OneLiner V15 iterative solution issues

We found some software bugs in the program's logic for iterative solution of VCCS, CIR and type-3 Wind Plant that caused incorrect current contributions results. The bugs affected the calculation of devices that output current in pre-fault conditions. This would be the case for CIR and Type-3 Wind Plant with non-zero setting of Unit MW generation, and for VCCS with non-zero current output settings at the pre-fault voltage level, as shown in the examples below:

Example of a Type-3 wind plant with non-zero prefault current output

Example of a VCCS with non-zero prefault current output

The bugs also affected some CIR devices with non-zero slope of -seq dynamic receive-current injection characteristics.

These software bugs were fixed in OneLiner V15.9 Build 47753, which ASPEN published on May 1, 2025.

We recommend that users update to the latest software build to benefit from this and other bug fixes.