谐振接地系统暂态特征自适应故障选线方法

Adaptive faulty line selection based on transient characteristics for resonant earthing system

分析了单相接地故障的暂态时域特征和暂态相频特征,基于此,提出谐振接地系统自适应选线方法。所提方法对频带错乱进行了调整,选用性能较好的小波函数防止小波混叠现象导致选线恶化;通过比例因子和暂态因子分别反映线路暂态零序电流的主要成分和过渡电阻的大小,对应2种因子的不同取值,通过幅值比较、极性比较和辅助判据实现自适应故障选线。仿真结果表明所提方法适用于不同的单相接地故障,可靠性高。

The transient time-domain and phase-frequency characteristics of single-phase grounding fault are analyzed and a method of self-adaptive faulty line selection is proposed for resonant earthing system,which adjusts the frequency band interleaving,selects the wavelet function with better performance to prevent the wavelet aliasing for proper faulty line selection,applies the proportion factor and transient factor to reflect the main components and transition resistance respectively,and realizes the adaptive faulty line selection by the comparison of amplitude and polarity and the assistant criterion according to different values of the two factors.Simulative results show the proposed method has higher reliability,suitable for different types of single-phase grounding fault.