Research on the Influence of Transition Resistance Characteristics on the Waveform of Fault Current Travelling Wave in Transmission Line

Travelling wave locating technology has become more and more mature. For operation and maintenance, it is also hoped to further determine the specific causes of faults, especially the causes of non-lightning faults. Various non-lightning faults are essentially different in the characteristics of the transition resistance, which leads to huge differences in the waveform of the travelling waves. In this paper, the generation principle of travelling waves is analyzed, a simplified equation that can describe the characteristics of current travelling waves is proposed, and the simulation and measured waveform are analyzed. The analysis results show that, for non-arcing nonlightning faults, the rising edge of the current travelling waves act as a step signal; for arcing non-lightning faults, since the development of arc requires a certain time, the rising edge of the current travelling waves will slow down. The rising edge is mainly affected by the arc gap length and the arc generation speed, and the rising time ranges from a few microseconds to tens of microseconds. The above analysis and conclusions can provide theoretical support for the identification of non-lightning faults based on current travelling waves.