pole and space-fundamental component of the armature m.m.f.wave. With the brushes in
the quadrature axis the angle between these fields is 90 electrical degrees, and its sine
equals unity. For a pole machine
(1-1)
In which the minus sign gas been dropped because the positive direction of the torque
can be determined from physical reasoning. The space fundamental of the sawtooth
armature m.m.f.wave is times its peak. Substitution in above equation then gives
(1-2)
Where, =current in external armature circuit;
=total number of conductors in armature winding;
=number of parallel paths through winding.
And
(1-3)
is a constant fixed by the design of the winding.
2
1
2 2
d
P
T
Fa
π
φ
? ?
=
? ?
? ?
1
Fa
2
8
π
(
)
2
a
a a
PC
T
i N m
m
φ
π
=
a
I
a
C
m
2
a
a
PC
K
m
π
=
a
e
a
e