가스절연 전력기기의 부분방전 측정을 위한 UHF 칩 센서 개발

Abstract

Different types of sensors working in Ultra-High-Frequency have been widely developed, since more than two decades, to detect the PD pulses occurring inside gas insulated apparatus(GIS, GITr, GIL, etc.) apparatus. Some of them have been commercially used for gas insulated apparatus and several advantages such as high sensitivity and less affected by external disturbances are attributed to them. In this work, a chip type UHF sensor has been designed with the smallest dimension for PD detection and then fabricated with a view to replacing the currently used patch type sensors. Its structure has been determined by 3-dimensional electro-magnetic simulation and then important characteristics such as gain, directivity and return loss have been evaluated in the working frequency ranges (0.3GHz-1.5GHz). In particular, the measured return loss of the prototype has been compared with that obtained by simulation. Moreover, laboratory tests have been carried out in order to investigate possibility to detect PD signals and also to find the PD source. For this work, 170kV GIS and 170kV GITr mock-up equipped with inspection windows and the artificial defect have been used. The sensitivity of the new Chip-type UHF sensor is compared to other internal mounted UHF sensors. Experimental investigation has been made for the PD pattern analysis by the conventional PRPD method respecting the IEC 60270 as well as finding PD location by “Trilateration method”. Ascribed to its high sensitivity detection below 10pC, PD location using artificial defect such as void has been realized at laboratory test.