A method for on-line monitoring of power cable insulation status

Abstract

The invention provides an online monitoring method for the insulation state of a power cable. A test signal sending device and a test signal receiving device are respectively placed at both ends of the cable to be tested, wherein the sending device sends a continuous high-frequency test signal, and the receiving device collects the high-frequency test signal. , and use the time-domain autocorrelation iterative filtering algorithm to process and analyze the received signal to obtain information such as the position and amplitude of the autocorrelation peak, so as to judge whether the insulation state of the cable to be tested is degraded, the location and degree of degradation, and realize Detection of cable insulation status.

Description

technical field [0001] The invention relates to the technical field of electric power secondary equipment, in particular to an online monitoring method for the insulation state of a power cable. Background technique [0002] With the rapid development of urban construction, power cables have gradually replaced overhead lines and become the main force of urban power transmission and distribution networks due to their small footprint and environmental friendliness. In recent years, the cables of State Grid Corporation and China Southern Power Grid Corporation have a large scale, rapid growth, and long running time. Some cables have approached or even exceeded their designed service life, and the failure rate has remained high for a long time. Most of the cable faults occur in the cable body, which is mainly caused by the aging of the main insulation. The cable is affected by various factors in operation, which leads to the aging of the insulating material, and finally causes t...

AI Technical Summary

Problems solved by technology

The off-line distance measurement method cuts off the power after the fault occurs and untie the power cable, and tests the fault distance through related equipment. This method has a long power outage time and affects social and economic production.

In addition, the offline detection method is to use manpower and material resources to find the cause and locate the fault point after the fault occurs, which is very inefficient

Live detection includes DC component method, dielectric constant method, distributed optical fiber temperature measurement, and partial discharge live detection, etc. These methods are only feasible in the ideal environment of the laboratory, but it is difficult to provide ideal results in actual field use

At present, online monitoring technology is still in its infancy, and there are not many products put into actual operation.

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