Electricity: electrical systems and devices – Safety and protection of systems and devices – With specific current responsive fault sensor
Patent
1983-06-22
1986-02-18
Moose, Jr., Harry E.
Electricity: electrical systems and devices
Safety and protection of systems and devices
With specific current responsive fault sensor
361 97, H02H 3093
Patent
active
045716587
ABSTRACT:
A control circuit is provided for applying energy to operate a circuit interrupter in response to, and a selected time after, the onset of overcurrent in an alternating-current line. The control circuit includes a transducer for producing output current proportional to the current in the line. The power supply includes an energy storage circuit that stores energy derived from the output current. The stored energy, which is maintained within a first range when there is no overcurrent in the line, energizes the power supply. A time-current trip signal generator circuit responds to output current representative of moderate overcurrent in the line by producing a trip signal after the passage of a time period that is inversely related to the overcurrent. An instantaneous trip signal generator circuit produces a trip signal in response to output current between a minimum and a maximum magnitude and increasing at a rate greater than a selected rate, which conditions indicate the presence of high overcurrent in the line. A switch or gate is responsive to either trip signal to apply the output current and the stored energy to the circuit interrupter. With moderate overcurrent in the line, neither the first range of stored energy nor the output current is sufficient to operate the circuit interrupter. Accordingly, the trip signal from the time-current trip signal generator circuit first causes the energy storage circuit of the power supply to store a sufficiently greater amount of energy before operating the switch.
REFERENCES:
patent: 3290556 (1966-12-01), Graham et al.
patent: 3713004 (1973-01-01), Skeehan
patent: 3831061 (1974-08-01), Boyd
patent: 4017766 (1977-04-01), Vercellotti et al.
patent: 4149210 (1979-04-01), Wilson
patent: 4225777 (1980-09-01), Schindler
patent: 4258403 (1981-03-01), Shimp
patent: 4259706 (1981-03-01), Zocholl
patent: 4297741 (1981-10-01), Howell
patent: 4347541 (1982-08-01), Chen et al.
patent: 4380785 (1983-04-01), Demeyer et al.
patent: 4442472 (1984-04-01), Pang
Keders et al., "A Current-Limiting Device for Service Voltages Up to 34.5kV", Jul. 18, 1976, 7 pages, IEEE PES Summer Meeting, Paper No. 76436-6.
Bottger, "The Application of Is- Limiters in Three Phase Systems", pp. 1-7, 1967, Calor-Emag Company, Germany.
Calor Emag Company, Leaflet No. 1197/6E, "Fault Levels Too High?", 2 pages, date unknown.
M. C. Blythe, "Limiting Fault Currents Between Private and Public Networks", 4 pages, Oct. 5, 1973, reprinted from Electrical Review, Calor-Emag.
N. Miyoshi et al., "Ultra-High Speed Protection Device-Fuji Ultrup Fuse", pp. 47-51, vol. 18, No. 1, Fuji Electric Review.
P. J. Kroon, "The Development and Application of a 69-kV Fault Current Limiter", pp. 237-244, Apr. 1, 1971, 7th IEEE/PES Transmission and Distribution Conference and Exposition.
J. Wafer, "The Impact of Solid-State Technology on Molded Case Circuit Breakers", pp. 605-611, Sep. 10, 1979, vol. IA-16, No. 5, Sep./Oct. 1980, IEEE Transactions on Industry Applications.
"Pyristor Pyrotechnic Systems", Carbone Ferraz, Inc. brochure, date unknown.
"Prototype Fault Current Limiter", EPRI Report, EL-1396, May 1980, pp. 7-1 to 7-19, 8-1, Palo Alto, Calif.
Lapacek James V.
Moose Jr. Harry E.
S&C Electric Company
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