Medium-voltage 27.5kv rail transit cable and its degassing method

A rail transit cable and medium voltage technology, applied in the direction of insulated cables, electrical components, cables, etc., can solve problems such as fire paralysis, power grid paralysis, damaged cables, etc., to reduce the possibility of breakdown, reduce overcurrent, The effect of extending the service life

Active Publication Date: 2016-10-26
HANGZHOU CABLE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The first purpose of the present invention is to solve the problem that the cable in the prior art cannot be completely digested when the short-circuit current is large, resulting in the overload of this section of the line, damage to the cable, or even paralysis due to fire, and to provide a method that can effectively reduce the cable load. A medium-voltage 27.5kV rail transit cable with the risk of damage to the cable and grid failure due to excessive overcurrent due to faults, and extending the service life of the cable in harsh conditions
[0007] Another purpose of the present invention is to overcome the problem that the degassing effect of the cable degassing process in the prior art is not good, the by-product gas in the cable cannot be effectively removed, and the dielectric properties and service life of the cable are affected; provide a A degassing method for medium-voltage 27.5kV rail transit cables that can effectively remove by-product gases in cables, improve dielectric properties, effectively reduce the possibility of breakdown due to electric tree discharge, and prolong the service life of cables

Method used

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  • Medium-voltage 27.5kv rail transit cable and its degassing method
  • Medium-voltage 27.5kv rail transit cable and its degassing method

Examples

Experimental program
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Effect test

Embodiment 1

[0052] Embodiment 1: as figure 1 As shown, a medium-voltage 27.5kV rail transit cable, the cable includes a conductor 1, a conductor shielding layer 2, an insulating layer 3, an insulating shielding layer 4, a semi-conductive buffer water-blocking layer 5, and a copper wire shielding layer from the inside to the outside. Layer 6, inner sheath 9, aluminum wire armor 10 and outer sheath 12. Outside the copper wire shielding layer, between the copper wire shielding layer and the inner sheath, copper tape tie 7 and inner low-smoke halogen-free tape 8 are wrapped layer by layer from inside to outside. Outside the aluminum wire armor, an outer low-smoke halogen-free glass cloth tape 11 is wrapped around the aluminum wire armor and the outer sheath. The insulating layer is a cross-linked polyethylene insulating layer. The outer sheath is rodent-proof low-smoke and halogen-free outer sheath. The inner sheath is low-smoke halogen-free inner sheath.

[0053] The copper wire shieldin...

Embodiment 2

[0055] Embodiment 2: A degassing method for a medium-voltage 27.5kV rail transit cable, including a heating chamber, a heating device and a temperature measuring device arranged in the heating chamber. The degassing method includes the following steps in sequence:

[0056] A: Put the cable into the heating chamber; then turn on the heating device and temperature measuring device in the heating chamber to heat the heating chamber, heat the room temperature in each heating chamber to 60-75°C, and keep the temperature within 60-75°C Keep warm for 70 to 75 hours;

[0057] B: Turn off the heating device in the heating chamber, so that the cables in the heating chamber are cooled together with the heating chamber;

[0058] C: Take out the cable.

Embodiment 3

[0059] Embodiment 3: A degassing method for a medium-voltage 27.5kV rail transit cable, including a first heating chamber 13, a second heating chamber 14, a third heating chamber 15, a fourth heating chamber 16 and a fifth heating chamber arranged side by side 17, and the two adjacent heating chambers are connected through threading channels 18. Two adjacent heating chambers among the first heating chamber, the second heating chamber, the third heating chamber, the fourth heating chamber and the fifth heating chamber are in close contact with each other. The first heating chamber, the second heating chamber, the third heating chamber, the fourth heating chamber and the fifth heating chamber are respectively equipped with a heating device and a temperature measuring device. The degassing method includes the following steps in sequence:

[0060] A: Pass the same cable through the first heating chamber, the second heating chamber, the third heating chamber, the fourth heating ch...

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PUM

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Abstract

The invention discloses a medium-voltage 27.5-kV rail transit cable and a degassing method thereof and aims at providing the cable and the degassing method thereof, thereby effectively reducing occurrence of a phenomenon that the over current of the cable is too large because of the fault and thus the cable is damaged, effectively eliminating the by-product gas in the cable, and improving the dielectric property. The cable comprises conductors, a conductor shielding layer, an insulating layer, an insulated shielding layer, a semi-conductive buffer water-blocking tape layer, a copper wire shielding layer, an inner sheath, an aluminium wire armoured layer, and an outer sheath. The copper wire shielding layer is formed by a plurality of copper wires distributed uniformly at the circumferential direction; the aluminium wire armoured layer is formed by a plurality of aluminium wires distributed uniformly at the circumferential direction; and the ratio of the sum of the cross sectional area of the copper wire shielding layer and the cross sectional area of the aluminium wire armoured layer to the cross sectional area of the conductor is between 0.8 to 1.2.

Description

technical field [0001] The invention relates to the field of cables, in particular to a medium-voltage 27.5kV rail transit cable and a degassing method thereof. Background technique [0002] Considering the use environment of rail transit cables, when a locomotive enters and exits a certain electric arm, the instantaneous load current increases and decreases; when multiple locomotives frequently pass by in the section, short-term or periodic overload will occur In such a use environment, there will be high requirements on the conductor capacity of the cable itself and the capacity of the metal shield. The metal shielding layer of the current rail transit 27.5kV power cables mostly adopts a metal tape shielding structure. The disadvantage of the metal tape shielding structure is that its strip cross-section is small, and it cannot be completely digested when the short-circuit current is large, resulting in overloading of this section of the line. Damage to the cable, and eve...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01B7/17H01B7/22H01B7/295
Inventor 孙永哲来进晟叶丽花周宇
Owner HANGZHOU CABLE
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