<i>Z</i> -source-based multilevel inverter with reduction of switches

Abstract

This study presents a new inverter topology based on mixture of cascaded basic units and one H-bridge unit. The basic unit includes one Z source, one DC voltage source and two switches generating two voltage levels. The cascaded basic units produce positive and zero-voltage levels and in the same time suggested inverter obtains positive, zero- and negative voltage levels, as a result the number of power semiconductor switches is reduced with respect to traditional multilevel inverters. In this topology, output voltage amplitude is not limited to DC sources voltage summation similar to traditional cascaded multilevel inverters and can be boosted with Z network shoot-through state control; therefore other DC/DC converters are not needed and it is more reliable against short circuit. Besides as compared with traditional Z-source inverter, total harmonic distortion of injected voltage is decreased in the suggested inverter topology. The performance of proposed topology and its controller are validated with simulation results using MATLAB/SIMULINK software and the validity of the proposed multilevel inverter-based Z source is verified by experimental results.