Page 92 - Electric Machinery Fundamentals

68 ELECTRIC MACHINERY FUNDAMENTALS

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- - +
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II \ \ \

Np N,
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FIGURE 2-2
Core-form transformer construction.
(

Np
0-
f------<>
Ns
fjj; §@

(a) (b)

FIGURE 2-3
(a) Shell-form transformer constmction. (b) A typical shell-form transformer. (Courtesy afGeneral
Electric Company.)

Power transformers are given a variety of different names, depending on
their use in power systems. A transformer connected to the output of a generator
and used to step its voltage up to transmission levels (110+ kV) is sometimes
cal1ed a unit transformer. The transformer at the other end of the transmission line,
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