The fast and slow signal components of partial discharges in SF/sub 6/ measurements of the electron and ion contributions to PD-signal
The fast and slow signal components of partial discharges in SF/sub 6/ measurements of the electron and ion contributions to PD-signal
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SF/sub 6 中局部放电的快速和慢速信号分量/测量电子和离子对局部放电信号的贡献
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
R. Pietsch
中科院分区：
文献类型：
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作者：
I. Herbst;R. Pietsch
多年来，IEC 270局部放电测量技术一直是国际标准。为了提高局部放电信号与热放大噪声的比率并降低对外部噪声的敏感度，“超”宽带技术被提出作为IEC 270的替代方案。本文将证明，在没有外部噪声的情况下，改进的S/N的假设是错误的，并且是基于对局部放电信号特征的普遍误解。气体绝缘系统中的局部放电信号通常被认为是纳秒范围内的非常快的信号，由快电子产生。我们不仅测量了一个典型放电源在正常工作条件下的快信号分量，而且还测量了一个慢信号分量。这些信号成分可以归因于快速移动的电子和缓慢移动的正负离子。我们发现，局部放电脉冲的慢部分比电子部分大2-14倍(按IEC 270，测量频率为100 kHz)，而且这两个部分的比例强烈地依赖于压力和几何形状。由于IEC 270方法集成了快和慢信号分量以及较小的连续脉冲，我们发现热噪声的缺点被由此导致的局部放电信号的增加所补偿。因此，在地理信息系统的质量保证测试中，仍可推荐采用常规技术。
For many years the IEC 270 partial discharge (PD) measurement technique has been the international standard. To improve the ratio of PD signal to thermal amplifier noise and to reduce sensitivity to external noise, "ultra"-wideband techniques have been proposed as an alternative to IEC 270. This paper will show that in the absence of external noise the assumption of improved S/N is false and based on a general misconception of the PD signal characteristics. Partial discharge signals in gas-insulated systems (GIS) are usually said to be very fast signals in the nanosecond range, created by fast electrons. We measured not only a fast but also a slow signal component for a typical discharge source under normal GIS operating conditions. These signal components can be attributed to fast moving electrons and slow moving positive and negative ions. We found that the slow part of the PD pulse is 2-14 times larger than the electronic part (measured at 100 kHz, in IEC 270), and also that the ratio of these two parts depends strongly on pressure and geometry. Since the IEC 270 method integrates fast and slow signal components as well as the smaller consecutive pulses we find that the disadvantage of thermal noise is compensated for by the resulting increase in PD signal. Therefore the conventional technique can still be recommended in quality insurance testing of GIS.<<ETX>>