Reduction of Circuit Devices in Developed Symmetrical/Asymmetrical Multilevel Converters

Abstract

In this paper, a developed configuration for multilevel voltage source inverters (MVSIs) is proposed. The proposed topology can be used as symmetric and asymmetric inverters. In asymmetric mode, DC source magnitudes are defined in a way that the number of output levels gets more than the case when the symmetrical DC sources are applied. In this regard, to calculate the required magnitudes of DC voltage sources several different solutions are proposed. In multilevel inverters, the overall costs, circuit size and installation area, complexity of control scheme and reliability are directly dependent on the number of circuit devices needed. The provided comparison study among suggested inverter in all defined solutions, cascaded H-bridge (CHB) and recently proposed converters, validates that the proposed inverter uses reduced number of circuit devices. The given simulation results confirm the feasibility of the proposed modular structure. Also, to approve the practicability of the proposed inverter, a prototype of the proposed topology has been implemented. Finally, simulation and experimental results are compared with each other and the provided comparison shows that the obtained results are in good agreements.