DC Windings

DC Windings A dc machine is a heteropolar structure with stationary poles and the rotating armature (Fig. 5.8). An alternating emf of the same wave shape as that of B-wave is induced in every coil. As the armature rotates, the emf s induced in the belt of coil-sides under a given pole is unidirectional and […]

Tooth Ripple

Tooth Ripple Because of lower reluctance of the magnetic path corresponding to the teeth as compared to the slots, the flux density wave in the air-gap is rippled as shown in Fig. 6.9. Unlike the space harmonics of the B-wave which move at the same peripheral speed as the fundamental, the tufts of flux embracing […]

AC Windings

AC Windings Ac windings are generally of a 3-phase kind because of the inherent advantages of a 3-phase machine. The armature coils must be connected to yield balanced (equal in magnitude and successive phase difference of 2r/3 rad) 3-phase emfs. To begin with the slots around the armature periphery must be divided into phase-bands. Phase […]

Introduction to Armature Windings

Introduction to Armature Windings We Know¬†that field and armature windings are the essential features of electric machines. The field windings are simple arrangements with concentrated coils (i.e coils in which all the turns have the same magnetic axis). Armature windings on the other hand comprise a set of coils (single or multiturn) embedded in the […]