Method for evaluating insulation aging state of 10kV XLPE cable

Abstract

The invention relates to a method for evaluating the insulation aging state of a 10kV XLPE cable. The method comprises the following steps of: preparing cable insulation layer slice samples; performing thermal aging treatment on the cable slices at a preset temperature to obtain XLPE insulation samples in different aged states; testing the aged samples by using a rapid ultra-low frequency dielectric loss detector based on an identification theory; drawing a dielectric loss-frequency curve graph in a single logarithmic coordinate system on the basis of measured data; and setting frequency ranges corresponding to the different aged states by taking corresponding frequencies appearing when a dielectric loss value reaches a preset value as evaluation standards according to the change trend characteristics on the curve graph, and evaluating the aging state of the cable according to a frequency appearing when the dielectric loss value of the test object reaches the preset value. By means of the method, the aging state of the insulation of the10kV XLPE cable can be effectively and accurately evaluated.

Description

technical field [0001] The invention relates to a method for evaluating the aging state of cable insulation, in particular to a method for evaluating the aging state of 10kV XLPE cable insulation. Background technique [0002] In recent years, with the rapid development of my country's economy and the continuous expansion of urban construction scale, the construction of power transmission and distribution infrastructure has developed rapidly. Cross-linked polyethylene (XLPE) cables have the characteristics of excellent electrical insulation performance, small footprint, convenient laying and burying, and low maintenance workload. At present, they have been widely used in urban medium and low voltage transmission and distribution lines. However, in actual operation, XLPE cables are usually affected by a variety of unfavorable factors, such as insulation thermal aging caused by long-term operation, water tree aging caused by moisture ingress, external force damage during insta...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above-mentioned problems existing in the prior art, the technical problem to be solved by the present invention is: the dielectric loss value measured at a single frequency is greatly affected by fluctuations in the external environment, and the accuracy of the test system is relatively poor, and the test results cannot reflect the insulation loss value. The real insulation state of the material

Images