【作者】 董新洲； 毕见广；

【Author】 DONG Xinzhou, BI Jianguang (Dept. of Electrical Engineering and Electronic Application, Tsinghua University, Beijing 100084, China)

【机构】 清华大学电机工程与应用电子技术系；

【摘要】 对于中性点非有效接地的配电系统,当某回线路发生单相接地时,系统的接地电流只有很小的电容电流,并且系统时常运行在不平衡状态,这导致利用工频量来选择接地线路很困难。本文以行波理论为基础研究了配电线路单相接地后所产生的暂态电流行波的传播规律和特点,以小波变换为工具刻划了该行波的接地故障特征并发现:单相接地瞬间所产生的初始暂态电流行波与接地方式无关,从而为接地选线开辟了新思路。论文最后给出了基于初始电流行波和小波的接地选线判据,一个仿真例用于证明本文理论推导和所提方法的正确性。更多还原

【Abstract】 Because power frequency fault current is very small in amplitude and the system may operate under an asymmetry condition, it has been a very difficult to correctly identify the faulted line when single phase to ground fault (SFG) occurs in distribution system with non-effectively grounded (NNG) neutral. After analyzing the characteristics of transient traveling waves resulted from SFG in distribution system, it is found that the initial transient current traveling waves is irrespective of the neural grounding mode when SFG occurs. According to fact described above, a new faulted line identification algorithm based on transient traveling waves (TTW) and wavelet transform is proposed..更多还原