US3694728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for altering current distribution in mesh-operated high voltage direct current transmission networks
Assignee: BBC Brown Boveri AG Germany
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Filing: 1971-03-18
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Granted: 1972-09-26
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Expires: 1991-03-18
Abstract
Abstract A high voltage direct current mesh-operated network comprises several interconnected stations for effecting an exchange of power by means of converters located at the stations and which are connected to alternating current networks, the station converters being operated selectively either in a rectifier mode or an inverter mode depending upon the direction of the flow of direct current over the branch line between any two stations. To control the level of the direct current flowing over the branch lines, an auxiliary regulatable rectifier arrangement is disposed in each branch and is constituted by two regulatable rectifier systems connected in an anti-parallel manner. One of the rectifier systems conducts while the other system blocks depending upon the direction of the current flow in the branch.
Inventors
- 👤 Karl-Werner Kanngiesser
- 👤 Dietrich Kluge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:21
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/36; Y; Y02; Y02E; Y02E60/00; Y02E60/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
187 words
A high voltage direct current mesh-operated network comprising several stations interconnected by high voltage direct current branch lines for effecting an exchange of power between the stations, converters located respectively at said stations and which are connected to an alternating current network, said converters being selectively operated in a rectifier mode or an inverter mode depending upon the direction of the direct current power flow over a branch line between any two stations, an auxiliary regulatable rectifier arrangement disposed in each branch line, each said rectifier arrangement being constituted by two regulatable rectifier systems connected in an anti-parallel manner, means rendering one of said rectifier systems conductive while the other remains non-conductive and vice versa dependent upon the direction of the flow of direct current between stations and means maintaining one of said rectifier systems in its nonconductive state until the current flow in the other rectifier system falls to zero when reversing the direction of current flow between stations thereby preventing flow of a circulatory current in the branch line between the two anti-parallel rectifier systems at the time of current reversal in the branch line.
Claim 2
Dependent Claim
187 words
A high voltage direct current mesh-operated network comprising several stations interconnected by high voltage direct current branch lines for effecting an exchange of power between the stations, converters located respectively at said stations and which are connected to an alternating current network, said converters being selectively operated in a rectifier mode or an inverter mode depending upon the direction of the direct current power flow over a branch line between any two stations, an auxiliary regulatable rectifier arrangement disposed in each branch line, each said rectifier arrangement being constituted by two regulatable rectifier systems connected in an anti-parallel manner, means rendering one of said rectifier systems conductive while the other remains non-conductive and vice versa dependent upon the direction of the flow of direct current between stations and means maintaining one of said rectifier systems in its nonconductive state until the current flow in the other rectifier system falls to zero when reversing the direction of current flow between stations thereby preventing flow of a circulatory current in the branch line between the two anti-parallel rectifier systems at the time of current reversal in the branch line.
Claim 3
Dependent Claim
163 words
A high voltage direct current mesh-operated network comprising several stations interconnected by high voltage direct current branch lines for effecting an exchange of power between the stations, converters located respectively at said stations and which are connected to an alternating current network, said converters being selectively operated in a rectifier mode or an inverter mode depending upon the direction of the direct current power flow over a branch line between any two stations, an auxiliary regulatable rectifier arrangement disposed in each branch line, each said rectifier arrangement being constituted by two regulatable rectifier systems connected in an anti-parallel manner, means placing one of said rectifier systems in operation while the other remains non-operative and vice versa dependent upon the direction of the flow of direct current between stations and means responsive to an increase in magnitude of the direct current power flow above a selected maximum value for activating the non-operative rectifier system thereby to by-pass the rectifier system which is in operation.
Claim 4
Dependent Claim
163 words
A high voltage direct current mesh-operated network comprising several stations interconnected by high voltage direct current branch lines for effecting an exchange of power between the stations, converters located respectively at said stations and which are connected to an alternating current network, said converters being selectively operated in a rectifier mode or an inverter mode depending upon the direction of the direct current power flow over a branch line between any two stations, an auxiliary regulatable rectifier arrangement disposed in each branch line, each said rectifier arrangement being constituted by two regulatable rectifier systems connected in an anti-parallel manner, means placing one of said rectifier systems in operation while the other remains non-operative and vice versa dependent upon the direction of the flow of direct current between stations and means responsive to an increase in magnitude of the direct current power flow above a selected maximum value for activating the non-operative rectifier system thereby to by-pass the rectifier system which is in operation.
Claim 5
Dependent Claim
50 words
A high voltage direct current mesh-operated network as defined in claim 2 and which further includes means responsive to an increase in gradient of the direct current power flow above a selected maximum value for activating the non-operative rectifier system thereby to by-pass the rectifier system which is in operation.
Claim 6
Dependent Claim
33 words
A high voltage direct current mesh-operated network as defined in claim 3 wherein said selected maximum value of the increase in current gradient is formed by the actual value of the direct current.
Claim 7
Dependent Claim
87 words
A high voltage direct current mesh-operated network as defined in claim 2 wherein said anti-parallel connected auxiliary rectifier systems are constituted by controllable valves to which control voltages from grid control units are applied and wherein said means responsive to an increase in the magnitude of the direct current power flow above a selected maximum value include means for changing the respective firing angles of said grid control units such that the non-operative rectifier system is activated thereby to by-pass the rectifier system which is in operAtion.
Claim 8
Dependent Claim
136 words
A high voltage direct current mesh-operated network as defined in claim 5 wherein said means for changing the respective firing angles of said grid control units in response to an increase in the magnitude of the direct current power flow above a selected value comprises means comparing the magnitude of the actual current flow with a selected maximum magnitude to determine both the deviation and its sense, and means responsive only to a deviation having a sense connotative of an increase in the actual current flow above said selected maximum value for advancing the firing angle of the grid control voltage for the valves of one of said rectifier systems by Alpha and for advancing the firing angle of the grid control voltage for the valves of the other rectifier system by 180* - Alpha .
Claim 9
Dependent Claim
35 words
A high voltage direct current mesh-operated network as defined in claim 2 wherein said anti-parallel connected rectifier systems function to limit the current in the branches of the direct current network to their maximum values.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |