Abstract
Power swings chargeable to hydraulic turbines have been found in hydroelectric plants built as far back as 1912. However, it has only been during the last ten years that much thought has been given to such swings, their characteristics, source, and elimination. The purpose of this paper is to supply technical data on the subject and to start such discussion as may lead to a better understanding of the problem. The paper shows that power swings are due to draft-tube surges. It deals with the characteristics of such surges, their relation to power swings, the elimination of surges and power swings in the field, if necessary, and a consideration of the factors of the design of a hydroelectric unit which will prevent small draft-tube surges from producing excessive power swings. However, the paper does not present a theoretical analysis of the true origin or source of draft-tube surges, which is a matter for further observation and study and for future discussion.
