| 摘要 |
PROBLEM TO BE SOLVED: To perform standardization by a small-capacity, small-sized DC power source, to standardize a grounding position even when there is a gap at the grounding point, and to eliminate an error resulting from low resistance of the winding of a load such as a transformer connected to a line. SOLUTION: Beginnings A, B, and C of lines are short-circuited. Ends A', B', and C' are also short-circuited. A switch S1 is turned on to supply a DC current to a three-phase power distribution line. A switch S2 switched from the position shown in the figure tens of ms later to apply a high voltage E2 which is charged in a capacitor C1 so far to the thee-phase power distribution line, thereby electrically destroying gap at the grounding point G. Currents I1, I2, and I3 of the respective phases are detected within subsequent 7 seconds. The distance (x) to the grounding point G is calculated from the ratio (I1+I2)/3 of I1+I2 and I3.
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