Page 213 - Solutions Manual to accompany Electric Machinery Fundamentals

7-3. Prove that the equation for the induced voltage of a single simple rotating loop
2
e ind     (7-6)

is just a special case of the general equation for induced voltage in a dc machine
E  A K   (7-38)

SOLUTION From Equation 7-38,
E  A K  

ZP
where K 

2 a
For the simple rotation loop,
Z = 2 (There are 2 conductors)
P = 2 (There are 2 poles)
a = 1 (There is one current path through the machine)

Therefore,
2 2
ZP    2
K  

1
2 a 2  
and Equation 7-38 reduces to Equation 7-6.
7-4. A dc machine has 8 poles and a rated current of 120 A. How much current will flow in each path at rated
conditions if the armature is (a) simplex lap-wound, (b) duplex lap-wound, (c) simplex wave-wound?
SOLUTION
(a) Simplex lap-wound:

a  mP     18 8 paths

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