Error related to signal dimension - Unable to determine signal dimensions.

I am doing an EV simulation on simulink. While simulating the system I got one error. The screenshot of the error message is attahced. The error showing switch is present inside the DC-DC converter, which is connected to the FC system. The image of that connection is also shown. Can anyone help me to solve the issue?

[Walter Roberson]

It looks odd that your LdCurr input is size 4 instead of size 1.

[Shelma George]

Yes, Voltage and current signals showing size 4, how can I solve this issue?

[Walter Roberson]

You will need to investigate why Bat_crnt is length 4.

[Saurav]

Can you attach the Simulink Model to investigate better?

[Shelma George]

When using battery alone as a source there is no issue, but when trying to add one more source like fuel cell and make DC link by combining voltage output of battery and fuel cell using mux or bus selctor the problem is arising.

Answer 1

[Kautuk Raj]

From your description, in the absence of the model file, I would assume that Simulink is unable to determine the size of signals without additional specification. This is especially the case with MATLAB function blocks since the code written inside this block undergoes code generation. The conversion of C-code requires signal dimensionality to be known in advance prior to code generation.

The solution to this is to make use of signal specification blocks to define the size of signals prior to inputting them back into MATLAB function block. You can learn more about it at the following MathWorks documentation page: https://www.mathworks.com/help/releases/R2021b/simulink/slref/signalspecification.html