Modeling, Analysis and Optimal Location of UPFC for Real Power Loss Minimization

The concept of Flexible AC Transmission system (FACTS) brought radical changes in the power system operation and control. A new technique using FACTS devices linked to the improvements in semiconductor technology opens new opportunities for controlling power and enhancing the usable capacity of existing transmission lines. The Unified Power Flow Controller (UPFC) is devised for the real time control and dynamic compensation of transmission systems, providing multifunctional flexibility required solving many of the problems facing the power delivery industry. In this paper, an improved UPFC steady-state mathematical model for the implementation of the device in the conventional Newton Raphson (NR) power flow algorithm has been developed from a two-voltage source equivalent of UPFC. An advantage of the model is that the model is capable of taking the losses of UPFC into account. GA is used for optimal placement of UPFC to minimize the total system losses. The proposed approach is tested on IEEE-14 bus test system. For different loadings it is shown that using optimal placement and optimal settings of UPFC, system line losses are reduced significantly.