Stability of Conowingo Hydroelectric Station Philadelphia Electric Company System

This paper gives a brief description of the Philadelphia Electric Company System with particular reference to the features influencing stability of the Conowingo Hydroelectric station, summarizes the various calculations and tests associated with the stability problem, and presents the record of operating experience from a stability standpoint during four years of service. Several cases of instability due to line faults have occurred. A thorough study was made of the matter, and as a consequence, changes were made in the equipment and system set-up involving the development and installation of higher speed circuit breakers and relays. Detailed records are given for all faults on the parts of the system which are intimately associated with the Conowingo development. These records show the improvement of stability obtained by the changes in the system and indicate attainment of a generally satisfactory condition.