Title page for ETD etd-093099-111035

Type of Document

Master's Thesis

Author

Qu, Dayu

Author's Email Address

dqu@vt.edu

URN

etd-093099-111035

Title

EMI CHARACTERIZATION AND IMPROVEMENT OF BI-DIRECTIONAL DC/DC CONVERTERS

Degree

Master of Science

Department

Electrical Engineering

Advisory Committee

Advisor Name	Title
Dr. Jason Lai	Committee Chair
Dr. Alex Q. Huang	Committee Member
Dr. Dan Y. Chen	Committee Member

Keywords

L-type converter
bi-directional DC/DC converter
electric vehicle
soft-switching
full-bridge converter
EMI

Date of Defense

1999-09-14

Availability

restricted

Abstract

A worldwide awareness of the environment is
accelerating fuel cell vehicle development.
With respect to power electronics, special
requirement is on the development of high
efficiency, high voltage ratio bi-directional
DC/DC converter for fuel cell energy system
management.

In this paper, two bi-directional DC/DC
converters, which are developed for Ford Motor
Company's fuel cell vehicle, are compared from
different aspects. Comparison is concentrated
on the circuit topology and EMI performance.
Emphasis is placed on soft-switch, hard-switch,
synchronized rectification, auxiliary start-up
winding and their effect on EMI performance in
this kind of isolated bi-directional converter.

Comparison includes circuits analysis and
test result. The EMI test setup is described.
EMI measurements are given and explained. EMI
solutions for bi-directional DC/DC converter
are discussed. An EMI filter is designed and
final test result is given.

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