Anwar S. Siddiqui , Naqui Anwer , Abdullah Umar
The smart grid can be viewed as a digital upgrade of the existing electricity infrastructure to allow for dynamic optimization of current operations as well as incorporate dynamic gateways for alternative sources of energy production. The smart grid is the modern day power transmission system with non conventional energy resources and FACTS controllers. The modern day power transmission system is a network of interconnection which connects systems at intra-regional, inter-regional and national level. Due to deregulation of the power sector, the basic transmission challenge is to provide a network capable of delivering contracted power from power supplies to consumers over a large geographical area. Power transfer in most integrated transmission system is constrained by transient and voltage stability. The power transfer capability of any transmission line largely depends on the reactance of the line keeping the transmission voltages constant. The mismatch of reactance between a group of transmissions lines result in uneven power sharing between them which may cause one or more lines to be overloaded beyond its rating. FACTS controllers can be effectively used to manage the flow of active and reactive powers of transmission systems such that no line is overloaded. This paper discusses the use of Series FACTS controllers in order to change line reactance and phase angle for controlling the power flow in a transmission system.