Trying to get it to the following passive cell balacing to run but unable to. Can I get help?

Hi, I am trying to create a passive cell balancing model alongside a battery CC-CV charging cycle. I used a relay to control when to start charging and when not to. The function used compares the SOCs of the 6 batteries and provides a result of y=1 or y=0 depending depending if the SOCs are equal or not respectively. However, when i run the simulation the time stops at 4 seconds. Does anyone have a solution to this? Thanks in advance.

Answer 1

[Xiangchun]

Hi Jayden,

I looked at your model. It seems that the solver is stuck at about 4.6 sec. I suggest that you try different types of solvers. Press Ctrl+E to bring up "Model Settings." Under "Solver," change the "Solver" to "ode23t (mod. stiff/Trapezoidal)."

Additionally, I noticed that you have a MATLAB function to compare SOCs and enable the Passive Cell Balancing block. This is not necessary. The same logic has been implemented in the "Passive Cell Balancing" block. The "Enable" port only asks whether we want to enable this block or not. For example, one might decide to enable this all the time. Alternatively, one might decide to enable this only after finishing the majority of a CC-CV charge. For more details, please see the documentation page Passive battery cell balancing algorithm - Simulink (mathworks.com). There is a similar example for your reference Battery Passive Cell Balancing - MATLAB & Simulink (mathworks.com).

Additionally, you can leverage the battery builder provided by Simscape Battery to generate a Simscape block that represents a battery pack made of 6 cells as shown in your model, with bleed resistors included. Please see this example Size Resistor for Battery Passive Cell Balancing - MATLAB & Simulink (mathworks.com).

Best wishes,

Xiangchun