Review on Different Methodologies of DC‐AC Converter

Abstract

This chapter reviews different methods of converting from DC to AC. This elaborates on single phase multilevel inverters (MLI) which have more advantages over conventional two level inverters. The necessity of pure energy and saving energy has caused a sudden increase in power generation and use of variable speed drives (VSD). Controlling the speed and torque of variable speed drives is very much necessary to increase efficiency of conversion. MLIs are the better choice compared to two level inverters, while conversion from DC to AC for different applications like Flexible AC transmission systems (FACTS), Variable speed drives, renewable energy power generation, and for utility applications. Presently, MLI plays a major role in DC-AC conversion. Various topologies are involved in improving overall efficiency of conversion, they are: diode clamped, flying capacitor, cascaded, and new hybrid MLIs are the important topologies used in various applications. This chapter explains various aspects of these topologies with respect to operation and switching pattern. It gives a detailed structure of new hybrid MLI topology for nine level operations using a stepped wave modulation technique. With the use of the stepped wave modulation strategy used in the MLI network, it is possible to achieve low Total Harmonic Distortion (THD) in the output waveform without using a filtering device. This chapter also elaborates the comparison of new hybrid MLI topology with other topologies that include cascaded, flying capacitor, and diode clamped MLI topologies. Nine levels are produced using two different input voltages in new hybrid MLI. It gives more quality output waveforms by giving more levels than other MLIs.