356 / 2017-03-03 08:45:26

Insulating Void Defect Analysis of Onsite 252kV GIS by Employing Partial Discharge UHF Diagnosis and Industry CT

partial discharge,UHF,insulating spacer,void defect,2921,industry CT,analysis method

In this paper, the insulating void defect inside the insulating spacer of onsite 252kV GIS is analyzed by ultra-high frequency (UHF) partial discharge (PD) diagnosed method and industry CT apparatus. The defect position of onsite GIS is located by using the time difference of arrival (TDOA) method of UHF signal. The pulse current method and UHF method is combined together to investigate the variation of PD signal by using the experimental regression in GIS experimental platform. Industry CT apparatus is used in order to verify the detection accuracy of PD detection and location method. It is shown that, the PD level above 115kV applied voltage is about 200pC and -12dBm under pulse current method and UHF method, respectively. A void with 1.285cm length and 0.447cm width is investigated in interface between insulating material and metal insert in insulating spacer. The PD detection example proposed in this paper is helpful for the PD diagnosis and risk assessment in GIS insulation.