Scalable multi-level power converter

Abstract

A multilevel power converter, or inverter, for converting a direct current electrical power to an alternating current electrical power includes one or more 2-level converters each including gallium nitride (GaN) transistors configured to switch two input lines to a three-phase output line. The multilevel power converter may be used in a motor drive circuit, which may provide a 3-phase AC supply. Two power converters, which may be 2-level or 3-level power converters, may be alternately switched to provide the AC power to an AC motor by an output stage including bi-directional switching transistors configured to switch a corresponding three-phase output lines from the multilevel power converters. The multilevel power converters switch input lines from a neutral-point clamped input stage including capacitors connected in series across input terminals having a DC voltage therebetween to energize a midpoint terminal with an intermediate voltage half of the voltage between the input terminals.

Description

[0001] Cross References to Related Applications [0002] This PCT International Patent Application claims the benefit and priority of U.S. Provisional Patent Application Serial No. 62 / 681,244, filed June 6, 2018, entitled "Scalable Multi-LevelPower Converter," the full disclosure of which U.S. Provisional Patent Application The contents are incorporated herein by reference. technical field [0003] The present disclosure generally relates to multilevel power converters for converting direct current (DC) power to alternating current (AC) power. More specifically, the present disclosure relates to such multilevel power converters for motor drive circuits. Background technique [0004] This section provides background information related to the present disclosure which is not necessarily prior art. [0005] Motor drives—also known as variable frequency drives (VFDs)—are used in a variety of applications to provide alternating current (AC) power to electric motors. Motor driv...

AI Technical Summary

Problems solved by technology

However, IGBTs and MOSFETs are limited in how fast they can operate and typically cannot operate at frequencies above 10kHz to switch the high currents required for motor drive applications

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