Cell balancing Uniform for DTSC ?

I have make double tiered Switched capacitor Based Active cell balancing of lithium ion cells closed loop simulation and it's working. But as I have to Connect Sum to lower soc among 3 from. What should I do to make it uniform ?

Answer 1

[Prathamesh]

Hi @abhay,

I understand that you are working on a double-tiered switched capacitor-based active cell balancing system for Li-ion batteries, and your simulation is functional. Now, you want to ensure that the balancing logic directs charge (or "Sum") to the cell with the lowest State of Charge (SoC) among three cells, and you want this to be uniform and closed-loop.

Below are the steps to implement Uniform Balancing logic:

1. Use a block or script to continuously monitor the SoC of each cell: SoC1, SoC2, SoC3.
2. Use the Min block or a MATLAB Function block to compute.

min_soc = min([SoC1, SoC2, SoC3]);  

3. Use a MATLAB Function block to output a selector signal:

function idx = min_soc_index(SoC1, SoC2, SoC3)
    [~, idx] = min([SoC1, SoC2, SoC3]);
end 

This gives you idx = 1, 2, or 3 depending on which cell has the lowest SoC.

4. Continuously monitor SoC and update the balancing path in real-time

5. Add hysteresis or a small threshold to avoid oscillations when SoCs are nearly equal.

Hope this helps.