CN220895243U - High-performance medium-voltage power cable - Google Patents

Abstract

The utility model discloses a high-performance medium-voltage power cable, which comprises a cable core, a cable core protection layer and an outer protection layer; the cable core comprises a filling frame, three metal shielding insulating wire cores, three soft conductors and three tile-shaped filling rubber strips, wherein the three metal shielding insulating wire cores are mutually stranded, and the filling frame is filled in a central area among the three metal shielding insulating wire cores; the three soft conductors are distributed outside contact points among the three metal shielding insulating wire cores, and the three tile-shaped adhesive tapes are respectively filled in side gaps among the metal shielding wire cores and respectively squeeze the three soft conductors. Has better conductivity, electric field uniformity, capacity of bearing short-circuit current and reliability.

Description

High-performance medium-voltage power cable

Technical Field

The utility model relates to a power cable, in particular to a high-performance medium-voltage power cable.

Background

The medium voltage power cable is widely used, occupies an important position in the power system, and is particularly used for an input line of a load-side step-down transformer to play a role in power transmission.

At present, the structure of the medium voltage power cable is provided with a metal shielding structure, and the metal shielding structure mainly comprises two types: the first type adopts a copper strip shielding structure, and particularly soft copper strips are overlapped and wrapped outside an insulating shielding; the second kind adopts a copper wire shielding structure, and is specifically a composite structure of a semiconductive buffer belt, a copper wire sparse winding and a counter-binding copper belt gap wrapping.

It is well known that metallic shields are mainly used for uniform electric fields and for carrying short-circuit currents, wherein the first copper shield structure can only carry general short-circuit currents, and if higher short-circuit currents are to be carried, the first copper shield structure is limited (there are difficulties in the process due to the larger increase of the cross-sectional area of the copper shield).

The second copper wire shielding structure can bear larger short-circuit current by adjusting the number or the wire diameter of the shielding copper wires. However, as the semiconductive buffer belt in the second copper wire shielding structure is electrified, heated, aged and slowly failed for a long time, under the action of the self weight of the cable and the action of the force between the metal shielding wire cores, the action of the shielding copper wires on the insulating external screen is more and more obvious, and finally the three-layer co-extrusion structure of the insulating wire cores is deformed to influence the service life of the cable, and in addition, a larger gap exists between the shielding copper wires of the shielding copper wire structure, so that the outer diameter of the cable is increased.

Moreover, the shielding copper strip is a soft pure copper strip, the conductivity of the shielding copper strip is good, oxidation discoloration and slow corrosion are easy to occur when moisture is met, the rebound resilience is poor after the shielding copper strip is subjected to cold and heat change, and an air gap is easy to form between the shielding copper strip and the insulating outer screen, so that the uniformity of an electric field is influenced.

Disclosure of utility model

Aiming at the problems of the existing medium voltage power cable in the aspect of metal shielding, the utility model aims to provide a high-performance medium voltage power cable which has better shielding performance and short circuit current bearing capacity and can effectively overcome the problems in the prior art.

In order to achieve the above object, the high-performance medium-voltage power cable adopted by the utility model comprises a cable core, a cable core protection layer and an outer protection layer.

In a preferred embodiment of the utility model, the cable core comprises a filling frame, three metal shielding insulating wire cores, three soft conductors and three tile-shaped filling rubber strips, wherein the three metal shielding insulating wire cores are mutually stranded, and the filling frame is filled in a central area among the three metal shielding insulating wire cores; the three soft conductors are distributed outside contact points among the three metal shielding insulating wire cores, and the three tile-shaped adhesive tapes are respectively filled in side gaps among the metal shielding wire cores and respectively squeeze the three soft conductors.

In a preferred embodiment of the utility model, each metal shielding insulating wire core comprises a conductor, and the periphery of the conductor is sequentially coated with a conductor shielding layer, a plastic insulating layer, an insulating shielding layer and a metal shielding layer from inside to outside; the periphery of the cable core is sequentially coated with the cable core, the cable core protection layer and the outer protection layer from inside to outside.

In a preferred embodiment of the utility model, the conductor is a layered compacted twisted type 2 single wire twisted round compacted conductor.

In a preferred embodiment of the utility model, the plastic insulation is extruded from a plastic insulation.

In a preferred embodiment of the utility model, the metallic shielding layer is formed by a metal strip tightly lapped over the insulating shield.

In a preferred embodiment of the utility model, the flexible conductor is formed by twisting a plurality of stranded wire conductors in the same direction, each stranded wire conductor is formed by twisting a plurality of flexible round wire strands, and the twisting direction of the stranded wire conductors is opposite to that of the single stranded wire conductors.

In a preferred embodiment of the utility model, the tile-shaped glue strip is foam-extruded from an elastomeric plastic.

In a preferred embodiment of the utility model, the outer sheath is formed of an extruded plastic sheath.

In a preferred embodiment of the utility model, the outer sheath is a composite structure of a metallic armor layer and a plastic sheath outside thereof.

Compared with the prior art, the high-performance medium-voltage power cable provided by the utility model has better conductivity, electric field uniformity, short-circuit current bearing capacity and reliability.

Drawings

The utility model is further described below with reference to the drawings and the detailed description.

Fig. 1 is a cross-sectional illustration of a high performance medium voltage power cable in an example of the utility model.

Detailed Description

The utility model is further described with reference to the following detailed drawings in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the implementation of the utility model easy to understand.

Referring to fig. 1, there is shown an example of the construction of a high performance medium voltage power cable provided by the present utility model.

As can be seen from the figure, the high-performance medium-voltage power cable provided in this example is mainly composed of a cable core 500, and a cable core protection layer 600 and an outer protection layer 700.

The cable core 500 in this example scheme mainly comprises a filling frame 200, three metal shielding insulating wire cores 100, three flexible conductors 300 and three tile-shaped filling rubber strips 400.

The three metal shielding insulated wire cores 100 are twisted with each other, the filling frame 200 is filled in the central area between the three metal shielding insulated wire cores, and the three metal shielding insulated wire cores 100 twisted with each other form a support from the inside;

Three soft conductors 300 are sequentially distributed outside contact points among the three metal shielding insulating wire cores 100;

Three tile-shaped adhesive tapes 400 are distributed on the soft conductors 300 of the side gaps of the three metal shielding wire cores 100, and simultaneously support the metal shielding insulating wire cores 100 distributed on two sides of the soft conductors 300.

In some embodiments of the present example, the metal shielding insulated wire core 100 specifically includes a conductor 110, and a conductor shielding layer 120, a plastic insulating layer 130, an insulating shielding layer 140 and a metal shielding layer 150 are sequentially coated on the periphery of the conductor 110 from inside to outside.

In some embodiments of the present example, the plastic insulation 130 in the metallic shielding insulated wire core 100 is extruded from a plastic insulation. The plastic insulation may be, for example, crosslinked polyethylene or polypropylene.

In some embodiments of the present example, the conductor 110 in the metallic shielding insulated wire core 100 is preferably a layered compacted stranded type 2 single wire stranded round compacted conductor.

For example, the conductor 110 may be made of copper, aluminum or aluminum alloy, and the compression degree of each layer is uniform, and the high-wear-resistance, high-precision and high-strength nano coating mold is selected to compress in a layered manner, so that the surface of the conductor 110 is smooth, the compression coefficient reaches more than 0.98, the inter-single-wire gap is small, the friction force is large, the inner screen is easy to squeeze in place, the inner screen recess or the air gap is not generated, the electric field is uniform and the discharge amount is small, the whole conductor is stressed and stable in structure and is not easy to deform when the cable is bent, the inter-single-wire slippage is small, and the action of the conductor shielding layer 120 on the periphery is uniform and the situation of excessive local acting force cannot occur.

Further, in this example, the pitch diameter ratio of the outer layer of the twisted conductor 110 is 15-20 times, so that the single wires of the conductor 110 are fully contacted, and the resistivity of the conductor 110 is small. Compared with the 2 nd round single wire stranded round compressed conductor (same material), the conductor has smaller resistance per unit length and larger cable current-carrying capacity under the same current-carrying capacity using condition, and the cable has smaller heating temperature rise, thereby having longer service life and higher reliability, having light weight, and the stranded conductor 110 compression coefficient reaching more than 0.98, and having small conductor outer diameter, thereby having small cable outer diameter and important light weight.

In some embodiments of the present example, the conductor shielding layer 120, the plastic insulating layer 130 and the insulating shielding layer 140 in the metallic shielding insulating core 100 are preferably co-extruded on the conductor 110 through three layers, so that the insulating structure is stable, and the insulation of the conductor 110 can be ensured.

In some embodiments of the present example, the metallic shield layer 150 in the metallic shield insulating core 100 is formed by tightly overlapping a metallic tape around the insulating shield 140. By way of example, the metal strip here is in particular an alloy copper strip, which serves for a uniform electric field, shields against external electromagnetic interference and carries short-circuit currents.

By way of further example, the alloy copper strip can be one of a brass strip, a tin bronze strip or an aluminum bronze strip, and the alloy copper strip has higher strength and hardness and better plasticity, weldability and corrosion resistance, so that the problems of the soft pure copper strip can be effectively solved.

In some embodiments of the present example, the filling frame 200 in the cable core 500 may be a polypropylene filling rope, a halogen-free low-smoke high-temperature flame-retardant filling rope, or a halogen-free low-smoke elastomer filling strip; the filling frame 200 is filled in the central area between the three metal shielding insulated wire cores, so that the three metal shielding insulated wire cores 100 twisted with each other can be supported and fixed from the inside, and the action of the force between the metal shielding insulated wire cores 100 is reduced.

By way of example, the filling frame 200 is formed by using corresponding filling ropes, which are matched with the metal shielding insulated wire cores 100, and the surface of the filling frame 200, which is in full contact with each metal shielding insulated wire core 100. The filling frame 200 arranged in this way can play a role in supporting and fixing the metal shielding layer 150, and can not be loosened and have a stable structure under the condition that the outer non-protection belt of the cable core is tightly tied.

In some embodiments of the present example, the flexible conductor 300 in the present cable core 500 is formed by twisting a plurality of bundle wire conductors in the same direction, each bundle wire conductor is formed by twisting a plurality of soft round wire bundles, and the twisting direction of the plurality of bundle wire conductors is opposite to the twisting direction of the single bundle wire conductor.

As an example, the material of the flexible conductor 300 in this example may be copper, tin-plated copper, or aluminum alloy. The flexible conductor 300 is matched with the tile-shaped adhesive tape 400, so that the flexible conductor 300 can be fully contacted with the surface of the metal shielding insulating wire core 100 under the extrusion of the tile-shaped adhesive tape 400, and the flexible conductor 300 and the metal shielding layer 150 together bear cable short-circuit current, and the capability of meeting larger short-circuit current is achieved through the structure and material design of the flexible conductor 300.

In some embodiments of the present example, the tile-shaped adhesive tape 400 in the cable core 500 is formed by foaming and extruding elastomer plastic, and is used for filling the gaps between the metal shielding wire cores 100 of the cable core 500, so that the cable core 500 is round; meanwhile, the tile-shaped adhesive tape 400 presses the flexible conductor 300 when being filled, so that the flexible conductor 300 is fully contacted with the metal shielding wire core 100.

In some embodiments of the present example, the core armor layer 600 in the present medium voltage power cable may be formed by overlapping and wrapping the armor tape around the core 500.

For example, the protective tape may be fiber or plastic film, so that the cable core protective layer 600 formed by the method can fasten and fix the cable core 100 and prevent the cable core 100 from being loosened due to the damage of the metal shielding wire core 100 caused by external force.

In addition, according to the product performance, the structure and the material design of the protective tape can also enable the cable core protective layer 600 to have the characteristics of insulation, heat insulation, flame retardance, fire resistance, water resistance and the like.

In some embodiments of the present example, the outer jacket 700 in the present medium voltage power cable may be an extruded plastic jacket, or a composite structure of a metal armor layer and an outer plastic jacket.

For example, the outer sheath 700 may be made of polyvinyl chloride, polyethylene, or polyolefin.

In some embodiments of the present example, the metal armor layer may be metal tape armor, or metal wire armor, and the material of the metal armor layer may be galvanized steel, aluminum, or aluminum alloy.

The foregoing has shown and described the basic principles, principal features and advantages of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims. The scope of the utility model is defined by the appended claims and equivalents thereof.

Claims (8)

1. A high performance medium voltage power cable, characterized in that the power cable comprises a cable core, a cable core protection layer and an outer protection layer;

The cable core comprises a filling frame, three metal shielding insulating wire cores, three soft conductors and three tile-shaped filling rubber strips, wherein the three metal shielding insulating wire cores are mutually stranded, and the filling frame is filled in a central area among the three metal shielding insulating wire cores; the three soft conductors are distributed outside contact points among the three metal shielding insulating wire cores, and the three tile-shaped adhesive tapes are respectively filled in side gaps among the metal shielding wire cores and respectively squeeze the three soft conductors.

2. The high-performance medium-voltage power cable according to claim 1, wherein each metal shielding insulating wire core comprises a conductor, and the periphery of the conductor is sequentially coated with a conductor shielding layer, a plastic insulating layer, an insulating shielding layer and a metal shielding layer from inside to outside; the periphery of the cable core is sequentially coated with the cable core, the cable core protection layer and the outer protection layer from inside to outside.

3. A high performance medium voltage power cable according to claim 2, wherein said metallic shield layer is formed by a metal tape tightly lapped over an insulating shield.

4. A high performance medium voltage power cable according to claim 2, wherein said plastic insulation is extruded from a plastic insulation.

5. The high performance medium voltage power cable of claim 1, wherein the flexible conductors are formed by co-current stranding of a plurality of wire conductors, each wire conductor being formed by stranding a plurality of flexible round wire strands, the direction of stranding of the plurality of wire conductors being opposite to the direction of stranding of the single wire conductor strand.

6. A high performance medium voltage power cable according to claim 1, wherein said tile-shaped rubber strip is foamed and extruded from an elastomeric plastic.

7. A high performance medium voltage power cable according to claim 1, wherein said outer sheath is comprised of an extruded plastic sheath.

8. The high performance medium voltage power cable of claim 1, wherein the outer jacket is a composite structure of a metallic armor layer and a plastic jacket external thereto.