What is the role of protective relays in power systems?

Protective relays play a crucial role in maintaining the reliability and safety of power systems. Their primary function is to monitor electrical parameters such as current, voltage, and frequency. When these parameters deviate from predetermined acceptable ranges—often indicative of potential faults, such as short circuits or overloads—the relays activate. This activation triggers circuit breakers or other protective devices to disconnect affected circuits, effectively isolating the fault from the rest of the power system. This process helps to prevent equipment damage, reduces the risk of system failure, and ensures the safety of personnel working on or near the system.

Enhancing efficiency, increasing voltage levels, or serving as backup power supplies are not the primary functions of protective relays. While these aspects are important in the overall operation of power systems, the specific role of protective relays is focused on fault detection and isolation to protect both equipment and personnel from harm. Thus, the monitoring and disconnection functionality is central to ensuring the stability and security of the electrical grid.