| 摘要 |
To reduce overvoltages when switching high-voltage circuit breakers, particularly when connecting unloaded overhead lines, closing resistors are used which, during closing of the breaker, are connected in parallel relationship with the main switching gap of the circuit breaker by means of an auxiliary switching gap. After the main switching gap is closed, the closing resistor is disconnected by opening the auxiliary switching gap before the main gap opens and keeping the auxiliary gap open until the main switching gap is reclosed. For this purpose, the high-voltage circuit breaker includes a movable auxiliary contact pin which is spring loaded in the opening direction of the auxiliary switching gap, and a connecting rod which is linked to the auxiliary contact pin and is connected, hinged, to a rotatably supported crank drive of the drive unit of the breaker. The crank drive has a gate aperture which forcibly guides one end of the connecting rod and comprises a first curved portion which is concentric with a rotating shaft for the crank drive, and an adjoining straight portion which is disposed at the end of the curved portion located along the direction of rotation of the crank drive during closing of the breaker and is disposed approximately radially outwardly with respect to the crank drive shaft.
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