关键词: 小电流接地系统 故障选线 小波包分析

Abstract:

According to the distributed power system fault characteristics, a new criterion based on the principle of maximum energy is built, which selects the  special frequency band that has the major characteristics of zero sequence current. Comparing the polarity of the special frequency band of each line with the polarity of the zero sequence voltage＇ s first half wave, a method is put forward to distinguish the fault lines in this paper. The single phasee-to-earth fault model of smallcurrent grounding systems is built with MATLAB/SIMULINK. The simulation suggests that the new criteria can distinguish co rrectly the fault lines, whose performance is independent on the grounding model of the centric dot and the fault occurring time, and the new criteria h as an excellent adaptability to various fault conditions.

Key words: small current neutral grounding system, fault line selection, multi-resolution analysis of wavelet