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US4384248A
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Method and apparatus for detecting shortcircuit in arm of GTO inverter
Assignee: Hitachi Ltd
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Filing: 1980-06-17
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Granted: 1983-05-17
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Expires: 2000-06-17
Abstract
Abstract Shortcircuit in an arm including a series connection of GTO's and reactors of an inverter is detected by sensing a voltage across the reactor. In one method, the shortcircuit in the arm is detected when voltages are coincidently applied to a P-line arm reactor and an N-line arm reactor for a predetermined time period. In another method, it is detected when an integrated value of a voltage across at least one of the reactors exceeds a predetermined level.
Inventors
- 👤 Yasuo Matsuda
- 👤 Kazuo Honda
- 👤 Takeo Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:16
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/122; H02H7/1225; G; G01; G01R; G01R31/00; G01R31/50; G01R31/52
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A method for detecting a shortcircuit in an arm of a GTO inverter provided with at least one pair of arms, each arm being composed of a series connection of a single gate turn-off thyristor and a single reactor, said method comprising the steps of: sensing the voltage across each of said reactors of said paired arms; detecting if said sensed voltages across said reactors last coincidentally for longer than a predetermined time period; and determining the shortcircuit in one of said paired arms when said voltages last coincidentally for longer than said predetermined time period.
Claim 2
Independent Claim
96 words
A method for detecting a shortcircuit in an arm of a GTO inverter provided with at least one pair of arms, each arm being composed of a series connection of a single gate turn-off thyristor and a single reactor, said method comprising the steps of: sensing the voltage across each of said reactors of said paired arms; detecting if said sensed voltages across said reactors last coincidentally for longer than a predetermined time period; and determining the shortcircuit in one of said paired arms when said voltages last coincidentally for longer than said predetermined time period.
Claim 3
Dependent Claim
50 words
A method for detecting a shortcircuit in an arm of a GTO inverter according to claim 1, wherein said predetermined time period is selected to be equal to a time period required for a snubber capacitor of the inverter to be charged to one half of the GTO anode voltage.
Claim 4
Independent Claim
118 words
An apparatus for detecting a shortcircuit in an arm of a GTO inverter provided with at least one pair of arms, each arm being composed of a series connection of a single gate turn-off thyristor and a single reactor, said apparatus comprising: (i) first means connected across one of the reactors of said paired arms for sensing a voltage thereacross; (ii) second means connected across the other of said reactors for sensing a voltage thereacross; (iii) third means connected to said first and second means for ANDing the outputs thereof; and (iv) fourth means connected to the output of said third means for detecting if said third means produces an output for longer than a predetermined time period.
Claim 5
Independent Claim
118 words
An apparatus for detecting a shortcircuit in an arm of a GTO inverter provided with at least one pair of arms, each arm being composed of a series connection of a single gate turn-off thyristor and a single reactor, said apparatus comprising: (i) first means connected across one of the reactors of said paired arms for sensing a voltage thereacross; (ii) second means connected across the other of said reactors for sensing a voltage thereacross; (iii) third means connected to said first and second means for ANDing the outputs thereof; and (iv) fourth means connected to the output of said third means for detecting if said third means produces an output for longer than a predetermined time period.
Claim 6
Dependent Claim
53 words
An apparatus for detecting a shortcircuit in an arm of a GTO inverter according to claim 3, wherein said predetermined time period for said fourth means is selected to be equal to a time period for a snubber capacitor of the inverter to be charged to one half of the GTO anode voltage.
Claim 7
Dependent Claim
45 words
An apparatus for detecting a shortcircuit in an arm of a GTO inverter according to claim 3, wherein said fourth means comprises a pulse width discriminator for determining if the pulse width of the output pulse from said third means has a predetermined pulse width.
Claim 8
Dependent Claim
48 words
An apparatus for detecting a shortcircuit in an arm of a GTO inverter according to claim 5 wherein said pulse width is selected to be equal to the time required for a snubber capacitor of the GTO to be charged to one half of the GTO anode voltage.
References Cited (Backward Citations)
US3343038A
Cited
US3524200A
Cited
US3916287A
Cited
US4133018A
Cited
US4231083A
Cited
US4228477A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |