How to resolve the singularity error over the integrators and probably caused by the high values for the amplitude of input signal?

Hello everyone, I am facing singularity error in my model. I tried with all of the different solvers and different sampling times. The probolem I have is that I do not have any idea of the value of absolute/relative error tolerance or Min/Max step size in the configuration parameteres. Can anyone please explain what are the criteria to set those values for a specific model? In my case my model is in the laplace domain, I have used some integrators and the error occurs over one of the integrator blocks.

Another problem in my model is concerning some 3D lookup tables.

one of the dimensions(breakpoints) in my lookup tables in the current amplitude. While creating the lookup table, the data I used were obtained from the measurements with very small current amlitudes while my model should work even for high current amplitude. I mean after creating the lookup tables and completing the model, for the model validation I am supposed to use a standard UDDS current signal which have high amplitudes. Therfore, that is kind of out of range and may cause the singularity. But I can not limit my input e.g. using a saturation block since my signal is a standard one and I want to compare the output of my model(voltage) with the one from measurements using the UDDS current signal.

Does anyone have any suggestion regarding this problem?

Any help is appreciated in advance, Sarah

[Iain]

If there is feedback in your model, it is entirely possible that it goes unstable at some intermediate point, (rather than at the output), which will cause the issue.