| 摘要 |
PURPOSE:To raise the impulse-resisting strength of a changeover switch, by composing the changeover switch of a driving mechanism and vacuum switch units and performing such connection that the contact and separation of the movable mechanism of the vacuum switch unit acts as a disconnecting switch coupled in series with the vacuum switch unit. CONSTITUTION:A changeover switch for one phase of a two-resistor on-load tap changer is composed of four vacuum switch units 1a-1d, one cam 2, two current limiting resistors 3ab, 3cd and a flexible tube 4. The vacuum switch units 1a-1d comprise vacuum switch means 11a-11d, cam followers 12a-12d, push springs 13a-13d, 14a-14d, upper fixed plates 15a-15d, lower fixed plates 16a-16d and flexible leads 17a-17b. The contact points of the cam followers and the cam are surely connected in series with current passages extending through the vacuum switch means. The contact points are closed before the closing of the vacuum switch means and opened after the opening of the switch means. |
