Effect of point polarity on conduction and burst current in an inhomogeneous field in transformer oil

Abstract

This paper presents a study of the effect of point cathode and point anode on conduction and burst currents under high fields in transformer oil from a transformer in service. It was found that, the current in point cathode is higher than the point anode, however, the rate of current decrease in point anode is faster. The amplitude of long duration conduction bursts in point cathode is larger than point anode. The total number of bursts per minute is larger for point anode than the point cathode. The conduction mechanism is discussed and the role of the liquid/metal interface is emphasised.