Abstract
Considering the fact that most problems in distribution lines are ground faults, we think that the technology to distinguish the causes in the distribution lines will be very useful in preventing faults beforehand or, at least finding any problems at an early stage. We analysed the waveforms of ground faults which were collected from data concerning problems in the districution lines and ground fault experiment. We then studied the possibility of technology which could predict classified groups drawn from the scale of Io (the waveform of ground fault's current) and Vo (the waveform of ground fault's voltage), and both of them in the ground faults. The results demonstrated that Io could be classified into three groups, that is, leaking ground faults are sine curve shaped, gap discharge ground faults are triangular and intermittent discharge ground faults are needle shaped. Also we calculated simulated equivalent impedance of the causes of ground faults by EMTP. Furthermore, we investigated the influence coused by the condition of the distribution lines. With these results, we proposed a technique which could predict the cause of problems in ground faults.
