SUPERIMPOSED MOVING SUM Approach for Protection of Transmission Lines Possessing UPFC

In this paper, a fault detection and faulty phase selection of a two generator two bus system with unified power-flow controller (UPFC) is studied extensively by generating the data in EMTDC/PSCAD environment. Distance relaying of transmission line having UPFC is a very challenging task. Different fault cases are simulated by placing the UPFC at the sending end of a 230kV transmission line in two generator two bus system. A one cycle three-phase current data are collected at 1 kHz sampling rate for detection and classification of different faults by moving sum based technique. The results presents the proposed technique of frequency domain analysis possesses very fast and accurate protection for UPFC based power transmission lines.