CAJ | 학술논문

针对电力电缆局部放电检测,介绍了基于新型S变换的时频分析方法,用于提取及分辨淹没在现场噪声干扰中的局放脉冲信号。局放信号是典型非平稳信号,单纯使用时域或者频域信息都不能很好地表示奇异信号的时变信息。最近发展的S变换是连续小波变换和短时傅里叶变换的一种结合与延伸,引入了幅度和宽度均随频率变换的高斯窗,具有与频率相关的渐进分辨率特性。局放信号的S变换图谱,在信号高频分量部分获得较高的时域分辨率,而在低频分量部分获得较高的频域分辨率,并可提取局放脉冲发生时刻及信号中心振荡频率等特征信息。对仿真信号和现场采集的电力电缆接地线上的局放信号应用S变换进行时频分析,并与短时傅里叶变换及Gabor变换等传统时频分析方法比较,结果显示S变换的时频分析可有效获取局放脉冲信息。
침대전력전람국부방전검측,개소료기우신형S변환적시빈분석방법,용우제취급분변엄몰재현장조성간우중적국방맥충신호。국방신호시전형비평은신호,단순사용시역혹자빈역신식도불능흔호지표시기이신호적시변신식。최근발전적S변환시련속소파변환화단시부리협변환적일충결합여연신,인입료폭도화관도균수빈솔변환적고사창,구유여빈솔상관적점진분변솔특성。국방신호적S변환도보,재신호고빈분량부분획득교고적시역분변솔,이재저빈분량부분획득교고적빈역분변솔,병가제취국방맥충발생시각급신호중심진탕빈솔등특정신식。대방진신호화현장채집적전력전람접지선상적국방신호응용S변환진행시빈분석,병여단시부리협변환급Gabor변환등전통시빈분석방법비교,결과현시S변환적시빈분석가유효획취국방맥충신식。
For partial discharge detection in power cables,a new-type S transform time-frequency analysis method is introduced to distinguish the partial discharge signals from field noise.Partial discharge signal is a typical non-stationary signal,and its characteristics can not be clearly expressed only by time-domain or frequency-domain information.S transform is a combination and extension of continuous wavelet transform and short time Fourier transform（STFT）.The S transform method employs a Gauss window,whose amplitude and width change with frequency.S transform achieves better time resolution in high frequency proportion,and better frequency resolution in low frequency proportion.Compared with traditional time-frequency representation like STFT and Gabor transform,the S transform is used to analyze the simulation and on-site detection signals from power cables earthing strap.The results show that S transform is effective in extracting partial discharge characteristic information.