Envelope Analysis and Defects Identification of Partial Discharge UHF Signals in GIS
Xiuchen Jiang · Gao dianya jishu · 2009
In order to detect and identify the defects in GIS,the ultra-high frequency(UHF)envelope detection circuit and high-speed data acquisition system was designed,and the tests of five typical defects in GIS were made in the laboratory and the envelope signal was acquired based on ultra-high frequency envelop detection circuit.A large number of experiments show that time-domain characteristics of partial discharge signals generated by the same defect model are similar,and envelopes are nearly identical.The time-domain characteristics of partial discharge signals generated by different defect models are different,and their envelope shapes are different.A new method of pattern recognition was proposed to analyze the characteristic parameters of the envelope signal at time-domain with BP neural network.PD pattern recognition results of testing data in lab indicate that the method is effective.