9-15. The transmission line of Problem 9-11 is connected between two infinite busses, as s...

9-15. The transmission line of Problem 9-11 is connected between two infinite busses, as shown in Figure P9-1. Answer the following questions about this transmission line.

Figure P9-1 A three-phase transmission line connecting two infinite busses together.

(a) If the per-phase (line-to-neutral) voltage on the sending infinite bus is 80∠10° kV and the per-phase voltage on the receiving infinite bus is 76∠0° kV, how much real and reactive power are being supplied by the transmission line to the receiving bus?

(b) If the per-phase voltage on the sending infinite bus is changed to 82∠10° kV, how much real and reactive power are being supplied by the transmission line to the receiving bus? Which changed more, the real or the reactive power supplied to the load?

(c) If the per-phase voltage on the sending infinite bus is changed to 80∠15° kV, how much real and reactive power are being supplied by the transmission line to the receiving bus? Compared to the conditions in part (a), which changed more, the real or the reactive power supplied to the load?

(d) From the above results, how could real power flow be controlled in a transmission line? How could reactive power flow be controlled in a transmission line?