Allocation of TCSC from transient stability viewpoint

Recently, transmission lines have become very long and complex, thus power systems have encountered many problems such as dynamic and voltage stability. One of the solutions to these problems is the application of flexible AC transmission systems (FACTS), which depend on power electronics technologies. In this paper the authors propose a method for determining the optimal allocation of FACTS devices from transient stability viewpoint thyristor controlled series compensator (TCSC) is applied for system stabilization as a typical FACTS device. Critical clearing time (CCT) is used as an index for TCSC allocation. A robust quadratic stabilizing control method is used as the control strategy. Furthermore we evaluate stability and power transmission capability of the system with TCSC allocation based on the proposed method and through numerical simulations it is shown that the proposed method is effective and can enhance the stability margin of existing power systems.