US4639848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for controlling an AC-DC converter system
Assignee: Toshiba Corp
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Filing: 1985-05-22
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Granted: 1987-01-27
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Expires: 2005-05-22
Abstract
Abstract In control of an AC-DC converter system including AC-DC converters (1A, 1B) having respective AC terminals connected to AC power systems (6A, 6B) and having respective DC terminals connected to each other, a fault in the AC power systems is detected, and upon occurrence of a fault in any of the AC power systems, the DC current of the AC-DC converter which is connected to the sound AC power system is adjusted in such a manner as to maintain the AC voltage of the AC-DC converter which is connected to the sound AC power system at a desired value.
Inventors
- 👤 Takami Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:53
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/66; H02M7/68; H02M7/72; H02M7/75; H02M7/757; H02M7/7575; H02J; H02J3/00; H02J3/36; Y; Y02; Y02E; Y02E60/00; Y02E60/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
A method for controlling an AC-DC converter system including a plurality of AC-DC converters having respective AC terminals connected to separate ones of a plurality of AC power systems and having respective DC terminals connected to each other, comprising the steps of: detecting a fault in any one of said plurality of AC power systems; and adjusting, when a fault occurs in a faulty one of the plurality of AC power systems, the DC current of the AC-DC converter which is connected to a sound AC power system of said plurality of power systems in such a manner as to maintain the AC voltage of the AC-DC converter which is connected to said sound AC power system at a desired value.
Claim 2
Independent Claim
121 words
A method for controlling an AC-DC converter system including a plurality of AC-DC converters having respective AC terminals connected to separate ones of a plurality of AC power systems and having respective DC terminals connected to each other, comprising the steps of: detecting a fault in any one of said plurality of AC power systems; and adjusting, when a fault occurs in a faulty one of the plurality of AC power systems, the DC current of the AC-DC converter which is connected to a sound AC power system of said plurality of power systems in such a manner as to maintain the AC voltage of the AC-DC converter which is connected to said sound AC power system at a desired value.
Claim 3
Dependent Claim
36 words
A method of claim 1, further comprising the step of performing a constant power control over the plurality of AC-DC converters when there is no fault in any one of said plurality of AC power systems.
Claim 4
Dependent Claim
27 words
A method according to claim 1, wherein, when the fault is detected, performing a bypass-pair operation in the AC-DC converter connected to the faulty AC power system.
Claim 5
Dependent Claim
31 words
A method according to claim 1, further comprising the step of preventing the DC current of the AC-DC converter connected to the sound AC power system from exceeding a predetermined value.
Claim 6
Independent Claim
219 words
A system for controlling an AC-DC converter system including AC-DC converters having respective AC terminals connected to AC electric power systems and having respective DC terminals connected to each other, comprising: means for detecting a fault in the AC power system; a constant power control circuit providing a first current reference value; means for providing a second current reference value for performing control to maintain the voltage of the AC power systems at a desired value; constant current control circuits respectively providing signals indicative of the control angles of the AC-DC converters; means for selectively applying the first and second current reference values to the constant current control circuits; said selectively applying means applying the first current reference value when the AC power systems are sound, and applying the second current reference value when a fault occurs in any one of the power systems; and the constant current control circuits being responsive to the first current reference value for controlling the AC-DC converters to maintain the interchanged power at a desired value when the AC power systems are sound, and responsive to the second current reference value to maintain at a desired value the AC voltage of the AC-DC converter which is connected to the sound AC power system when a fault occurs in the other AC power system.
Claim 7
Independent Claim
219 words
A system for controlling an AC-DC converter system including AC-DC converters having respective AC terminals connected to AC electric power systems and having respective DC terminals connected to each other, comprising: means for detecting a fault in the AC power system; a constant power control circuit providing a first current reference value; means for providing a second current reference value for performing control to maintain the voltage of the AC power systems at a desired value; constant current control circuits respectively providing signals indicative of the control angles of the AC-DC converters; means for selectively applying the first and second current reference values to the constant current control circuits; said selectively applying means applying the first current reference value when the AC power systems are sound, and applying the second current reference value when a fault occurs in any one of the power systems; and the constant current control circuits being responsive to the first current reference value for controlling the AC-DC converters to maintain the interchanged power at a desired value when the AC power systems are sound, and responsive to the second current reference value to maintain at a desired value the AC voltage of the AC-DC converter which is connected to the sound AC power system when a fault occurs in the other AC power system.
Claim 8
Dependent Claim
21 words
A system of claim 5, wherein said means for providing the second current reference value comprises a constant voltage control circuit.
Claim 9
Dependent Claim
63 words
A system of claim 5, wherein said means for providing the second current reference value comprises a constant reactive power control circuit, the second current reference value provided by the constant reactive power control circuit being determined to maintain the reactive power supplied to the AC-DC converter at a value to maintain the AC voltage of the AC-DC converter at the desired value.
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) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |