Comparison of nonisolated dc-dc converters from the efficiency point of view

Abstract

In order to define the most appropriate power electronic converter topology for a specific application, several aspects must be analyzed, such as cost, efficiency, size, and volume of the chosen structure. However this may not be a trivial task in converters with high number of active and passive switches. This work introduces the concept of commutated power applied to six nonisolated dc-dc topologies, that are: buck, boost, buck-boost, Cúk, SEPIC, and Zeta. The study carried out on the paper intends to establish qualitative criteria to determine which type of converter is the most adequate one for a given application and the chosen operating point. Besides, it aims to validate the theoretical assumptions by calculating the conduction and switching losses in the semiconductor devices properly. By using SPICE modeling and related simulation software, the performance of each one of the aforementioned converters is evaluated from the energy efficiency point of view.