Title :
Design and Manufacturing of Single-Switch Flyback Converter with Planar Transformer For
Practical Evaluating of Its Effect on the EMI of the Converter
Abstract :
Power switching converters widely are using in electrical and electronic systems. With developing
the equipment, needs for high efficiency and low volume switching converters are increasing day by
day. One-switched flyback hard switching converter has lowest quantity of element between the
other isolated switching converters and because of not having the inductor in output and also
absence of reset circuit for transformer, has suitable volume and price in proportion to the other
isolated. But main disadvantage of hard flyback switching converter is high stress voltage that
component must be tolerated. Using soft flyback switching converter is one of the solution for this
problem. However even with using soft switching method, large dimension of transformer and high
leakage inductance, large amount of capacitor between primary and secondary winding steel
influence on production of soft switching on decreasing stress voltage and EMI of converter. For
improving these parameters, it could be using planar transformer in soft switching flyback
converter, which mentioned in this thesis. On the other hand, the way of winding implementation in
this kind of transformers is very important. In this research is introducing some structure for
implementation of primary and secondary winding in soft switching flyback converter. For studying
the performance of offered structure, the soft switching flyback converter design and produce, then
volume and EMI of converter are evaluating. Also using common mode choke and faraday shield as
two way of EMI reducing consider with practical measurements. Practical results show that in
addition to impressive reduction of volume and mass of converter, converter's EMI decrease with
planar transformer. For the purpose of radiated EMI decreasing a shield place on just planar
transformer instead of whole converter. The mentioned item inspected in one of paper in recent
years witch in about soft ZCT flyback switching converter and considered the practical results.
Keywords :
ZCT Flyback Coverter, electromagnetic interference (EMI), Soft Switching, Planar Transformer