In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. Types of Protective Relays: Protective relays are categorized by their mechanism (electromagnetic, static, mechanical) and function. Protective Relays - Technical Seminar Nov 2016 - Copyright: IEEE 2 Abstract: Protective relays and devices have been developed over 100 years ago to provide “lastline”of defense for the electrical systems. They are intended to quickly identify a fault and isolate it so the balance of the system. The rectangular devices are test connection blocks, used for testing and isolation of instrument transformer circuits. The first numerical relays were released in 1985. Its main purpose is to safeguard electrical equipment like transformers, generators, and transmission lines from damage due to. 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.
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