POWER CONVERSION DEVICE

摘要

A power conversion device includes transformers provided with primary windings connected to input terminals and secondary windings including pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells connected to the secondary windings of the transformers; and a control circuit for controlling ON/OFF of switching elements. The converter cells are each include a converter and the inverter that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers, to the input terminal of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal of each phase, to thereby perform three or more-level power conversion.

主权项

1. A power conversion device which performs power conversion between input terminals of multi-phase AC and output terminals of multi-phase AC, comprising:
a voltage-transformer device including primary windings connected to the input terminals and secondary windings comprising pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells including switching elements, in which their input ends are connected to the respective single-phase open windings, and their output ends are connected in mutually serial fashion to the output terminal of each phase, said converter cells each performing conversion between a single-phase AC and another single-phase AC; and a control circuit for controlling ON/OFF of the switching elements; wherein the converter cells each comprise: a capacitor series connection; a converter that converts a single-phase AC voltage from the input ends into a three or more-level DC voltage and outputs it to the capacitor series connection; and an inverter that converts a DC voltage from the capacitor series connection into a single-phase AC voltage and outputs it to the output ends.