 15-20% higher with respect to the cable with XLPE insulation. Due to the high thermomechanical characteristics of this rubber, bending of the cable causes insignificant mechanical stresses of the insulation layers, which significantly reduces the likelihood of an uneven distribution of electrical tension in the insulation thickness.

Claims (6)

1. A three-core power cable, in which layers are sequentially laid on top of each conductive core, namely, a first conductive shield, insulation, a second conductive shield, a layer of conductive tape and a metal shield, said conductive wires with these layers are twisted into the core either directly or around the bundle extruded from a polymeric material, on top of the specified core, either a separation layer, an inner shell and an outer shell are sequentially applied, or will separate the inner layer, the inner shell, the armor and the outer shell, or the inner shell and the outer shell, or the inner shell, the armor and the outer shell, wherein said insulation is made of ethylene-propylene rubber with reinforcing hydrophobic filler, said first and second electrically conductive screens are made of ethylene-propylene rubber containing soot, and the said armor is made of either galvanized steel tapes or galvanized steel wires. 2. The cable according to claim 1, in which the separation layer is made of either a crepe or cable paper tape, or a polypropylene tape, or a non-woven fabric tape, or a rubberized fabric tape. 3. The cable according to claim 1, in which the conductive conductors are made in cross section in the form of sectors. 4. The cable according to claim 1, in which the metal shield is made of either a plurality of copper wires or a plurality of copper wires, on top of which either a copper tape made in the form of a winding, or a pile of copper wires made in the form of a winding, or metal is laid the screen is made in the form of a plurality of wires of aluminum or aluminum alloy, wrapped with a tape made of aluminum or aluminum alloy. 5. The cable according to claim 1, in which the inner sheath is made of either rubber or PVC compound with a frost resistance of -50 ° C to -60 ° C, or a low combustibility PVC compound with an oxygen index of at least 32, or PVC of low fire hazard plastic compound with an oxygen index of at least 28, or from a halogen-free polymer composition with an oxygen index of at least 32. 6. The cable according to claim 1, in which the outer sheath is made of either a halogen-free polymer composition with an oxygen index of at least 32, or a low flammability PVC compound with an oxygen index of at least 32, or a PVC compound with a frost resistance of -50 ° C to -60 ° C, or of PVC compound of reduced fire hazard with an oxygen index of at least 35.