Roger Ray

US Patent:

40203964, Apr 26, 1977

Filed:

Mar 10, 1976

Appl. No.:

5/665650

Inventors:

John C. Gambale - Livingston NJ
Roger E. Ray - Parsippany NJ

Assignee:

Westinghouse Electric Corporation - Pittsburgh PA

International Classification:

H02H 726

US Classification:

361 64

Abstract:

This disclosure relates to a protective relaying system for a polyphase power transmission line in which at least two separate line operating conditions at a remote end of a protected line section are transmitted to a local end of the line section over a single communication channel. In the preferred illustrated embodiment, the operating conditions of three-line conductors are sequentially transmitted whenever a fault condition is sensed on any one or more of the three-line conductors. During the normal, non-faulted operation, a coded signal is continually transmitted to maintain the time derived signals at the receiver in substantial synchronism with the time derived signals of the transmitter. The coded signal also establishes a trip inhibiting or guard signal at the receiver.