EEVblog Electronics Community Forum
Electronics => Power/Renewable Energy/EV's => Topic started by: Le_Bassiste on June 07, 2017, 10:06:11 am
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browsing through many of the DC-optimizer raving articles, maxim seem to have invented the bee's knee with their cell-string optimizer/MPPT chip.
https://www.maximintegrated.com/en/products/industries/solar-energy.html (https://www.maximintegrated.com/en/products/industries/solar-energy.html)
took me a while to figure out that such a contraption would still live in the junction box, rather than being integrated into the PV panel itself, what the name is (somehow) suggesting. :palm:
so, what's the deal? anybody out there actually using it, or using PV modules that feature the maxim solution, or at least gave it a tear down for the heck of it? i wonder why panel makers actually would break out all of the cell strings rather than just the internal DC bus, as more
conections to the outside world could mean an impact on long-term reliability. and, besides of that, optimizers did exist before, using dead-cheap microcontrollers for PWM and MPPT, that could be used (i.e., cloned) for cell-string level optimization as well.
why is there such a hype around this particular part that seems to be non-existent, even on maxim's website?
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Typical semi company flyer, see what interest there is from anybody big out there then maybe design the part!
Notice NO data sheet, not even a physical description beyond integrate it in your module.
Probably will never be available as a component you can buy in less than 10K quantities and that's if they decide to design it at all.
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Hi guys,
My first post to this forum.
I was also looking for this Maxim chip late September last year.
I have some special 2.6 watt CIGS cells to assemble and will use them in the strings.
The initial two chip numbers from Maxim integrated VT8012 and VT8020 chips.
However only one has been available now = VT8020EQD-D01.
[Update: there is also this one - VT8020FQX]
Hope this helps, although it has been frustrating for me to get any one to sell some of them.
Minimum order direct from Maxim is 40.
Interesting report here -->> www.nrel.gov/docs/fy14osti/62024.pdf (http://www.nrel.gov/docs/fy14osti/62024.pdf)
Cheers,
JRM.
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Something odd is going on when you can't get a datasheet for a chip.
I'm interested in more discussion about it. It claims to be a "highly integrated DC-DC converter". So it requires a fairly large inductor?
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it depends on what you would consider being a fairly large inductor, either mechanically or electrically.
in an application like a solar PV dcdc-optimizer, the inductor would fit into a matchbox volume-wise, the inductance value dependendant on the output voltage of the solar PV panel and the inductor ripple current that the designer would shoot for, maybe a couple of 100 µH.
interesting that the VT8024EQD-C01 was already EOL-flagged on the ground of being not lead-free. wonder what the non-leaded part number is, then.
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the inductor would fit into a matchbox volume-wise, the inductance value dependendant on the output voltage of the solar PV panel and the inductor ripple current that the designer would shoot for, maybe a couple of 100 µH.
A couple of hundred uH at 10 amps would be several matchboxes in size so I think not. To get the size of the inductance down the would have to switch at quite a few Mhz and then there's the issue of EMC compliance filtering!
I see there is a panel manufacturer mentioned on there site incorporating these parts, the nrel report doesn't seem to do it any favors, very limited gain in the off season only.
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TIGO Maximizer
http://www.interpv.net/tech/tech_view.asp?idx=564&part_code=010050014&page=2 (http://www.interpv.net/tech/tech_view.asp?idx=564&part_code=010050014&page=2)
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http://www.ti.com/lit/ds/symlink/sm72442.pdf (http://www.ti.com/lit/ds/symlink/sm72442.pdf)
This chip is still available and looks like it is similar.