IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 05, 2015 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 1009 Application of UPFC used IEEE Bus Standard System for Minimizing the Transmission Losses Miss. Dipali V. Patil 1 Prof. Parag Chourey 2 1,2 Department of Electrical Engineering 1,2 Sant Gadgebaba Amravati University, Amravati, Maharashtra, India Abstract— The unified power flow controller (UPFC) is the most versatile and advanced member of flexible ac transmission systems (FACTS) devices .This is the capable of controlling real -reactive power flows, as well as providing voltage magnitude control in power networks through a transmission line by placing the UPFC. This paper presents a comprehensive review on the with and without UPFC placed on transmission line. Voltage source inverter based UPFC device control parameters with respect to reduction in the transmission line losses and total system real power loss to enhance the power system security. This paper describes the basic principle of operation of UPFC, its advantages and to compare its performance with the one of the FACTS equipment available. Key words: FACTS Controller, UPFC Controller Real – Reactive Power Flow, Voltage Source Inverter I. INTRODUCTION Flexible AC transmission system is an evolving technology to help electric utilities [1]. Its first concept was introduced by N.G Hingorani, in 1988 (FACTS) is very popular and essential device in power systems. The (FACTS) concept based on applying power electronics technology to existing AC transmission systems, improves stability to increase usable power transmission capacity to its thermal limit. FACTS family with very attractive features. The system planner has to select a controller out of the set of FACTS Controllers, for improving the system operation, based on cost benefit analysis proposed the Unified Power Flow Controller (UPFC) concept in 1991[1]. In this paper the injection model of UPFC is used to investigate its effect on load flow and loss reduction in power system. In this study the Newton-Raphson algorithm is modified to consider the benefits of having UPFC in the power system The optimum place for installing UPFC in order to have minimum loss in the system The proposed concept is known as Flexible AC Transmission Systems (FACTS) [1]. The two main objectives of FACTS are to increase the transmission capacity, control Power flow over designated transmission routes and minimizing the transmission losses.[1-3] The UPFC is the most versatile and complex of the FACTS devices, combining the features of the STATCOM and the SSSC. The UPFC can provide simultaneous control of all basic power system parameters, viz., transmission voltage, Impedance and phase angle. It is recognized as the most sophisticated power flow controller currently, and probably the most expensive one. In this review paper, presents real and reactive power flow control through a transmission line by placing UPFC at the sending end. When no UPFC is installed, real and Reactive power through the transmission line cannot be controlled. II. LITERATURE REVIEW UPFC is primarily used for independent control of real and reactive power in transmission lines for a flexible, reliable and economic operation and loading of power system. The UPFC, which was proposed by Gyugyi in 1991, is one of the most complex FACTS devices in a power system today .Now recently all three parameters that affect real and reactive power flow on the line, i.e. the line impedance, voltage magnitudes at the terminals of the line and power angle, were controlled separately. It can be using various types of FACTS devices such as a Static Var Compensator (SVC), a Thyristor Controlled Series Capacitor (TCSC), a phase shifter etc. But our focus on UPFC. However, the UPFC allows simultaneous or independent control of these parameters with transfer from one control scheme to another in real time. Also, the UPFC can be used for voltage support, transient stability improvement and damping of low frequency power oscillations. M. Noroozian L. Angquist et. al 1993[11] The proposed model is used to demonstrate some of the features of UPFC for optimal power flow control applications. This paper shows that a UPFC has the capability of regulating the power flow and minimizing the at the same time. This outstanding feature can be utilized for various power flow control applications, for example, overload relief, loop flow minimization, etc. Since the size of UPFC has a great impact on power system performance and also in view of the device cost, the optimal dimensioning of UPFC for a specific application is quite important. Such a subject is handled in this paper and a dimensioning algorithm is proposed. Renz et.al.1999 [8] The shunt converter of the UPFC controls the UPFC bus voltage/shunt reactive power and the dc link capacitor voltage. The series converter of the UPFC controls the transmission line real/reactive power flows by injecting a series voltage of adjustable magnitude and phase angle. Tanushree Kaul, Pawan Rana et. al. 2013[12] In the recent years ecological concerns and high installation costs have put constraints over construction of new plants and overhead lines in many countries, thereby forcing existing system to be used more efficiently rather than constructing new lines, industry has tended towards the development of technologies or devices that increase transmission network capacity while maintaining or even improving grid stability. Our main objective is to meet the electric load demand reliably while simultaneously satisfying certain quality constraints imposed on the power supply Until a few years ago, the only means of carrying out this function were electromechanical devices such as switched inductors or capacitor banks and phase shifting transformers, however, specific problems related to these devices make them not very efficient in some situations they are not only relatively slow, but they also cannot be switched frequently, because they tend to wear out quickly.