High voltage cable partial discharge detection method

Abstract

The invention relates to a high voltage cable partial discharge detection method. The method comprises the steps that 1) a partial discharge signal sensor respectively collects discharge pulse signals of a middle connector and a terminal head of a cable, and transmits the discharge pulse signals to a signal processor in real time; 2) the signal processor preprocesses the received discharge pulse signals, and transmits the preprocessed signals to an upper industrial personal computer; the upper industrial personal computer generates a discharge pattern according to the characteristics of the received signals, compares the discharge pattern with a set partial discharge threshold to determine whether partial discharge exists, positions the partial discharge, and displays a detection result and cable insulation defect state information. Compared with the prior art, the high voltage cable partial discharge detection method provided by the invention has the advantages of high cable detection and diagnosis accuracy and the like.

Description

technical field [0001] The invention relates to a method for detecting the state of high-voltage cable equipment, in particular to a method for detecting partial discharge of high-voltage cables. Background technique [0002] Power cable lines are more and more widely used in urban power grids, and there is a tendency to gradually replace overhead transmission and distribution lines. The safe and reliable operation of power cables is directly related to the reliability of power supply in urban power grids. It is imperative to promote the condition maintenance of cable lines . The basis of implementing condition-based maintenance is to obtain real-time status information of equipment. Compared with other equipment, the acquisition of real-time cable status information and accurate fault diagnosis are more important and more difficult. This is because: ①The cable is different from other equipment. The cable body is made in the factory, while the cable connector must be instal...

AI Technical Summary

Problems solved by technology

Compared with other equipment, the acquisition of real-time cable status information and accurate fault diagnosis are more important and more difficult. This is because: ①The cable is different from other equipment. The cable body is made in the factory, while the cable connector must be installed on site. The quality of on-site construction is affected by artificial craftsmanship and installation environment, and may not meet the quality control requirements in the factory. Therefore, the cable joint often becomes the weak point of the cable system: and the structure of the cable joint is relatively complicated. Defect location and evaluation of the severity of defects more difficult

②Cables, especially high-voltage transmission cables, have a short running time and less experience in operation and maintenance, and further research on their insulation characteristics is needed: ③Currently commonly used XLPE insulated cables are characterized by sudden and large failures. , There is often no sign before insulation breakdown; ④The cable is installed underground, and the distance is very long. No matter inspection, live detection, maintenance, and diagnosis are time-consuming and labor-intensive, it is not easy to implement; ⑤Due to the capacity of test equipment and other reasons, domestic high-voltage cables The main insulation AC withstand voltage test is generally not carried out during a power outage, so that the state of the main insulation cannot be assessed and inspected

[0005] Judging from the application effect of partial discharge detection instruments used in China, imported instruments are still highly recognized, and the common problems of these instruments are: the data processing process is not open and transparent, it is difficult to carry out secondary development, and it is difficult to conduct in-depth research on test results , different detection instruments are difficult to achieve standardization, and the detection lacks thresholds and diagnostic standards, so the detection results are difficult to use as the decision-making basis for condition-based maintenance

For the formation and development process of partial discharge, there is currently a lack of experimental and theoretical basis, and further research is needed