250W boost converter

[dhan_pow]

Input votage range: 30 to 40V from a battery
Output requirement: 50V, 5A
Please suggest the optimum topology,operating frequency and type of core to achieve good efficiency with minimum space requirement.

i built one pushpull with mosfet switches, operating frequency 100kHz and a ferrite toroid core.But even at 2.5A load, I m getting efficiency of 65% only.

 

[BradtheRad]

Do your waveforms resemble this simulation?

Notice upwards of 20A peak being drawn from the supply. The inductor needs to carry 19 or 20A without saturating.

The smoothing capacitor needs to withstand pulses of 13A. A bank of capacitors is a good idea.

The above figures can be reduced slightly if you go further into CCM.