Signal quality monitor for protective relay system

摘要

A signal quality monitor, and a protective relay system using the monitor, which utilizes both AC and DC signals from the receiver agc stage to monitor a plurality of different signal parameters. A signal responsive to the noise in the communication channel which transmits at least one of the protective relay signals used in a protective relay comparison function, is also used in the trip circuits of the associated circuit interrupter to continuously adapt or modify the trip level in response to channel noise.