I. Introduction
The electrical power systems are extremely complex networks [1] covering vast area with several generators, different level transformers, numerous interconnected transmission lines and multiplicity of loads. Hence electrical power systems are adjudged as one of the most multifaceted and complicated control system in existence. Consequently, an interconnected power scheme control and operation must ensure that all operational variables are coordinated and structured within acceptable ranges under any given conditions [2]. Contingencies, ever increasing power demand and distribution together with limited or no expansion of the grid system result in overloading of the lines, generation and operation around system limit [3], [4] and [5]. Achieving reliable and secure power system is critical challenge. FACTS devices are being increasingly used in the network to address some of these challenges. FACTS have been used for power flow control, voltage control/regulation and stability enhancement [6] and [7]. FACTS controllers are incorporated into the power system in shunt on the buses or in series with the transmission lines or hybrid of shunt with series connection to accomplish these several control tasks [8], [9] and [10]. An IPFC, a recent generation FACTS devices which enables control of active power and reactive power, consists of two Voltage Source Converters (VSCs) which are technically Static Synchronous Series Compensators (SSSCs). Each converter can regulate reactive power in their respective transmission line of installation through series injection of voltage. The real power is exchanged between the VSCs via a common bi-directional DC link.