231 Ishit Shah, Neha Srivastava, Yogesh Prajapati, Jigar Sarda International Journal of Electronics, Electrical and Computational System IJEECS ISSN 2348-117X Volume 4, Special Issue March 2015 Implementation of UPFC for Improving the Power flow and Voltage Profile Ishit Shah 1 , Neha Srivastava 1 , Yogesh Prajapati 2 , Jigar Sarda 3 1 (Electrical, M.E. Student at Birla Vishvakarma Mahavidyalaya, V.V.Nagar, India), 2 (Electrical, Asst. Professor at Birla Vishvakarma Mahavidyalaya, V.V.Nagar, India), 3 (Electrical, Asst. Professor at Charotar University of Science and Technology, Changa, India). ABSTRACT As the present scenario of Power system network is getting huger and complex, it’s giving rise to th e need of an effective tool to incorporate in the system so that the power flow can be maintained at an optimum level. This not only helps to maintain the voltage stability but also helps to reduce the losses. Thus, the main objective of this paper is to enhance the Power flow using UPFC controller. The UPFC which is a type of FACTS device controller has been used here which proves to be an effective tool that improves power transfer capability of the system and at the same time keep the system, stable and reliable. The UPFC model has been implemented here and is also included in the N-R load flow algorithm to minimize the losses of the system and thus improve the Voltage stability. The analysis has been performed on IEEE-14 bus system. Keywords: Enhancement of Power flow; Improvement of Voltage Level; Newton-Raphson Load flow; Unified Power Flow Controller (UPFC); MATLAB. I. INTRODUCTION Today’s Power system network is a complex network which are frequently prone to disturbances and faults. At the same time, the Unpredictable Power demand is creating a need for a faster, accurate and reliable system that can overcome the present day power system problems. At present voltage stability issue is one of the major concerns in the power system network. It can be configured by using the FACTS devices. The FACTS devices can be grouped into three categories: Series, Shunt and combination of Series-Shunt controllers. The series controllers are used to inject voltage in series with the line, shunt controllers are used to inject current and a combination of these two helps to inject voltage through the series part and inject current through the shunt part of the system at the point of connection. The Unified Power Flow Controller (UPFC) (a type of series-shunt combination) , which was proposed by GyuGyi in the year 1991[7], is a type of FACTS device which utilizes Voltage Source Converters (VSC) to control the parameters like voltage, phase angle, impedance, that mostly affects the power flow in a transmission line. It can be used to control power flow, enhance the voltage, mitigate the oscillation in the system, etc. Thus, it is capable of controlling both active and reactive power. Hence to meet the ever increasing power demand and solve the major concerns of today’s power system network scenario, UPFC proves to be an effective device that can control the comprehensive power flow efficiently [8]. IEEE-14 bus system is used for the system under