Power system security enhancement by OPF with phase shifter

This paper presents an integrated optimal power flow (OPF) with phase shifter approach to enhance power system security. The general OFF calculations are hourly based and the control variables of OFF are continuous. However, the calculations of phase shifter are daily based, and the variables related to phase shifter are discrete, Therefore, the general OFF cannot be directly used to solve this problem. The paper develops the rule-based OFF with phase shifter scheme to bridge the problems. In order to effectively alleviate the line overloads, the ranking of phase shifter locations is conducted based on contingency analysis and sensitivity analysis. The best phase shifter sites are identified and selected into rule-based system accordingly. The handshaking procedure between the adjustment of the selected phase shifters and OFF calculation is proposed using rule-based method. The hourly-based OFF problem is solved by the extended quadratic interior point method, IEEE 30-bus system is used to test the proposed scheme.