GANDHINAGAR INSTITUTE OF TECHNOLOGY Elements of electrical design “TOPIC” Armature windings BRANCH -ELECTRICAL ENGINEERING Prepared by; (130120109043) Pranjali Pathak (130120109044) Vaibhavi Pathak Guided by: Prof. Jaimini Gohel

Elements of an armature windings A turn – two conductors connected to an end by an end connector

Elements of an armature windings A coil – several turns connected in series

Elements of an armature windings A winding – several coils connected in series

Elements of an armature windings The angle between centers of adjacent poles is 180o (electrical) 180o electrical = 90o mech N 360o electrical = 180o mech S S N

Elements of an armature windings The angle between centers of adjacent poles is 180o (electrical) If coil sides are placed 180o electrical apart, the coil is said to be full-pitch N a b a b 180oelec S S N

Elements of an armature windings The most common ways of connecting coils for armature windings: Lap winding Wave winding Ends of the coils are connected to the commutator bars In DC machines most of the coils are full-pitch.

Elements of an armature windings Lap winding Commutator bar One coil between adjacent commutator bars 1/p of total coils are connected in series No. of poles  no. of brushes  no. of parallel paths

Elements of an armature windings

Elements of an armature windings Wave winding p/2 coils in series between adjacent commutator bars ½ of all coils between brushes Regardless of no. of poles, there are always 2 parallel path The distance between end coils (commutator pitch) is 2(C1)/p where C is the no. of commutator bars

Elements of an armature windings

Field winding

Rotor and rotor winding

Armature winding Lap and Wave winding Lap winding A = P Wave winding The armature windings are divided into no. of sections equal to the no of poles Wave winding A = 2 It is used in low current output and high voltage. 2 brushes

Lap Winding We can conclude, in a lap winding, the number of parallel paths, “a” is always equal to the number of poles, “P” and also to the number of brushes.

Wave Winding In wave windings, the number of parallel paths, ”a” is always two and there may be two or more brush positions.

Mush winding Mush winding is a type of AC armature winding. In mush winding the coil span should be odd. It essentially consists of number of long and short conductors, the number being dependent on the number of slots per pole per phase. Connection is made between a long and short conductor only. The winding proceed till all the conductors are connected.

The following diagram shows the developed winding diagram of a 4 pole 24 slots 3 phase alternator 

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