A Brushless Cylindrical-Rotor 4-Pole Three-Phase Synchronous Generator Without Exciter

Abstract

A suitable structure for small-capacity generator must be simple, robust, highly reliable and maintenance-free.
The authors present an original brushless cylindrical-rotor type 4-pole three-phase synchronous generator without excitor. The stator is provided with a 4-pole three-phase main winding and a 2-pole single-phase exciting winding, and rotor field coils are connected with diodes, respectively, so as to make the same pole magnetic field as the stator main winding. The each field coil is consisted of a half-wave rectification circuit. The rotor field excitation is controlled proportionally by the stator dc exciting current.
By the scheme that the stator main winding is connected to leading capacitors at the terminals for shunt excitation, and connected to the full-wave rectifier at the neutral point and the rectified current supplied to the stator exciting winding for series excitation, a brushless self-excited three-phase synchronous generator has been achieved.
In this paper the circuit configuration of the generator and the experimental results using a 2kVA prototype machine are shown.