Kevin managed to collect a bunch of numbers on the power conversion efficiency of the MPPT last weekend. The numbers that came back look great and the real version of the tracker should be about 0.5% greater all around due to slightly different components.
Here are the graphs we managed to obtain. Output voltage in both plots is approx 110V...
The graph above is a plot of efficiency(Ordinate y-axis) vs input power(Abscissa x-axis) (boost factor is being held relatively constant at 3-5). We don't yet have enough data points to hold the boost factor constant so that's why the graph is not very smooth.
The graph above is a plot of efficiency(Ordinate y-axis) vs Boost factor(Abscissa x-axis) Input current is at roughly 5A. I think it's interesting how the top of the graph flattens out. I'm not sure yet if this is what is actually happening, or the precision of our instruments are what's causing it.
We have a lot more data at different input currents/power but we will keep that data to ourselves for now... We did actually test up to boost factors of approx 60 (<2V input)...
Anyway after exams are done we will be finally starting array construction! I can already tell you without question that this array will easily be the most risky and most innovative thing our team has ever done! This is going to take some real precision and attention to detail, hopefully we can pull it off!
See Ya!
Tim Gamber
Electrical Engineering Manager
