Electrical Machine - IES Academy
Electrical Machine - IES Academy
Electrical Machine - IES Academy
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India’s No. 1<br />
<strong>IES</strong> <strong>Academy</strong><br />
Transformer<br />
Chapter-1<br />
I = I + I<br />
2 2<br />
e m c<br />
(b)<br />
(c)<br />
Effect of transformer winding resistance: the winding resistances are no longer<br />
considered zero and their effect is included.<br />
Effect of leakage flux: Other than the<br />
mutual flux that links both the primary<br />
and secondary windings, there exists<br />
some leakage flux which exists only in<br />
the primary winding and is in phase<br />
with Ie. This leakage flux induces an emf<br />
in the primary winding given as<br />
E<br />
x 1 =− jIe<br />
x . 1<br />
Hence total voltage drop in the primary<br />
winding and voltage in the primary at<br />
no load is<br />
Ie( r1 + jx1)<br />
= Ie<br />
z1<br />
V = V ' + Ie( r + jx )<br />
1 1 1 1<br />
E<br />
a<br />
and E<br />
Even at full load, primary leakage<br />
impedance drop is about 2 to 5 % of the<br />
applied voltage, so that the magnitude of<br />
V1’ or E1 does not change appreciably<br />
from no load to full load.<br />
b<br />
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