Question

3.44 A 130-MVA, 13.2-kV three-phase generator, which has a positive- sequence reactance of 1.5 per unit on the generator base, is connected to a 135-MVA, 13.2 A/115 Y-kV step-up transformer with a series impedance of (0.005+ j0.1) per unit on its own base. (a) Calculate the per-unit gen- erator reactance on the transformer base. (b) The load at the transformer terminals is 15 MW at unity power factor and at 115 kV. Choosing the transformer high-side voltage as the reference phasor, draw a phasor dia- gram for this condition. (c) For the condition of part (b), find the trans- former low-side voltage and the generator internal voltage behind its reactance. Also compute the generator output power and power factor.

Fig: 1