High step-up Z-source DC-DC converter with flyback and voltage multiplier

Abstract

Recently, because of the pollution problems of the fossil fuels, demand of renewable energy sources is increased. Solar panels and fuel-cells generate low voltage, therefore high voltage gain dc-dc converters are needed to boost their low output voltage to meet the inverters required voltage. Z-source converter has several advantages such as high voltage gain, isolated energy source from the load side, clamped switch voltage and positive output voltage polarity, therefore it is a suitable choice for high step-up applications. This paper presents a non-isolated high step-up dc-dc converter which is the derivation of z-source converter and has a higher voltage gain in comparison to the conventional converters. This advantage makes this converter a suitable choice for photovoltaic applications. Moreover, high boost voltage is obtained with low duty cycle and the energy of leakage inductances is absorbed so the efficiency is increased. A 100 W laboratory prototype to convert 24–300 V is implemented to verify the theoretical and simulation results.