Relay comparison is a protective strategy that involves comparing signals from multiple protection relays installed on different parts of a power system. These relays monitor the electrical parameters of the system and are designed to respond to abnormal conditions such as short circuits or ground faults. By comparing the signals from these relays, relay comparison enables the identification of faults with precision, ensuring that only the affected portion of the system is disconnected.

    How Relay Comparison Works

    In a typical power system, multiple relays are positioned at various points, such as substations, transformers, and generators. When a fault occurs, the relays detect abnormal conditions like overcurrent or under-voltage. The core principle of relay comparison is that these relays continuously monitor the system and communicate with each other, sharing their data.