Simulink algebraic loop Error

Hello,I'm doing project on current controller Model Predictive based PV system.When I'm running my simulation,I get the following error: An error occurred while running the simulation and the simulation was terminated Caused by: Simulink cannot solve the algebraic loop containing 'power_PVarray_grid_avgO/PV Array/Diode Rsh/Product5' at time 1.13725 using the LineSearch-based algorithm due to one of the following reasons: the model is ill-defined i.e., the system equations do not have a solution; or the nonlinear equation solver failed to converge due to numerical issues. To rule out solver convergence as the cause of this error, follow either of the suggested actions. If the error persists in spite of the above changes, then the model is likely ill-defined and requires modification. I checked the embedded block where it says the problem is, but my code seems fine. Is there a way I could solve or debug this problem? I do not have any idea how to go about it further in debugging?

Any suggestions on debugging this error would be highly appreciated.

Thanks!!

Answer 1

[ag]

Hi Iqra,

Algebraic loops occur when an input port with direct feedthrough is driven by the output of the same block, either directly, or by a feedback path through other blocks which have direct feedthrough. In most of the cases the solution is to model the system so that the loop is no longer present. In some cases, adding a small delay (Either discrete delay block or continuous memory block) to the system at its highest level might remove the loop. However, this can, in some situations, add unnecessary dynamics which may affect the results.

For a better understanding of Algebraic loops and how can they be solved, I kindly suggest you to go through the following MATLAB answers post: https://www.mathworks.com/matlabcentral/answers/95310-what-are-algebraic-loops-in-simulink-and-how-do-i-solve-them

Hope this helps!