New Multilevel Current-Source PWM Inverter with Full-Bridge Inductor Cells

Abstract

This paper proposes a generalized circuit configuration of a new multilevel current-source inverter (CSI). In this new topology, a three-level CSI of which all the power switches are connected at an identical potential level line works as a main inverter circuit, and inductor cells are connected in parallel with the main inverter as auxiliary circuits. The inductor cells are composed by full-bridge power converters with inductors across the bridges. The inductor cells work to generate intermediate level currents of the output to obtain a multilevel current waveform without any additional external DC power sources. Five-level and nine-level PWM inverter configurations, including their chopper circuits as DC current-power sources, are verified through computer simulations. Furthermore, an experimental prototype of a five-level CSI is setup and is tested. The results show that the circuit works properly to generate the five-level output current waveform, which proves feasibility of the proposed strategy.