Characterization of high-frequency time-domain e↵ects arising from the transmission line substitutions of reactive components in a buck converter

Abstract

The work presented in this dissertation is a continuation of a line of research that suggests that the energy storage components within a DC-DC converter may be a source of high frequency e↵ects in power converter circuits. It is shown that for physically large energy storage compo- nents, conventional models are insucient for modelling the e↵ects of these components and that a transmission line approach is required. Very little work has been done within switching circuits using transmission line theory for the primary components themselves, specifically re- garding the time-domian e↵ects of these components. A significant finding of this work is that it is shown that both in simulation and experimental results these components do indeed have a measurable e↵ect on the output of the converter. Furthermore, this dissertation explores time-domain quantification methods for these distributed e↵ects, and shows that the delay ratio between the transmission lines is a key parameter in determining the magnitude of the e↵ects. This work provides strong experimental evidence for the existence of distributed e↵ects occurring from energy storage components within a DC-DC converter, and indicates that this area of research is worth further investigation. Advancements into our understanding of the high-frequency operation of DC-DC converters have become increasingly rare, necessitating a new perspective. This work focusses on using transmission line theory to model energy storage components within a DC-DC converter, and investigating the e↵ects of doing so. The research firstly introduces the design, simulation and experimental evidence for inductors and capacitors using transmission line theory. In fact, it is shown that in order to accurately model a physically large reactive component, transmission line modelling is required. Thereafter, these components in a physically large form are then applied to a DC-DC buck converter circuit where it is shown that the converter manifests high frequency e↵ects that are not predicted by conventional models, but is adequately shown using transmission line models. The e↵ects of these components are then investigated, and it is shown that the delay ratio between the transmission lines is a key parameter in determining the magnitude of the e↵ects. This work provides strong experimental evidence for the existence of distributed e↵ects occurring from energy storage components within a DC-DC converter, and indicates that this area of research is worth further investigation.