Effects of insulation barrier board on power transformer PD detection using acoustics

Abstract

Partial discharge (PD) in power transformer occurs due to high electric field strength in voids resulting in degradation of insulation. PD test is one of the pass criteria of power transformers after completion of repairs in transformer workshop. In order to facilitate quick repair of the defected area the localisation of the PD source is important. This research paper presents the result of the investigation of the effect of insulation barrier board on the acoustic wave propagation and detection. A couple of experiments carried out in the model transformer tank considering the case with transformer insulation barrier board with different thicknesses and being placed between PD source and the sensor at the different positions. From the results of the experiment, after thorough analysis, it was concluded that the barrier board influences the PD wave propagation, and this points to the fact that it can affect the PD localisation.