Abstract: Gas-insulated metal-enclosed switchgear (GIS) may occurs mechanical faults such as poor contact of the switch contacts during operation, which leads to abnormal vibration signals. To investigate the characteristics of these vibration signals and achieve fault diagnosis,a GIS experimental platform was established to simulate different contact states, then the collected vibration signals are subjected to wavelet denoising and complementary set empirical mode decomposition(CEEMD), and the sensitive components are extracted for reconstruction through the calculation of correlation coefficients. Ultimately, the results show that under normal conditions, the vibration signal spectrum of GIS contacts is primarily distributed in 100 Hz and its integer multiples. When it contacts faults occur, the high-frequency components in the vibration signal spectrum increase significantly and a distinct triple harmonic component emerged. Moreover, the amplitude of the component will increase as the degree of the fault intensifies. By reconstructing the fault signal through this rule, the high-frequency impact components contained in the fault signal can be clearly presented.

    Key words: gas-insulated metal-enclosed switchgear(GIS); vibration signal; complementary set empirical mode decomposition(CEEMD);wavelet denoising; fault monitoring