PMU based fault location for double circuit transmission lines in modal domain

This paper proposes a new fault location technique for EHV double circuit transmission lines using synchronized current and voltage measurements from both ends. Double circuit lines faces difficulties in fault location due to mutual coupling. Modal transformation is used to decouple the coupled transmission line equations. Fault detection and location indices in terms of modal components of measured currents and voltages are derived. The transmission lines are modeled as equivalent π in the modal domain so as to compensate the effect of charging current. The proposed indices are tested by simulation in ATP and implementing the algorithm in MATLAB. The simulation results shows that the proposed method can effectively locate ground as well as phase faults in presence of fault resistance.