A synchronous generator rated 10 MVA, 13.8kV (line-to-line) is supplying a Y-connected load over a transmission line. The synchronous reactance, Xs, of the synchronous generator is 0.2 p.u. on its own base. The transmission line is modeled with a series impedance of 1.0+j2.0 p.u. on a base of 20MVA, 15.0kV. The impedance of the load is 300+((j50)ohms/phase). It is found that the line-to-line voltage across the load has a magnitude of 13.0kV.
(a)Compute the per unit values of the transmission line and load impedances, and the load voltage, on the generator MVA and kV bases.
(b)Determine the amount of reactive power from a shunt capacitor located at the load, in per unit, required to correct the load power factor to 1.0.
(c)Compute the per unit terminal voltage and the per unit excitation voltage of the generator (magnitude and angle for both).
(d)Compute the per unit real and reactive power flowing into the transmission line from the generator terminals. Use the "exact" power flow equations.
(e)Should the real power consumed by the load be higher or lower than the real power computed in part (d) ? Justify your answer.
(f)Use the power equations for a synchronous generator to compute the per unit real and reactive power flowing out of the generator terminals.
(g)Should the reactive powers computed in parts (d), (f) be the same or different? Justify your answer.
(h) It was noticed (in the field) that when the load was turned off (0 real power consumption) that the generator began to operate leading, yet the engineer was not able to replicate this behavior using the model described above. Explain what is deficient about this model.