Input and Output capacitor for BOOST Converter

Thread Starter

YoGMan

Joined Sep 20, 2017
76
Hello all.
I am designing a boost converter for solar panels (mppt). I have 10 mF capacitors (10,000 uF) only, which are more than the value I need.The lesser the voltage ripple , the better it will be for me. Can I use larger value capacitors or will a too large value affect other things than voltage ripple ?
 

fourtytwo

Joined May 2, 2017
33
You don't say what your panel power is but in general large capacitors are NOT good, the reason is they shunt the panel/s with a low impedance when insolation increases causing the MPP to be lower than it should be and when insolation reduces the capacitor supplies the load instead of the panel! You will also find your tracking algorithm will have to run very slowly due to the very slow time-constant meaning your will not be able to follow clouds or other dynamic shadows very well.

I for example only use a few uF of foil capacitors on a 1Kw array, the first converter that performs MPPT switches at 125Khz, it is then followed by more storage to support 50hZ AC loads.
 

BobTPH

Joined Jun 5, 2013
2,204
Too much capacitance will affect the response time. I.e. it will take a long time for the output to come up to the required voltage.

Bob
 
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