Hello,

I have a LTspice simulation model containing a solar cell string connected to a dc-dc converter. The output of the solar cell string is the input of the converter. Attached is a simplified schematic of the circuitry.

I want to implement maximum power point tracking (MPPT) to the solar cell string to fix the maximum power point on the IV curve of the solar cells.
I've tried this with a voltage source (V_mpp) parallel to the solar cell string for which I set the voltage equal to V_mpp (for a string of 6 regular cells this is about 2.7V). I've tried to work with the resistance of V_mpp, from zero to 1Gohm, but with mixed results.

Is there another way to implement a MPPT logic in LTspice such that I can lock Impp and Vmpp of the IV curve of the solar cell string?

Best regards,

Boudewijn

 

You could use a BV source set to V=v(in)*i(X1) to track the power the cells are producing.

 

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You could use a BV source set to V=v(in)*i(X1) to track the power the cells are producing.

Thank you for your reaction, Ill investigate this!

 

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I'm aware of the P&O algorithm. I currently have the Imp and Vmp values of the solar cell strings at different levels of irradiance and for different string sizes, but I don't know how to implement this in LTspice.

 

Could someone perhaps show an example circuit..?
thanks in advance!

 

Does the buck converter have a fixed output voltage?
Is the load fixed? If so, what happens when the cells generate more power than the load demands?