International Journal of Automation and Power Engineering Volume 1 Issue 9, December 2012 www.ijape.org 193 Introduction to FACTS Controllers: A Technological Literature Survey Bindeshwar Singh, K.S. Verma, Pooja Mishra, Rashi Maheshwari, Utkarsha Srivastava, and Aanchal Baranwal Department of Electrical Engineering, Kamla Nehru Institute of Technology, Sultanpur‐228118(U.P.), India Email: bindeshwar.singh2025@gmail.com Abstract This paper presents a review on applications of Flexible AC Transmission Systems (FACTS) controllers such as Thyristor Controlled Reactor (TCR), Thyristor Controlled Switched Reactor (TCSR), Static VAR Compensator (SVC) or Fixed Capacitor‐ Thyristor Controlled Reactor (FC‐TCR), Thyristor Controlled Series Capacitor (TCSC), Thyristor Controlled Switched Series Reactor (TSSR), Thyristor Controlled Brakening Reactor (TCBR), Thyristor Controlled Voltage Reactor (TCVR), Thyristor Controlled Voltage Limiter (TCVL Thyristor Controlled Switched Series (TSSC), Thyristor Controlled Phase Angle Regulator (TC‐PAR) or Thyristor Controlled Phase Shift Transformer (TC‐PST), Static Synchronous Series Compensator (SSSC), Static Synchronous Compensator (STATCOM), Distributed Static Synchronous Compensator (D‐STATCOM), Generalized Unified Power Flow Controller (GUPFC), Unified Power Flow Controller (UPFC), Inter‐link Power Flow Controller (IPFC), Generalized Inter‐link Power Flow Controller (GIPFC),and Hybrid Power Flow Controller (HPFC), Semi‐ conductor Magnetic Energy Storage (SMES), Battery Energy Storage (BESS), in power system environments for enhancement of performance parameters of power systems such as reactive power support, minimize the real power losses, improvement in voltage profile, improvement in damping ratio of power systems, provide the flexible operation and control etc. Authors strongly believe that this survey article will be very much useful for the researchers, practitioners, and scientific engineers to find out the relevant references in the field of enhancement of performance parameters of power systems by different FACTS controllers such as series, shunt, series‐shunt, and series‐series connected FACTS controllers are incorporated in power systems. This article is very much useful for researchers for further research work carryout in regarding with the application of FACTS controllers in power system environments for enhancement of performance parameters of systems. Keywords FACTS; FACTS Controllers; TCR; TSC; TCSC; SVC; TC‐PAR; SSSC; STATCOM; D‐STATCOM; UPFC; GUPFC; IFPC; GIPFC; and HPFC; SMES; BESS; TCBR; TSSR; Power System (PS); Performance Parameters of Systems Nomenclatures HVDC High Voltage Direct Current PSS Power System Stabilizers AP Active Power RP Reactive Power VSC Voltage Source Converter VSI Voltage Source Inverter VS Voltage Stability VI Voltage Instability VC Voltage Collapse VP Voltage Profile VR Voltage Regulation SSVS Steady State Voltage Stability TS Transient Stability APTC Available Power Transfer Capacity PQ Power Quality SSR Sub‐synchronous Resonance OPF Optimal Power Flow NRFL Newton Raphson Load Flow FL Fuzzy Logic NN Neural Network GA Genetic Algorithm PSO Particle Swarm Optimization POD Power Oscillation Damping DGs Distributed Generations SS Steady State FCL Fault Current Limiting