diy solar

diy solar

Has anyone got an experience on which MPPT algorithm is the most efficient at broken cloudy days?

rin67630

Solar Enthusiast
Joined
Apr 29, 2020
Messages
1,066
Location
Nort-Rhine-Westphlia Germany
I just wonder which MPPT algorithm should be the most efficient at broken cloudy days?
Just polling the power for changes every second while the irradiance may be changing for the same amount as well will not be effective.
My
Polling power much faster will be a waste of resources and impact the quiescent consumption.
Probably the best way will be to detect this stage and switchover to fixed panel voltage, reserving real MPPT to full sunny and full overcast days?

Has someone got an experience with that?
 
There are several MPPT algorithms that would be suitable for different conditions. The most common one on charge controllers, Perturb and Observe might not be the best for all conditions, but it's easy to implement. You could use a combination of Incremental Conductance and Constant Voltage to get best results in cloudy conditions with constantly changing irradiance.
 
There are several MPPT algorithms that would be suitable for different conditions. The most common one on charge controllers, Perturb and Observe might not be the best for all conditions, but it's easy to implement. You could use a combination of Incremental Conductance and Constant Voltage to get best results in cloudy conditions with constantly changing irradiance.
Thank you for confirming. I must now figure out how to detect the condition and switch-over the strategy accordingly.
 
Perturb and Observe is ideal where the user has no idea how their magic solar controller, or the solar panels actually work, and only wants to buy it cheap from China and just connect it up and run it without having to do anything else.

But realistically, if you know the peak power voltage of your solar panels, either by reading the rating plate or by test and measurement, a better way of doing it is to constantly load the panels down to that known voltage.

In effect, the solar controller becomes a simple shunt voltage regulator, increasing the loading on the panels when there is plenty of sun, and reducing the loading when its cloudy. It can in effect be almost instantaneous in response and never gets confused by very rapidly changing conditions. Its then just a case of reducing the output to prevent overcharging of the battery in the usual way.
 
Back
Top