Simulating voltage-controlled current sources with pre-fault voltage option of “Assumed flat”

Starting in v14.7, OneLiner can run fault simulation in networks having voltage-controlled current sources (VSC) with the pre-fault voltage option set to "Assumed flat". It has been brought to our attention that when this option is in use, the VSC current injection result is wrong in cases when the VSC terminal is connected to one end of a wye-delta transformer – a common network configuration. (This problem also happens when the VSC is connected to one end of a phase shifter, but that is rarely done in practice.).

If you must use the "Assume flat" prefault voltage option, you can avoid these problems if you also instruct OneLiner to "Ignore phase shift of transformers and phase shifters". The following pictures show the File | Preferences dialog boxes with these options highlighted.

Additional details about OneLiner fault simulation Prefault voltage options are available in Section 4.9 of OneLiner online help/user manual.