US3777250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter for replacing notches in electric waves
Assignee: Allis Chalmers Corp
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Filing: 1973-05-07
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Granted: 1973-12-04
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Expires: 1993-05-07
Abstract
Abstract A wave filter arrangement reproduces the output voltage from a generator on a reduced scale with any notches in the generator output voltage caused by flow of current through the generator impedance replaced in the replica wave. A stepdown current transformer derives a reduced magnitude replica of the current flowing through the generator, a stepdown potential transformer generates a reduced magnitude replica of the output voltage from the generator, and an auxiliary inductance, which is a scale model of the generator subtransient reactance, is connected across the current transformer secondary winding so that the replica of the generator voltage and the voltage drop across the auxiliary inductance are additive and remove notches and other distortions from the reduced scale reproduction of the generator voltage.
Inventors
- 👤 E Kaeser
- 👤 A Geiersbach
- 👤 M Neumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:46
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/27; H02M5/271
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
125 words
In an electrical wave filter arrangement for deriving a replica of the output voltage from an electrical power source and for removing from the replica voltage commutation notches and other distortions which appear in the source output voltage as a result of flow of electrical current through the impedance of said source, the combination of means for deriving a voltage which is a replica of the output voltage from said power source, current sensing means for producing an output indicative of the output current from said power Source, and an auxiliary impedance which is a scale model of said impedance of said power source coupled across the output of said current sensing means so that the voltage drop thereacross is additive to said replica voltage.
Claim 2
Dependent Claim
125 words
In an electrical wave filter arrangement for deriving a replica of the output voltage from an electrical power source and for removing from the replica voltage commutation notches and other distortions which appear in the source output voltage as a result of flow of electrical current through the impedance of said source, the combination of means for deriving a voltage which is a replica of the output voltage from said power source, current sensing means for producing an output indicative of the output current from said power Source, and an auxiliary impedance which is a scale model of said impedance of said power source coupled across the output of said current sensing means so that the voltage drop thereacross is additive to said replica voltage.
Claim 3
Dependent Claim
60 words
In an electrical wave filter arrangement in accordance with claim 1 wherein said power source is an alternating current generator which supplies power to a bank of controlled rectifiers, said wave filter arrangement reproduces the air gap voltage of said generator, and the inductance of said auxiliary impedance is a reduced scale model of the subtransient reactance of said generator.
Claim 4
Dependent Claim
34 words
In an electrical wave filter arrangement in accordance with claim 1 wherein said current sensing means is a stepdown current transformer and said auxiliary impedance is connected across the secondary of said current transformer.
Claim 5
Dependent Claim
63 words
In an electrical wave filter arrangement in accordance with claim 3 wherein said current transformer has a turns ratio of n to 1, said replica voltage deriving means is a stepdown potential transformer having a turns ratio of m to 1, and said auxiliary impedance is an inductive reactance whose inductance is approximately equal to n/m times the inductance of said power source.
Claim 6
Dependent Claim
76 words
In an electrical wave filter arrangement in accordance with claim 1 wherein said power source includes a magnetic element and the impedance of said power source varies as a function of the magnitude of said electrical current flow therethrough, and wherein said auxiliary impedance is an inductive reactance including a magnetic element and whose impedance varies as a function of the magnitude of electrical current flow therethrough in approximately the same manner as said power source.
Claim 7
Dependent Claim
24 words
In an electrical wave filter arrangement in accordance with claim 1 wherein said auxiliary impedance is an inductive reactance whose inductance is selectively adjustable.
Claim 8
Dependent Claim
128 words
In an electrical wave filter arrangement for reproducing the input voltage to an electrical device possessing impedance in order to eliminate from the reproduction distortions appearing in the output wave from said device as a result of current flow through the impedance of said device, the combination of means for deriving a voltage which is a replica of the output voltage from said device, current sensing means for producing an output indicative of the current flowing through said device, and an auxiliary impedance coupled across the output of said current sensing means and connected so that the voltage drop thereacross is additive to said replica voltage, whereby distortions are eliminated from the potential appearing across the series arrangement of said auxiliary impedance and said replica voltage deriving means.
Claim 9
Dependent Claim
128 words
In an electrical wave filter arrangement for reproducing the input voltage to an electrical device possessing impedance in order to eliminate from the reproduction distortions appearing in the output wave from said device as a result of current flow through the impedance of said device, the combination of means for deriving a voltage which is a replica of the output voltage from said device, current sensing means for producing an output indicative of the current flowing through said device, and an auxiliary impedance coupled across the output of said current sensing means and connected so that the voltage drop thereacross is additive to said replica voltage, whereby distortions are eliminated from the potential appearing across the series arrangement of said auxiliary impedance and said replica voltage deriving means.
Claim 10
Dependent Claim
24 words
In an arrangement in accordance with claim 7 wherein said auxiliary impedance is a reduced scale model of the impedance of said electrical device.
Claim 11
Dependent Claim
57 words
In an arrangement in accordance with claim 8 wherein said current sensing means is a stepdown current transformer and said auxiliary impedance is an inductor coupled across the secondary winding of said current transformer and whose inductance is a function of both the turns ratio n of said current means and the inductance of said electrical device.
Claim 12
Dependent Claim
45 words
In an arrangement in accordance with claim 9 wherein the magnitude of said replica voltage is approximately 1/m that of said output voltage from said device and the inductance of said auxiliary inductor is approximately equal to n/m times said inductance of said electrical device.
Claim 13
Dependent Claim
29 words
In an arrangement in accordance with claim 9 wherein said means for deriving said replica voltage is a potential transformer having a turns ratio of approximately m to 1.
Claim 14
Dependent Claim
42 words
In an electrical filter arrangement in accordance with claim 7 wherein said device is an alternating current electrical power source for a bank of controlled rectifiers and said auxiliary impedance is a reduced scale model of the impedance of said powEr source.
Claim 15
Dependent Claim
45 words
In an electrical filter arrangement in accordance with claim 12 wherein said electrical device is an alternating current generator, said filter arrangement reproduces the air gap voltage in said generator, and said auxiliary impedance in a scale model of the subtransient reactance of said generator.
Claim 16
Dependent Claim
57 words
In an electrical filter arrangement in accordance with claim 13 wherein said auxiliary impedance includes a magnetic element and the inductance of said auxiliary impedance varies as a function of the magnitude of current flow therethrough in the same manner that said subtransient reactance of said generator varies as a function of the magnitude of generator current.
Claim 17
Dependent Claim
107 words
An electrical wave filter arrangement for reproducing the voltage behind the subtransient reactance of an alternating current generator comprising, in combination, stepdown current transformer means having a secondary winding for providing an output indicative of the output current from said generator, potential deriving means for generating a voltage which is a replica of the output voltage from said generator, and an auxiliary inductor connected across said secondary winding so that the voltage drop thereacross is additive to said replica voltage, the inductance of said auxiliary inductor being a scale model of the inductance of the winding of said generator, whereby distortions are eliminated from the reproduction voltage.
Claim 18
Dependent Claim
107 words
An electrical wave filter arrangement for reproducing the voltage behind the subtransient reactance of an alternating current generator comprising, in combination, stepdown current transformer means having a secondary winding for providing an output indicative of the output current from said generator, potential deriving means for generating a voltage which is a replica of the output voltage from said generator, and an auxiliary inductor connected across said secondary winding so that the voltage drop thereacross is additive to said replica voltage, the inductance of said auxiliary inductor being a scale model of the inductance of the winding of said generator, whereby distortions are eliminated from the reproduction voltage.
Claim 19
Dependent Claim
59 words
An electrical wave filter arrangement in accordance with claim 15 wherein said current transformer has a turns ratio of n, said potential deriving means generates a voltage whose magnitude is equal to approximately 1/m that of said generator output voltage, and the inductance of said auxiliary inductor is approximately equal to n/m times the inductance of said generator winding.
Claim 20
Dependent Claim
167 words
An electrical filter arrangement for reproducing the voltage behind the subtransient reactance of a polyphase alternating current generator having star connected stator phase windings and supplying an SCR cycloconverter through output phase busses comprising, in combination, a plurality of stepdown current transformers each of which is coupled to one of said output phase busses and has a secondary winding, a plurality of stepdown potential transformer means for deriving voltages which are reduced magnitude replicas of the phase-to-neutral output voltages of said generator, and a plurality of auxiliary inductors each of which is a reduced scale model of the inductance of a generator stator phase winding and is connected across said secondary winding of one of said current transformers so that the voltage drop thereacross is additive to the replica voltage derived by one of said potential transformer means, whereby any commutation notches appearing in said generator output voltages are eliminated in the reduced scale reproduction voltages appearing from one side of each auxiliary inductor to said neutral.
Claim 21
Dependent Claim
167 words
An electrical filter arrangement for reproducing the voltage behind the subtransient reactance of a polyphase alternating current generator having star connected stator phase windings and supplying an SCR cycloconverter through output phase busses comprising, in combination, a plurality of stepdown current transformers each of which is coupled to one of said output phase busses and has a secondary winding, a plurality of stepdown potential transformer means for deriving voltages which are reduced magnitude replicas of the phase-to-neutral output voltages of said generator, and a plurality of auxiliary inductors each of which is a reduced scale model of the inductance of a generator stator phase winding and is connected across said secondary winding of one of said current transformers so that the voltage drop thereacross is additive to the replica voltage derived by one of said potential transformer means, whereby any commutation notches appearing in said generator output voltages are eliminated in the reduced scale reproduction voltages appearing from one side of each auxiliary inductor to said neutral.
Claim 22
Dependent Claim
53 words
An electrical filter arrangement in accordance with claim 17 wherein the turns ratio of each said current transformer is n, the turns ratio of each said potential transformer means is m, and the inductance of each auxiliary inductor is approximately equal to n/m times the inductance of a phase winding of said generator.
Claim 23
Dependent Claim
93 words
An electrical filter arrangement in accordance with claim 18 wherein said generator is three phase and each said potential transformer means has a primary winding connected across a pair of said generator phase busses, the primary windings of said plurality of potential transformer means are connected in delta and the secondary windings thereof are also connected in delta, and including three resistances connected in wye, each junction between potential transformer secondary windings being connected to one side of one of said auxiliary inductors and also to one side of one of said resistances.
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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) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |