Deterioration of contact state of GIS main circuit will lead to main circuit failure. At present

there is still a lack of effective online monitoring means. In this paper

through temperature rise test

it is found that vibration signal spectrum of GIS shell will change during the test

which has a certain influence on selection of characteristic quantity. This paper considers that influence of temperature should be fully considered when judging contact state of GIS main circuit through vibration to ensure that measured state is close to running state. According to the test data

with the temperature rising

the amplitude of lower part of frequency increases

while the amplitude of higher part decreases

and finally reaches a stable state. The vibration data after stabilization are selected for comparative analysis

and it is found that as the severity of internal contact defects in GIS increased

the proportion of high-frequency signals increased. In this paper

low frequency band and high frequency band are classified with 600 Hz as the cutoff frequency point according to intra-class and inter-class distance criterion. The ratio of the sum of high-frequency amplitude and the sum of amplitude of the whole frequency band is taken as the characteristic parameter

and it is verified that this characteristic parameter can be used to effectively distinguish different contact states through data statistics.