US 4,286,317 AGranted

Forced commutation power converter arrangement in reverse voltage free circuit configuration

AssigneeBBC Brown, Boveri & Company, Limited

InventorKarl Kommissari

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Abstract

With forced commutation static power or current converters having extinguishing or interruption circuit connected to the individual power switching branches and employing controllable extinguishing or turnoff valves, there exists the problem of unsymmetrical voltage build-up in the extinguishing circuits with corresponding overload or overdimensioning of the extinguishing valves, also referred to as commutation valves. This problem is solved, according to the invention, by arranging the usual commutation capacitor between the power switching branches, i.e., the load circuits, and the extinguishing valves, i.e., the commutation valves, and by arranging a damping circuit between the commutation capacitor and the extinguishing valves. The damping circuit is connected, by special valves, with positive and negative limiting potential. The undesired non-symmetry is thus effectively reduced.

Claims8

Dependent claims

A forced commutation power converter arrangement in reverse voltage free circuit configuration comprising:

positive and negative direct current input terminals and an output terminal;
a pair of series connected capacitors connected across said positive and negative input terminals and also to each other at a first connection point;
a commutation circuit composed of:
a first plurality of controllable current converter means arranged in parallel opposition and connected at one side to said first connection point;
a commutation capacitor connected to the other side of said controllable current convertor means;
a commutator choke connected between said commutation capacitor and a second connection point;
a load circuit connected across said positive and negative terminals, and composed of:
a second plurality of controllable current converter means connected between said inputs and said second connecting point;
a first plurality of non-controllable current converter means connected in parallel opposition to said second controllable current converter means;
and
two first chokes, each connected between one of said inputs and a respective one of said second plurality of controllable current converter means;
said commutator capacitor being connected between said first plurality of controllable current converter means of said commutation circuit and said pluralities of controllable and non-controllable current converter means of said load circuit;
and
a damping circuit connected between said commutator capacitor and said first plurality of controllable current converter means, and comprising a plurality of current converter means, so as to receive, through its plurality of current converter means, voltages supplied to said positive and negative input terminals of said power converter arrangement.

11 more elements

Dependencies are inferred from the claim text.