The single-phase transformer of Problem 7.1 is to be connected as a stepdown autotransformer to...

The single-phase transformer of Problem 7.1 is to be connected as a stepdown autotransformer to transform the voltage from 2400V down to 2160V.

a. Draw the connection diagram including the series impedance and shunt admittance.

b. Determine the autotransformer kVA rating.

c. Determine the a, b, c, d, A, and B generalized constants.

d. The autotransformer is serving a load of 80 kVA, 0.95 lagging power factor at a voltage of 2000V. Including the impedance and shunt admittance, determine the input voltage, current, and complex power.

e. Determine the per-unit impedance and shunt admittance based upon the autotransformer rating. How do these values compare to the perunit values of Problem 7.1?

Problem 7.1

A single-phase transformer is rated 100kVA, 2400–240V. The impedances and shunt admittance of the transformer are