Guru
Joined: 26/01/2019
Location: United StatesPosts: 408
| Posted: 09:06pm 22 Mar 2019 |
Thank you Andrew, Tony. There is a significant possibility that my inexperience and naivety is moving me in this direction.
Yes, I intend to series connect 3x 300 Wpp, 30Vmpp, 9A Isc panels.
This specific boost convertor has a suicidal design where it does not monitor the maximum current that can flow through it to maintain load regulation.
So, on startup if the load draws enough current to cause a heavy draw from the input, AND the source can oblige, this specific boost convertor will happily go along even if the di/dt exceeds its nominal values in a misguided attempt at load regulation.
This of course makes this specific boost convertor go boom very easily.
Additional current sensing circuit might mitigate this challenge?
Now, this is not of consequence, I don't think, if PV Panels are connected to this boost convertor directly: PV Panels naturally limit current so as long as Isc < nominal Imax of the MOSFET + Diodes, I think we should be fine.
However, this excludes an alternate design that Tony suggested that hooks up a capacitor bank to the PV Panels that really addresses power point hunting very simply.
Tony's design of a capacitor bank goes very nicely with a transformer based step up (boost?) convertor though.
So if this boost convertor adventure turns bad, I will have to start learning about transformers, how they work, how to wind them, test them etc.
For now, transformer cores are really turning out to be a real issue. The ones on eBay are not only expensive (shipping can exceed cost of transformer) but they are not spec'd properly.
The companies that sell transformer cores with nice datasheets want hundreds of dollars for a 1kVA capable core.
So for me, the route would be to use less expensive salvaged cores but that requires me to figure out specs by running tests on them, which I am currently not equipped to do (although it's on my TODO list).