A certain oil filled 100 MVA three phase transformer is rated at 345 kV / 25 kV, 75 degree C temperature rise, FOA, 60 Hz, connected delta / grounded wye. The equivalent circuit of the transformer has leakage impedance of Z = R + jXL = 11.0 +j100 ohms / phase and magnetizing and core branch Rc and Xm (in parallel) of Rc = 55 k-ohm / phase and Xm = 30 k-ohm / phase. All of this data is referred to the high side of the transformer.
(A) If the low side of this transformer is open circuited, find the current on the high side of the transformer if the high side is energized to 345 kV.
(B) The transformer is now operated at rated load and unit power factor. Estimate the active power losses in the transformer leakage branch R +jXL.
(C) Find the rated high side current of this transformer.