CN104269218A - Water-tree-prevention ultrahigh-voltage cross linked polyethylene insulating power cable - Google Patents

Abstract

The invention provides a water-tree-prevention ultrahigh-voltage cross linked polyethylene insulating power cable, and belongs to the technical field of power cables. According to the technical scheme, the water-tree-prevention ultrahigh-voltage cross linked polyethylene insulating power cable comprises a conductor, an inner semiconductive shielding layer, a water-tree-prevention cross linked polyethylene insulating layer, an outer semiconductive shielding layer, a semiconductive expansion buffer layer, an inner protective layer, a waterproof layer and an outer protective layer; the inner protective layer is made of sparsely-wound copper wires or copper belts, the outer protective layer is a polyethylene, inflaming retarding polyethylene or semi-hard inflaming retarding polyethylene jacket, and the surface of the outer protective layer is coated with a semiconductive coating. The water-tree-prevention ultrahigh-voltage cross linked polyethylene insulating power cable has the advantages that the possibility of cable faults caused by water branches is reduced, the service life is long, inflaming retarding and environmental protection are achieved, and the water-tree-prevention ultrahigh-voltage cross linked polyethylene insulating power cable can be widely applied to the field of ultrahigh-voltage power cables.

Description

Waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable

Technical field

The invention belongs to power cable field, be specifically related to waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable.

Background technology

Power cable is defeated, the requisite electric product of distribution, be also apply the most generally in power cable, the most extensively, the one that has the call.

Along with progress and the expanding economy of society, the degree of dependence of the mankind to electric energy is more and more higher, increasing to the demand of electric energy.But most countries all also exists primary energy and the unbalanced problem of distribution of productive force in the world, therefore, build Large Copacity, at a distance electrical network and obtain the great attention of national governments.For reducing the line loss in remote conveying electric process, high voltage power transmission technology need be adopted.China, just at develop actively superhigh pressure, special ehv power transmission circuit, along with the development of EHV transmission technology, proposes more and more higher requirement to the important component part-power cable of electrical network, must withstand the test of high pressure, superhigh pressure.Because crosslinked polyethylene (XLPE) cable has good electric property, transmission capacity, large (Long-term service temperature can reach 90 DEG C, instantaneous short-circuit temperature can reach 250 DEG C), lightweight, production process is few, speed of production is fast, the manufacturing cycle is short, high drop or vertical run, installation and maintenance can facilitate advantages of simple structure and simple, obtain the favor of user, more and more welcome at power department, it constantly increases at high pressure, extra-high-tension cable field portion, has the trend replacing other type cable gradually.At present, 220KV and following electric pressure high-tension cable mainly adopt crosslinked polyetylene insulated in the world, and 500KV level and above cross-linked polyethylene insulated cable have also been applied in supertension line.

Long-time running and use experience show, water tree is aging is cause the crosslinked polyetylene insulated performance degradation of high-tension cable until one of the principal element destroyed.The definition that DL/T 1070-2007 standard is set water is " in insulation, there is moisture, electric stress and some risk factor, some microchannels as developed into when impurity, projection, space charge or ion ".The moisture that has its source in that water tree produces invades crosslinked polyetylene insulated layer.Cable in use, reach good water resistant tree effect, the moisture in insulator and hole will be reduced as far as possible, remove the jut that interface between semi-conductive layer and insulating barrier easily causes electric field to concentrate, reduce the expansion of tree discharge, even if generation water tree, the continued growth that water also can be suppressed to set and the electric discharge of suppression water tree.But actual is in cable running, still cannot ensure the formation eliminating water tree completely, in high-voltage cross-linked polyethylene sheathed running, there is poplar bundles electric discharge in various degree, cause decreasing insulating, sometimes also because the electric branch crosslinked polyetylene insulated layer breakdown accident of the high-tension cable that causes that discharge occurs.

Summary of the invention

Technical problem to be solved by this invention is, for the deficiencies in the prior art, provides that a kind of water treeing resistance performance is good, the ultra-high voltage cross-linking polyethylene-insulated power cable of long service life.

For solving the problems of the technologies described above, the technical solution adopted in the present invention is: waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable, comprises conductor, inner semiconductor layer, water resistant sets crosslinked polyetylene insulated layer, out semiconductor layer, partly leads expansion buffer layer, sheath, water blocking layer, outer jacket, described sheath adopts to be dredged around copper wire or copper strips, described outer jacket is polyethylene, flame-proof polyethylene or semihard flame-retardant pvc sheath, surface application one deck semiconducting coating.

Described outer jacket is semihard flame-retardant pvc sheath.

The material of described inner semiconductor layer and described out semiconductor layer is the one in ethene-vinyl acetate copolymer (EVA), EVA-carbon black composite material, EVA-carbon black-multi-wall carbon nano-tube composite material, EVA-carbon black-graphene microchip composite material, ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA).

The material that described water resistant sets crosslinked polyetylene insulated layer is set inhibitor, antioxidant, metal deactivator and sensitizer cross-linking radiation formed by low density polyethylene (LDPE), carbon black, water.

Described material of partly leading expansion buffer layer is made up through calendering of matrix structure layer and material structure layer; Described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by nonwoven fabrics or woven dacron is made; Described material structure layer in thermoplastic elastic body, adds auxiliary agent make, and described auxiliary agent is the one in carbon black, zinc oxide, water-proofing powder.

Described water blocking layer is that semiconductive intumescent blocks water twining package tape.

Beneficial effect of the present invention is as follows:

In waterproof of the present invention tree ultra-high voltage cross-linking polyethylene-insulated power cable, insulating barrier adopts water resistant tree cross-linking polyethylene materials, and this material property is excellent, and structure is simple, and manufacturing process is uncomplicated, and external diameter is little, lightweight, and ampacity is large, and it is unrestricted to lay difference in level; Add the screen of one deck semiconductive material at conductive surface, the conductor equipotential of it and conductively-closed and with insulating barrier good contact, thus avoid, between conductor and insulating barrier, partial discharge occurs; Add the screen of one deck semiconductive material at surface of insulating layer, the insulating barrier of it and conductively-closed has good contact, with metallic sheath equipotential, thus avoids, between insulating barrier and sheath, partial discharge occurs; Inside and outside semiconductive shielding layer Main Function makes Electric Field Distribution even, reduce electric field strength, reduce the air gap on conductor and insulating barrier interface, improve the initial corona discharge of cable and the resistance to free discharge performance of cable, and reduce the temperature rise of insulating barrier to a certain extent, protection main insulation; Insulating barrier water resistant tree crosslinked polyethylene has higher thermal coefficient of expansion and lower modulus of compressibility, when cable is from cold conditions to time hot, because temperature increase makes insulator expand, uncontrollable harmful effect can be produced to the performance of power cable, therefore put at out semiconductor layer peripheral hardware and partly lead expansion buffer layer; Described sheath adopts to be dredged around copper wire or copper strips, described outer jacket is polyethylene, flame-proof polyethylene or semihard flame-retardant pvc sheath, semihard flame-retardant polyvinyl chloride, this sheath material shore D level hardness can reach 50 ~ 55, not only substantially increase the scrape abrasion resistance of oversheath, and improve the insulation property of sheath material, meet the requirement that high-tension cable lays, improve job stability and the reliability of power cable with cross-linked polyethylene insulation, improve the useful life of cable.

Waterproof of the present invention tree ultra-high voltage cross-linking polyethylene-insulated power cable water tree resistant property is good, and can reduce the cable fault probability caused because of water tree is 46% ~ 72%, extends 0.3 ~ 0.7 times useful life, fire-retardant, heat-resisting, environmental protection, can be widely used in EHV XLPE power cable.

Accompanying drawing explanation

Fig. 1: the generalized section of waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable of the present invention.

Embodiment

In order to illustrate further in more detail instead of limit the present invention, provide the following example by reference to the accompanying drawings.

Embodiment one

Waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable of the present invention, comprise conductor 1, inner semiconductor layer 2, water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8; The outside of conductor 1 is by order coated inner semiconductor layer 2 successively from inside to outside, and water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7 and outer jacket 8.

Wherein, described conductor 1 forms for copper conductor is stranded, adopts and presses stranded circular configuration; Described inner semiconductor layer 2 is ethene-vinyl acetate copolymer (EVA); Described out semiconductor layer 4 is ethylene-butyl acrylate copolymer (EBA); Partly lead expansion buffer layer 5 to be made up through calendering of matrix structure layer and material structure layer, described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by nonwoven fabrics is made, and described material structure layer in ethylene propylene diene rubber, adds carbon black make; Described sheath 6 adopts to be dredged around copper wire; Described water blocking layer 7 to block water twining package tape for semiconductive intumescent; Described outer jacket 8 is polyethylene, surface application one deck semiconducting coating.

Embodiment two

Waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable of the present invention, comprise conductor 1, inner semiconductor layer 2, water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8; The outside of conductor 1 is by order coated inner semiconductor layer 2 successively from inside to outside, and water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8.

Wherein, described conductor 1 forms for copper conductor is stranded, adopts and presses stranded circular configuration; Described inner semiconductor layer 2 is EVA-carbon black composite material; Described out semiconductor layer 4 is ethylene-ethyl acrylate copolymer (EEA); Partly lead expansion buffer layer 5 to be made up through calendering of matrix structure layer and material structure layer, described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by nonwoven fabrics is made, and described material structure layer in polyethylene, adds zinc oxide make; Described sheath 6 adopts to be dredged around copper strips; Described water blocking layer 7 to block water twining package tape for semiconductive intumescent; Described outer jacket 8 is flame-proof polyethylene, surface application one deck semiconducting coating.

Embodiment three

Waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable of the present invention, comprise conductor 1, inner semiconductor layer 2, water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8; The outside of conductor 1 is by order coated inner semiconductor layer 2 successively from inside to outside, and water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8.

Wherein, described conductor 1 is for copper and aluminum conductor is stranded forms, and adopts and presses stranded circular configuration; Described inner semiconductor layer 2 is EVA-carbon black-multi-wall carbon nano-tube composite material; Described out semiconductor layer 4 is ethylene-butyl acrylate copolymer (EBA); Partly lead expansion buffer layer 5 to be made up through calendering of matrix structure layer and material structure layer, described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by woven dacron is made, and described material structure layer in ethylene propylene diene rubber, adds waterproofing agent make; Described sheath 6 adopts to be dredged around copper wire; Described water blocking layer 7 to block water twining package tape for semiconductive intumescent; Described outer jacket 8 is semihard flame-retardant polyvinyl chloride, surface application one deck semiconducting coating.

Embodiment four

Waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable of the present invention, comprise conductor 1, inner semiconductor layer 2, water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8; The outside of conductor 1 is by order coated inner semiconductor layer 2 successively from inside to outside, and water resistant sets crosslinked polyetylene insulated layer 3, and out semiconductor layer 4 partly leads expansion buffer layer 5, sheath 6, water blocking layer 7, outer jacket 8.

Wherein, described conductor 1 is for copper and aluminum conductor is stranded forms, and adopts and presses stranded circular configuration; Described inner semiconductor layer 2 is EVA-carbon black-graphene microchip composite material; Described out semiconductor layer 4 is ethene-vinyl acetate copolymer (EVA); Partly lead expansion buffer layer 5 to be made up through calendering of matrix structure layer and material structure layer, described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by woven dacron is made, and described material structure layer in polyethylene, adds carbon black make; Described sheath 6 adopts to be dredged around copper wire; Described water blocking layer 7 to block water twining package tape for semiconductive intumescent; Described outer jacket 8 is semihard flame-retardant polyvinyl chloride, surface application one deck semiconducting coating.

The material that water resistant described in above embodiment sets crosslinked polyetylene insulated layer 3 is all by low density polyethylene (LDPE), and carbon black, water tree inhibitor, antioxidant, metal deactivator and sensitizer cross-linking radiation form; Described sensitizer can adopt dimethacrylate tetraethylene glycol ester, trimethacrylate acid trihydroxy propyl ester, succinic acid diine propyl ester, triallyl isonitrile urea acid esters etc.

In sum, clearly, all any amendments done according to technical support essence of the present invention still belong in scope that the technology of the present invention supports with changing for every claim that the present invention's " waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable " addresses and technical support.

Claims (6)

1. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable, it is characterized in that: comprise conductor, inner semiconductor layer, water resistant sets crosslinked polyetylene insulated layer, out semiconductor layer, partly lead expansion buffer layer, sheath, water blocking layer, outer jacket, described sheath adopts to be dredged around copper wire or copper strips, and described outer jacket is polyethylene, flame-proof polyethylene or semihard flame-retardant pvc sheath, surface application one deck semiconducting coating.

2. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable as claimed in claim 1, is characterized in that: described outer jacket is semihard flame-retardant pvc sheath.

3. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable as claimed in claim 1, is characterized in that: the material of described inner semiconductor layer and described out semiconductor layer is the one in ethene-vinyl acetate copolymer, EVA-carbon black composite material, EVA-carbon black-multi-wall carbon nano-tube composite material, EVA-carbon black-graphene microchip composite material, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer.

4. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable as claimed in claim 1, is characterized in that: the material that described water resistant sets crosslinked polyetylene insulated layer is set inhibitor, antioxidant, metal deactivator and sensitizer cross-linking radiation formed by low density polyethylene (LDPE), carbon black, water.

5. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable as claimed in claim 1, is characterized in that: described material of partly leading expansion buffer layer is made up through calendering of matrix structure layer and material structure layer; Described matrix structure layer is that the even coating carrying out semi-conductive adhesive by pad dyeing mode by nonwoven fabrics or woven dacron is made; Described material structure layer in thermoplastic elastic body, adds auxiliary agent make; Described auxiliary agent is the one in carbon black, zinc oxide, water-proofing powder.

6. waterproof tree ultra-high voltage cross-linking polyethylene-insulated power cable as claimed in claim 1, is characterized in that: described water blocking layer is that semiconductive intumescent blocks water twining package tape.