A zero-current-switching PWM flyback converter with a simple auxiliary switch

Author

Chung, Henry Shu-Hung ; Hui, S.Y. ; Wang, Wei-Hua

Author_Institution

Dept. of Electron. Eng., City Univ. of Hong Kong, Hong Kong

Volume

14

Issue

2

fYear

1999

fDate

3/1/1999 12:00:00 AM

Firstpage

329

Lastpage

342

Abstract

A simple and effective approach of turning an isolated hard-switched converter design into a soft-switched one is presented. By adding an auxiliary winding, switch and small capacitor to the conventional pulsewidth modulation (PWM) isolated flyback converter, all switches and diodes are softly turned on and off. No extra active or passive voltage clamp circuit is needed to suppress voltage stress on the switching devices that were usually found in classical converters. A zero-current-switching (ZCS) PWM flyback converter topology with multiple outputs is analyzed and examined. The proposal inherently utilizes the leakage inductance of the “flyback” transformer to achieve ZCS of all switching devices. A complete steady-state DC analysis and the operating principle are described. The performance of an 80 W experimental converter prototype with dual-voltage outputs is included

Keywords

DC-DC power convertors; PWM power convertors; power semiconductor switches; power transformers; switching circuits; transformer windings; 80 W; PWM flyback power converter; PWM isolated flyback converter; ZCS; auxiliary winding; flyback transformer; leakage inductance; multiple outputs; operating principle; performance; simple auxiliary switch; soft-switching; steady-state DC analysis; switching devices; zero-current-switching; Capacitors; Circuits; Clamps; Diodes; Pulse width modulation; Pulse width modulation converters; Switches; Switching converters; Turning; Zero current switching;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/63.750187

Filename

750187