PERFORMANCE OF DISTANCE RELAY WITH DIFFERENT IMPEDANCE CHARACTERISTICS IN THE PRESENCE OF STATCOM FOR VARIOUS FAULTS ON TRANSMISSION LINES

Abstract

The rapid growth of electrical power demand necessitates the construction of transmission lines and power grids without compromising power quality. To achieve high power quality, advancements in semiconductor devices are utilized in the form of Flexible AC Transmission Systems (FACTS) [1]. FACTS devices compensate the system by altering parameters, especially power system impedance and power angle, making it essential to analyze system performance and transmission line protection, as relay settings depend on line impedance. The distance relay is a critical protective relay in this regard. FACTS devices include SVC, TSC, TCR, TCSC, and self-commutated VAR compensators such as STATCOM [2]. SVCs are used for damping power swings and improving stability [3]-[4]. Among FACTS devices, STATCOM is the most versatile, providing both leading and lagging reactive power, fast response, low harmonic content, no inrush current, and good dynamic performance [5]. DSTATCOM is commonly used for reactive power compensation. This work analyzes distance relay performance with different impedance characteristics in the presence of DSTATCOM using MATLAB/Simulink, and a communication-aided scheme ensures correct zone-1 operation without mal-operation.