Question

The iron loss and full load copper loss of 100 KVA, 6600/400 Volts single phase

transformer are 600W & 900W. Calculate the efficiency at full load and half load, at 0.8 pf

lag.​

Answer 1

The efficiency is 81.6 kVA

To find:

the efficiency of a full load and a half load.

Given:

Iron loss = 600 W

Copper loss = 900W

Solution:

Maximum efficiency is 81.6 kVA

A transformer's maximum efficiency happens when copper losses equal iron losses. Efficiency is maximum at a certain proportion of full load, "k."

k= √(W_i/W_Cu )

Where W_i is the iron loss and W_Cu is the copper loss

kVA at maximum efficiency is given by the equation

kVA at ƞ_max=Full load kVA × √(W_i/W_Cu )

For the given copper and iron loss;

k= √(600/900 )

k= 0.816

Presently, the load where maximum efficiency occurs is provided by,

= k * 100kVA

=81.6 kVA

#SPJ1