
2-6 Power Electronics and Motor Drives
to angle n
r
β), the vectors of the mmf fundamental components created by the two layers will also be
shied by the same angle.
Let us dene A
layer
as the amplitude of the mmf fundamental component produced by each layer
and K
d
as the distribution coecient of the single layer. e amplitude of the resultant mmf can be
calculated as
A A
n
A K
Z
I
r
d
f
fundamental layer layer
; where= ⋅ =2
2
1
2
cos
β
π
A K
n
Z I
d
r
f
fundamental
= ⋅ ⋅cos
β
π
K
n
r
r
= cos
β
2
(2.8)
e coecient K
r
is called shortening coecient of the winding. is coecient is equal to 1 when
the two layers are superposed in the same slots (n
r
= 0). Obviously, in th