upfc siting and sizing in power network using two different evolutionary algorithm

in emerging electric power systems, increased transactions often lead to the situations where the system no longer remains in secure operating region. the flexible ac transmission system (facts) controllers can play an important role in the power system security enhancement. however, due to high capital investment, it is necessary to locate these controllers optimally in the power system. facts devices such as upfc can regulate the active and reactive power control as well as being adaptive to voltage-magnitude control simultaneously because of their flexibility and fast control characteristics. placement and sizing these devices in suitable location can lead to control in line flow and maintain bus voltages in desired level and so improve voltage stability margins. moreover, this adjustment can improve voltage profile system along with reducing the power system losses. this paper proposes a systematic method by which optimal location and sizing of unified power flow controller (upfc) to be installed using two different evolutionary algorithm. facts devices model is incorporated into a newton-raphson algorithm to perform load flow analysis. optimizing its location becomes a concern when coming to the practical implementation stage. proposed algorithm is tested on ieee 24 bus power system for optimal allocation as well as sizing of upfc device and results are presented.