2007 Volume 127 Issue 2 Pages 389-396
We investigated propagation properties of Lamb waves in gas insulated switchgear (GIS) tank to diagnose insulation performance of GIS. The acoustic signals excited by a free metallic particle colliding with the tank sheath were measured using AE sensors. The Wavelet Transform was applied to decompose the wave data into its time-frequency components. As the result, difference of propagation properties of Lamb waves is clearly seen on different size of GIS tank. Based on the characteristics of Lamb waves, algorithms for location identification of a free metallic particle were examined in model GIS using two AE sensors. As the result, we propose a new system for location identification of a free metallic particle in GIS. Moreover, it is verified that the new identification system is suitable to diagnostic technique for GIS.