The invention discloses an abnormal vibration analysis-based GIS (gas insulated
switchgear) mechanical fault diagnosis method and
system. The GIS (gas insulated
switchgear) mechanical fault diagnosis method includes the following steps that: vibration signals on a GIS are acquired; de-noising
processing is performed on the acquired signals through using a threshold de-noising method; various kinds of feature information contained in the signals are extracted by using a
narrowband noise aided multivariate empirical mode
decomposition (EMD) method; the power feature of the signals is extracted by using a
power density function, and the maximal amplitudes of the power spectra of all IMF of each channel are calculated so as to form power feature matrixes under measured conditions; and a power
feature matrix under a normal condition and / or power feature matrixes under various kinds of fault conditions which are obtained through tests are adopted as judgment criteria of faults. Compared with a traditional method, the method and
system of the invention have no influence on the normal operation of a whole power
system, and can monitor the running state of the GIS safely and reliably, and are suitable for being applied to GIS substations of various
voltage levels.