So today I had a little time to test Peter’s brainbord on my main solar controller. Exciting…. :p
Because I took another power pcb, so other component tolerances I had to do the calibration all over again, but I’m trained now. It’s actually going verry smooth now I know all things I need to think about now. Even when full solar and battery were connected I could set all the parameters without things blowing up.
Yesterday I had problems with my LCD screen, very sensitive. But as expected my wires were to long between my lcd and pcf8574, added 100nF to the 5V line on the LCD, and 100nF + 1µF close to the pcf8574, all problems solved.
You see a few boards but it's because I reused a board from another project.
This is my testing setup, yes there is some work left to make everything a bit euhh... :p

Early morning testing with low battery, here an mppt controller makes a lot of sense, 10A in almost 14A out...

1700W going in the battery:
Power keeps climbing, temperature of inductor was climbing under those currents so I switched on the fan. I need to figure this out.
This was about maximum power level for today, that is for a +-6700Wp array.
Evening energy harvest:

One thing I noticed was that the voltage-in was dropping under high power, I think this has to do with some things:
--> voltage drop in the cables + brakers, my testsetup is not well dimensioned
--> there is a lot of 100hz voltage ripple in my system, there is also the backfeeding and loads that are creating voltage ripple and maybe upset the program.
--> the inductor is not really designed for more then 30A, so it's probably saturating at this point.
--> There is some ringing around the mosfet, about 15V-20V at high power levels on top of the input voltage.
--> the driver power supply is providing more then 15V, so I probably need to adjust the gate resistors or lower this voltage.
--> I need to check the resistor before my gatedriver, 1100R is to high, should be more like 390R for the FOD3182
--> the inductor is making a bit of noise when looking for the mpp, but I guess that's something physically.
--> There is little time during the day my panels are not shaded, that's why I will use 3 controllers for the roof of my house.
Votage and current readings were verry stable, and the acs sensors were consistent, and need a stable voltage, I think there will be some drift under temperature changes, but it wont matter for the algorithm.
For the record I'm using 1000uF capacitors, I know the program was written and based on other parameters but it's really working great.
I'm using a traco TEN-3-4812WIN power supply powered by my battery, it has 18-75V input range and 12V 250mA out, it's not cheap (12.5€) but should be reliable.
But the brainbord is realy a great thing, this makes my powerboard a very powerfull and programmable device, I'm verry verry satisfied with the performance!
Edited 2020-11-21 06:24 by nickskethisniks