10kV polypropylene insulation power cable

Abstract

The utility model belongs to the technical field of cables, and discloses a 10kV polypropylene insulated power cable, which comprises three groups of cable cores, the three groups of cable cores are lapped together through a cable wrapping tape, a polypropylene rope filling layer is arranged in a gap between the cable cores and the cable wrapping tape, a polyvinyl chloride sheath layer is wrapped outside the cable wrapping tape, and the polyvinyl chloride sheath layer is wrapped outside the cable wrapping tape. Each cable core comprises a stranded copper conductor, a polypropylene semi-conductive conductor shielding layer coats the outside of each stranded copper conductor, a polypropylene insulating layer coats the outside of each polypropylene semi-conductive conductor shielding layer, and a polypropylene semi-conductive insulating peelable shielding layer coats the outside of each polypropylene insulating layer. The polypropylene semi-conductive conductor shielding layer, the polypropylene insulating layer and the polypropylene semi-conductive insulating strippable shielding layer are sequentially arranged outside the stranded copper conductor, so that catenary three-layer co-extrusion with lower eccentricity can be realized, the production efficiency is improved, and the carbon emission can be reduced by more than 40%.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and more specifically, to a 10kV polypropylene insulated power cable. Background Art

[0002] Cross-linked polyethylene (XLPE) cables have the advantages of excellent electrical performance, large transmission capacity, light weight, and easy installation and maintenance. They have become one of the core power equipment in urban underground rail transit power transmission systems. At present, XLPE accounts for more than 96% of the medium-voltage cables produced and operated in China. However, with the continuous improvement of the cable quality and environmental protection requirements in power grid construction, the shortcomings of XLPE cables in use are gradually reflected, mainly in the following aspects:

[0003] 1. The current-carrying capacity is limited. The maximum operating temperature of XLPE cross-linked cable can only reach 90°C. During peak power consumption or emergency situations, the cable current carrying capacity reaches saturation and can only be used at a reduced capacity, resulting in safety hazards in the power grid.

[0004] 2. Recycling after retirement is difficult. The service life of XLPE cables in a normal environment is about 20-30 years, and they have been used in China for more than 30 years. For cities where cross-linked polyethylene cables were used earlier, there will be a large amount of old cable equipment to be retired and replaced in the next 5-10 years, while urban cable channel resources are tight and urban management and environmental protection requirements are high. Since XLPE is a thermosetting polymer, the insulation of the cable cannot be melted and processed again after retirement. Incineration, cracking, burial and other methods not only consume a lot of energy, but also have a great negative impact on the environment.

[0005] 3. The cross-linking process is complex and energy-consuming. XLPE cables require a high-voltage, high-temperature inert environment during the cross-linking process. The extrusion process also requires precise control to prevent scorching and other phenomena. The process is relatively complex. In addition, cross-linking byproducts are prone to cause microporous defects and partial discharge, which can easily lead to space charge accumulation under high-voltage electric fields, which not only seriously shortens the service life of the cable, but also has an adverse effect on the health of factory workers.

[0006] Based on the above analysis, XLPE can no longer meet the usage requirements, and it is urgent to develop a thermoplastic insulated cable that can replace XLPE insulation. Utility Model Content

[0007] The utility model aims to provide a polypropylene insulated power cable with low eccentricity and realize engineering application.

[0008] The present application provides a 10kV polypropylene insulated power cable adopts the following technical solution:

[0009] A 10kV polypropylene insulated power cable comprises three groups of cable cores, the three groups of cable cores are wrapped together by cable tape, a polypropylene rope filling layer is further arranged in the gap between the cable core and the cable tape, the cable tape is externally wrapped with a polyvinyl chloride sheath layer, the cable cores each comprise a twisted copper conductor, the twisted copper conductor is externally coated with a polypropylene semi-conductive conductor shielding layer, the polypropylene semi-conductive conductor shielding layer is externally coated with a polypropylene insulation layer, the polypropylene insulation layer is externally coated with a polypropylene semi-conductive insulation strippable shielding layer, and the polypropylene semi-conductive insulation strippable shielding layer is externally coated with a copper tape metal shielding layer.

[0010] Furthermore, the thickness of the polypropylene semi-conductive conductor shielding layer is 0.7-1.0 mm.

[0011] Furthermore, the thickness of the polypropylene insulation layer is 4.0-4.5 mm.

[0012] Furthermore, the thickness of the polypropylene semi-conductive insulating strippable shielding layer is 0.6-1.0 mm.

[0013] In summary, the present application includes at least one of the following beneficial technical effects:

[0014] (1) The present application can realize a catenary three-layer co-extrusion with low eccentricity by sequentially arranging a polypropylene semi-conductive conductor shielding layer, a polypropylene insulating layer and a polypropylene semi-conductive insulating strippable shielding layer on the outside of the stranded copper conductor, thereby improving production efficiency and reducing carbon emissions by more than 40%;

[0015] (2) Cables with this layer structure can be recycled, downgraded and reused after retirement;

[0016] (3) The long-term operating temperature of the conductor of this cable system can reach 105°C. Compared with the traditional cross-linked polyethylene cable with a long-term operating temperature of 90°C, the current carrying capacity can be increased by more than 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a cross-sectional schematic diagram of the present application.

[0018] Description of the numbers in the figure:

[0019] 1. Cable core; 11. Twisted copper conductor; 12. Polypropylene semi-conductive conductor shielding layer; 13. Polypropylene insulation layer; 14. Polypropylene semi-conductive insulation strippable shielding layer; 15. Copper tape metal shielding layer; 2. Cable tape; 3. Polypropylene rope filling layer; 4. Polyvinyl chloride sheath layer. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application; obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application without making creative work are within the scope of protection of the present application.

[0021] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] Embodiment 1:

[0024] The present application is further described in detail below in conjunction with the accompanying drawings.

[0025] The embodiment of the present application discloses a 10kV polypropylene insulated power cable, comprising three groups of cable cores 1, the three groups of cable cores 1 are wrapped together by cable tapes 2, a polypropylene rope filling layer 3 is further arranged in the gap between the cable cores 1 and the cable tapes 2, the cable tapes 2 are wrapped with a polyvinyl chloride sheath layer 4 on the outside, the cable cores 1 all include twisted copper conductors 11, the twisted copper conductors 11 are all coated with a polypropylene semi-conductive conductor shielding layer 12 on the outside, the polypropylene semi-conductive conductor shielding layer 12 is all coated with a polypropylene insulation layer 13 on the outside, the polypropylene insulation layer 13 is all coated with a polypropylene semi-conductive insulation strippable shielding layer 14 on the outside, and the polypropylene semi-conductive insulation strippable shielding layer is all coated with a copper tape metal shielding layer 15 on the outside.

[0026] See also Figure 1As a further preferred embodiment of the present invention, the thickness of the polypropylene semi-conductive conductor shielding layer 12 is 0.7 mm, the thickness of the polypropylene insulating layer 13 is 4.5 mm, and the thickness of the polypropylene semi-conductive insulating strippable shielding layer 14 is 1.0 mm.

[0027] Among them, the performance indicators of polypropylene insulation materials are tensile strength not less than 20MPa; tensile elongation at break not less than 400%; melting temperature not less than 160℃; dielectric strength not less than 35MV / m. The performance indicators of semi-conductive shielding materials are room temperature (20℃) resistivity not more than 100Ω·cm, resistivity not more than 2500Ω·cm at 105℃, tensile strength not less than 12MPa, and elongation at break not less than 220%.

[0028] A section of 10kV polypropylene insulated power cable was prepared by adopting the technical solution of the present application, and the technical indicators achieved by the cable were:

[0029] (1) Electrical performance: Partial discharge (under 1.73U0) pC has no detectable discharge above the background; thermal cycle test, current is passed through the conductor to make the conductor temperature reach (110-115)℃, and 20 thermal cycles are completed as required; impulse voltage test (110-115℃, 75kV, 10 times for positive and negative electrodes respectively);

[0030] (2) Non-electrical properties: Insulation tensile strength before aging ≥ 15N / mm2; elongation at break ≥ 400%; insulation thermal shrinkage (150°C, 1h) ≤ 4%.

[0031] The implementation principle of a 10kV polypropylene insulated power cable in the embodiment of the present application is as follows: the present application can realize a low eccentricity catenary three-layer co-extrusion by sequentially arranging a polypropylene semi-conductive conductor shielding layer 12, a polypropylene insulation layer 13 and a polypropylene semi-conductive insulation strippable shielding layer 14 on the outside of the twisted copper conductor, thereby improving production efficiency and reducing carbon emissions by more than 40%; the cable with this layer structure can be recycled, downgraded and reused after retirement. The long-term operating temperature of the conductor of the cable system can reach 105°C, and compared with the traditional cross-linked polyethylene cable with a long-term operating temperature of 90°C, the current carrying capacity can be increased by more than 10%.

[0032] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A 10kV polypropylene insulated power cable, characterized in that: The invention comprises three groups of cable cores (1), wherein the three groups of cable cores (1) are wrapped together by a cable tape (2), a polypropylene rope filling layer (3) is further arranged in the gap between the cable core (1) and the cable tape (2), the cable tape (2) is externally wrapped with a polyvinyl chloride sheath layer (4), the cable cores (1) each comprise a twisted copper conductor (11), the twisted copper conductor (11) is externally coated with a polypropylene semi-conductive conductor shielding layer (12), the polypropylene semi-conductive conductor shielding layer (12) is externally coated with a polypropylene insulation layer (13), the polypropylene insulation layer (13) is externally coated with a polypropylene semi-conductive insulation strippable shielding layer (14), and the polypropylene semi-conductive insulation strippable shielding layer (14) is externally coated with a copper tape metal shielding layer (15).

2. A 10kV polypropylene insulated power cable according to claim 1, characterized in that: The thickness of the polypropylene semi-conductive conductor shielding layer (12) is 0.7-1.0 mm.

3. A 10kV polypropylene insulated power cable according to claim 1, characterized in that: The thickness of the polypropylene insulation layer (13) is 4.0-4.5 mm.

4. A 10kV polypropylene insulated power cable according to claim 1, characterized in that: The thickness of the polypropylene semi-conductive insulating strippable shielding layer (14) is 0.6-1.0 mm.

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