A transmission line plays an important role in an
electric power system to distribute electricity from power plants to
substations. Distance relay as the primary protection of the
transmission line serves to isolate faults. Arc resistance emerged
during faults may affect the performance of the distance relay.
Distance relay even can work incorrectly due to a mistake in
identifying the faults.The purpose of this study is to determine the
effect of fault arc on the transmission line to the performance of
distance relay at transmission line 150 kV. In this research,
modeling system used NEPLAN software. Then, short circuit
simulation in the area around the tip of zone one protection was
conducted to determine the value of the arc resistance using
Warrington equation. Simulation results of the distance relay
performance with arc resistance were compared to those without the
resistance. The simulation results showed that the arc resistance
could reduce the effectiveness of distance relay to protect the
transmission line. In one phase to ground faults, the reach of the
zone one protection was approximately 74% out of 80%. While in
two and three phases to ground faults, it was about 76% out of 80%.
