Advisor: Dr. Mehdi Ferdowsi
Dr. Pourya Shamsi
Date & Time: Monday October 09, 2023 at 11:00AM
Abstract: This thesis is focused on developing and analyzing new high voltage gain DC-DC power electronic converters. The proposed converters in this dissertation are suitable candidates for connecting low voltage sources such as photovoltaic (PV) panels or fuel cell (FC) stacks to a DC microgrid or DC link of an inverter. The proposed converters provide desired characteristics such as high voltage gain at a low or medium duty cycle values, low voltage stress on power semiconductors, and continuous input current. Initially, the research introduces three novel converter topologies: First, two quadratic converters based on the combination of a three-winding coupled inductor (CI) and voltage multiplier cells (VMC) are proposed. Due to the quadratic voltage gain function, these converters can provide a very high voltage gain at a low duty cycle. Second, a dual-switch converter based on the integration of a switched-capacitor (SC) cell with a three-winding CI is proposed. Because of the SC cell used in this topology, a very low voltage stress appears on the power switches of this converter. Third, an impedance-source-based converter using an active clamp is proposed. Unlike the conventional CI-based converters, in which higher voltage gain is achieved by using a higher turns ratio for the windings of the CI, this impedance-source-based converter can achieve substantial voltage gain with lower turns ratios. Finally, a general method for analyzing single-switch step-up DC-DC converters with an output inductor and different SC cells is presented. The steady-state analysis, design guidelines, and detailed comparisons between the proposed converter and existing converters are covered in this research. Additionally, to validate the theoretical analysis, 200W – 300 W benchtop experimental prototypes are developed for each converter.