Three-level three-phase quasi-Z-source neutral-point-clamped inverter with novel modulation technique for photovoltaic application

Abstract

This paper presents a three-phase three-level neutral-point-clamped quasi-Z-source inverter as a novel solution for photovoltaic applications. The topology was derived by combining properties of the quasi-Z-source networks with those of three-level neutral-point-clamped inverters. A case study system, a steady state analysis and a novel special modulation technique for shoot-through states distribution during the whole operation period are described. Component design guidelines for a three-phase system are presented. All theoretical findings have been confirmed by simulation and experimental results. A “full SiC” experimental prototype was developed. A comprehensive study of the converter's efficiency is provided.