| 摘要 |
<p>PROBLEM TO BE SOLVED: To lower the possibility of dielectric breakdowns by controlling an air exhauster or a sealing device, adjusting a gas pressure inside a tightly closed container so as to increase the dielectric breakdown voltage of a gas-installed switchgear, and increasing the difference between the operation voltage and breakdown voltage. SOLUTION: If a partial discharge occurs by a metal foreign matter inside a tightly closed container of a gas-insulated switchgear 1, a detection signal from a partial discharge detector 2 is inputted to a controller 4. If the partial discharge occurs at a gap in a gas and sealing pressure is 0.5MPa, then an electromagnetic valve 7 is opened. By the opening of the electromagnetic valve 7, an SF6 gas of the gas-insulated switchgear is discharged into an exhaust tank 5 through a gas piping 9, and the rated working pressure of 0.5MPa drops to a minimum working pressure of 0.4MPa. If the gas pressure of the gas- insulated switchgear 1 reaches the minimum working pressure, signals from a pressure sensor 3 are inputted to a control 4, the electromagnetic valve 7 is closed, the discharge of the SF6 gas is stopped, and a metallic foreign matter is removed.</p> |
