3: A 200-km, 230-kV, 60-Hz three-phase line has a positive-sequence series impedance z = 0.08 +j0.48 2/km and a positive-sequence shunt admittance y =j3.33 x 10-6 S/ km. At full load, the line delivers 250 MW at 0.99 p.f. lagging and at 220 kV. Using the nominal circuit, calculate: (a) the ABCD parameters, (b) the sending-end voltage and current, and (c) the percent voltage regulation.

1 PROBLEM 20020° V rms, Vbn 1. A balanced three-phase Y-Y system has the phase voltages of Van 200/120° V rms, and Ven = 2002(-120°) Vrms. The load impedance per phase is Z₁ = 50 - j100 n. a Van Vcn n Vbn Ia Ib Ic B Zu (b) Determine the line currents Īa, Ip and Īc. (c) Determine the total average power delivered to the three loads. N C = ZL (a) The balanced three-phase circuit has a negative phase sequence. Circle your choice. (1) True (ii) False

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A single phase transmission line delivers 1500 kW at 33 kV at 0.8 p.f. lagging. The total resistance and inductive reactance of the line are 10 2 and 15 2 respectively. Determine     (i) sending end voltage (ii) sending end p.f. and (iii) efficiency of transmission.