Multilevel converter based intelligent universal transformer

Abstract

A multilevel converter-based, intelligent, universal transformer includes back-to-back, interconnected, multi-level converters coupled to a switched inverter circuit via a high-frequency transformer. The input of the universal transformer can be coupled to a high-voltage distribution system and the output of the universal transformer can be coupled to low-voltage applications. The universal transformer is smaller in size than conventional copper-and-iron based transformers, yet provides enhanced power quality performance and increased functionality.

1 . A power conversion device, comprising: 
 a multilevel converter configurable to convert an input waveform having a first frequency into a second waveform having a second frequency, wherein the second frequency is higher than the first frequency;    a transformer coupled to the multilevel converter and configurable to transform the second waveform from a first voltage level to a second voltage level, wherein the first voltage level is higher than the second voltage level; and    a switched inverter circuit coupled to the transformer and configurable to convert the transformed, second waveform into a third waveform for use with a power application.