Phase-Shifting Transformers' Model for Optimal Load Flow Formulation

In the present paper phase-shifting transformer (PST) is discussed using suitable connection of transformer. PST is an important electrical component used for optimal load flow. It may be adjusted to minimize total generation cost or/and transmission losses. The PSTs play the important role and have different applications in electric power systems. This article presents a multi-objective optimization methodology for power systems including PST. A simple model for PST is developed based on Newton's algorithm. In this model, the admittance matrix of the system is modified with PST in its equivalent circuit. In this study, a multi-objective optimization regarding to total generation cost and total transmission losses for power systems including PST is developed. Numerical results on different test systems show that the proposed model can provide better optimization with regulating a small number of PST. The developed PST model into an optimal load flow has been confirmed using the standard IEEE 30-bus and IEEE 118-bus test systems.