Power conversion device

摘要

A power conversion device connected with a three-phase power system through a transformer, including unit converters cascade-connected so that reactors are unnecessary, and volume and weight are reduced. The secondary winding of the transformer is an open winding having six terminals. A first converter group, includes a circuit which has three converter arms, which are star-connected, connected to three of the terminals of the secondary winding. A second converter group, having three different converter arms which are star-connected, is connected to three other terminals of the secondary winding. A neutral point (the point where the star connection is made) of the first converter group, and a neutral point of the second converter group are made to be the output terminals of the power conversion device.

主权项

1. A power conversion device comprising at least three series circuits in parallel with each other, each comprised of a voltage source and a controlled current source, connected in series,
wherein the at least three series circuits of the voltage source and the controlled current source are connected in parallel, and parallel connection points of the series circuits connected in parallel form output terminals, and wherein: in each of the at least three series circuits, the voltage source includes a secondary winding of a transformer, the secondary winding including a first winding and a second winding; the transformer includes a primary winding which is connected to an alternating current power system; the controlled current source is comprised of a plurality of unit converters cascade-connected to one another; and the secondary winding is wound on an iron core of the transformer so as to have a first magnetomotive force cancel a second magnetomotive force to suppress a direct current bias magnetism of the iron core, the first magnetomotive force being generated by a direct current component of a current flowing through the first winding, and the second magnetomotive force being generated by a direct current component of a current flowing through the second winding.