This document discusses different types of armature windings used in DC motors and generators including lap, wave, simplex, duplex, and triplex windings. It explains the characteristics of each type of winding such as the number of parallel paths through the armature, the relationship between back and front pitch, and how they are connected to the commutator segments. The document also covers closed winding configurations and how they provide multiple parallel paths while maintaining a zero resultant EMF around the complete armature circuit.

1. Presenter Name- Kumar Goswami
B.E.(ELECTRICAL ENGG.)

3. • LAP windings1
• WAVE windings2

5.  Lap winding- In lap winding, the finishing end of
one coil is connected to a commutator segment and
to the starting end of the adjacent coil situated
under the same pole and so on, till all the coils have
been connected.This winding is known as lap
winding because the side of successive coils overlap
each other.

6. • SimplexWindings1
• MultiplexWindings2

7.  In the simplex winding there are many parallel paths
or circuits through the winding as there are field
poles on the machine.

8. • Duplex windings1
• TriplexWindings2

9.  Double andTriple windings are used on
armature designed for supply of large currents
at low voltage.
 The purpose of such a winding to increase the
number of parallel paths enabling the armature
to carry a large total current.
 At the same time reducing the conductor
current to improving the commutation
condition.

10.  Double winding consist of two similar simplex
windings placed in the alternator slots on the
armature and connected to alternator
commutator segments,
 Triple winding consist of three similar windings
occupying every third slot and connected to
every third commutator segment.

11.  The coil or back pitchYb must be
approximately equal to the pole pitch ie.
Yb=Z/P where z is the number of conductors on
armature and p is the number of poles.
 The back pitch Yb should be either lesser or
greater than front pitch Yf by 2m where m is
the multiplicity of the winding.
ie.Yb =Yf+2m
where m=1 for simplex winding
m=2 for duplex winding
m=3 for triplex winding

12.  WhenYb>Yf the winding progress from left to
right and so known as progressive winding.
 WhenYb<Yf the winding progresses from right
to left there it is known as retrogressive
winding.

13.  The back pitch and front pitch must be odd .
 The average pitch is given by
 Yav =Yb+Yf/2
 And should be equal to the pole pitch Z/P
 The resultant pitchYR is always even
 Ie. Resultant pitchYR=2 for simplex lap winding
 YR=4 for duplex lap winding
 YR=6 for triplex lap winding

16.  The winding start from any coil side returns
back to that coil side after connecting all the
coil sides once hence it is singly re-entrant
closed winding .
 Back pitch and front pitch of all the coils
remain the same and odd number.
 The total number of brushes is equal to the
number of poles, and the brushes are
connected to the coil sides, which
instantaneously lie between the poles and
have no emf induced in them.

17.  There are as many parallel paths in the
armature as the number of poles.
 The emf between +ve and –ve brushes is equal
to the emf generated in any of the parallel
paths,I Z is the total number of armature coil
sides and P is the number of poles, then
armature coil sides connected in series in each
path=Z/P

18.  Total generated emf E =E M F generated
per path =Average emf per coil side *Z/P
 eav* Z/P
 Round the complete armature winding,
the resultant emf is zero , so that there
will be no circulating current round the
closed winding.

20.  The ends of each armature coil are connected to
commutator segments some distance apart, so that
only two parallel paths are provided between the
positive and negative brushes.

23.  Number of conductors in each path = Z/2
 The generated emf is equal to the average emf
induced in each conductor *Z/2
 E= eav * z/2
 Current flowing through the each conductor is
equal to the current per path Ia/2 where Ia is the
armature current.
 The resultant emf round the circuit is zero.