Realistic Machine – A realistic synchronous machine will have resistance ra and leakage reactance x1 per armature phase which can be assumed to be lumped in series between the terminal voltage V, and the air-gap emf Er for each machine phase.
The circuit diagram of the machine on a per phase basis is drawn in Fig. 8.8(a) for the generating mode (armature current in same direction as Er). From Fig. 8.8(a)
The resistance of a synchronous machine armature is usually very small and can generally be neglected in performance analysis