Advent in power electronics enhanced the dynamic performance of modern powersystem and Flexible AC Transmission Systems (FACTS) provided vital solution for it.FACTS are basically thyristor-controlled devices which control the active and reactivepower flow in the network and are equally adaptive to voltage magnitude control thus,utilize the existing power network optimally. But increase in complexity, configurationsand total power transmitted lead to a number of problems in relation to transmissionline protection. The most widely used protection system in case of high voltage and extrahigh voltage transmission lines is Distance protection. However, installation of seriescompensation system creates problems for protective relays and fault locators due tochange in the magnitudes and directions of fault voltages and currents in the networksand causes malfunctioning of the distance relay. Since protection of transmission linesplays crucial role in improving the stability and reliability of electric power systems,this paper also throws light on the impact. MATLAB/SIMULINK is used effectively inmodelling and simulation of distance relay as well as transmission line compensatedwith thyristor-controlled series compensator. The simulation results illustrate theeffective use of MATLAB/SIMULINK in understanding the behaviour of distance relayin protecting the transmission lines with and without compensation.