Sensitivity check for UHF PD detection on power transformers

Abstract

It is known that failure due to insulation defects are often preceded by partial discharge activity. Over the last years, online diagnostic methods for power transformers have been investigated. In this paper the sensitivity of one of these methods, the UHF PD detection technique, has been applied on five different high- and medium voltage transformers with power ratings in the range of 14 to 500 MVA. From these experiments, the sensitivity of the UHF technique to detect partial discharges in power transformers has been proven. Based on these results, a sensitivity check similar to GIS is proposed in this paper.