What is the primary purpose of protective relays in transmission and distribution systems?

The primary purpose of protective relays in transmission and distribution systems is to minimize damage and isolate problems. Protective relays are specialized devices designed to detect abnormal conditions, such as short circuits, overloads, or equipment failures, within the electrical system. When such conditions are detected, these relays initiate protective measures, such as tripping circuit breakers or disconnecting faulty equipment from the system.

By isolating the problem quickly, protective relays help prevent further damage to equipment and maintain the stability and integrity of the overall power system. This rapid response is essential to ensure the safety of both the system and personnel, while also maintaining service to unaffected areas of the grid.

Enhancing voltage stability, controlling load flow, and reducing operational costs, while all important aspects of power system management, do not directly relate to the central function of protective relays. Instead, protective relays focus primarily on the detection and isolation of faults to safeguard both the equipment and the reliability of the power supply.