Page 44 - Electric Machinery Fundamentals

20 ELECTRIC MACI-llNERY FUNDAMENTALS

=--
i

N= 200 A= 12cm 2
turns

{g = 0.05 em
'c=50cm

(a)

(b)

FIGURE 1-9
(a) A simplified diagram of a rotor and stator for a de motor. (b) The magnetic circuit corresponding to (a).

The magnetic circuit corresponding to this machine is shown in Figure 1-9b. The total re-
luctance of the fl ux path is thus
'R... ~ 'R, + CR., + 'R, + CR.2
~ 166,000 + 284,000 + 16,600 + 284,000 A' tumslWb
~ 751,000 A ' turnslWb (
The net magneto motive force applied to the core is
'if ~ Ni ~ (200 turns)( 1.0 A) ~ 200 A • turns
Therefore, the total flux in the core is