Vacuum degree on-line monitor of vacuum circuit breaker based on pulse discharge detection

Abstract

The invention discloses a vacuum degree on-line monitor of a vacuum circuit breaker based on pulse discharge detection, which is realized by the following steps: weak pulse discharge signals generated by decrease of vacuum degree in the vacuum circuit breaker are detected by a field measurement probe arranged under the vacuum circuit breaker; high speed analog / digital (A / D) conversion is carried out on data related to partial discharge through transmission channels as well as a corresponding filter device, an applicator and a converter to obtain three-phase fundamental waves and high frequency signals; the three-phase fundamental waves are subjected to balance operation to obtain relative changes of peripheral fields to correspond to changes of vacuum degree, and the high frequency signals correspond to partial discharge signals to reflect the changes of vacuum degree; the processed fundamental wave signals have no noise jamming, and interphase interference can be eliminated by carrying out simple phase balance movement on the processed fundamental wave signals; and the pulse signal strength of the partial discharge signals are bigger and bigger along with the decrease of the vacuum degree as the partial discharge signals are converted into energy signals. Therefore, the strength of direct current signals and the strength of high frequency signals can be utilized as double criterions for the decrease of the vacuum degree of the circuit breaker, thus the monitor has high sensitivity on on-line monitoring.

Description

Technical field [0001] The invention relates to an on-line detection device of a power system, in particular to an on-line monitoring device based on pulse discharge detection. Background technique [0002] As vacuum circuit breakers are more and more widely used in medium and low voltage fields, breaking and closing accidents caused by air leakage in the interrupter and insufficient vacuum degree occur from time to time. The core of the vacuum circuit breaker is the vacuum interrupter. In a certain degree of vacuum, the reliability of the vacuum switch can be guaranteed. The relevant standards of the vacuum interrupter stipulate: "The internal gas pressure in the vacuum interrupter used to assemble the vacuum circuit breaker should be lower than 1.33×10 -3 Pa", which refers to the measurable parameters under static conditions. The internal gas pressure of the vacuum interrupter in operation is actually a dynamic parameter, and the dynamic pressure when breaking the current...

AI Technical Summary

Problems solved by technology

The main problem with this method is that the sensitivity of its measurement has yet to be further verified

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