boost converter problem

[savage67]

Hi dears.
i will design a 36 to 280 V 700W boost converter. to control it i will use attiny861 8 bit mcu. but i know that regulation will be very hard. 60kHz and 8bit PWM is not capable of controlling this boost converter.because max and min duty cycle rates for max and min loads are in a very narrow region. for example Dmin =0.8 Dmax=0.85.

Is there any one who has experiences on boost converter.

I must use a mcu because i will use a mppt algorithm.
Please help me.

 

[Tahmid]

Hi savage67,
36 to 280v means a Vout/Vin ratio of (280/36) = 7.8. Power rating = 700W. With these things in mind, boost converter isn't a wise choice at this power level. You should instead use push-pull or full-bridge topology. If you have the proper program, use attiny else you can use a cheap easily available PWM chip like SG3524 / SG3525 / SG3526 / TL494 / TL594 / UC3846 / LM5030 and many others. I've had great success by using SG3525 and push-pull topology.
Hope this helps.

 

[powerpratik]

Hi Dear.
you want to do jusy 7.8 times high output.
Do u think about input current? its too high.
if you only double the o/p from i/p the duty cycle of the PWM is about 0.5.
in your case it is too high.
And size of inductor and capacitor is also too high....
Hope this helps.