STATCOM Impact on Distance Relay Performance

Abstract

Flexible AC Transmission System devices provide for better utilization of already existing transmission systems as well as newly installed and upgraded systems. The use of such devices in the power transmission systems introduce new situations and variable operating conditions that need to be addressed in the fields of power system protection, system stability etc.

In this work, the effect of introducing a STATCOM device in the send-end and mid-point of a moderately long transmission line is analyzed.   The analysis concerns the effect of such device on the performance of the power line distance protection. Extensive series of various fault studies were conducted using MATLAB/SIMULINK models of a distance relay, STATCOM device, and the power transmission system under study. Obtained results confirmed the idea of varied apparent impedance seen by the distance relay. In conclusion a distance relay may not operate dependably in presence of STATCOM device without prior actions considered in the relay setting stages.