Available transfer capability evaluation and enhancement using various FACTS controllers: Special focus on system security

Nowadays, because of the deregulation of the power industry the continuous increase of the load increases the necessity of calculation of available transfer capability (ATC) of a system to analyze the system security. With this calculation, the scheduling of generator can be decided to decrease the system severity. Further, constructing new transmission lines, new substations are very cost effective to meet the increasing load and to increase the transfer capability. Hence, an alternative way to increase the transfer capability is use of flexible ac transmission system (FACTS) controllers. In this paper, SSSC, STACOM and UPFC are considered to show the effect of these controllers in enhancing system ATC. For this, a novel current based modeling and optimal location strategy of these controllers are presented. The proposed methodology is tested on standard IEEE-30 bus and IEEE-57 bus test systems with supporting numerical and graphical results.