- Protection Relays (Overcurrent, Distance, Differential)

This technical article is to cover the most important principles of four fundamental relay protections: overcurrent, directional overcurrent, distance....

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Overview

Protection relays are essential in electrical power systems, automatically isolating faults to minimize damage and maintain stability. Three common types of protection relays are overcurrent, distance, and differential relays, each designed to detect specific fault types and react accordingly. 

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Specification

This technical article covers the four fundamental protection principles. For simplicity in explaining the key ideas, we consider three phase bolted faults.