Modeling and Analysis of a Scott or T connection Transformer in Power Flow Analysis through the Newton-Raphson Method

Abstract

Power flow analysis is typically used for power system operation and planning. The Newton-Raphson method among power flow analysis methods is a strong and reliable method. Three-phase transformers indispensable for voltage regulation must be modeled for reliable power system operating and planning. In this paper, we enhance the Newton-Raphson method for analyzing unbalanced power systems, including Scott or T connection transformers. For this purpose, this paper proposes the universal nodal admittance matrix for correct transformer modeling. For verification, the known IEEE test systems are used and the accuracy of the proposed method is verified by comparing the percentage error. The verified transformer modeling method and proposed Newton-Raphson method can contribute to the correct modeling of unbalanced three-phase Scott or T connection transformers so that it can be used for planning and operating power systems, including Scott or T connection transformers.