Research on the fault location of transmission line compensated by FACTS

Flexible Alternative Current Transmission Systems (FACTS) based on Voltage Source Converter (VSC) is used for voltage regulation in transmission and distribution systems. FACTS can rapidly supply dynamic VARs required during system faults for voltage support. The apparent impedance is influenced by the reactive power injected or absorbed by FACTS, which will result in the under reaching or over reaching of distance relay. This paper presents simulation results of the application of distance relays for the protection of transmission systems employing FACTS controllers. The complete digital simulation of FACTS within a transmission system is performed in the MATLAB/Simulink environment using the Power System Block set (PSB). An efficient method based on wavelet transforms, fault detection, classification and location is proposed using ANN technique which is almost independent of fault impedance, fault distance and fault inception angle of transmission line fault currents with FACTS controllers.