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LibreSolar / mppt-2420-hc

MPPT charge controller with HS load switch and CAN bus
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Inductor saturation for 24V batteries #2

Open martinjaeger opened 3 years ago

martinjaeger commented 3 years ago

The inductor layout turned out to be too optimistic for full power (20A) in 24V systems. As the ripple current increases with the output voltage, the inductor is driven into saturation and the core gets too warm (>80°C).

We are currently doing further testing with a larger inductor wound around two stacked cores such that it will still fit to the PCB as it is now. Updates after testing will be posted here.

intrinsicaly commented 9 months ago

Did you mange to progress any further with this one?

martinjaeger commented 9 months ago

Yes, kind of. It works very well with larger inductor, but the board design would have to be updated to fit the inductor.

intrinsicaly commented 9 months ago

Is that something you are considering by any chance?

martinjaeger commented 9 months ago

Not at the moment, unfortunately. Have to focus on some paid-for projects first.

intrinsicaly commented 9 months ago

I appreciate that. Thanks for your works thus far.

intrinsicaly commented 6 months ago

Hi Martin, I note on your schematic pdf that you have 2 stacked ms-130060-2 cores. Is that in response to this issue of saturation or is this the original design?

martinjaeger commented 6 months ago

Two stacked cores is one possible solution. Another solution would be a larger core in general. The original design had only one core.

intrinsicaly commented 6 months ago

Thanks for that. I appreciate your time while you are busy with paid work. Would you be able to help this novice with some info from the design. Looking at the design schematic I can see that you are targeting 53uH for the inductor, 21 turns 27AWG 40 strand copper wire but I am unsure of the info below; VLon (V) and VLoff (V) and f(Hz)