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US5576625A
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Test method and apparatus for testing a protective relay system
Assignee: Toshiba Corp
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Filing: 1995-02-02
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Granted: 1996-11-19
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Expires: 2015-02-02
Abstract
Abstract A relay test apparatus for testing a protective relay operation of a protective relay system comprises GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal, simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal and inputting the simulation signal to a corresponding protective relay, and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.
Inventors
- 👤 Yukio Sukegawa
- 👤 Tetsuo Matsushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:29
CPC Classifications
G; G01; G01R; G01R31/00; H; H02; H02H; H02H7/00; H02H7/26; H02H7/261; H02H7/263; G01R31/327; G01R31/3271; G01R31/3272; G01R31/3277; G01R31/3278; H02H3/00; H02H3/02; H02H3/04; H02H3/044
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
A relay test apparatus for testing a protective relay operation of a protective relay system including: protective relays, provided in electric-supply stations connected through electric transmission lines, for performing an accident judging operation using electricity amounts detected in the electric-supply stations; and a transmission system, connecting the protective relays, for transmitting an electricity amount signal, corresponding to the electricity amount detected in the one electric-supply stations, to the other protective relay, the relay test apparatus comprising: GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal; simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal simulating the electricity amount signal and inputting the simulation signal to a corresponding protective relay as the electricity amount signal; and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.
Claim 2
Dependent Claim
182 words
A relay test apparatus for testing a protective relay operation of a protective relay system including: protective relays, provided in electric-supply stations connected through electric transmission lines, for performing an accident judging operation using electricity amounts detected in the electric-supply stations; and a transmission system, connecting the protective relays, for transmitting an electricity amount signal, corresponding to the electricity amount detected in the one electric-supply stations, to the other protective relay, the relay test apparatus comprising: GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal; simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal simulating the electricity amount signal and inputting the simulation signal to a corresponding protective relay as the electricity amount signal; and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.
Claim 3
Dependent Claim
125 words
The relay test apparatus according to claim 1, wherein each of the synchronous starting units comprises: an absolute time setting circuit in which a test start time, when the simulation signal is output to a corresponding protective relay of the protective relay system, is set; a timer, to which the time signal is input by the corresponding GPS receiver and the test start time is input by the absolute time setting circuit, for outputting a test start signal when a time represented by the time signal coincides with the test start time; and a starting circuit for outputting a starting signal to a corresponding simulation signal generator, upon receipt of the test start signal from the timer, so as to start the simulation signal generator.
Claim 4
Dependent Claim
152 words
The relay test apparatus according to claim 1, wherein each of the protective relays comprises: electricity amount input means for inputting the electricity amount detected in the electric-supply station and the simulation signal; a converting circuit for converting the electricity amount and the simulation signal input by the electricity amount input means to a signal of a level suitable for the protective relay and outputting an electricity amount signal and a converted simulation signal; a sample hold circuit for sampling the electricity amount signal and the converted simulation signal output from the converting circuit; and an accident judging circuit for performing an accident judging operation using the electricity amount signal or simulation signal sampled by the sample hold circuit of the electric-supply station and the electricity amount signal or simulation signal sampled by a sample hold circuit of the protective relay of the other electric-supply station and transmitted through the transmission system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-19 | 2000-05-20 | 2000-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-19 | 2004-05-20 | 2004-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-19 | 2008-05-20 | 2008-11-19 | $7700.00 | Window Closed / Lapsed |