US3639810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power system monitoring relay
Assignee: National Aeronautics and Space Administration
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Filing: 1971-02-18
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Granted: 1972-02-01
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Expires: 1991-02-18
Abstract
Abstract An electrical power system subsidiary relay for controlling system normalizing and operation recording mechanisms which in response to detection by the relay of system frequency deviation from standard operating frequency derives in a differentiatoramplifier circuit component thereof an acceleration of deceleration signal predictive of system disturbance conditions. Adjustable devices in circuits interconnected with the differentiator-amplifier circuitry are settable to predetermine the sensitivity, or magnitude for response, and the minimal response and pickup timing for the relay.
Inventors
- 👤 Ferber R Schleif
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:26
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/42
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
177 words
Acceleration and deceleration monitoring relay having means deriving frequency deviation signals, and comprising differentiator means producing in response to receipt of said deviation signals therein a further signal representative of the rate of change of said frequency deviation signals, said differentiator means having cooperatively related therein an operational amplifier to which are operatively connected as feedback inputs thereto a sensitivity adjustment means and a settable signal limiting means, a further operational amplifier connected to said differentiator means and to which is operatively connected as a feedback input thereto a settable signal timing means, said further amplifier being responsive to an input of said rate of change signals for producing relay activation control signals which reach an effective control magnitude in a time determined by the setting of said settable signal timing means, relay actuating devices and an energizing voltage source therefor having in operative association therewith a switching arrangement connected to said further operational amplifier and operatively responsive to said activation control signals supplied thereto from said further amplifier to activate said devices from said energizing source.
Claim 2
Dependent Claim
177 words
Acceleration and deceleration monitoring relay having means deriving frequency deviation signals, and comprising differentiator means producing in response to receipt of said deviation signals therein a further signal representative of the rate of change of said frequency deviation signals, said differentiator means having cooperatively related therein an operational amplifier to which are operatively connected as feedback inputs thereto a sensitivity adjustment means and a settable signal limiting means, a further operational amplifier connected to said differentiator means and to which is operatively connected as a feedback input thereto a settable signal timing means, said further amplifier being responsive to an input of said rate of change signals for producing relay activation control signals which reach an effective control magnitude in a time determined by the setting of said settable signal timing means, relay actuating devices and an energizing voltage source therefor having in operative association therewith a switching arrangement connected to said further operational amplifier and operatively responsive to said activation control signals supplied thereto from said further amplifier to activate said devices from said energizing source.
Claim 3
Dependent Claim
128 words
The relay of claim 1 wherein said differentiator means comprises circuitry having a capacitor element chargeable with positive and negative signals arising from an acceleration and deceleration, respectively, of said frequency deviation, and said signals limiting means thereof comprising first and second limiting circuits, adapted to affect acceleration and deceleration signals, respectively, each having connected therein an associated set of resistors in series and having connections in said first and second limiting circuits to positive and negative source voltages, respectively, and to an output terminal of said differentiator amplifier, an adjustable conductive tap contact for each said resistor set settable to adapt said resistor set associated therewith as a voltage divider which determines the magnitude of an opposing signal in said related feedback input to said differentiator amplifier.
Claim 4
Dependent Claim
72 words
The relay of claim 2 wherein said sensitivity adjustment means comprises a potentiometer having the resistance element thereof connected between said differentiator amplifier output terminal and at a ground between said positive and negative voltage sources, and an adjustable tap thereof connected through a feedback resistor to an input terminal of said differentiator amplifier, and each of said limiting circuits further comprising a transistor amplifier in the respective feedback circuit connections thereof.
Claim 5
Dependent Claim
91 words
The relay of Claim 1 wherein said further operational amplifier comprises in said feedback input of said signal timing means thereof a circuit including a graduated set of capacitors connected together at one terminal thereof to an output terminal of said further amplifier and having the opposite terminals of said capacitors individually connected to separate terminals, and a conductive tap selectively adjustable to one of said opposite terminals to complete a conductive path through a selected capacitor for said feedback input, and a resistor connected in parallel with said circuit path.
Claim 6
Dependent Claim
163 words
The relay of claim 1 wherein said switching arrangement includes first and second switching transistors and a transistor amplifier in a circuit adapted to connect said energizing voltage source to said relay actuating devices, a further circuit coupling an output terminal of said further operational amplifier to said first and second transistors, said further circuit including oppositely poled diodes in respective branch circuits thereof adapted to selectively apply said control signal in accordance with the polarity thereof to a trigger-circuit for a predetermined one or the other of said first and second transistors, a collector to base circuit coupling said first transistor to said second transistor, and a collector to base circuit coupling said second transistor to said transistor amplifier, whereby energization of said triggering circuit of either said first and second transistor by said control signal obtains conduction of said second transistor and in turn of said transistor amplifier in said circuit connecting said voltage source to energize said relay actuating devices.
Claim 7
Dependent Claim
35 words
The relay of claim 1 wherein a reactance drop is connected to the input of said means producing said frequency deviation signals so as to compensate for any phase shift due to generator quadrature reactance.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |