Design analysis and implementation of embedded type switched boost multilevel inverter with reduced switches for pv interfacing

Abstract

With the constant usage of fossil fuels and their severe impact on the newlineenvironment, demand for energy from renewable resources such as solar, newlinewind, tides, biomass, etc., has reached a new high. Among such alternative newlinesources, the photovoltaic (PV) solar energy conversion system has developed newlinefrom being a niche in market applications into a mature technology used for newlinemainstream energy generation. Virtually inexhaustible, its advantages also newlineinclude the production of clean and reliable energy leading to improved newlineenergy security, diversity in energy supply, and lessening the dependency on newlineimported fuels. Despite the growth, solar energy conversion is restricted by newlinethe impact of environmental factors that affect the overall efficiency of the newlinesystem. Partial shading is one of these factors, which results in a reduction in newlinethe panel s photocurrent. A significant impact of partial shading comes from newlinethe array interconnection where series connected strings are more susceptible newlineto shading than parallel connected panels. Hence in this work, a more robust newlineconnection, a series-parallel type PV array with shorter series strings is used, newlinethat lessens the effects of partial shading to the array. But in such cases, the newlinePV array supplies the required power with low voltage and high current, newlinehence a high gain converter is required. Generally, various types of multi-stage and single-stage converters are being developed to boost the output voltage of the PV system. Z-Source Inverters (ZSI) were proposed to overcome the problems of the conventional voltage and current source, as they provide buck-boost characteristics. It consists of an X-shaped impedance network with two inductors and two capacitors to couple the main power converter and the power source. problem of inverter leg short circuits. It can increase or decrease the output voltage and does not use any time delay in turning on the power switches; hence making it highly reliable for applications requiring high output gain, as in cases of renewable source interfaces. In recen