The Maximum Energy of Wavelet Decomposition Approximation -Related Adaptive Wavelet De-Nosing for Partial Discharge UHF Pulse in GIS
Li Hua1, Yang Xinchun1, Li Jian2, Chen Jiao1, Cheng Changkui1
1. Chengdu Electrical Power Department SiChuan Electrical Power Company Chengdu 610041 China 2. State key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China
Abstract：Interference suppression was one of the key technologies in on-line partial discharge(PD) monitoring of gas insulated switchgear(GIS). Although ultra-high-frequency (UHF) is qualified to avoid low-frequency noises, the system white noise from the high voltage transmission line still make it difficult to accurately measure the level of PD. For active inhibition of the white noise interference and improving the precision of the UHF detection methods, this paper presents a adaptive de-noising scheme, which is suitable for de-noising UHF signal detected by the UHF detection system of PD in GIS. The method utilizes various basic wavelet to decompose a signal, and calculate and compare the signal energies caused by decomposition using different wavelets in each scale. The basic wavelet corresponding to the maximum signal energy is considered as the optimum wavelet in the current scale, thus the optimum wavelets family of all the scales is obtained, and the soft threshold function presented by Donoho is used to de-nosing . The result of de-noising a UHF signal generated by an artificial insulation defect convinces that the adaptive wavelet de-noising method is more effective to suppress the white noise mixed in UHF signal than the other wavelet-based de-noising method, it has an good practical value in on-line PD monitoring of GIS.
李化, 杨新春, 李剑, 陈娇, 程昌奎. 基于小波分解尺度系数能量最大原则的GIS局部放电超高频信号自适应小波去噪[J]. 电工技术学报, 2012, 27(5): 84-91.
Li Hua, Yang Xinchun, Li Jian, Chen Jiao, Cheng Changkui. The Maximum Energy of Wavelet Decomposition Approximation -Related Adaptive Wavelet De-Nosing for Partial Discharge UHF Pulse in GIS. Transactions of China Electrotechnical Society, 2012, 27(5): 84-91.
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2012, Vol. 27 
