Relays and Relay Protection of a Modern Hydro-Plant

The object of this paper is to discuss in detail a number of different relays and their application. Since the subject is limited to the applications as found in a modern hydro-plant, only those relays of this particular plant will be discussed. The discussion must necessarily be limited to this extent due to the numerous types of relays now available. Hence, this paper naturally divides itself into two distinct parts, namely, a discussion of those types of relays that are used in connection with a specific plant, and the application of these relays to this particular plant.