Optimal Location of FACTS to Optimize Power System Security

In this paper, the placement of FACTS devices (Static Var Compensator SVC and Thyristor Controlled Switched Capacitor TCSC) in a network is approached. According to small signal stability, they are located in order to increase the stability margin between the nominal active power at a load and where the Hopf bifurcation occurs in the transient model. With this goal, a disturbance (progressive increment in an active power load) is induced at the bus that leads the system sooner to instability. FACTS are introduced in the less exploited adjacent line to that bus according to the transmitted active/reactive power ratio. The TCSC presents better stability margins and oscillation damping. The SVC can be equipped with an auxiliary controller for better results. When the Hopf bifurcation does not occur before the power flow divergence, FACTS only improve the system if implemented in the steadystate model.