What is the primary purpose of a protective relay?

The primary purpose of a protective relay is to detect faults in electrical systems. Protective relays play a crucial role in ensuring the safe operation of power systems by monitoring electrical conditions. They are designed to sense abnormalities, such as overcurrent, undercurrent, overvoltage, undervoltage, and other conditions that could indicate a fault. Once a fault condition is detected, the relay can initiate actions to isolate the affected part of the system, thereby preventing damage to equipment, reducing the risk of hazards, and maintaining system stability.

In essence, protective relays serve as the first line of defense in protecting infrastructure and ensuring system reliability, which is vital for any electrical network. Their ability to quickly identify and respond to faults is essential to prevent cascading failures and ensure safety for both personnel and equipment.