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|Title: ||Research on a zero-current-switched (ZCS) isolated full-bridge boost converter with multiple inputs|
|Other Titles: ||Duo xiang shu ru ling dian liu kai guan ge li quan qiao sheng ya bian huan qi zhi yan jiu|
|Authors: ||Leung, Siu Wai (梁兆威)|
|Department: ||Department of Electronic Engineering|
|Degree: ||Master of Philosophy|
|Issue Date: ||2007|
|Publisher: ||City University of Hong Kong|
|Subjects: ||DC-to-DC converters.|
|Notes: ||CityU Call Number: TK7872.C8 L48 2007|
108 leaves : ill. 30 cm.
Thesis (M.Phil.)--City University of Hong Kong, 2007.
Includes bibliographical references (leaves 103-108)
|Abstract: ||This thesis presents a research on the zero-current-switching (ZCS) isolated
full-bridge (FB) boost converter with multiple inputs.
By connecting a simple auxiliary circuit, between the full-bridge input and the
input choke, in each module, the transformer leakage inductance and output capacitance
of the switching devices are used to create a quasi-resonant path for facilitating
zero-current-switching of all switching devices.
A new switching strategy for the auxiliary circuit used with the modular-based
structure will be discussed. The control only requires a simple control circuit. By
monitoring the low-side FB switches gate signals of the corresponding module, the
operation of the auxiliary circuit integrates into the FB circuit and each auxiliary circuit
operates independently among the modules. Thus, the operation of the multiple-input
structure will not be affected by the newly added auxiliary circuits, but, at the same time,
all switches become zero-current-switched.
The contents of this thesis are as follows.
In Chapter 1, an introduction on historical development of switching mode
power supplies will be given. An energy efficient burn-in process will be discussed. It
can save up huge amount of energy. A modular-based converter for the burn-in system
will be discussed.
In Chapter 2, a brief investigation on the characteristics of different
multiple-inputs DC-DC converter will be given. The advantages and disadvantages of
those converters will be studied and discussed. There are many requirements in
conducting burn-in process. Some critical characteristics of the multiple-inputs DC-DC
converter are needed to be considered.
In Chapter 3, a comparative study would be given on different methods that
converts hard-switched isolated full-bridge boost converter into a soft-switched one and
eliminating the effect of the unavoidable leakage inductance of the isolation transformer.
It will be shown that those discussed methods cannot be applied directly into
modular-based isolated full-bridge boost converter structure. Limitations of those
topologies will be discussed.
In Chapter 4, the proposed modular-based, zero-current-switching (ZCS),
isolated full-bridge boost converter with multiple inputs will be introduced. A new
control strategy to the auxiliary circuit will be introduced. Then, detailed steady state
analysis on the chosen modular-based structure including the proposed auxiliary circuit
will be given. Then, the calculation method of the soft-switching criteria will be given.
The value of all passive components can be determined by the maximum loading and
minimum loading condition. A 290W prototype including 2 modules with different
voltage and current input has been built to show the performance. Moreover,
experimental measurement results will be given to compare between the actual
performance and the theoretical predictions. The effectiveness of the proposed auxiliary
circuit on improving the conversion efficiency will also be studied.
In Chapter 5, an overall conclusion of the research topics and some suggestions
for further research will be given.|
|Online Catalog Link: ||http://lib.cityu.edu.hk/record=b3947933|
|Appears in Collections:||EE - Master of Philosophy |
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