Indian Journal of Science and Technology

Abstract

Objectives: Inter-area frequency oscillations are one of the major problems in the present power systems for smooth operation to transfer power from one area to another area through weak tie-lines. Methods/Statistical Analysis: If oscillations are not damped out quickly, problem like system instability, cascade failure and even blackouts may occur. Local mode of oscillations can be damped out by using Power System Stabilizers (PSS) but damping inter-area mode of oscillations using PSS may not be possible always. The major concerns in power system operation were damping power system oscillations. Flexible Alternating Current Transmission System(FACTS) technology has been used extensively for power control, voltage regulation, increasing the transient stability, and decreasing system oscillations. Among all FACTS devices, Unified Power Flow Controller (UPFC) ismost efficient which has the potential to increase the power flow and stability of the transmission line. Due the constantly changing nature of power system Conventional PI controller is not applicable. To overcome the drawback Artificial Intelligent(AI) techniques like Fuzzy Logic and Neural Network are combined as Neuro-Fuzzy based Controller. In this paper an Adaptive Neuro-Fuzzy Interface System(ANFIS) based UPFC is designedto enhance system stability. Findings: The main idea of FACTS technology is to improve controllability and optimizing the utilization of existing power system capacities using the high speed and reliable power electronic devices instead of mechanical controllers. FACTS controllers like UPFC provides set of interesting capabilities such as reactive power compensation, power flow control, voltage regulation, damping of oscillations. Thispaper has focused on the investigationofperformanceand the comparison ofUPFC on powerflowwithANFIS and Proportional Integral(PI) controllers.The comparative results of Eigen value and damping ratio with PI and ANFIS controllers have been shown. Thecomprehensive simulationcases areexaminedandtheresultsshows thattheproposedmodelare botheffectiveand reliable indampingtheinterareaoscillations oftwoareasystem. Applications/Improvements: The simulation studies are carried out in MATLAB/SIMULINK to analyze the performance and comparison of designed ANFIS and PI Controller.
Keywords: Adaptive Neuro-Fuzzy Interface System(ANFIS), Proportional Integral (PI) Controller,System Stability, Inter-area Oscillation, Unified Power Flow Controller (UPFC)