Damped oscillatory wave lower cable local discharge detection device and method

Abstract

The invention discloses a damped oscillatory wave lower local cable local discharge detection device and method. The detection device comprises a signal coupling unit and a broadband amplifying unit; the signal coupling unit comprises a detection impeder and a coupling capacitor, one end of the detection impeder is connected with the low-voltage side of the coupling capacitor, and the other end of the detection impeder is connected to the ground; the broadband amplifying unit comprises an attenuator, an attenuator driving circuit, a latch and an amplifier. The signal coupling unit is coupled with original signals which discharges locally and is coupled with reflection signals at the end portion of a cable. The coupled locally-discharged signals are amplified for a proper time by the amplifier and passes through the effective frequency band of the amplifier, a large amount of interfering signals and background noise are removed through filtering, and the signal to noise ratio of the locally-discharged signals is sufficiently improved. Finally, the amplified signals are transmitted to the input end of a collecting card so that a digital meter can process the locally-discharged signals.

Description

technical field [0001] The invention relates to an on-line partial discharge detection method of a cross-linked polyethylene cable (XLPE), in particular to a cable partial discharge detection device and detection method under damped oscillatory waves. Background technique [0002] XLPE cables are widely used in transmission lines and distribution networks at home and abroad due to their reasonable structure, technology, excellent electrical performance and high safety. However, during the production, transportation, installation and operation of cables, various defects such as air gaps, burrs and impurities may occur. Defects or long-term operation lead to deterioration of cables prone to partial discharge. Under the action of long-term partial discharge, it will further lead to breakdown of cable insulation. Once an accident occurs, it may cause large-scale power outages in cities, stop production of enterprises, and hospitals. Power failure will cause large economic losse...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problem that the sensitivity of on-site detection of cable partial discharge is not high at present, and provides a cable partial discharge detection device and detection method under damped oscillating waves to effectively improve the sensitivity and signal-to-noise ratio of partial discharge signal detection

Images