A Robust Fault Detection and Discrimination Technique for Transmission Lines

The complex and large power systems of modern time with distributed generation are more prone to the faults. Conventionally, the zone based primary and backup protection relies mainly on the information of positive sequence impedance sensed by the relay to protect these lines. The phenomena such as power swings, load encroachment, etc., can also result into low impedance and can trigger the cascade tripping of relays. In this paper, we proposed a robust fault detection and discrimination (RFDD) technique for transmission lines, which utilizes a robust method of phasor estimation to compute accurate fault impedance along with a feature value extracted from the samples of voltage and current signals. The effectiveness of the proposed RFDD technique has been tested and validated on IEEE 14-bus system, six generator 23-bus system and reduced NEREB 29-bus Indian power system with distributed generation using Siemens PSS/Sincal software. The results from simulation explore that RFDD technique can enhance the capability of distance protection relays for the future electric grids.