There is an example model in Simscape, which was introduced by MathWorks and is compatible with MATLAB R2023b and later versions. The example shows how to model a power-split hybrid electric vehicle (HEV) with a simple rule-based controller for speed tracking simulation. The power-split HEV is a series-parallel hybrid system. Please refer to the below link for more details about this example:
Additionally, there is a model in file-exchange that models a parallel-series hybrid-electric vehicle. Please refer to the below link for more details about the model:
https://www.mathworks.com/matlabcentral/fileexchange/28441-hybrid-electric-vehicle-model-in-simulink
You can refer to any of the above models and modify it as per your requirements to model a series HEV.
I hope this helps.
