| 摘要 |
<p>PURPOSE:To speedily and accurately specify an accident occurrence position without making a patrol by impressing a voltage to an area where the gas insulation opening and closing device(GIS) is stopped from operating because of the presence of a ground fault point, and deciding the ground fault point. CONSTITUTION:For example, a ground fault accident occurs in a section 16 of the GIS which is sectioned with insulating spacers 10 and 11. A generated arc moves fast in the GIS along a conductor and stops at the spacer 11 and the arc stays at the insulating space part until a ground fault current is cut off. Breakers 1 - 4 are tripped under the command of a protection relay and a thick-line part is disconnected from the system. In this state, an AC power source 17 is connected to the secondary side 8a of a gas PT (gas insulation voltage transformer) 8 for an A type bus to excite the PT 8 reversely and when an AC voltage is impressed to the stop range of the thick-line part, partial discharger is caused at the spacer 11 which is damaged by the arc at the time of the ground fault because of an AC voltage generated by the reverse excitation. A high frequency pulse voltage which is induced owing to the partial discharge is detected by the buried electrode of the insulating spacer. Further, the damage insulating spacer is specified.</p> |
