150V 45A MPPT - roll your own


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poida

Guru

Joined: 02/02/2017
Location: Australia
Posts: 1400
Posted: 08:19am 31 Mar 2020      

  wiseguy said  Sorry Poida I missed 2 places 1 above the spec & 1 below where you have already ordered 5 x PCBs.  Note to self: do not read too hastily & before my first coffee.

When I skimmed the subject I thought the Spec was also aimed at hardware & a suitable topology selection - I know you will soon sort out the software.

When the software is ready I look forward to applying it to my hardware to try out.

Can I confirm that your MPPT scheme assumes VPanel is higher then VBatt so boost is not required ?


Mike, for sure the idea is to take a solar array of voltage well bigger than the battery. I view a reasonable design of a solar array/CC/inverter/battery to have the solar array about 50 to 100% larger voltage than the battery.
Why?
The high voltage let's you use thinner wire from array to CC. In my case the cable run is 30 meters or more. I do not like I2R losses. I can live with marginal Rds(on) losses due to high voltage MOSFET choices.

The reason for MPPT is to produce a design that can take any and all used and abused panels we can buy for small$. Chances are the panels are not optimal for a simple 2 in series PWM setup (for eaxample..) MPPT will take all voltages within reason and convert to useful charge outputs.

The amount of energy available during early morning and late evening is small and I do not care for special conditions where MPPT is dropped in favor of straight through connection of panel array to battery. The code will run MPPT and the DC-DC converter when power IN is not enough.

The code will look for lower Vin compared to Vbattery and turn off.
I also want it to look for no battery load and turn off.
It would be nice if it was idiot proof and just survived all attempts to kill it.
Edited 2020-03-31 18:19 by poida
wronger than a phone book full of wrong phone numbers