A Hybrid Scheme for Fault Locating in Transmission Lines Compensated by the TCSC

The power electronics-based devices are being used to improve the flexibility, controllability, and reliability of the power systems. Among these instruments, the thyristor-controlled series compensator (TCSC) is widely used at long transmission lines to compensate the series impedance/reactance of the line and to increase the maximum transferrable power and thus improving stability margins of the power system. However, TCSC impacts the equivalent impedance of the power line, and thus the conventional method for fault detecting and fault locating fails to work appropriately. This paper presents a novel hybrid method for modifying the performance of the distance relay on a TCSC-equipped transmission line. The proposed technique is evaluated through modeling and simulation results in Matlab/SIMULINK. The results prove that the proposed method improves the accuracy and performance in detecting the fault location in the series compensated transmission lines to prevent the malfunction of the relay operation.