Question

(d A transmission line is protected by a distance relay. During a B-C phase-to-phase fault on this line, the secondary values measured by the relay are: a-60.4 +j12.03 V --27.36-j44.41 V Ve36.18+j37.38 V --2.2-j1.33 A e-2.2 +j1.33 A i) Find primary value of the positive sequence fault impedance measured by the relay assuming a VT ratio of 132kV/110V, and a CT ratio of 800:1. (ii) Estimate the distance to fault knowing that the per unit length positive sequence impedance of the line is ZI-(0.03+j0.38)2/km 35%

Answer 1

3 Ye a 2 3 27.36 3414 3 +3738 丨£3.00 22+1 2.3.1893 (54. 33 40 +j 7,7277) => Ya

2 3 3 3.8loS a, s Za,p