Maschinenfabrik Reinhausen Gmbh

Oliver Brueckl

Dieter Dohnal

Hans-Henning Lessmann-Mieske

Anatoli Saveliev

Udo Hertel

Armin Hirthammer

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

The invention relates to an on-load tap changer comprising semiconductor switching elements for uninterrupted switching between winding taps of a tapped transformer. According to the invention, contact bars are provided which extend in the direction of the path of the fixed tap contacts and can be contacted using contact bridges that can be jointly moved by a contact slide in such a way that direct electrical connections to the charge diverter and electrical connections to the inputs and the output of the semiconductor switching elements can be established.

On-load tap changer comprising semiconductor switching elements

The invention relates to the arrangement of a stepping switch on a control transformer, wherein either only the mechanical contact system () of the stepping switch or also its load changeover switch () is or are arranged within the tank () of the transformer, under the transformer cover () and above the iron yoke ().

Arrangement of a stepping switch on a control transformer

The invention relates to an on-load tap changer comprising semiconductor switching elements for uninterrupted switching between fixed tap changer contacts which are electrically connected to winding taps of a tapped transformer. Each of the fixed tap changer contacts can be connected to a charge diverter either directly or, during switching, via the semiconductor switching elements that are connected therebetween. According to the invention, the charge diverter has fixed, divided diverting contact pieces in order for the semiconductor switching elements to be electrically isolated from the transformer winding during stationary operation.

An on-load tap changer with semiconductor IGBT switching elements for uninterrupted switching over between winding taps of a tapped transformer, has two load branches connectable with the respective winding taps and each load branch is electrically connected with a common load output line through a respective series circuit consisting of two oppositely connected IGBTs. A diode is connected parallel to each IGBT, and the two diodes in each load branch are connected oppositely to one another. A respective mechanical switch is connected in series with the series circuit of IGBTs and parallel diodes in each load branch. A respective varistor is connected parallel to each parallel circuit of IGBT and diode, and the varistors are so dimensioned that the respective varistor voltages are lower than the maximum blocking voltage of the respective parallel IGBTs but higher than the maximum instantaneous value of the tap voltage.

Tap switch with semiconductor switching elements

The invention relates to a method for switching without any interruption between two winding taps (tap n, tap n+1) of a tap-changing transformer, wherein each of the two winding taps is connected to the common load output line via in each case one mechanical switch (Ds) and a series circuit, arranged in series thereto, comprising two IGBTs (Ip, In) which are switched in opposite directions.

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Waldmuenchen, Germany

Oliver Brueckl