| 摘要 |
PROBLEM TO BE SOLVED: To easily and efficiently specify a fault point such as a ground fault point or a short circuit point in a fault section in a short time without measuring all electric poles in the fault section even when a short circuit between lines occurs in a pole transformer. SOLUTION: In this method, ground impedances and inter-phase impedances in respective phases of distribution lines 10, 12 are measured by use of a high-frequency power source, a voltage measurement sensor and a current measurement sensor. When the ground impedance in one phase is extremely smaller than the ground impedances in the other phases, it is decided that on accident is a ground fault accident. When one inter-phase-ground impedance is extremely smaller than the other inter-phase-ground impedances, it is decided that the accident is a short circuit accident. Currents are measured in two points sandwiching a connection point of the high-frequency power source, and it is decided that the short circuit accident occurs in a direction showing a larger current value. |
