International Journal of Advanced Engineering Research and Science (IJAERS) [Vol-4, Issue-1, Jan- 2016] https://dx.doi.org/10.22161/ijaers/4.1.2 ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 5 Improving the Voltage Stability and Performance of FACTS Controller in Transmission Line Network Mr. Pravin B.Mali, Mr. Nilesh S. Mahajan ME-II, Department of Electrical Engineering, SSBT’s College of Engineering & Technology, Bambhori, Jalgaon, India Assist. Prof, Department of Electrical Engineering, SSBT’s College of Engineering & Technology, Bambhori, Jalgaon, India Abstract — Conventionally Shunt Compensation is used to increase the transfer capability of a transmission line. By using FACT’S controllers one can manage the variables such as voltage magnitude and phase angle at selected bus and line impedance. Objective of this paper is to recover dynamic voltage control and consequently increasing system load ability for 50 Hz Frequency. Now a day, five well known FACT’S devices generally used for this purpose. These FACT’S devices are (SVC) Static VAR Compensator, (TCSC) Thyristor Controlled Series Capacitor, (STATCOM) Static Synchronous Compensator, and (UPFC) Unified Power Flow Controller and (SSSC) Static Synchronous Series Compensator. The voltage drop occurs when a system is loaded beyond its highest load ability point, then many investigation methods have been projected for the study of this difficulty. Mainly of These techniques are based on the classification of system stability. These stable points are typically referred as points of voltage collapse. This paper present modeling and simulation of STATCOM & SVC in Matlab Simulink for dynamic voltage performance of transmission line network. Keywords— FACTS controllers, dynamic performance of STATCOM & SVC, VAR, Voltage Stability. I. INTRODUCTION Power Generation, Transmission and Distribution are difficult process, requiring the working of many components of the power system in cycle to make the most of the output. One of the major components to form a main part is the reactive power in system. It is necessary to sustain the voltage to deliver the active power through the lines. Different types of load required reactive power for their operation. To improve the performance of ac power systems, we need to manage this reactive power in a resourceful way and this is called as reactive power compensation [2-3]. There are two aspects to the trouble of reactive power compensation: load compensation and voltage support. Load compensation consists of improvement in power factor, balancing of actual power drawn from the supply, better voltage regulation, etc. of large variable loads. Voltage support consists of decrease of voltage variation at a given terminal of the transmission line. Series compensation and shunt compensation used to change in parameters of the system to give better-quality VAR compensation. In recent days, static VAR compensators like the STATCOM have been developed [4]. These quite satisfactorily do the job of absorbing or generating reactive power with a faster time response from (FACTS) Flexible AC Transmission system. FACTS devices allows an increase in transmission capability of apparent power through a transmission line and gives much better stability by doing adjustment of parameters that manage the power system. By using FACTS controllers control the variable elements such as voltage magnitude and phase angle at selected bus and line impedance [2]. There are five well known FACTS devices utilized by the utilities for this reason. Each of them has its-own characteristics and limits. 1.1 Troubles in Transmission line Network There are so many problems happens in Transmission, Distribution and Utilization system they are as follows, Voltage Sag, Swells, Dynamic stability limit Voltage fall down, Transient stability limit, Reduce circulating reactive power, [3-5].Voltage stability limit, Voltage flicker, Damping and oscillations etc. This paper present modeling and simulation of STATCOM & SVC for 50 Hz Frequency in Matlab Simulink for Impacts of SVC and STATCOM on power system are investigated during fault through and grid disturbance. Lastly Comparison of SVC and STATCOM are carried out for the duration of instability. 1.2 Advantages of Facts Controller 1) Increase the system security through raising the transient stability limit, limiting short circuit currents and over loads, managing cascading black-outs [3].& damping electro- mechanical oscillations of power systems and machines. 2) Provide secure tie-line connections to neighboring utilities and regions thereby decreasing overall generation reserve requirements both sides. 3) Provide upgrade of lines, Reduce the reactive power flow, thus allowing the lines to carry more active power.