| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To pinpoint insulation deterioration parts nondestructively even power lines connected to gas insulated switching devices. <P>SOLUTION: The electric current flowing through two power lines the one end is shunt of power lines formed by power cable is inputted into galvanometer 15 through a noise invasion preventing circuit 14 maintaining a predetermined insulating strength to ground, while zero-calibrated of the galvanometer is applied in a condition direct-current voltage is not applied to the two power lines and direct-current voltage below a permissible direct-current voltage of the gas insulated switching device connected to the power cable from a direct-current voltage power source 17 is applied at proportionally divided position of a measuring side resistance 13 of Wheatstone bridge circuit. Finally, using a ratio arm maintaining a predetermined insulating strength to ground, the current flowing into the galvanometer is calibrated to zero by changing the proportionally divided position of a measuring side resistance and thus the insulation deterioration position of power line is located based on the ratio of proportionally divided position of measuring side resistance calibrated with ratio arm. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
