Gas Insulated Transformer 내부 부분방전 측정을 위한 UHF sensor 개발

Abstract

With a view of detecting the PD pulses occurring inside Gas Insulated Transformer (GITr), a wide band UHF internal sensor has been designed and then fabricated. The structure has been determined using 3-dimensional electro-magnetic simulation and directivity and return loss have been evaluated in the operating frequency range (0.3GHz-3GHz). In particular, the measured return loss of the prototype has been compared with that of the simulation. Four different types of artificial defects have been also manipulated for their PD pattern based on the conventional PRPD method. For this purpose, experimental investigations have been carried out by the use of selected sensor introduced at the fixed location inside a 170kV/25kV mock-up with inspection windows. In this case, each defect has been placed at a given place near the high voltage electrode. Throughout this work, some experimental results and conclusion have been obtained.