Multiplex communications – Wide area network – Packet switching
Patent
1991-07-03
1993-11-30
Olms, Douglas W.
Multiplex communications
Wide area network
Packet switching
370 13, 370103, 375110, 371 82, 340659, 340660, 340664, 361 64, 361 68, H04J 314
Patent
active
052672310
ABSTRACT:
A differential protective relay system includes protective relays 19A and 19B at the terminals of a protected transmission line segment 21. Analog signals QL1 and QL2 are sampled at the respective ends of the protected line segment 21, digitally encoded using delta modulation and biphase-mark encoding, multiplexed and transmitted over a 1.544 Mbps T1 communication channel 20 to the other end of the line where they are decoded and compared with the local signal at that end. Power is removed from the protected line segment if the difference between the local and remote signals exceeds a predefined value. Biphase-mark encoding is employed so that a clock signal may be recovered from the decoded signals.
REFERENCES:
patent: 4275429 (1981-06-01), Church et al.
patent: 4464697 (1984-08-01), Sun
patent: 4484245 (1984-11-01), McFall
patent: 4538195 (1985-08-01), Elmore
patent: 4612594 (1986-10-01), Yamaura et al.
patent: 4675774 (1987-06-01), Gonnam et al.
patent: 4675775 (1987-06-01), Sun et al.
patent: 4689710 (1987-08-01), Anzai
patent: 4706155 (1987-11-01), Durivage et al.
patent: 4760487 (1988-07-01), Kwong et al.
Digital Communications: Fundamentals and Applications, Sklar B., Prentice-Hall, Englewood Cliffs, N.J., 1988 pp. 1, 81, 633-639.
ABB Power T&D Company Inc.
Blum Russell
Olms Douglas W.
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