Abstract
This paper developed a novel quad-inverter
configuration for multilevel six-phase asymmetrical open-winding
AC converter. Proposal found to be suited for (low-voltage/highcurrent)
applications such as AC tractions and ‘More-Electric
Aircraft’ propulsion systems. Modular power circuit comprises of
standard four three-phase voltage source inverter (VSI) and each
connected to the open-end windings. Each VSIs are incorporated
with one bi-directional switching device (MOSFET/IGBT) per
phase and two capacitors with neutral point connected. Further,
an original modified single carrier five-level modulation
(MSCFM) algorithm is developed in this work and easy for
implementing in real digital processors. The proposed modulation
algorithm is capable of generating, 5-level voltages at each output
of four VSI as one equivalent to multilevel inverter. The total
power is among the four DC sources and quadruples the
capabilities of VSIs. A set of observed results is presented with
numerical software analysis (Matlab/PLECS) in balanced
working conditions. Always the results shown good agreement in
the developed theoretical background.