Good morning to everyone,
I would like to bring the following issue to your kind attention: I am trying to model a Thermoelectric Generator applied to photovoltaic panel using Simulink - Simscape, but I have two issues. Let me start by saying that I have no experience using Simulink.
If I leave the default solver details parameters I get the following warning mesage: "Solver was unable to reduce the step size without violating the minimum step size value of 6.27151E-11 for 3 consecutive times at time 17652.7. This usually may be caused by violating algebraic constraints in the differential-algebraic system or by the high stiffness of the system. Try tightening the error tolerances, and/or the tolerances for computing consistent conditions. If the problem persists, please check the system or increase the solver Number of consecutive min steps violation parameter."
If I increse the "number of consecutive min steps" from 3 to 10 the warning mesage does not appears. In any case I obtain an output signal in the scope that presents a series of sudden peaks and valleys, as if there were discontinuities.
I tried relaxing the relative tolerance from the default values of 1e-03, but the problem persists. I am using the ode23t solver that is the only solver that does not provides error messages or a large number of warning messages.
In order to simulate the operation of the system for 25 days, I entered 25243600 seconds as the stop time.
I attach two images of a graph among many that present the same problem.
I would be very happy and grateful if anyone can help me, please.
Best regards.
I expect the signal to be smoother and not have such sudden spikes.
As input to the system I provide the external conditions of irradiation, inclination of the sun's rays and environmental temperature for the entire day at an hourly rate, through the "repeating table" block. When I load the data for January I don't encounter any problems, when I load the data for the other months the problems arise, a sign that the input data probably also has an influence on the problem.
I am unfamiliar with the topic that you are trying to simulate. However, based on my experiences in simscape multibody, getting the "Solver was unable to reduce the step size without violating the minimum step size" warning is due to a tiny problem in your model.
For example, in my experience, it was due to a misalignment between 2 frames for just 0.00024mm which was lower than the tolerance but still affected the simulation by getting this warning and reducing the speed of the simulation.
So, I am going to suggest you check your model again.