冲击电压下SF_6气体在极不均匀场中局部放电的时频特征  

Time-Frequency Characteristics of Partial Discharge of SF_6 Gas in an Extremely Uneven Field under Impulse Voltage

作　　者：任重 董明[1] 任明[1] 杨彦博[1] 肖智刚[1] 邱爱慈[1,2] 

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]西北核技术研究所,西安710024

出　　处：《西安交通大学学报》2013年第8期115-120,共6页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50907051)

摘　　要：为了研究冲击电压下GIS腔体内绝缘缺陷局部放电的发生发展机理,采用短时傅里叶变换(STFT)、伪Wigner-Ville分布和Gabor分布理论,对标准负极性操作冲击电压下SF6气体在极不均匀场的局部放电光信号和电流信号的时频特征进行了分析。结果表明:STFT、伪Wigner-Ville分布和Gabor分布均能有效提取放电信号的时频特征,但Gabor分布具有较好的时频聚集性,不具有交叉干扰项,且对信号的时频特征的刻画最为细致,而STFT的时频聚集性较差,伪Wigner-Ville分布则存在固有交叉干扰项;冲击电压下局部放电光信号和电流信号在时频平面的分布不同,光脉冲的能量上升到峰值的时间要小于电流脉冲。To investigate the mechanism of partial discharge （PD） of insulation defects in gasinsulated metalenclosed switchgear （GIS） under impulse voltage, timefrequency characteristics of optical signals and current signals of PD are analyzed with short time Fourier transform （STFT）, pseudo WignerVille distribution theory and Gabor distribution theory. The analysis reveals that： 1） The timefrequency characteristics of PD signals can be effectively extracted; 2） Gabor distribution of PD signals is endowed with the best timefrequency aggregation behavior without crossinterference items and reflects the most detailed characteristics of PD signals in timefrequency plane; 3） STFT of PD signals possesses the poorest timefrequency aggregation behavior and 4） Pseudo WignerVille distribution of PD signals includes several inherent crossinterference terms. The timefrequency characteristics of the optical signals and the current signals of PD are different and the rising time of the optical pulse is less than that of the current pulse in timefrequency plane.

关 键 词：时频 局部放电 冲击电压 极不均匀场 

分 类 号：TM835.4[电气工程—高电压与绝缘技术]