Warpspeed
Solar Wizard
O/k Ace, keep us in the loop !
There are quite a few twelve volt Guys out there, but I just built what was needed here.
There are quite a few twelve volt Guys out there, but I just built what was needed here.
Vmp moves considerably with temperature and irradiance.
The panel being directly connected to the battery when the mosfets close. This also results in very poor power transfer for higher voltage panels.
Sorry I missed the fact the choke and it’s diode were externalIt certainly does, but that has a lot less of an effect than most people have been led to believe.
I have been thinking about all this for years, and I just had to try the idea.
Once you have a means of easily adjusting the actual operating point up and down manually with a potentiometer, you might be amazed at how little the bulk charging current varies over a very wide operating voltage range at the panels.
Sure, temperature and insolation effect the actual peak power voltage, but if you can crank that voltage through a wide range of adjustment and only see a very few percent change in bulk charging current, what is that trying to tell you ?
What really DOES matter, is controlling the loading on the panels to changing insolation, and this circuit does that brilliantly.
To put all this another way, the solar panels are a (relatively) high impedance current source.
Even a slight change in loading has a very large effect on the voltage at the panels.
If you can track that, you have the game beat.
Its basically all about impedance matching the load impedance to the source impedance.
Its of far less importance to get the solar voltage operating point exactly right, than to track a very wide loading adjustment range, to keep it "somewhere near" the peak power voltage. And then use efficient power conversion to do it.
Just wait and see the results other people are getting with this before passing final judgement, its very early days yet.
I was truly blown away by what I was actually seeing, it was totally unexpected.
NEVER at any time is the battery directly connected to the solar panels.
You are quite wrong there, a buck regulator does nothing of the kind. The choke effectively isolates the input switched high voltage waveform from the lower voltage output dc waveform. The switched input voltage is averaged, and at very high efficiency.
Oh, by the way, I am a retired power electronics design engineer, I used to design the switching power supplies in mass produced commercial equipment among many other things.
None is suggesting Vmp is the greatest thing on the planet. Mppt delivers small incremental gains. Far more gains over conventional PWM are as as pointed out by “ warspeed “ to be had by power conversion technology ie boost conversion and manual operating point selection.Per Wikipedia it is an MPP setup. You just don't have tracking. For fixed panel and battery setup does it really matter? Whenever I look at my SCC's the panel voltage is only varying a few volts.