Question

Plate values ​​of a three-phase transformer are given below:
1600 kVA, 15 kV / 400 V, 50 Hz, io = 1.2%; ukN = 6%, idle losses 2450 W, rated
copper losses of power 14500 W; Dy5.
a) Calculate primary and secondary line and phase currents.
b) Secondary at 75% load in power factor with 0.85 inductance and 0.85 capacity
calculate the voltage separately. Compare and interpret the results. capacity
at what time of day can the upload be seen? To prevent voltage change
What solution should be applied?
c) Calculate the rated operating efficiency and maximum efficiency of the transformer.
d) Draw the fastening group. How is this transformer parallel with the transformer Dy11 connected
run?
e) If this transformer is operated at 60 Hz, which sizes change how?
Your review.

Answer 1

In the Output Equation, the flux density depends on the type of material used to construct the Transformer Core; the current density depends on the type of cooling provided; and the window space factor is a constant. Therefore, the KVA rating is directly proportional to the product of frequency, area of the window and cross-sectional area of the limb. In other words, the KVA rating is directly proportional to the product of frequency and the size of the transformer.

For a given Transformer Rating, as the frequency increases, the product of window area and cross-sectional area of the limb decreases; this means the size of the Transformer core and the amount of iron required for the core decreases. Therefore as the frequency increases, the transformer becomes lighter and smaller in size.