Q. 50 Voltages phasors at the two terminals of a transmission line of length 70 km have
a magnitude of 1.0 per unit but are 180 degree out of phase. Assuming that the
maximum load current in the line is 1/5th of minimum 3-phase fault current. Which one of the following transmission line protection schemes will not pick up for this condition ?
(A) Distance protection using ohm relay with zoen-1 set to 80% of the line
impedance.
(B) Directional over current protection set to pick up at 1.25 times the
maximum load current
(C) Pilot relaying system with directional comparison scheme
(D) Pilot relaying system with segregated phase comparison scheme
Answer:(*)
Explanation:
Not Required.
