Design, Simulation and Implementation of a High Step-up Z-source DC-DC Converter with Flyback and Voltage Multiplier

Abstract

Nowadays, because of pollution problems of the fossil fuels and their unpleasant effects on the earth planet and people life, renewable energy sources such az photovoltaic (PV) cells and fuel cells are considered to produce electrical energy. These sources directly convert solar energy and chemical energy to electrical energy, respectively. Since the output voltage of PV cells is low, a high step-up dc-dc converter is needed to increase this low voltage to meet inverter input required voltage.

In this thesis, a novel high step-up dc-dc converter (which is the derivation of z-source converter) is introduced. This converter has a higher voltage gain in comparison to the conventional converters. This advantage makes this converter a suitable choice for high step-up applications, such as boosting the low output voltage of solar panels. Also, by choosing appropriate turns ratio of the coupled inductors, the proposed converter can be used for a wide range of voltage gain.

First, the z-source converter is analyzed and the conventional high step-up converters are discussed. Then, the new high step up converter is proposed and analyzed. The converter is simulated and the results are compared to the theoretical results. The proposed converter is then experimentally tested. The experiment results verify the theoretical and simulation results. Finally, the proposed converter is compared to the conventional ones and it’s advantages such as having higher voltage gain are confirmed.