Knowledge Base

Phase Shift Groups

In three-phase power systems, transformers with wye-connected windings on one side and delta-connected windings on the other are commonplace, as are three-winding transformers with a combination of wye and delta-connected windings. Such connections introduce phases shifts with multiples of 30°. In a standard (positive sequence) power flow these phase shifts need not be modeled; however, increasingly they are being modeled by explicitly adding multiples of 30° phase shifts to the transformers. This results in corresponding phase shifts in the solution angles. These phase shifts must be properly represented when the power flow is used as the starting point for fault analysis or harmonic analysis (such as that needed for TPL-007 geomagnetic disturbance studies.) To help keep track of these phase shifts, PowerWorld Simulator added the Phase Shift Group (PSG) object. This feature was introduced in Simulator version 24 in build dates after August 25, 2025 and is described in this presentation.

Tags: Documentation,Fault Analysis,GIC,Presentation,Simulator

August 25, 2025