Abstract
<title>Abstract</title> <p>This paper presents an electromagnetic modeling methodology for a 600 MVA phase-shifting transformer, developed using limited manufacturer design data combined with DC hysteresis measurements. Phase-shifting transformers play a critical role in controlling active power flow within interconnected power systems, yet their accurate representation for transient studies remains challenging due to restricted access to detailed design information, particularly for units already in service. To address this, both saturation-based and hysteresis-based modeling approaches are formulated and parameterized from experimentally obtained DC hysteresis loops. The transformer is also modelled in ATPDraw using a dynamic hysteresis model with prescribed core materials, enabling an accurate representation of nonlinear magnetic characteristics. The proposed models are validated against factory acceptance test results, showing good agreement across the relevant operating conditions. Furthermore, the model is independently verified through implementation in RelaySimTest software, confirming its suitability for low-frequency transient analysis and protection studies. The results demonstrate that DC hysteresis measurements provide an effective basis for transformer parameterization, enabling accurate reproduction of the nonlinear magnetic behavior.</p>