Comparative analysis of DC-DC converters for photovoltaic maximum power point tracking applications

Abstract

Photovoltaic can be termed as a method to convert light into electricity at the atomic level, a photovoltaic material exhibits a state known as the photoelectric effect which causes them to absorb photons of light and release electrons. Due to larger demand of clean energy, this has led to the improvement of solar energy power generator device which is known as the solar panel. Solar panel comprises of multiple solar cells that convert sunlight into DC voltage, this output voltage or power is unstable due to several factors such as partial shadow, internal resistance, manufacturer defect and lots more. Therefore, undesirable factor that affects the output of solar module can be controlled by regulating the power output using maximum power point tracking algorithm. There are several methods for MPPT algorithm. The DC-DC converter is one of the most important electronic devices. Buck converter can be used to step down the output voltage, while the boost converter can be used to step up the output voltage. SEPIC and buck-boost converter can be used to step up or step down the output voltage. The main focus in this project is to compare between the converters in terms of tracking maximum power point MPP independently on the environment conditions. Solar module, SEPIC, buck, boost and buck- boost converter are all developed with MATLAB Simulink using SimPowerSystem Library. The result of this study indicated that, SEPIC converter is the most suitable converter for MPPT algorithm as a DC-DC power controller circuit because the SEPIC converter overcomes two limitations, first is non-operational region that appears in buck and boost converter. Second limitation is negative output voltage that appears for buck-boost converter. Also this work proved that the best converter which can work with high efficiency is SEPIC converter.