Determination of critical factors for optimal positioning of Phase-Shift Transformers in interconnected systems

Phase-Shifting Transformers (PST) are installed in order to block or facilitate certain power flows. The installation of a single device affects power flows in a wider geographical area. Therefore, determining the optimal location for the Phase Shift transformer is of the utmost importance. Firstly, this paper presents summarizes the key factors for the installation of Phase Shift Transformers. Secondly, it give the prerequisites for the installation and finally, and thirdly it determines the deduced critical factors which have to be analyzed from the local (substation level), and global (system-wise) perspective. Given the necessity for regional approach when determining optimal PST location, this paper focuses on selected results of possibilities for active power flow control using PSTs in the South Eastern Europe (SEE) transmission grid. At the end, in the form a a power flow anaylsis, such an example is presented.