DESIGN AND HARDWARE IMPLEMENTATION OF MULTILEVEL INVERTER

Abstract

An inverter is utilized to transform a DC source into an AC source using power electronic components. It can be achieved using two types of inverters, one is two level inverter and another is multilevel inverter (MLI). MLI has been implemented in various applications, such as motor drives, power conditioning devices, renewable energy generation and distribution. PWM inverters can simultaneously control output voltage, frequency and it can reduce the THD content in output waveform. This project aims in the study of different MLI topologies, primarily focused in the study of Cascaded H bridge (CHB) and Switched Capacitor MLI (SCMLI). Several multilevel topologies have been developed, but as the output voltage level increases, it also increases the number of switches, switching stresses, losses and voltage unbalancing across the capacitors, etc. CHBMLI is more efficient compare to the other topologies of multilevel inverter but not as efficient as Switched Capacitor MLI. SCMLIs are the most widely used because of self-voltage balancing and voltage boosting over conventional ones with reduced number of DC sources.