On-load tap changer and method for actuating an on-load tap changer

A method for actuating an on-load tap-changer, the on-load tap-changer comprising a diverter switch configured to perform a switchover from a first fixed contact to a second fixed contact of the on-load tap-changer;

• and a selector configured to powerlessly preselect fixed contacts, the fixed contacts being the first fixed contact and the second fixed contact, the selector comprising a first selector arm and a second selector arm which are configured to be actuated independently of one another and configured to contact each of the fixed contacts, the diverter switch comprising, for performing the switchover, a main path comprising a mechanical switching element, the main path being configured to connect the first selector arm to a load take-off lead via the mechanical switching element, a first auxiliary path comprising a first semiconductor switching element, the first auxiliary path being parallel to the main path and configured to connect the first selector arm to the load take-off lead, and a second auxiliary path comprising a second semiconductor switching element, the second auxiliary path being configured to connect the second selector arm to the load take-off lead, the method comprising:
• switching over from a first fixed contact to a second fixed contact by executing a switchover operation comprising:
• closing the first semiconductor switching element,
• switching over the second selector arm to the second fixed contact and opening the mechanical switching element,
• actuating the first semiconductor switching element and the second semiconductor switching element in such a way that a load current is switched over from the first fixed contact to the second fixed contact,
• switching over the first selector arm to the second fixed contact,
• closing the mechanical switching element, and
• opening the second semiconductor switching element;
• and
• selectively assuming:
• a first stationary position, in which the first selector arm and the second selector arm contact the first fixed contact and the first selector arm is connected to the load take-off lead via the main path, and
• a second stationary position, in which the first selector arm and the second selector arm contact the second fixed contact and the first selector arm is connected to the load take-off lead via the main path.