9000 MW are to be transmitted from a hydraulicpower plant to a load center located 500 km away from the plant . Find the surge impedance load and based on the practical line loadability determine the number of three phase,60 Hz lines required to transmit this power, with one line out of service (hints add one more line to whatever obtained)) for the following case: (a) 345 kV lines with Zc= 297 ohm (b) 765 kv lines with Zc= 266 ohm
Assume Vs=1.0 pu Vr= 0.95 pu and delta=35' (practical line lodability crieteria) Also asuume that the lines are uncompensated and widely seprated such that there is negligible mutual coupling between them.