Non-isolated high-frequency-link to feed auxiliary bridges of asymmetrical cascaded multilevel inverter

Asymmetrical multilevel inverters can generate very high number of levels in output voltage. However, power shared by lower voltage bridges is very small compare to the bridges with highest voltage. To optimize hardware implementation, these lower voltage auxiliary bridges are usually fed by the dc bus of the main bridge by using isolated converter. This paper proposes a non-isolated buck-boost converter to feed the auxiliary bridges. Motivation of this work is to reduce the number of switches and better passive element (inductor) utilization. Function of the proposed non-isolated power supply and its control is verified in MATLAB/Simulink.