Single-Phase Three-Level Neutral-Point-Clamped Inverter Based on Modified Z-Source Network With Reduced Voltage Stress on Capacitors

Abstract

This article presents a new topology for single-phase three-level neutral-point-clamped inverter. The proposed topology uses a modified Z-source network that for the same boost factor has lower voltage stress across the capacitors in comparison to the traditional Z-source inverters. Therefore, this topology leads to a lower capacitor size as well as decreased cost. In this article, the different operating modes of the proposed inverter in steady-state are analyzed. Moreover, voltage stress across capacitors, voltage ripple of capacitors, and current ripple of inductors are calculated using dc and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\omega $ </tex-math></inline-formula> components analyses. Then, the proper values of inductors and capacitors are designed. The proposed inverter is compared with the traditional inverter topologies to show its advantages and disadvantages. The effectiveness of the proposed inverter is tested by using a laboratory-built prototype and simulation under MATLAB/Simulink environment.