ACOUSTIC DIAGNOSIS OF GAS INSULATED SUBSTATIONS - A THEORETICAL AND EXPERIMENTAL BASIS

Loose particles and discharges inside the ducts of a Gas Insulated Substation (GIS) are considered hazardous to the insulation system. These irregularities or flaws can be detected by using acoustic sensors placed on the enclosure. An elementary review of sound propagation in a GIS, together with corresponding experimental results are presented. By using ultrasonic acoustic emission sensors an excellent sensitivity to discharges and moving particles is obtained. The method offers possibilities for a quantification of the flaws, and thereby for a risk analysis. However, the degree of certainty of such an analysis is still low, especially for particles. © 1990 IEEE