UHF partial discharge monitoring and expert system diagnosis

This paper examines the ultra high frequency (UHF) partial discharge (PD) measuring technique and its use in online monitoring for gas insulated substations (GIS). Taking two special PD defects as examples, some crucial aspects of PD monitoring are highlighted. Furthermore, the interpretation of measuring results is discussed on the basis of these examples, and an advanced expert system for automatic defect type interpretation is presented. Early fault recognition can be achieved by continuous UHF PD monitoring.