A Self-Regulated Self-Excited Brushless Three-Phase Synchronous Generator

For the purpose of light-weight and compact implementation of generation set, many attempts have been made by some researchers in a development of brushless self-excited synchronous generator without ac exciter. We proposed, in a previous paper, a “novel self-excitation scheme” by which the 2nd-space harmonic component of armature mmf is used for exciting the rotor field system. This excitation scheme has a positive feature that the effect of series excitation characteristic, as well as a self-excited and brushless inplementation without ac exciter, is automatically obtained. However, in case of the system configuration of the generator reported previously, there was a problem that the voltage regulation in the inductive load condition was very large. To remove the above disadvantage this paper presents a new system configuration of the generator with self-regulating feature that can compensate the voltage regulation automatically. The new generator consists of a stator installing two three-phase windings, externally connected to a load and a capacitor bank respectively, and a rotor with field and harmonic windings.In this paper the system configuration and theoretical concepts of the presented generator are described, and detailed experimental investigations with a laboratory machine are also shown.