Acoustic monitoring of HV equipment with optical fiber sensors

This paper presents the preliminary results on the application of optical fiber sensor (OFS) for the measurements of discharging signals in insulating oil. An all-optical-fiber-sensing system using a Mach-Zehnder interferometry technique was constructed. It was found that the pressure wave produced by discharges at the needle-sphere electrodes could be detected by OFS, which was compared with signals from a current probe and PZT sensor. By comparing amplitudes of acoustic signal measured by OFS, a correlation between acoustic and electrical discharge signals was observed.