armature winding.pptx

7/30/2019 Armature Winding.pptx

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Engr. Jerny D. Catibayan,BSEE

Instructor, EE Dept.

Technological Institute of the Philippines - Manila


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Is virtually the heart of the dynamo. It is where the voltage is generated in the

generator or; Torque is developed in the motor The armature coil (copper conductor) ends

are soldered to the commutator, afterwhichthe latter is turned down and undercut.


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Lap windingthe coil ends are connected to adjacent

commutator segmentsWave winding

the coil ends are connected to commutatorsegment very nearly, but never exactly, equalto the distance between poles of the samepolarity (alternate poles).

pair of poles = 360 electrical degrees


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The distance between the two sides of a coilmust be equal to the distance between two

adjacent poles. Coil span must be 180 electrical degrees, or

approximately so.


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Ys = S/P k

Where : Ys = coil pitch, in slotsS = total number of armature slotsP = number of poles

k =any part of S/P that is subtractedto make Ys an integer5


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Calculate the coil pitches (coil spans) and

indicate the slots into which the first

coils should be placed for the followingarmature windings: (a) 28 slots, four

poles; (b) 39 slots, four poles; (c) 78 slots,

six poles; (d) 121 slots, eight poles; (e)258 slots, 14 poles


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Designates the coil end connections to thecommutator.

equal to the plex or multiplicity(m

) of la wound armature winding (e.g., simplex,duplex, triplex, etc.)


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Equal to the highest common factor

between the number of commutator

segments and the plex of the winding.


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Determine the commutator pitches Yc and thedegrees of re-entrancy for the following

windings:a. Simplex lap, 29 segmentsb. Duplex-lap, 29 segmentsc. Duplex-lap, 42 segmentsd. Triples-lap, 47 segmentse. Triplex-lap, 48 segmentsf. Quadruplex-lap, 394 segments


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When the current passes through anyarmature winding, it always divides into an

even number of parallel paths. Simplex lap winding > divided into P

paths(P=Number of Poles)

Duplex-lap winding > divided into 2xP paths

Thus, in general, there are mxP parallel armaturewinding paths in lap winding. represents


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1. a six-pole duplex-lap winding has how manyparallel paths?

2. An eight-pole triples-lap has ___ parallelpaths?


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Number Slots Segments

Poles Windings Ys Yc Parallelpaths

Re-entrancy

1 27 27 4 SL

2 66 66 6 DL

3 63 63 6 DL

4 160 160 6 TL

5 147 147 8 TL

6 222 222 8 QL


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Only one difference this is simply themanner in which the coil ends of the two

types are connected to the commutator.


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Where: Yc = commutator pitchC = total number of commutator

segments

P= number of poles() = use either operation to havean integer commutator pitch.

Yc = (C 1)/(P/2)


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Calculate the commutator pitches Yc for thefollowing (simplex-wave wound) pole andcommutator segment combinations: (a) sixpoles,34 segments; (b) eight poles, 63segments: (c) 10 poles, 326 segments. In eachcase, trace the winding around the

commutator once; start at segment 1 showthat after one trip around the commutator, asegment is reached that is one behind or oneahead of the starting segment.


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1. In simplex-lap winding there are as manyparallel paths between positive and negativebrushes as there are poles, while the number of

parallel paths in simplex wave winding is two,regardless of the number of poles.

2. The conductors in each of the P paths of a lapwinding are distributed under two poles, a north

and a south pole, whereas the conductors ineach of the two paths of a wave winding aredistributed under all the poles.


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In simplex wave winding, after the windingtraced once around the commutator, the last

coil end arrives one segment behind or aheado the starting point.A m-plexYc to be chosen that after the

winding is traced once around thecommutator, the last coil end arrives msegments behind or ahead.


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This condition can be fulfilled using themodified equation:

Yc = (Cm)/(P/2)


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Determine the commutator pitch Yc for a four pole duplex-wave-wound armature having

120 commutator bars. Trace the windingaround the commutator once, starting atsegment 1, and show that after one triparound the commutator, a segment isreached that is two behind or ahead of thestarting segment.


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Number Segments Poles Winding Yc Tracing

1 65 6 DW

2 90 6 TW

3 124 8 QW

4 213 10 TW


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REFERENCES:Electrical Technology by Theraja

(chapter 26)Electrical Machines by Siskind

(page 45.)

armature winding.pptx

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