电路相关Noises elimination for online detecting faulty insulator.pdfVIP

P2-22 NOISES ELIMINATION FOR ONLINE DETECTING FAULTY INSULATOR Y. C. Cheng, C. R. Li, Lijian Ding, Jingchun Wang, Wei Wang North Chma Electric Power University (Beijing) Beijing 100085,P. R, China Abstract According to recent researches, insulator co- ground line in our laboratory. These pulses are about 50 rona pulses through the ground line of the tower could ns of rise-time and about lOOns to 400ns of pulse width. be used to identi@ faulty insulators on transmission Their main energy distributed within 20MHz. Contrarily, lines. But there are many noises in ground lines in field, leakage and harmonic noise has very low frequency, and which make it impossible to detect insulator corona carrier noise distributes from 3kHz to lMHz in China. pulses. Some methods of aparting insulator corona The Rogowski coil sensor has high sensibility only at pulses form these noises are described in this paper. A certain frequency range according to its core and coils. high frequency sensor with a filter is used to eliminate When we decrease coils of sensor, the leakage and har- periodic noises, such as leakage current, harmonic and monic noise will be abated for their frequency beyond carrier. A pattern identification based on pulse statistic the high sensibility frequency range of sensor. characteristics is used to remove pulse noises, such as HV line corona and line clip corona. The biggest difficulty of parting signal from sine kind of