Acoustic monitoring of electrical discharges using fibre-optic based techniques

The authors describe preliminary research into the application of optical fibre sensing techniques for acoustic monitoring of partial discharges in gas insulated substations (GIS). Suitable candidate techniques for their measurment are described. The experimental results show that with the correct optical technique and electronic processing, partial discharges of the order of 10³ pC can be detected corresponding to displacements in the GIS wall of approximately 10^-12 m. The experimental results are shown to be in agreement with theoretical predictions based upon the excitation of acoustical resonances of the GIS module