US6304468B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase synchronization system for connecting a power converter to a power distribution system
Assignee: Hitachi Engineering and Services Co Ltd
•
Filing: 2000-12-27
•
Granted: 2001-10-16
•
Expires: 2020-12-27
Abstract
Abstract A power converter system includes: a circuit breaker having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling the power converter, wherein, during a return to grid connected operation, the power converter is controlled such that the phase of an output voltage of the power converter matches the phase of the system voltage, and the circuit breaker is closed, so as to prevent an overcurrent during a changeover from the self commutated operation to the grid connected operation of the power converter.
Inventors
- 👤 Masaya Ichinose
- 👤 Motoo Futami
- 👤 Shigeta Ueda
- 👤 Kazuo Suzuki
- 👤 Akira Maekawa
- 👤 Yasuhiro Kiyofuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:29
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02J; H02J3/00; H02J3/28; H02J3/32; G; G05; G05F; G05F1/00; G05F1/66; G05F1/67
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
123 words
A power converter system comprising: switching on/off means having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling said power converter, wherein said power converter supplies electric power to said load through said transformer and is connected to said power system through said switching on/off means, and said controller outputs a control signal for adjusting an output phase of said power converter on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof so as to eliminate a phase difference between the power system-side ac voltage and the load-side ac voltage.
Claim 2
Dependent Claim
123 words
A power converter system comprising: switching on/off means having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling said power converter, wherein said power converter supplies electric power to said load through said transformer and is connected to said power system through said switching on/off means, and said controller outputs a control signal for adjusting an output phase of said power converter on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof so as to eliminate a phase difference between the power system-side ac voltage and the load-side ac voltage.
Claim 3
Dependent Claim
29 words
The power converter system according to claim 1 , wherein said controller outputs a signal for opening or closing said switching on/off means in accordance with the phase difference.
Claim 4
Dependent Claim
31 words
The power converter system according to claim 2 , wherein said controller has a current controlling system for switching over a current command between system interconnection operation and self commutated operation.
Claim 5
Dependent Claim
30 words
The power converter system according to claim 1 , wherein said power converter is further connected to a wind power generator system, and said power converter has energy storage means.
Claim 6
Dependent Claim
120 words
A power converter system comprising: switching on/off means having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling said power converter, wherein said power converter supplies electric power to said load through said transformer and is connected to said power system through said switching on/off means, and said controller outputs a signal for opening or closing said switching on/off means on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof in response to a phase difference between the power system-side ac voltage and the load-side ac voltage.
Claim 7
Dependent Claim
120 words
A power converter system comprising: switching on/off means having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling said power converter, wherein said power converter supplies electric power to said load through said transformer and is connected to said power system through said switching on/off means, and said controller outputs a signal for opening or closing said switching on/off means on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof in response to a phase difference between the power system-side ac voltage and the load-side ac voltage.
Claim 8
Dependent Claim
29 words
The power converter system according to claim 5 , wherein said controller outputs the signal for closing said switching on/off means when the phase difference is close to zero.
Claim 9
Dependent Claim
30 words
The power converter system according to claim 5 , wherein said power converter is further connected to a wind power generator system, and said power converter has energy storage means.
Claim 10
Independent Claim
106 words
A method of controlling a power converter which supplies electric power to a load and is connected to the load and to a power system through switching on/off means, comprising the steps of: adjusting an output phase of said power converter on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof so as to eliminate a phase difference between the power system-side ac voltage and the load-side ac voltage during self commutated operation of said converter; and closing and switching on/off means when said phase difference is close to zero.
Claim 11
Independent Claim
106 words
A method of controlling a power converter which supplies electric power to a load and is connected to the load and to a power system through switching on/off means, comprising the steps of: adjusting an output phase of said power converter on the basis of an ac voltage on a power system side of said switching on/off means and an ac voltage on a load side thereof so as to eliminate a phase difference between the power system-side ac voltage and the load-side ac voltage during self commutated operation of said converter; and closing and switching on/off means when said phase difference is close to zero.
References Cited (Backward Citations)
US4218625A
Cited
US4314189A
Cited
US4667283A
Cited
US4797799A
Cited
US4797570A
Cited
US5111377A
Cited
US5255176A
Cited
US5446645A
Cited
US5625539A
Cited
JPH089648A
Cited
JPH0866048A
Cited
US6128204A
Cited
US6140803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-10-15 | 2005-04-16 | 2005-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-15 | 2009-04-16 | 2009-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-15 | 2013-04-16 | 2013-10-16 | $7700.00 | Window Closed / Lapsed |