Error Running Test01_SIG

Good morning,

I have been successful running the OpenLoop simulink model but I receive the following error when I try to run the Test01_SIG model:

Trouble solving algebraic loop containing ‘Test01_SIG/Simple Induction Generator/SIG_Slop’ at time 0. Stopping simulation. There may be a singularity in the solution. If the model is correct, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)

Can anyone offer suggestions? Thanks,

Ryan Neahr

Dear Ryan,

Algebraic loops arise from direct feedthrough of input to output in blocks, which act like constraints that have to be solved algebraicly along with the time-integration of the states of the model. Well established initial conditions will help a solution with algebraic loops. We are working on modifications of FAST that will improve how the FAST S-Function block is initialized, but this statement also applies to blocks in the model added by the user. Before FAST is updated, adding a simple time-delay block (with a very small delay) in your feedback loop will eliminate the algebraic and speed up the simulation considerable. When doing so, however, I suggest you play around with the Simulink intergrator and time steps to ensure that the solution is converging properly.

I hope that helps.

Best regards,

Dear Jason,

I appreciate the suggestion; that is all that was required.