The integrator in Simulink

[bflbfl]

Hi,

I am trying to solve the laser rate equations in Simulink using the integrator block. But it gives an error message each time I run the simulation:

'Derivative input 1 of 'rate_equation_15_2_2012/Phy1-eq./Integrator3' at time 0 is Inf or NaN. Stopping simulation. 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 have tried to reduce the error tolerances as well as reducing the step size. The I also tried to provide an initial value to the integrator block but it does not work. I shall appreciate any help in this connection.

Regards

 

[mmwave]

,

Dr. Smith

Hi Dr. Smith,

Thank you for reaching out. It sounds like you are encountering a common issue when solving the laser rate equations in Simulink. This error message typically indicates that the solution has reached a singularity, which means that one of the equations in your model is becoming undefined.

One possible solution is to check your equations for any errors or inconsistencies. It may also be helpful to review the initial conditions and make sure they are appropriate for your system.

Another approach is to try using a different solver in Simulink, such as the ode15s solver, which is designed to handle stiff equations like the laser rate equations.

If these suggestions do not resolve the issue, please provide more details about your model and equations so that I can offer more specific advice. Best of luck with your simulation.