As an essential component of power transformers,the detection and diagnosis of incipient partial discharge(PD)activities of bushings are of great significance.A 35-kV oil-impregnated paper(OIP)bushing is investigated....As an essential component of power transformers,the detection and diagnosis of incipient partial discharge(PD)activities of bushings are of great significance.A 35-kV oil-impregnated paper(OIP)bushing is investigated.The bushing is modelled by coaxial theory and electromagnetic(EM)simulation.As the paths of PD-induced ultra-high frequency(UHF)signal propagating in the bushing are OIPs and oil gap,small attenuation during signal propagation is seen.Since OIP is composed of het-erogeneous media compared with pure oil,there will be relatively less UHF signal leakage from OIPs,whereas more leakage from the oil gap.This leakage provides the possibility of non-contact detection outside the bushing by UHF method.PD mea-surements with UHF method are carried out on the bushing.Then,the minimum energy method is used to extract time-difference-of-arrival(TDOA),and Chan al-gorithm is adopted to locate points of UHF signal radiation.High accuracy locating with a small error of 15 cm has been achieved.The contactless UHF method-based tests have demonstrated the effectiveness of online monitoring and locating of bushing PD.展开更多
基金Jiangsu Planned Projects for Postdoctoral Research Funds,Project funded by China Post-doctoral Science Foundation(2019M661828)the Science and Technology Project of State Grid Corporation of China(No.J2019008)+1 种基金The authors gratefully acknowledge the financial support from China Scholarship Council(No.201,906,835,029)2019 CAST Outstanding International Youths Exchange Program and Ministry of Science and Inno-vation of Spain,National Program of Scientific and Technical Research and Innovation(PID2019-107126RB-C21).
文摘As an essential component of power transformers,the detection and diagnosis of incipient partial discharge(PD)activities of bushings are of great significance.A 35-kV oil-impregnated paper(OIP)bushing is investigated.The bushing is modelled by coaxial theory and electromagnetic(EM)simulation.As the paths of PD-induced ultra-high frequency(UHF)signal propagating in the bushing are OIPs and oil gap,small attenuation during signal propagation is seen.Since OIP is composed of het-erogeneous media compared with pure oil,there will be relatively less UHF signal leakage from OIPs,whereas more leakage from the oil gap.This leakage provides the possibility of non-contact detection outside the bushing by UHF method.PD mea-surements with UHF method are carried out on the bushing.Then,the minimum energy method is used to extract time-difference-of-arrival(TDOA),and Chan al-gorithm is adopted to locate points of UHF signal radiation.High accuracy locating with a small error of 15 cm has been achieved.The contactless UHF method-based tests have demonstrated the effectiveness of online monitoring and locating of bushing PD.
