Impact of Static Synchronous Compensatoron Performance of Distance Protection of Transmission Lines

Abstract

The effect of static synchronous compensator (STATCOM) installed at transmission line on the performance of distance protection is investigated in this paper. The paper explores an apparent impedance calculation procedure for transmission line incorporating STATCOM based on the power frequency sequence circuits. A detailed model of 6 pulses STATCOM and its control and a mho relay model are proposed and integrated into the transmission system. The paper investigates distance protection operation of transmission lines with STATCOM connected at the midpoint during several operation conditions. Installation of STACTOM in the midpoint to control the reactive power flow affects the operation accuracy of distance relays. The simulation results of distance relays for the protection of transmission line incorporating STATCOM are presented. The analytical calculations show the impact of STATCOM on the distance protection relays during the different faults conditions. The study is carried-out using PSCAD/EMTC software.