Abstract:
This work presents a three phase, nine level, switched-capacitor based H-bridged
multilevel inverter topology. The presented inverter configuration is capable of
synthesizing five output voltage levels with a single isolated DC voltage source per phase.
The power circuit configuration is a modification of the conventional H-bridge inverter by
the addition of an auxiliary circuit. This auxiliary circuit consists of two active power
switches, a diode and a capacitor. Proper control of the consisting elements in the auxiliary
circuit generates existing input voltage across the capacitor bank; so that two isolated
voltage sources are impressed across the H-Bridge. The resultant effect of this is the
synthesis of multilevel output voltage waveform whose peak value doubles that of the
single DC source per phase. The multiple carrier, in-phase disposition, pulse width
modulation scheme is used to generate the gating signals for the power switches. The
validity of the system is verified through MATLAB/SIMULINK simulations and
experimental results. The three phase design presented herein is rated 2kW, with an input
DC voltage of 100V and peak phase and line voltage values of 200V and 400V
respectively
