Studies on Improving the AC Outward Transmission Capacity of Sichuan Power Grid by Utilization of Phase-Shifting Transformers

In this paper, the feasibility analysis of the utilization of phase shifting transformers (PSTs) to improve the AC outward transmission capacity of Sichuan power grid (SCPG) is presented. Firstly, the authors analyze the working principle of PST, as well as the rules for selecting its location. Then, the AC outward transmission limit of SCPG is studied with PSASP software. Finally, the PST is used to change the power flow distribution of lines on border of SCPG. Simulations results show that the PST can significantly improve the AC outward transmission capacity of SCPG. At the same time, short-circuit current of SCPG is also reduced.