Electricity: electrical systems and devices – Safety and protection of systems and devices – With specific quantity comparison means
Patent
1985-10-02
1987-08-11
Pellinen, A. D.
Electricity: electrical systems and devices
Safety and protection of systems and devices
With specific quantity comparison means
361 82, 361 85, 361 76, H02H 326
Patent
active
046866019
ABSTRACT:
A phase comparison type ground distance relay for a predetermined phase of three-phase AC transmission line includes a phase coincidence detector responsive to phase coincidence between an operating signal and a plurality of polarizing signals. Zero suppression networks are utilized for deriving second and third polarizing signals in order to improve discrimination between internal and external faults; thereby increasing the reliability of the relay operation and the security of the protection system. The second polarizing signal comprises that portion of a signal which exceeds a predetermined threshold value and which is related to the product of a signal proportional to the net current flowing in all three phases of the power system and the positive sequence replica impedence of the transmission line. The third polarizing signal comprises the sum of a signal related to the product of a negative sequence component of the current flowing in a predetermined phase of the AC power system and the positive sequence replica impedence of the transmission line; and that portion of a signal which exceeds a predetermined threshold value and which is related to the product of the net current flowing in all three
phases of the system and the positive sequence replica impedence of the transmission line.
REFERENCES:
patent: 3374399 (1968-03-01), Dewey
patent: 3882361 (1975-05-01), Hinman, Jr.
patent: 3992651 (1976-11-01), Hodges
patent: 4034269 (1977-07-01), Wilkinson
patent: 4161011 (1979-07-01), Wilkinson
patent: 4342062 (1982-07-01), Hodges
patent: 4403268 (1983-09-01), Keeney, Jr.
patent: 4405966 (1983-09-01), Cavero
patent: 4420788 (1983-12-01), Wilkinson et al.
patent: 4433353 (1984-02-01), Wilkinson
Alexander George E.
Wilkinson Stanley B.
General Electric Company
Jennings Derek S.
Pellinen A. D.
Policinski Henry J.
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