SINGLE-PHASE-TO-GROUND FAULT LINE SELECTION METHOD FOR DISTRIBUTION LINES

摘要

The present invention provides a method of selecting a single-phase-grounding line of a wiring line through a phase current comparison. The method includes: sampling a three-phase current traveling wave in a distribution line, and defining a direction pointing from a bus bar toward the line as a forward direction of the current; In the case of a single-phase-ground fault in the distribution line, it is a step to compare the amplitude and polarity difference before and after the fault of the three-phase current traveling wave. The current amplitude of any one of the three-phase currents is 1.5 times or more than the amplitude of the other two-phase current traveling wave. When the polarity of the large and largest phase current traveling wave is opposite to the polarity of the remaining two-phase current traveling wave, it is judged that a fault has occurred on the load side of the measuring point of the line, and the phase with the largest amplitude of the current traveling wave is judged as the faulty phase. step; and when the amplitude difference of the three-phase current traveling wave is within a predetermined value and has the same polarity, determining that a failure has occurred on the power supply side of the measurement point; Consists of including. By the technical solution of the present invention, it is possible to implement an accurate line selection for a single-phase-grounding failure of a distribution line.