The article provides an overview of protective relaying principles and their applications for high-voltage power system components. It covers the protection methods for generators, transformers, buses, and transmission lines using various relay types to detect and isolate faults. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems. A single-phase model of a simple power system is developed using the Power System Blockset. : 4 The first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as. The Institute of Electrical and Electronic Engineers (IEEE) defines a relay as “an electric device that is designed to respond to input conditions in a prescribed manner and, after specified conditions are met, to cause contact operation or similar abrupt change in associated electric control.
[PDF Version]