一种基于小波包分析的小电流接地电网单相接地故障选线新方法

作将小波包用于小电流接地电网发生单相接地故障后的暂态零序电流分解，提出了一种基于波形识别的判据：只要在故障电流的某高频段上，大多数采样点服从故障特征，根据少数服从多数原则便可正确判断故障线路。此方法可靠性高、抗干扰能力强、无需在现场进行定值调节，适用于具有不同接地方式的配电网。

A NEW WAVELET PACKET ANALYSIS BASED METHOD TO DETECT FAULTY LINE FOR SINGLE PHASE TO GROUND FAULT OCCURRED IN DISTRIBUTION NETWORK WITH SMALL CURRENT NEUTRAL GROUNDING

Applying the wavelet packets to the decomposition of transient zero sequence current that appears after the single phase to ground fault occurred in the distribution network with small current neutral grounding, a new criterion based on waveform recognition is put forward, i.e., provided in a certain high frequency band of the fault current the majority of sampled points conform to the fault characteristics, so according to the principle that the minority is subordinate to the majority the fault line can be correctly detected. This method has high reliability, strong ability of anti-interference. This method needs not the on-site adjustment of the settings and is suitable to the distribution networks with different grounding modes.