Power flow estimation and line-loss-minimization control using UPFC in loop distribution system

This paper presents the line loss minimization control using a UPFC (Unified Power Flow Controller) with power flow estimation in a loop distribution system. The minimization of line loss is realized by eliminating the circulating current using the UPFC in the loop system. In the control of the UPFC, all line current in the loop distribution system are necessary. Therefore, the condition and scheme for estimating the all line currents are derived. The effectiveness of the proposed control scheme has been verified by experiments using the laboratory prototype in the 200V-system.