Research of the vibration characteristics in GIS Disconnector under different Contact State

Because its small size and high reliability, GIS is used more and more widely in substation, so it is very necessary to detect and prevent the faults in the operation. In the actual operation of GIS, there are a large number of accidents caused by mechanical failure except discharge fault detection. And at present the most extensive research on GIS is studying the detection of discharge fault of GIS. However when GIS exists the mechanical defects such as the poor switch contact without discharge, GIS would exist abnormal vibration except the normal vibration under the alternating electric power in alternating current drive. The abnormal vibration of GIS has great harm to the GIS body, so this paper studies the method to detect the contact state in GIS disconnector by collecting and analyzing the vibration signal. According to contrastive analysis of measurement results, this paper gets the results: vibration signal of 100Hz can be detected and the amplitudes in horizontal direction is a little higher than that in vertical direction when the GIS disconnector operates well. And obvious vibration signal can be detected in the frequency of 50Hz and 200Hz in FDS when the GIS disconnector has a loose contact. Take the amplitude of 100Hz as the reference value, the ratio of amplitudes between 50Hz and 100Hz and the ratio of amplitudes between 200Hz and 100Hz can be regarded as the characteristic quantity indicating the connection state of disconnector. If the ratio of 200Hz is larger than 0.2 and the ratio of 50Hz is between 0.1 and 0.3, it can be convinced that the GIS disconnector has a loose contact. If the ratio of 200Hz is larger than 0.5 and the ratio of 50Hz is larger than 0.2, it can be convinced that there is serious mechanical defect in the GIS disconnector.
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