OPERATION AND CONTROL OF CASCADED H-BRIDGE MULTILEVEL INVERTER WITH PROPOSED SWITCHING ANGLE ARRANGEMENT TECHNIQUES

Abstract

Cascaded H-bridge multilevel inverter is one of the most promising inverter topologies for converting the DC output of renewable energy resources such as: photovoltaic power systems, fuel cells and solar thermal panel into AC power supply. It has received wide spread acceptability due to its capability to produce high quality output AC waveform with low switching frequency. However, cascaded H-bridge inverter topology is not capable of producing good output voltage AC waveform when switching angle arrangement techniques are not appropriately selected. Therefore, this research work has been performed motivated strongly by this key issue in this field of research to be resolved. In this paper, a new set of switching angle arrangement techniques have been proposed to obtain good quality output voltage and current waveform from cascaded H-bridge multilevel inverter. The validity and effectiveness of proposed switching angle arrangement techniques have been verified using a simulation of a cascaded H-bridge multilevel inverter with inductive load through PSIM software. Simulation results indicate that the output voltage and current AC waveform produced via proposed switching angle arrangement techniques have the lowest total harmonic distortion as compared to those produced by Equal-phase method and Half-equal-phase method.

Keywords

• Multilevel inverter
• Photovoltaic
• Power quality
• Switching angle
• Total harmonic distortion