US4939486A
Expired / Lapsed
US
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Filter equipment for power lines
Assignee: ABB AB
•
Filing: 1989-01-04
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Granted: 1990-07-03
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Expires: 2009-01-04
Abstract
Abstract Filter equipment for power lines has a double-tuned shunt filter (F1) which has a series resonance circuit (C1, L1) connected in series with a parallel resonance circuit (C2, L2). The capacitor banks of the two resonance circuits are formed so as to have opposite signs on the temperature coefficent of the capacitor capacitance.
Inventors
- 👤 Bernt Bergdahl
- 👤 Jan T. Holmgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:42
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/06; H03H7/17; H03H7/1741; H03H7/1758; H03H7/1791
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
88 words
Filter equipment for a power line with a double-tuned shunt filter for reduction of voltage or current harmonics which originate from the static convertors connected to the power line, said shunt filter having a series resonance circuit with a first capacitor bank and a first inductor, and a parallel resonance circuit with a second capacitor bank and a second inductor, wherein one of the capacitor banks has a capacitance having a positive temperature coefficient and wherein the other capacitor bank has a capacitance having a negative temperature coefficient.
Claim 2
Dependent Claim
88 words
Filter equipment for a power line with a double-tuned shunt filter for reduction of voltage or current harmonics which originate from the static convertors connected to the power line, said shunt filter having a series resonance circuit with a first capacitor bank and a first inductor, and a parallel resonance circuit with a second capacitor bank and a second inductor, wherein one of the capacitor banks has a capacitance having a positive temperature coefficient and wherein the other capacitor bank has a capacitance having a negative temperature coefficient.
Claim 3
Dependent Claim
24 words
Filter equipment according to claim 1, wherein said series resonance circuit and said parallel resonance circuit have respective resonance frequencies that are substantially equal.
Claim 4
Dependent Claim
21 words
Filter equipment according to claim 1, wherein said shunt filter is tuned to two adjacent harmonic frequencies of the power line.
Claim 5
Dependent Claim
21 words
Filter equipment according to claim 2, wherein said shunt filter is tuned to two adjacent harmonic frequencies of the power line.
Claim 6
Dependent Claim
59 words
Filter equipment according to claim 1, wherein said convertor is connected to an a.c. power line; and wherein said shunt filter is tuned to the two frequencies f1=(n.p+1).f0 f2=(n.p-1).f0 where n is an integer greater than or equal to 1; p is the pulse number of the convertor; and f0 is the fundamental frequency of said a.c. power line.
Claim 7
Dependent Claim
59 words
Filter equipment according to claim 2, wherein said convertor is connected to an a.c. power line; and wherein said shunt filter is tuned to the two frequencies f1=(n.p+1).f0 f2=(n.p-1).f0 where n is an integer greater than or equal to 1; p is the pulse number of the convertor; and f0 is the fundamental frequency of said a.c. power line.
Claim 8
Dependent Claim
59 words
Filter equipment according to claim 3, wherein said convertor is connected to an a.c. power line; and wherein said shunt filter is tuned to the two frequencies f1=(n.p+1).f0 f2=(n.p-1).f0 where n is an integer greater than or equal to 1; p is the pulse number of the convertor; and f0 is the fundamental frequency of said a.c. power line.
Claim 9
Dependent Claim
59 words
Filter equipment according to claim 4, wherein said convertor is connected to an a.c. power line; and wherein said shunt filter is tuned to the two frequencies f1=(n.p+1).f0 f2=(n.p-1).f0 where n is an integer greater than or equal to 1; p is the pulse number of the convertor; and f0 is the fundamental frequency of said a.c. power line.
Claim 10
Dependent Claim
41 words
Filter equipment according to claim 1, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 11
Dependent Claim
40 words
Filter equipment according to claim 2, and for connection to an a.c. power line, wherein said first capacitor bank has capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 12
Dependent Claim
41 words
Filter equipment according to claim 3, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capactior bank has a capacitance having a positive temperature coefficient.
Claim 13
Dependent Claim
41 words
Filter equipment according to claim 4, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 14
Dependent Claim
41 words
Filter equipment according to claim 5, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 15
Dependent Claim
41 words
Filter equipment according to claim 6, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 16
Dependent Claim
41 words
Filter equipment according to claim 7, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 17
Dependent Claim
41 words
Filter equipment according to claim 8, and for connection to an a.c. power line, wherein said first capacitor bank has a capacitance having a negative temperature coefficient; and wherein said second capacitor bank has a capacitance having a positive temperature coefficient.
Claim 18
Dependent Claim
20 words
Filter equipment according to claim 9, wherein said first capacitor bank has capacitors formed with a plastic film as dielectric.
Claim 19
Dependent Claim
19 words
Filter equipment according to claim 9, wherein said second capacitor bank has capacitors formed with impregnated paper as dielectric.
Claim 20
Dependent Claim
19 words
Filter equipment according to cliam 17, wherein said second capacitor bank has capacitors formed with impregnated paper as dielectric.
Claim 21
Dependent Claim
19 words
Filter equipment according to cliam 17, wherein said second capacitor bank has capacitors formed with impregnated paper as dielectric.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |