Conversor multinível baseado na interconexão em cascata de conversores de três braços.

Abstract

In this work, topologies of multilevel converters are studied and compared.The topology presented here is a generalization and its structure is formed by the interconnection of cascade three-leg converters. This topology has some advantages over conventional topologies for three-phase converters, such as those formed by the cascade H-bridge, as it permits to reduce levels of currents and voltages on switches, the THD currents, the WTHD voltages and losses on semiconductors switches. Other advantages include the ease of interconnection of the modules that make up the structure of the converter, easy maintenance, good fault tolerance and application in high voltage and current systems. Dynamic model of the system is presented and two PWM strategy (Level-Shifted PWM and Interleaved PWM) are used to control the switches in order to generate the reference voltage desired. Comparisons in terms of harmonic distortion and semiconductor power losses, between proposed and conventional cascade H-bridge have been carried out. Simulation results obtained by MATLABR are shown.