Maschinenfabrik Reinhausen Gmbh

Udo Hertel

Karsten Viereck

Anatoli Saveliev

Oliver Brueckl

Junliang Wu

Armin Hirthammer

Oliver Brückl

A method monitors capacitor bushings of a three-phase AC mains, which has first, second, and third mains lines respectively associated with first, second, and third: phases, capacitor bushings, and mains voltages. Each of the capacitor bushings has: a conductor connected with the associated mains line, and an electrically conductive foil enclosing the conductor. The method includes, for each of the phases: determining, at a predetermined initial instant for a characteristic variable, which is characteristic for the respective capacitor bushing, a corresponding characteristic value; determining, at a predetermined later instant after the initial instant for the characteristic variable, a corresponding normalised characteristic value in dependence on the respective characteristic value and/or on at least one of remaining characteristic values; and checking whether the normalised characteristic value has impermissibly changed.

Method and device for monitoring capacitor bushings for an alternating-current grid

A tap changer with semiconductor switching elements for uninterrupted switching between winding taps of a tapped transformer has two load branches connected with the winding taps of the tapped transformer and that each comprise a respective mechanical main contact that in stationary operation conducts current of the respective load branch and produces an electrical connection with a load shunt. Each load branch also has parallel to the respective main contact a series circuit consisting of a further respective mechanical contact as well as a respective semiconductor switch. These semiconductor switches are electrically connected together at a side remote from the respective contacts and lead to a mechanical transfer contact whose other side is connected with the load shunt. A connection of the main contacts as well as the further mechanical contacts is effected by a movable contact support.

Tap changer

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Wuppertal, Germany

Udo Hertel