Modulation Strategies of Multilevel Inverter

Multi Level Inverter (MLI) is a power electronic system that produces output voltage from several levels of DC input voltages. The attractive feature of this technology is mainly in the range of medium to high voltage application and offers a number of advantages when compared to the conventional two-level inverter. Multilevel inverters are used in power conversion system due to improved voltage and current waveforms. It is recently emerged as very important alternatives in high power medium voltage applications because of their advantage over the conventional one and their capability to reduce the undesirable harmonics. So that performance and efficiency of the system is improved. The concept of multilevel inverter is introduced with an aim to reduce switching losses and to obtain the output voltage with multiple steps to achieve the improved power quality and higher voltage capability. Multilevel inverters are used in high voltage AC motor drive, distributive generation, high voltage direct transmission as well as SVC applications.