软开关的双管正激电源设计方案.pdf

Quasi-ZVS Active Auxiliary Commutation Circuit for Two Switches Forward Converter J.E. Baggio, L. Schuch, H.L. Hey, H.A. Gründling, H. Pinheiro, J.R. Pinheiro Federal University of Santa Maria CT / NUPEDEE / GEPOC 97105-900 – Santa Maria – RS – Brazil e-mail: josebaggio@ieee.org, renes@ctlab.ufsm.br Abstract: This paper presents a family of single-ended process. converters that adequately designed and commanded can The effects associated to these three factors are minimized perform ZVS turn-off and turn-on with a value near to zero by the use of zero voltage switching. However, some circuits namely Quasi-ZVS (QZVS) at main switches. The auxiliary do not operate with ZVS in all operation conditions. Even if circuit presents low reactive energy and is composed of one the voltage across the switch do not reaches zero, an inductor, one diode and one switch, which operate with ZCS. To demonstrate the feasibility of the proposed technique, it is improvement of the converter performance can be obtained, applied to a two switches forward converter. It is not necessary by using auxiliary circuits that reduce the voltage to values the use of a third winding in the transformer neither auxiliary near to zero. This is the basic