OneLiner iterative solution

We discovered a software bug in the simulation results reporting logic in OneLiner V15.7 and earlier. When the iterative solution of some nonlinear devices, such as voltage-controlled current sources, does not converge, a warning message does not always appear in the report.

Without the program's warning message, users can only tell that the solution did not converge if they scrutinized the numerical values in the solution report closely.

The convergence criteria of the non-linear device solution in OneLiner is very similar to that of the Gauss-Seidel method of solving power flow. The program monitors each device's power-factor angle and current magnitude in every iteration.  The iteration will stop when:

a) These monitored parameters stay within a narrow tolerance band from one iteration to the next, i.e., the convergence has been reached, or 

b) A pre-determined maximum number of iterations has been executed. In these cases, the deviation of the device's current magnitude and/or power factor angle in the result can be larger than the desired tolerance thresholds.

This software bug has been fixed in the new minor version release of OneLiner V15.8. We recommend users update their software to the latest version to take advantage of all the bug fixes and improvements.