ABSTRACT
This chapter discusses the main sources of alternating current which consists of two groups: the stator, a stationary part of the machine and the rotor, a rotating part of the machine. They produce machine's magnetic circuit, whose function it is to concentrate on a strong magnetic field in the airgap between the stator and rotor. The chapter focusses on armature reaction that describes the effect of the armature field over the excitation field to distort the resultant field. There are three armature currents: purely resistive, purely inductive and purely capacitive, that produces a magnetic field and rotates within the air gap between the stator and rotor at synchronous speed. The chapter talks about generator which converts torque into current and the transmission/distribution line, that again converts the current back into torque. It supplies a purely capacitive load which increases the strength of the combined rotor/ armature fields that causes the terminal voltage to increase for increasing values of load current.
