A new approach for congestion management via optimal location of FACTS devices in deregulated power systems

This paper investigates a novel optimization-based methodology for placement of flexible AC transmission systems (FACTS) devices in order to relieve congestion in the transmission lines while increasing static security margin and voltage profile of a given power system. The optimizations are carried out on the basis of location, size and number of FACTS devices. Thyristor controlled series capacitor (TCSC) and static Var compensator (SVC) are two mainly emerging FACTS devices and they are used in this paper to reduce the congestion. The problem is formulated according to sequential quadratic programming (SQP) problem in the first stage to accurately evaluate static security margin with congestion alleviation constraint in the presence of FACTS devices, and in the next stage a simulated annealing (SA) based optimization method is used to find the optimal solution. The proposed placement approach reduces the congestion in the transmission lines and enhances distance of voltage collapse point without use of high computational burden procedures such as continuation power flow method. The IEEE 14-bus test system is selected to validate the proposed approach.