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Medium-voltage crosslinked polyethylene cable terminal unshaded corona test method

A cross-linked polyethylene, corona test technology, used in the direction of testing dielectric strength and other directions

Active Publication Date: 2012-09-26
甘肃省电力公司刘家峡水电厂 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, no matter at home and abroad, there is currently no early-stage search method for the internal defects of newly produced cable heads and cable heads in use.

Method used

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  • Medium-voltage crosslinked polyethylene cable terminal unshaded corona test method
  • Medium-voltage crosslinked polyethylene cable terminal unshaded corona test method
  • Medium-voltage crosslinked polyethylene cable terminal unshaded corona test method

Examples

Experimental program
Comparison scheme
Effect test

experiment example 1

[0029] Experimental example 1. Unshielded corona test of medium voltage XLPE cable head

[0030] YJV, which has been used for 8 years, was selected for the test 22 ─3×185mm 2 ; 8.7 / 15kV; 350 meters long cross-linked polyethylene cable as a test product. In order to facilitate the observation of the corona of the cable during the test, the cable head is first made by using the current process of fitting the stress tube, and the stress tube is made of high dielectric constant plastic. A 3×4mm square hole must be cut on the stress tube at the cutout of the semi-conductive layer for the cable head of the stress tube, but the sheath tube or weather-resistant tube as the auxiliary insulating layer is not installed temporarily. The test site was selected in a dark room without any light source.

[0031] according to figure 1 As shown, ground the ground wire 5 of the cable shielding layer, connect the terminal of the cable lead wire 1 to the high voltage test connection wire 2, an...

experiment example 2

[0036] Experimental example 2. Unshielded corona inception voltage test of medium voltage XLPE cable wrapped around stress cone

[0037] This test method is the same as that of Experimental Example 1 above, and compared with Experimental Example 1. In order to avoid the quality deviation of different cables, especially the difference in the thickness and material of the cable insulation layer, the deviation of the experimental results is caused. The test chooses the same YJV that has been used for 8 years 22 ─3×185mm 2 ; 8.7 / 15kV; 350 meters long cross-linked polyethylene cable as a test product. In experimental example 1, on the other phase core wire of the same cable that has been fitted with a stress tube and has undergone the corona test of experimental example 1, use the wrapping stress cone process to make a medium-voltage XLPE insulated stress cone cable terminal head , Carry out the comparative test of the corona inception voltage of the cable head. The patent appl...

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Abstract

The invention discloses a medium-voltage crosslinked polyethylene cable terminal unshaded corona test method. The method comprises the following steps of: according to the existing cable alternating-current withstand test standard, carrying out alternating-current withstand voltage test on the tested cable terminal for 5 minutes under the test voltage which is 2.5 times of the normal operation phase voltage of the medium-voltage crosslinked polyethylene cable for test by taking a medium-voltage crosslinked polyethylene unshaded cable terminal which is not provided with an insulation protection casing as a tested main body and taking a frequency conversion series resonant alternating-current withstand voltage test device which is stipulated by the existing power system in a dark room as a test device; observing and recording the corona intensity of the cutting opening of the semiconducting layer of the cable terminal in the alternating-current withstand test, namely the corona of the cable terminal; and measuring the corona temperature by an infrared temperature measuring meter. According to the invention, the alternating-current withstand voltage test of the crosslinked polyethylene cable can be completely carried out before the outer layer insulation casing is sleeved; and the test is carried out in advance, so that the insulation level and the operation reliability of the cable terminal can be still detected, and the insulation defects of the cable terminal can be discovered in advance.

Description

technical field [0001] The invention belongs to the technical field of quality inspection of the insulating structure strength of a cable terminal head, and in particular relates to an unshielded corona test method for a medium-voltage cross-linked polyethylene cable terminal head. Background technique [0002] The power system refers to the voltage level of 6 ~ 35kV as medium voltage, and the medium voltage power grid refers to the power grid or power system with a voltage level of 6 ~ 35kV. [0003] Medium voltage cross-linked polyethylene (XLPE) power cables are widely used to transmit electric energy both at home and abroad. When using cross-linked polyethylene cables, both ends of the cable must be made of cable terminals, which are called cable terminals in the industry; when using cables to transmit power over long distances, it is necessary to connect two or more cables, and connect adjacent To connect two cables, it is necessary to make a cable intermediate joint. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/12
Inventor 王恩选段忠义沈利平付廷勤曾需要刘发展朱国海吴云顺刘世泽
Owner 甘肃省电力公司刘家峡水电厂