Performance of cascaded multilevel inverter by employing single and three-phase transformers

Abstract

Among the mature multilevel converter topologies, cascaded multilevel H-bridge inverter is promising one which is an alternative for grid-connected photovoltaic/wind-power generator, flexible alternating current systems and motor drive applications. In this study, a cascaded multilevel inverter with low-frequency three-phase transformers and a single dc power source is proposed. This new topology aims to reduce the number of components and so reduce the complexity of the circuit. As three-phase transformer is employed harmonic components of the output voltage and switching losses can be diminished considerably. To evaluate its relative performance it is compared with the conventional converters. Computer aided simulations are performed through Matlab/Simulink and simulation results are presented to verify the performance of proposed cascaded multilevel inverter. Further it is validated with prototype experiments.