Available at: https://digitalcommons.calpoly.edu/theses/2988
Date of Award
5-2025
Degree Name
MS in Electrical Engineering
Department/Program
Electrical Engineering
College
College of Engineering
Advisor
Taufik
Advisor Department
Electrical Engineering
Advisor College
College of Engineering
Abstract
This thesis entails the design, modeling, simulation, construction, and analysis of a new isolated DC-DC buck-boost converter with Zero-Current-Switching (ZCS) operation, continuous input current, and a low-side switch to simplify driving requirements. The proposed converter was designed to regulate a 5V output from an input range of 15V-18V, at a rated output power of 20W, and a switching frequency range of 90kHz-500kHz. Software simulations are performed to develop a mathematical model that describes the converter’s modes of operation, as well as the current and voltage waveforms of the resonant power components. Results from hardware experimentation confirm that the converter effectively provides the desired 5V output voltage at different loads and input voltage values. Furthermore, the converter operating at nominal input voltage and full load conditions yields an efficiency of 59.88% and a peak-to-peak input voltage ripple of 2.91%. Hardware results also verify the ZCS property of the proposed converter, but the output voltage peak-to-peak ripple exceeds the expected performance due to the presence of voltage overshoot. Potential solutions to the ripple issue are discussed and evaluated along with recommendations for future improvements. Overall, the results of the study demonstrate the potential of the proposed converter as an isolated alternative to the conventional buck-boost converter.