Topology for 1KW DC-DC converter

[Aucosticraft]

I need 1KW 350VDC at the output and input of 24-28VDC. I thought a lot on this, but could not zero down any topology. I feel following are ok.

1) Full Bridge (H-Bridge) : but then better is the losses from two transistors is lowered to single. as input voltage is comparatively low.

2) Pushpull: this seems fairly ok. but still not sure.

Also on net I read that dual stage conversion gives better result. I don't know what is this about.

or any other topology would make more sense? pls suggest.

 

[wally7856]

You can get some ideas from here.

http://www.st.com/internet/com/TECH...AL_LITERATURE/APPLICATION_NOTE/CD00201961.pdf

 

[Aucosticraft]

Thanks wally

 

[Tahmid]

I would suggest using full-bridge at this power level to prevent chances of any damage due to slight mismatch between the two push-pull windings. However, if high side drive or the increased MOSFET counts presents a problem, push-pull may be used even at this power level. Ensure symmetry between the two push-pull windings.