A Self-Excited Synchronous Generator for Isolated Power Supply

This paper describes an engine-driven self-excited synchronous generator with a minimal air gap and a static voltage regulator, which has been designed for mobile or isolated power systems. There is no exciter. Voltage buildup is provided by the residual magnetism of hard-steel field-pole laminations. The field current is provided by a set of silicon rectifiers, supplied in part from the generator voltage and in part from the line current, with a circuit designed to hold constant volts per cycle, regardless of load changes. Test data are given which show that the generator has high efficiency, good overload capacity, and remarkably high motor starting ability.