Distributed high voltage cable partial discharge online monitoring and positioning system

Abstract

The invention provides a distributed high voltage cable partial discharge online monitoring and positioning system comprising a signal preprocessing module, a partial discharge acquisition module, a data signal processing module, a communication module, a data analysis module and a power supply module. The signal preprocessing module performs filtering and amplification functions on sensor coupling signals; then the partial discharge acquisition module acquires, displays and stores the signals processed by the signal preprocessing module; and then the data are transmitted to the data signal processing module to be analyzed and processed, partial discharge parameters and discharge spectrum information are calculated, the data are remotely transmitted to the data analysis module through the communication module, and the required voltage of the functions is supplied by the power supply module. The accuracy and the sensitivity of cable partial discharge monitoring can be enhanced by using high sampling rate and high pulse capture repetition rate, and positioning and identification of the partial discharge fault points of the cable can also be realized. Phase matching can be performed on the acquired partial discharge by using external power frequency signals or internal power frequency signals according to the field conditions so that the mode identification accuracy of partial discharge can be enhanced.

Description

technical field [0001] The invention belongs to the technical field of electric cable partial discharge detection, and in particular relates to an on-line monitoring and positioning system for distributed partial discharge of high-voltage cables. Background technique [0002] At present, cross-linked polyethylene (XLPE) cables have been widely used in the national grid, and their insulation performance is directly related to the safe operation of the grid. Due to poor cable manufacturing technology and improper installation of cable accessories on site, the cable will generate partial discharge, which will affect the cable. Insulation, partial discharge is an important parameter of cable insulation aging, so it is particularly important to monitor and locate partial discharge of cables. [0003] The traditional partial discharge detection of power cables is to conduct live detection at a single point (cable joint or terminal) to determine whether there is partial discharge. ...

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Problems solved by technology

[0006] (1) The cable partial discharge online monitoring system has a large equipment volume, and a large number of optical fiber cables need to be laid on site, so the monitoring cost is high; each unit of the distributed cable partial discharge online monitoring needs to collect synchronously, so as to complete the partial discharge positioning later

[0007] (2) On-line partial discharge monitoring system for cables, relying on the installed power frequency current sensor to collect power frequency signals to trigger three-channel synchronous acquisition, the system collects 20ms power frequency cycle time, multiple continuous data acquisitions are large, and data analysis and positioning are slow , the phase information of partial discharge is calculated from the power frequency signal, and it is impossible to detect the cable lines that have not been in operation

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