A 220 kV, 150 MVA, 60 Hz three-phase transmission line is 140 km long. The characteristic parameters of the transmission line area:
r = 0.12 Ω / km; x = 0.88 Ω / km ; y = 4.1 × 10-6 S / km
Where r is the resistance, x is the reactance, and y is the shunt admittance.
The voltage at the receiving end of the transmission line is 210 kV. Assume that the transmission line is a short transmission line.
If the line is supplying a rated voltage, which of the following is/are true?1
At 0.85 pf lagging, the sending end voltage is 158.6 kV
2
At 0.85 pf lagging, the sending end voltage is 275 kV
3
At unity if, the sending end voltage is 238.3 kV
4
At 0.85 pf leading, the sending voltage is 191.4 kV