A three-phase Y-Y transformer is rated at 25 MVA, 13.8-kV:69-kV and has a single-phase equivalent series impedance 62 + j388 m? Referred to the low-voltage winding

What are the possible vector groups?

Draw the transformer per phase equivalent circuit in per unit.

A three-phase short circuit is applied to the low-voltage winding. Calculate the voltage applied to the high-voltage winding which will result in rated current into the short circuit.

The short circuit is removed and a three-phase load is connected to the low-voltage winding. With rated voltage applied to the high-voltage winding, the input power to the transformer is observed to be 18 MW at 0.75 power-factor lagging. Calculate the line-to-line terminal voltage at the load.

Answer rating: 100% (QA)

Given that data is shown below Given data is 25 mVA 138 Kv09 KV R OL jX ... View the full answer