What is the primary function of distance protection relays in substations?

The primary function of distance protection relays in substations is to detect faults based on electrical distance. These relays monitor the impedance or distance to a fault on a transmission line, which allows them to determine whether a fault is within the zone of protection. By measuring the voltage and current flowing in the system, a distance relay can calculate the apparent impedance and, therefore, identify how far away the fault is from the relay. This capability enables the relay to quickly isolate faulty sections of the system while minimizing the impact on unaffected areas, ensuring reliable and safe operation of the electrical network.

The other options do not accurately describe the main role of distance protection relays. While optimizing energy distribution and managing power factor corrections are important aspects of overall system management, they do not relate specifically to the fault detection process. Similarly, enhancing the monitoring of equipment is a broader function that encompasses many tools but is not the singular focus of distance protection relays, which are specifically designed for detecting faults based on the distance to a fault.