PERFORMANCE AND COMPARATIVE ANALYSIS OF HYBRID MULTILEVEL CONVERTER TOPOLOGIES

Abstract

In recent years, multilevel converters have found deeper penetration in industries due to its iitherent advantages over conventional two level converters. Many new topologies have been proposed in last decade as an improvement to conventional multilevel topologies. The present work includes the performance and comparative analysis of new hybrid multilevel converters. Basic features of conventional multilevel topologies are elaborated and their present status in industry is discussed. New hybrid multilevel topologies are discussed in detail and their performance for induction motor application has been evaluated. A comparison is presented between these topologies based on their harmonic spectrum, efficiency, switch count, number of levels and PlY. SPWM control scheme is used for harmonic reduction. An approximate SPWM method is discussed which requires low processing power and hence can be implemented using microcontroller. Hardware is developed based on symmetrical hybrid multilevel inverter and its performance is analyzed experimentally. 111