INTER POLES

 Inter-poles

• Inter-poles are long but narrow poles placed in inter-polar region and has the polarity of succeeding ( incoming ) poles for generator action and preceding poles for motor action.

• The inter-poles winding is designed to neutralize armature MMF in inter-polar region. It has an additional duty to create an inter-polar flux density that induces a commutation voltage in the coil undergoing commutation such that it cancels reactance voltage of the coil.

• The inter-pole winding carries the armature current as it is connected in series with the armature winding. The presence of inter-poles ensures spark -less linear commutation.

• The inter-pole is kept narrow so that influence is restricted to coil undergoing commutation only and does not spread to other neighboring coils. However bar is winder at bottom to prevent saturation and improve response.

• Inter-poles work satisfactorily irrespective of the load, the direction of rotation and mode of operation of the machine.