The result of AC current output is abnormal in electric circuit simulation using Simulink

I simulated a simple AC circuit containg an AC Voltage Source and a Resistor from Simsacpe library, and using a Current Sensor and a Scope to show the current. The circuit model is as follows:

When I set the Stop Time to be 5 seconds, the result shown in Scope is right which is shown below:

However, when I set the Stop Time to be 10 seconds, the result shown in Scope is abnormal which is shown as follows:

How to solve this problem? Thanks very much!

[Sabin]

Could you attach the model so we can look into this behavior?

[zhaoyun wu]

I use another model which was attached to demonstrate the problem I met. The electric circuit is as follows:

This composed of an AC voltage source and a capacitor. Besides, the current and voltage of the capacitor is simulated and shown by the scope. The parameters of the voltage source and capacitor is listed below:

the parameter of the voltage source

the parameter of the capacitor

When the stop time was set to be 0.2, 1, 3, 5, 11 seconds, the outputs of scope is right which are shown below.

But when the stop time was set to be 2, 4, 10 seconds, the outputs of the scope were wrong, which are as follows:

This problem is very weird, I don't know how to solve it.

The version of mathlab I am using is R2021b (academic version).

[zhaoyun wu]

Thank you very much for your comment!

Answer 1

[Sabin]

This appears to be related to how the solver computes the step size. By explicitly setting the ‘Max step size’ in the Configuration Parameters (for example 0.1) would fix the issue.

[zhaoyun wu]

Thanks very much!