Motion and Size Estimation of a Free Moving Metallic Particle in GIS based on Propagation Properties of Acoustic Waves

Abstract

We have investigated propagation properties of Lamb waves and motion characteristic of free moving metallic particle in gas insulated switchgear (GIS) tank to diagnose insulation performance of GIS. We have proposed a new identification technique of the defect location in GIS based on the time-frequency analysis of the Lamb waves using the Wavelet Transform. In this paper, we measured the acoustic signals excited by a metallic particle colliding with the tank sheath. Furthermore, we measured the moving particle under the high electric field in GIS using a high speed video camera. As a result, it was examined that the relationship between maximum lifting height and the flight time during subsequent impacts of a moving particle. Moreover, we estimated particle size based on propagation properties of Lamb waves.