Power cable insulation state on-line monitoring method

Abstract

The invention provides a power cable insulation state on-line monitoring method, which comprises the following steps that: test signal transmitting equipment and test signal receiving equipment are respectively arranged at two ends of a cable to be tested, the transmitting equipment transmits continuous high-frequency test signals, the receiving equipment acquires the high-frequency test signals, and a time domain self-correlation iterative filtering algorithm is adopted to perform signal processing and analysis on the received signal to obtain information such as the position and amplitude of an autocorrelation peak value, so that whether the insulation state of the cable to be tested is degraded or not, the degradation position and the degradation degree are judged, and detection of the insulation state of the cable is realized.

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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