US4009433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for compensating reactive power
Assignee: Siemens AG
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Filing: 1975-11-12
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Granted: 1977-02-22
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Expires: 1995-11-12
Abstract
Abstract An arrangement for compensating reactive power in a three phase network using two converters with the same no load d-c voltage in which the two converters are coupled in parallel on the d-c side and shorted by a common choke with the one converter operated with a delayed firing time and the other with an advanced firing time and a d-c current in the choke regulated to a constant value by influencing the firing angles of the two converters in opposite directions.
Inventors
- 👤 Gottfried Moltgen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:53
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/18; H02J3/1821; H02J3/1835; H02J3/1842; H02J3/185; Y; Y02; Y02E; Y02E40/00; Y02E40/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
118 words
Apparatus for compensating the reactive power in a three phase network comprising: a. a first converter operated with advanced firing time and having an a-c input coupled to the network and providing a d-c output; b. a second converter operated with delayed firing time and having the same no load d-c voltage as said first converter having its a-c input coupled to the network and having its d-c output coupled in parallel to the d-c output of said first converter; c. a common choke short-circuiting the outputs of said first and second converters; and d. means coupled to influence the operation of said first and second converters so as to maintain the d-c current in said choke constant.
Claim 2
Dependent Claim
118 words
Apparatus for compensating the reactive power in a three phase network comprising: a. a first converter operated with advanced firing time and having an a-c input coupled to the network and providing a d-c output; b. a second converter operated with delayed firing time and having the same no load d-c voltage as said first converter having its a-c input coupled to the network and having its d-c output coupled in parallel to the d-c output of said first converter; c. a common choke short-circuiting the outputs of said first and second converters; and d. means coupled to influence the operation of said first and second converters so as to maintain the d-c current in said choke constant.
Claim 3
Dependent Claim
122 words
Apparatus according to claim 1 wherein each of said converters includes a power section, a control unit for generating firing pulses and a control device for generating a control input for said control unit, said control device comparing an actual value with a predetermined desired value in order to develop its output and further including means to measure the reactive power in said network having its output coupled as the actual value input to the control device of said first converter and wherein said means for maintaining a constant d-c current in said choke comprises a current transformer coupled in series with said choke and providing its output as an actual value input to the control device associated with said second converter.
Claim 4
Independent Claim
89 words
A method of operating apparatus for compensating the reactive power in a three phase network, the apparatus including first and second reactive power converters having the same no load voltages and having their a-c inputs coupled to the line and their d-c outputs coupled in parallel and short-circuited through a common choke comprising the steps of: a. operating the first converter with the delayed firing time; b. operating the second converter with an advanced firing time; and c. maintaining the d-c current in the choke at a constant value.
Claim 5
Independent Claim
89 words
A method of operating apparatus for compensating the reactive power in a three phase network, the apparatus including first and second reactive power converters having the same no load voltages and having their a-c inputs coupled to the line and their d-c outputs coupled in parallel and short-circuited through a common choke comprising the steps of: a. operating the first converter with the delayed firing time; b. operating the second converter with an advanced firing time; and c. maintaining the d-c current in the choke at a constant value.
Claim 6
Independent Claim
30 words
The method according to clam 3 wherein said d-c current is maintained at a constant value by influencing the firing angles of said first and second converters and opposite directions.
Claim 7
Independent Claim
30 words
The method according to clam 3 wherein said d-c current is maintained at a constant value by influencing the firing angles of said first and second converters and opposite directions.
Claim 8
Dependent Claim
54 words
The method according to claim 3 and further including: a. controlling the firing angle of one of said converters as a function of the reactive power in the three phase network to be compensated; and b. controlling the firing angle of the other converter as a function of the d-c current in the choke.
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) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |