Abstract :
Phase resolved PD distributions and the evolution of the PD values during the measuring time which are perceived by trained operators were up to now described by hand made pictures, with some comments and appreciations. In recent time, PD recording and analysing systems are available on the market. This paper reports on the practical use of a PD analysing system TEAS 570 in connection with a research and development order on a 110 kV oil impregnated voltage transformer