Q:   What does it mean if my fault simulation didn’t converge?

A:   Converge is determined by comparing a computed quantity against a specified tolerance.  At the end of a simulation, if the magnitude of the computed quantity exceeds the allowable tolerance, non convergence is declared.  Non-convergence can occur in the prefault solution and/or the fault solution within OneLiner.

 

To illustrate the concept of non-convergence, consider a particular CIR model within a network.  If the current output from a CIR model does not settle to a steady value before the maximum number of iterations is exceeded (meaning its current output magnitude or angle changes from one iteration to the next by more than the specified tolerance), that CIR model would be declared non-converged for the simulation.

 

Beginning in OneLiner V15.8, the solution tolerance criteria can be specified in the Fault Options dialog box. Judgment must be used to determine acceptable tolerance levels for your network model and studies.