MATLAB: Simulink: Thermal conductance in a PV system

Question

Dear community,

I am trying to simulate the heat transfer in a PV system. There, I am struggeling a bit with the thermal conduction. I try to explain as good as I can what I try to achieve and what I did so far, so bear with me reading this short text :).

So far, I have implemented:

• Heat transfer by sun irradiation (on solar cell level)
• Heat transfer with atmosphere by radiation & convection (on solar cell level)

To complete my simulation for now, I miss the heat transfer with atmosphere by conduction (on solar cell level)

I looked into several examples (Photovoltaic Generator, House Heating System, Motor Thermal Circuit) to get an idea of how the thermal conduction between different bodies may be simulated. In my understanding, I would need to use a thermal resistance between the two bodies. Another alternative suggested by literature is the one in the image below: putting the conductive heat transfer element in series with heat transfer by radiation/convection, where the "Conductive Heat transfer" elements are filled with the area & thermal conductivity of the cell. But here, I am struggeling with the thickness I should enter.

Which would be your implementation?

I hope my questions are clear. A consent would already be enough, although I prefer a more detailed explanation to understand Simulink/Simscape better and enjoy the software even more!

Thank you all in advance.

Answer 1

Hi Philipp,

My knowledge of heat transfer are strongly based on electrical machines on a very practical level, which might be different to what you are studying, which means that I might be completely wrong about this.

As far as I know, for such scenarios, the heat transfer between the solid and the fluid is normally doninated by convection, since the thermal conductivity of the air is very low and the process is in open space. Furthermore, in practice the conduction is often included in convection, becasue it is usually impossible to seperate the two with normal measurement techniques. However, in some circumstances the two methods of heat transfer can be and will be seperated due to research interests, e.g., boiling water in a kettle.

For your case here, I believe you could model the air and the sun as two individual nodes, and connect them to your PV cell with convection and radiation respectively.