How to couple electrochemical model of a cell with simscape "battery" for battery pack modelling modelling?

I have simulated a single cell with the electrochemical model (P2D/DFN) of a cell. I wish to use the model for simultaneously simulating all cells of an entire battery pack. I could either go for programming the circuit manually, or using the simscape to couple the results for each cell into a simulink circuit. Is there any references I could go through to help me with either of these methods? Because I couldn't seem to find it myself. Research papers do not really make it very clear how the programming needs to be handled.

Answer 1

[Joel Van Sickel]

It should be easier to go the Simulink path. The challenge you will have it is interfacing it with a Simscape Network. You will likely implement each cell as a voltage controlled current source. So the model will take a current as an input, and output it's voltage for the next time step. You can also have other inputs and outputs such as thermal data. This will be easiest if you can model at least some of the terminal resistance in Simscape instead of your P2D/DFN network but I'm not sure if you'll have that information. You can use a variable resistor so that it changes over time. There is also the issue of how to call the electrochemcial model from Simulink. One way is to use a matlab function in Simulink to call your model. If your model happens to be in c/c++, an FMI/FMU implementation, or have an s function implementation, you could also put it directly into Simulink.

Hopefully that gives you a little bit of an idea on how to start. Please feel free to add follow up questions as you try and move forward.

If you need some free training on the Simulink and Simscape models, please use this:

https://matlabacademy.mathworks.com/

[Chaitanya Singh]

I seriously appreciate this answer. Thank you! I'll try this out soon.

Answer 2

[Jakub]

Generally, I found a chance to adapt the P2D/DFN since it may be represented by DAE model. To do that you have to declare a new Simscape domain and provide of proper equations in the block. You can look at the example of the very end of the Simscape Language Guide:

https://www.mathworks.com/help/pdf_doc/simscape/simscape_lang.pdf

The presented case is about introducing of electrochemical domain. Of course DFN model operates on different variables so you have to change them. I'd never try to implement DFN model, but I belive it is possible in that way :).

Btw. you may be interested of the novel cell block called single particle model which will be introduced in 2024a. For details see the prerelease documentation:

Battery model with single-particle approach - MATLAB (mathworks.com)