Batterypack with variable number of cells

Hello,

I'm currently trying to implement a batterypack in Simulink using simscape. Each cell is modeled with 2 RC elements, a serial resistance and an OCV Voltage source. I know connected 20 of those cells in parallel and 2 in serial. What i want to do now is to be able to vary the number of cells in parallel and serial connection. I thought of implementing switches that would open or shortcut not cells based on a set variable (e.g. if VarSerial=2 the battery pack would consist of to serial cells.If VarSerial=1 all serial cells should be shortcutted) but each switch comes with an internal resistance that can't be set to zero. Is there any way to implement my model? Maybe with an enable block?

Regards

[Birdman]

Share your model(export to r2017a)

[SmaShBr0ther]

The model is still work in progress. If I now want to run the model with only 15 parallel cells, how could I handle this without having to delete the cells by hand?

Answer 1

[Birdman]

I checked your model, the only useful way that I could find is using Variant Subsystem. It enables you to select any subsystem that you want and you wouldn't have to delete the cells by hand. For more information, see the link below:

https://www.mathworks.com/help/simulink/examples/variant-subsystems.html

[SmaShBr0ther]

Thanks for your help. So this means that i have to model every possible combination of cells and put them all into subsystems. And then the variant subsystem will runn the subsystem as needed?

[Birdman]

We can say that. The thing to do is you will create a mask and selections from that mask on a subsystem. For instance, if you want to activate 5 cell, you will select the value '1' and etc. This way, you will be able to create so many options. At the end of all possible combinations for you, you can create a last option which includes all the cells and you can reach it by selecting the value '25'. I hope this is clear.

[SmaShBr0ther]

I just realized that variant subsystems are not available with physical signals. This makes it more complicated to implement this with my model.

[Birdman]

No, it is. Right click your physical subsystem, go to Subsystem&Model Reference->Convert Subsystem to->Variant Subsystem. It automatically creates it for you.