Error in Simulink - Derivative of state '1' in block at time 301.02267725 is not finite. The simulation will be stopped. There may be a singularity in the solution.

I get the following error -

An error occurred while running the simulation and the simulation was terminated

Caused by:

• Derivative of state '1' in block 'gam_control1/PID Controller2/Integrator/Continuous/Integrator' at time 301.02267725611046 is not finite. The simulation will be stopped. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)

I am using a manually created signal (using signal editor) as an input into a PID controller. I have tried to select ODE15 from the model configurations and also tried tightening the absolute error. Nothing works. The simulation stops at 300 s. I need it to run till 550 s. Please help.

Answer 1

[Salman Ahmed]

Hi Riya,

This problem occurs oftenly. This is usually caused because of Inf or NaN output produced at a block. Set the diagnostic "Inf or NaN block output" to error in the configuration settings. If this is the issue, you will get the error as follows:

An error occurred while running the simulation and the simulation was terminated

Caused by:

• Block 'BlockName' outputs 'NaN' for element x of output port x at major time step 0

where BlockName is the block in which error is thrown.

You can debug your model from there to bypass NaN or Inf values from reaching the integrator.

[samet gul]

Thank you, it helped a lot.

[Chunjie]

Thanks! I found the problem by your method!

Answer 2

[davood fateh]

hi

What is mean of "you candebug your model from there to bypass NaN or Inf values from reaching the integrator."?

Which part?

Thanks.

Answer 3

[worod]

derivative of state '1' in block 'FOPID/Fractional PID controller/Fractional derivative1/Transfer Fcn1' at time

0.01408153786115585 is not finite. The simulation will be stopped. There may be a singularity in the solution. If not, try

reducing the step size (either by reducing the fixed step size or by tightening the error tolerances) .

how can i solve this problem when using FOPID in simulink?

[Sam Chak]

Hi @worod

Please post a new question. Despite receiving the same error message, the issue with your FOPID system is different from @Riya Gujarathi's original PID system problem.