FPGA Control of Cascaded Multilevel Inverters: Implementation with Experiments

Abstract

The main objective of this paper is to design and development of a FPGA based cascaded multilevel inverter with reduced harmonic distortions on the output. Due to the increased usage of power electronic converters for processing the power, the power quality issues become the hot research topic in the recent past. As the power level increases, the voltage level is increased accordingly to obtain satisfactory efficiency. During the last decades, the voltage rating of fast switching high voltage semiconductors such as the Insulated Gate Bipolar Transistor (IGBT) has increased. Still, there is a need for series connection of switching devices. The multilevel power converter has shown growing popularity. The fundamental advantages of the multilevel converter topologies are low distorted output waveforms and limited voltage stress on the switching devices and hence the reduced electromagnetic interferences on the output waveforms. The main disadvantages are higher complexity and more difficult control but it can be overcome by using modern digital controllers. In this work, the performance parameters are analyzed with the developed prototype of a three phase cascaded multilevel inverter designed with digital controller for reduced power quality issues with induction motor drive experimentally with the options to use it for harnessing the renewable energy too. The main focus has been on the quality of output waveform and the result obtained with the developed experimental hardware s