Analysis of voltage-adjustable brushless synchronous generator without exciter

Two types of brushless single-phase synchronous generators without a rotating exciter have been proposed. The theoretical and experimental results of their characteristics are presented. The stator of the generator is equipped with two separate windings having different pole numbers: one is the single-phase load winding and the other is the DC exciting winding. It has been verified theoretically and experimentally that the output voltages are kept nearly constant even under constant stator DC current, and that the voltages can be adjusted in a wide range by the stator DC current. The proposed generators are useful not only as constant-speed generators, but also as maintenance-free variable-speed variable-load generators, such as wind generators.<>