Nine-level Inverter based Solar Power Generation for Micro Grid Application

Abstract

This paper mainly focuses on to design a nine- level inverter for power generation using solar system to produce a nearly sine wave with reduced total harmonic distortion. The input from PV array is boosted using a dc-dc boost converter and fed into the nine-level inverter as three independent voltage sources. The capacitor selection circuit converts the three output voltage sources into a four-level dc voltage and it is further converted into nine-level ac voltage by full bridge converter. Hence the proposed system generates a sinusoidal output which is in phase with the utility voltage. The advantages of the proposed system is, it uses only nine power electronic switches, which results in reduced voltage stress and reduced total harmonic distortion without using any filter in utility side. Whereas, traditional system uses 16 power electronic switches and four independent dc voltage sources to produce a nine-level output voltage. By using minimum number of power electronic switches, the proposed system is compact and robust. Keywords: Capacitor Selection Circuit, Nine-level AC Voltage, Nine-level Inverter, Sinusoidal Output, Total Harmonic Distortion