Brushless and self-excited single-phase alternator

The paper describes a brushless, self-excited alternator in which the reverse-rotation component of the armature m.m.f. is used to increase the excitation current as the load is increased. The excitation scheme is power-factor sensitive, since the increase is greater as the load becomes more inductive, and the voltage regulation is within that normally required from single-phase self-excited machines. An analysis is presented in which the nonlinearities essential for stable operation are discussed, and close agreement between predicted and measured load characteristics is obtained.