Increased edge rates and switching frequencies have led to higher efficiency and increased power density for dc-dc converter topologies utilizing wide band-gap (WBP) devices. These improvements in intended behavior come with a cost in the form of elevated EMI profiles and higher magnitude CM currents, which cause challenges in fielded systems. Therefore, there is an increasing need to model the CM behavior for these systems and provide efficient EMI mitigation techniques. A method to decompose a system’s mixed-mode (MM) behavior into its differential-mode (DM) and common-mode (CM) behavior is utilized in this thesis. This thesis analyzes the role of filter inductor asymmetry in decreasing emissions in common dc-dc converters while preserving the intended behavior of these systems.
The proposed decomposition method is applied to buck and boost converters. This method produces common-mode equivalent models (CEMs) that provide simplified expressions for the CM behavior of systems. CEMs are developed for both simplified and practical implementations of the considered topologies. Analysis of these CEMs reveals that both converters demonstrate similar CM behavior trends for the simplified models but exhibit different CM behavior trends for the practical models. Two prototype buck converters are then utilized to empirically validate the CEMs for this topology. A low-power prototype is utilized to validate the simplified model. This example demonstrates the necessity of considering high-frequency voltage ripple to accurately represent the CM behavior of this topology. A high-power prototype is utilized to validate the practical model. This example demonstrates the sensitivity of a fielded system to unintended couplings with the grounding network.
|Commitee:||Brovont, Aaron, Freeborn, Todd|
|School:||The University of Alabama|
|Department:||Electrical and Computer Engineering|
|School Location:||United States -- Alabama|
|Source:||MAI 82/1(E), Masters Abstracts International|
|Subjects:||Electrical engineering, Engineering|
|Keywords:||Common mode, Electromagnetic compatibility, Electromagnetic interference, Equivalent circuits, Power electronics|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be