CN201532808U - Single-phase 27.5kV power cables for electrified railways - Google Patents

Abstract

The utility model relates to a cable, in particular to a single-phase 27.5kV power cable for an electrified railway. The electric railway single-phase 27.5kV power cable of the utility model includes a wire core, and the outer side of the wire core is wrapped with a metal shielding layer, an inner lining layer, a non-magnetic metal wire armor layer and an outer sheath in turn from the inside to the outside, and the wire core is wrapped from the inside to the outside. To the outside, there are conductor core, conductor shielding layer, insulation layer and insulation shielding layer. The conductor core is a cylindrical pressed copper conductor. The three layers of conductor shielding layer, insulation layer and insulation shielding layer are co-extruded and tightly covered on the surface of the conductor core. . The power cable of the utility model satisfies the requirements of the cable withstand voltage level and grounding in the electrified railway system, and can effectively ensure the safe operation of the line. In addition, the product has simple structure, strong applicability, convenient construction and high reliability, and can be widely used in 27.5kV cable lines of electrified railways.

Description

Single-phase 27.5kV power cables for electrified railways

technical field

The utility model relates to a cable, in particular to a single-phase 27.5kV power cable for an electrified railway.

Background technique

At present, due to the particularity of 27.5kV single-phase (to-ground) electrified railways in my country, the withstand voltage level is equivalent to the 42kV withstand voltage requirements of power system equipment, which is between 35kV and 66kV voltage system levels. At the same time, the railway single-phase direct grounding working mode and The characteristics of short-term load changes are very different from those of the power sector, resulting in cables that cannot be fully used with 27.5kV equipment.

Utility model content

The technical effects of the utility model can overcome the above defects, and provide a single-phase 27.5kV power cable for electrified railways, which has a simple structure and good versatility.

In order to achieve the above object, the utility model adopts the following technical scheme: it includes a wire core, and the outside of the wire core is sequentially wrapped with a metal shielding layer, an inner liner, a non-magnetic metal wire armor layer and an outer sheath from the inside to the outside, and the wire core is composed of From the inside to the outside, there are conductor core, conductor shielding layer, insulation layer and insulation shielding layer. The conductor core is a cylindrical pressed copper conductor. The conductor shielding layer, insulation layer and insulation shielding layer are co-extruded and tightly wrapped on the conductor core surface.

The conductive core is made of multiple copper single wires twisted and compressed to form a cylindrical conductor, and the conductor core is covered with a conductor shielding layer based on polyolefin, and a low-density polyethylene based material with peroxide Cross-linked polyethylene insulation layer as a cross-linking agent and insulation shielding layer based on polyolefin.

The metal shielding layer is composed of sparsely wound soft copper wire and copper tape, and the copper tape is reversely bound on the surface of the copper wire. A semi-conductive wrapping layer is respectively arranged between the metal shielding layer and the wire core, and between the metal shielding layer and the inner lining layer as a buffer layer. The inner lining layer is made of PE or PVC material, and the inner lining layer is evenly and tightly extruded on the surface of the semi-conductive wrapping layer outside the metal shielding layer. The non-magnetic metal wire armor layer is tightly arranged and wound on the outer surface of the inner lining layer, and the non-magnetic metal wire armor layer is wrapped tightly with wrapping tape. The outer sheath is evenly and tightly covered on the surface of the armored outer wrapping layer. The outside of the outer sheath should be evenly coated with graphite material as a semi-conductive layer. According to the requirements of the use environment, the cable of the utility model can also be made into a low-smoke, halogen-free, flame-retardant or low-smoke, low-halogen, flame-retardant type.

The utility model provides a 27.5kV power cable which can be used in the electrified railway, meets the requirements of the cable withstand voltage level and grounding in the electrified railway system, and can effectively ensure the safe operation of the line. In addition, the product has simple structure, strong applicability, convenient construction and high reliability, and can be widely used in 27.5kV cable lines of electrified railways.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in detail:

Fig. 1 is a schematic diagram of the internal structure of the utility model.

Detailed ways

The ground-to-ground cable of the present utility model includes a wire core, and the outer side of the wire core is sequentially wrapped with a metal shielding layer 6, an inner lining layer 7, a non-magnetic metal wire armor layer 8 and an outer sheath 10, and the wire core is sequentially wrapped from the inside to the outside. The outer part is the conductor core 1, the conductor shielding layer 2, the insulating layer 3 and the insulating shielding layer 4 in sequence.

The conductor core 1 is made of copper single wire tightly twisted, the conductor shielding layer 2, the insulating layer 3, and the insulating shielding layer 4 are extruded together by three layers, the nominal thickness of the conductor shielding layer 2 is 0.8mm, and the thinnest part is not less than the standard 80% of the nominal value, the nominal thickness of the insulation is 12mm; the average thickness of the insulating layer 3 is not less than the nominal thickness, and the thickness of the thinnest point at any point is not less than 90% of the nominal value.

The metal shielding layer 6 is composed of sparsely wound soft copper wires and copper tapes, and the copper tapes are reversely bound tightly on the surface of the copper wires. Between the metal shielding layer 6 and the wire core, and between the metal shielding layer 6 and the inner lining layer 7, a semi-conductive wrapping layer 5 is respectively arranged as a buffer layer. The inner liner layer 7 is uniformly and tightly wrapped on the surface of the semiconductive wrapping layer 5 outside the metal shielding layer. 8 layers of non-magnetic wire armor are closely arranged and wound on the outer surface of the inner lining layer 7, and the non-magnetic wire armor layer 8 is wrapped tightly with wrapping tape 9 for the outside. The outer sheath 10 evenly and tightly covers the surface of the wrapping tape 9 . The outside of the outer sheath 10 is uniformly coated with graphite material as the semiconductive layer 11 .

The coverage rate of the semi-conductive wrapping layer 5 on the outside of the core is not less than 25%. The metal shielding layer 6 adopts the form of sparse winding of copper wire. The copper wire should be wound on the core with a pitch not exceeding 10 times the diameter of the pitch circle. And always keep in contact with the wire core. The average gap between adjacent copper wires is not greater than 4mm, and the gap between any two adjacent copper wires is not greater than 8mm. Copper wire with a thickness of 0.1 mm and a width of 30-40 mm should be bound in reverse, and the cross-sectional area of the metal shielding layer 6 should meet the short-circuit current requirements. The two semi-conductive wrapping layers 5 are wrapped with plastic tape or cloth tape with the same insulation and temperature resistance level, and the overlapping rate is not less than 25%. The inner lining layer 7 is made of PE or PVC material, and the non-magnetic metal wire armor layer 8 is tightly wound outside the inner lining layer 7 by non-magnetic metal wires, which can avoid excessive cable eddy current loss and cause cable heating and reduce current-carrying conditions. Withstand a certain short-circuit current, and can withstand a certain tension, to prevent damage to the cable during construction and laying. The wrapping tape 9 is a two-layer wrapping tape, and the covering rate is not less than 25%.

The outer sheath 10 is made of PE or PVC material, the nominal thickness is 3.0mm, and the thinnest point is not less than 85%-0.1mm of the nominal value. Inner liner 7 and outer sheath 10 of flame-retardant, low-smoke, halogen-free, flame-retardant, and low-smoke, low-halogen flame-retardant cables are made of flame-retardant PE, flame-retardant PVC or low-smoke, Smoke low halogen flame retardant polyolefin material, the wrapping tape 9 should be wrapped with four layers of flame retardant cloth tape for class A flame retardant, and two layers of flame retardant cloth tape should be used for class B flame retardant to meet the combustion level and smoke density requirements.

Claims (7)

1. A single-phase 27.5kV power cable for electrified railways, comprising a wire core, the outside of the wire core is wrapped with a metal shielding layer, an inner liner, a non-magnetic metal wire armor layer and an outer sheath successively from the inside to the outside, and it is characterized in that the wire The core is the conductor core, the conductor shielding layer, the insulation layer and the insulation shielding layer from the inside to the outside. The conductor core is a cylindrical pressed copper conductor. conductor core surface. 2. The electrified railway single-phase 27.5kV power cable according to claim 1, characterized in that the metal shielding layer is composed of sparsely wound annealed copper wire and copper tape, and the surface of the copper wire is bound tightly by the copper tape in reverse. 3. The electrified railway single-phase 27.5kV power cable according to claim 1 or 2, characterized in that a semi-conductive wrapping layer is respectively arranged as a buffer between the metal shielding layer and the core, and between the metal shielding layer and the inner lining layer layer. 4. The electrified railway single-phase 27.5kV power cable according to claim 3, characterized in that the inner lining layer is evenly and tightly extruded on the surface of the semi-conductive wrapping layer outside the metal shielding layer. 5. The electrified railway single-phase 27.5kV power cable according to claim 3, characterized in that the non-magnetic metal wire armor layer is tightly arranged and wound on the outer surface of the inner liner, and the non-magnetic metal wire armor layer is wrapped with a wrapping tape Bandage tightly. 6. The electrified railway single-phase 27.5kV power cable according to claim 3, characterized in that the outer sheath is evenly and tightly covered on the surface of the wrapping tape. 7. The electrified railway single-phase 27.5kV power cable according to claim 6, characterized in that the outside of the outer sheath is uniformly coated with graphite material as a semiconductive layer.

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