MPPT test rig has been re-arranged to make it easier to see what's what. Here I explain what each section does and how it works. Also some ideas on how this project should progress from here.
And did you see the temperature today? 25 degrees C - lovely!
And did you see the temperature today? 25 degrees C - lovely!
Yy
Make a string inverter by putting panels in series to 12f or 24 v
Hi, if you use the 31khz pwm output of the arduino you will solve the problem of noise.
OH, OUCH!!!! That high frequency really hurt my ears! Yeah, you were definitely hearing it!
I did a MPPT buck charger with arduino and I had the same noise problems. My converter was for 250W, 30V.
Not sure yet. I expect it'll end up being almost continuous. Too much discontinuity and the efficiency will suffer. On the other hand, there's no point having a larger inductor than necessary. If we get any sunny winter days, I want to get the scope on the buck converter components and tweak the PWM frequency to see the effects.
The Soln1 is pretty neat – I've not started on Lithium batteries yet, but I need to soon. Did you see his Motor Paraglider videos? Amazing.
Ah, good idea – although it's effectiveness would depend on the output impedance of the sensor amplifier. May give that a try.
For the amperage you can also put a small cap across the sense-output and ground. Not pretty but should be enough for this application
It seems you've already thought about this quite a bit more than I have (:
At the moment I'm just trying to maximise panel power, so I'm measuring panel volts and amps. Later I will put the same measuring devices on the battery side and measure power delivered to the battery. With all that data, the CPU will be able to display an efficiency percentage.
Then I can probably answer your other questions about buck converter efficiency and how the panel size affects things. I just don't know at the moment.
Any reason you are measuring on the panel side, not on the battery side?
I'm assuming the buck converter's efficiency curve is non-linear, so an increase in power output from the panel may not always mean an increase in power to the battery.
It may be that any difference is small enough to not matter with large-ish panels.