Modern excitation systems for large synchronous machines

AN EXCITATION SYSTEM consists essentially of an exciter and means for its regulation. Originally, manual control of voltage was used widely. With the development of power systems using modern apparatus, automatic control, in general, has come to play an important part in the progress of the electric power industry. Therefore, it is in keeping with this progress that voltage regulators have been used increasingly and have become an important factor in making possible further economies and improvements in system reliability. The increased use and acceptance of voltage regulators has been a great stimulus to the advancement of the art with the result that with the past few years several new types have been developed, placed in regular service, and are performing successfully.