Modeling and analysis of the single-core phase shifting transformer and its differential protection

In this paper, the analysis and simulation of a single-core asymmetrical phase shifting transformer (PST) is presented. PSTs are usually used for varying the voltage phase angle between the two systems, which provides controlling active power flow through transmission (tie) line. The essential part of this work was related to developing an appropriate simulation model of the single-core phase shifting transformer in MATLAB/ Simulink environment. In addition, this paper presents testing results of a selected PST differential protection scheme (proposed in the literature) for various disturbances. The testing outcomes provide useful information about limitations of the selected algorithm and create basis for further research.