1. Electrical Elements Design (2150904)
Active Learning Assignment
on
Concentric Windings
Prepared By:
Patel RajalKumar H.
(160123109013)
Guided By :
Prof. Purv Mistry
Electrical Department
Batch-B3Gandhinagar Institute of Technology1
2. Introduction
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• Three-phase concentric winding consists of coil groups laid in
the slots so that all the coils of each group are concentric.
• That is, the coil with the smallest slot pitch is surrounding by
the coil with the next larger slot pitch and so on to make up a
coil group.
• Each coil consists of several turns and the cross-over from one
coil to the next is indicated by a short slanted line (jumper).
3. AC Armature
Windings
Single layer
winding
Double layer
winding
Concentric
winding
Mush
winding
Lap
winding
Wave
winding
Hemitro
-pic
Whole
coil
winding
Integral
slot
Fraction
-al slot
Integral
slot
Fraction
-al slot
Types of AC armature winding
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4. Concentrated armature winding
• Concentrated winding is employed where number of slots
on the armature is equal to number of poles in the machine.
• This armature winding of alternator gives maximum output
voltage but not exactly sinusoidal.
• Here, number poles = number of slots = number of coil sides
, which is shown in below fig.
• Here, one coil side is inside one slot under one pole and
other coil side inside other slot under next pole.
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6. Construction of concentrated winding
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• In order to construct the diagram for a winding, the following
data must be known:
S - The number of slots in the stator
P – The number of poles
m – The number of phases
YS – The pitch of the winding
a – The number of parallel circuits in the windings
7. • The pitch of the winding is determined by
the formula
• The pitch is the distance between two sides
of a coil expressed as the difference between
the numbers of the slots in which the sides
lie.
• Another important value of the winding of
ac machines is the number of slot per phase
per pole denoted by the letter q. It can be
determined by the formula
P
S
YS =
mP
S
q
⋅
=
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8. Example#1: on concentric winding
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Full-Pitch ( average pitch)
i.e. there are two coils in a group
i.e. there is two coil groups per phase6
2
4
3
2
3K =⋅=⋅=
P
2
43
24
pm
S
q =
⋅
=
⋅
=
6
4
24
p
S
YS ===
10. PROCEDURE FOR CONSTRUCTING OF
CONCENTRIC WINDINGS
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Data: S= 24, P = 4, a = 1, q = 2, K = 6
11. Coil Groups of Phase A
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2. The first and second slots will be occupied by left-hand
sides of the first coil group of phase A.
3. Leave four, or 2q slots free for other two phases occupy
slots 7 & 8 with the right hand side of the first coil group.
4. Next to it will lie a second coil group of the same size which
occupies slots 9,10,15,16.
12. Coil Groups of Phase B
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slots4
30
120120
=
°
°
=
°
=
α
λ
30
24
720
===
S
γ
α
13. Coil Groups of Phase C
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