Doctoral Dissertations


Lisheng Shi


"Dc-dc power electronic converters supplying electric power to digital processors, data centers, and telecommunication systems are required to exhibit a fast dynamic response in response to their instantaneous electric load variations. This requirement is becoming more and more stringent as the operating voltage of such loads is continuously reducing. This voltage level reduction has reached a point where conventional control approaches can barely meet the dynamic response demanded by such loads. In order to overcome this issue, several approaches focusing on the dynamic response improvement for dc-dc converters have been proposed in the literature. Unfortunately, most of them have at least one of the disadvantages including less dynamic response improvements, potential instability issues, electromagnetic interference problems, power stage complexity, controller complexity, significant additional cost, and large volume. In this dissertation, new approaches which are relatively simple and affordable have been proposed. The solutions proposed herein utilize different power stage buck type topologies in addition to applying new control schemes during load transients. More specifically, a new three-level flying-capacitor buck dc-dc converter, a new H-bridge enhanced buck topology, an extended buck type topology, and three new transient controllers are introduced. In addition to the proposed new approaches, a comprehensive survey of the existing strategies has been presented. Furthermore, one of the existing methods has been generalized and applied to other buck-type dc-dc configurations. Most of the work presented in this dissertation has been analyzed in theory and then verified via simulation models and experimental hardware. It is demonstrated that the proposed solutions can significantly improve the dynamic response of dc-dc power supplies"--Abstract, page iv.


Ferdowsi, Mehdi
Crow, Mariesa

Committee Member(s)

Chowdhury, Badrul H.
Corzine, Keith, 1968-
McMillin, Bruce M.


Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering


Missouri University of Science and Technology

Publication Date


Journal article titles appearing in thesis/dissertation

  • Review of dynamic response improvement approaches in dc-dc power electronic converters.
  • Studies on flying capacitor voltage regulation in three-level dc-dc power converters.
  • Dynamic response improvement in a buck type converter using capacitor current feed-forward control.
  • A novel transient control strategy for dynamic response improvement in buck type converters.
  • Dynamic response improvement in a new three-level buck type converter.
  • Dynamic response improvement in an H-bridge enhanced buck converter.
  • Unified charge balance controller and its applications in buck type converters.


xvi, 147 pages

Note about bibliography

Includes bibliographical references.


© 2010 Lisheng Shi, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Subject Headings

DC-to-DC converters -- Design
Electric current converters -- Stability
Transients (Dynamics)

Thesis Number

T 10176

Print OCLC #


Electronic OCLC #


Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Share My Dissertation If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the button above.