Performance investigation on Quasi Z source cascaded multilevel inverter for PV system

Abstract

The continuous increase in power demand leads to the attraction of alternative green energy sources. Photo Voltaic (PV) power generation is one of the most promising renewable green energy technologies used as an alternative source of power. The integration of PV to the load requires the support of power electronic converter for performance enhancement. The complications in power electronics converters are rapidly evolving, as their applications are extensively used with the stand-alone/grid-based systems. This complexity can be minimized by developing a topology with the combination of Quasi Z-Source Cascaded Multilevel Inverter (QZS-CMI). Because, it has the benefits of boost up voltage in single stage and it generates high-quality output voltage waveform with improved reliability. In this research work, the emerging applications and the trends of this proposed inverter to PV power generation are discussed. The different levels of operations of QZS-CMI inverters are simulated. The simulation results are analyzed based on power loss and efficiency. The seven level QZS-CMI offers quality power. This seven level QZS-CMI configuration has been developed with three H- bridges connected in cascade (namely upper and lower H-bridges).The upper inverter operates at high switching frequency capable of developing a twolevel output. The other two inverters develop multilevel output and they operate at fundamental switching frequency. This seven level QZS-CMI analysis has been carried out by various Pulse Width Modulation (PWM) control techniques such as phase disposition, phase opposition disposition, alternate phase opposition disposition PWM and carrier overlapping PWM. newline