ev controller
"high power DC DC converter 4kW ...96V to 200V
1) Push-Pull converter is best.
96V is moderate voltage for power FETs, Push-Pull has advantage of two low side switches (FETs).
2)full bridge only for forward converter?
Push-Pull has same performance as full-bridge with half the number of FETS.
4) have circuit design?
Circuit schematics of similiar power on the web.
5)forward converter can be used for step up? Yes. Output voltage depends on transformer winding ratio.
6)what is the most difficult part of this converter?
Transfomer design. Integrated magnetics (Planar transformers) may be the easiest since one needs only the cores. Since planar cores have high surface to volume ratio, better cooling allows higher frequency operation ... around 250KHz.
7)major loss = ? Generally losses are highest in the power FETs. However a good design balances losses across all of the power components.
8)Output rectification ... synchronous FETs.
At the output voltage and current levels ... synchronous FETs provide the best performance.
Good luck, hope this is not your first design at this power level.
Example current mode PWM controller:
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or a cascaded current mode controller:
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Planar transformer catalog at:
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Planar cores:
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http://www.ferroxcube.com/
Articles:
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