Page 582 - Basic Electrical Engineering
P. 582
Full-load copper loss = 400 W
At half load
Output = 10 × 10 3
Core loss = 350 W (remains constant at all loads)
= 100 W (variable loss, varies as square of
Copper loss
the load)
Example 6.11 A 5 kVA, 1000/200 V, 50 Hz single-phase transformer has
the following no-load test, i.e., the open-circuit test and the short-circuit test
data.
No-load test conducted at the low-voltage side:
W = 90 W, I = 1.2 A, V = 200 V
0
0
The short-circuit test conducted at the high-voltage side:
W = 110 W, I = 5 A, V = 50 V
sc
sc
sc
Calculate the efficiency of the transformer at full-load 0.8 p.f. lagging. What
will be the equivalent resistance of the transformer windings referred to high
voltage side?
