Patent US5798632A successfully refreshed from Google Patents.
US5798632A
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US
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Variable speed wind turbine generator with zero-sequence filter
Assignee: Alliance for Sustainable Energy LLC
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Filing: 1997-06-06
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Granted: 1998-08-25
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Expires: 2017-06-06
Abstract
Abstract A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.
Inventors
- 👤 Eduard Muljadi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:26
CPC Classifications
F; F03; F03D; F03D7/00; F03D7/02; F03D7/0272; F03D9/00; F03D9/10; F03D9/11; F03D9/20; F03D9/25; F03D9/255; H; H02; H02J; H02J3/00; H02J3/04; H02J3/06; H02J3/38; H02J3/381; H02J7/00; H02J7/32; H02P; H02P9/00; H02P9/007; H02P9/14; H02P9/26; H02P9/30; H02P9/46; F05; F05B; F05B2220/00; F05B2220/70; F05B2220/706; F05B2270/00; F05B2270/10; F05B2270/1016; F05B2270/20; H02J2101/00; H02J2101/20; H02J2101/22; H02J2101/24; H02J2101/28; H02P2101/00; H02P2101/15; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/56; Y02E10/70; Y02E10/72; Y02E10/76; Y02E70/00; Y02E70/30
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
146 words
Generator apparatus, comprising: a variable speed rotor that is magnetically coupled to a plurality of electrically excited stator windings that are connected together at a common node; filter means connected electrically to at least one of said stator windings for passing current that has a first characteristic and for blocking current that has a second characteristic; a chargeable energy storage device connectable electrically, but not through said filter, to said stator windings; switch means positioned between said energy storage device and said stator windings for connecting and disconnecting said energy storage device to and from said stator windings; and load connection means for making an electrical connection of a load through said filter means to at least one of said stator windings, said electrical connection of the load to at least one of said stator windings being positioned between said stator winding and said switch means.
Claim 2
Dependent Claim
146 words
Generator apparatus, comprising: a variable speed rotor that is magnetically coupled to a plurality of electrically excited stator windings that are connected together at a common node; filter means connected electrically to at least one of said stator windings for passing current that has a first characteristic and for blocking current that has a second characteristic; a chargeable energy storage device connectable electrically, but not through said filter, to said stator windings; switch means positioned between said energy storage device and said stator windings for connecting and disconnecting said energy storage device to and from said stator windings; and load connection means for making an electrical connection of a load through said filter means to at least one of said stator windings, said electrical connection of the load to at least one of said stator windings being positioned between said stator winding and said switch means.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1, wherein said filter is a zero sequence filter.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2, including a transformer connected between said zero sequence filter and said load.
Claim 5
Dependent Claim
16 words
The apparatus of claim 2, wherein said zero sequence filter includes a plurality of inductive elements.
Claim 6
Dependent Claim
39 words
The apparatus of claim 4, wherein each of said plurality of inductive elements is connected to one of said stator windings and each of said stator windings is connected to at least one of said plurality of inductive elements.
Claim 7
Dependent Claim
14 words
The apparatus of claim 5, wherein said stator windings consists of three stator windings.
Claim 8
Dependent Claim
16 words
The apparatus of claim 6, wherein said plurality of inductive elements consists of three inductive elements.
Claim 9
Dependent Claim
16 words
The apparatus of claim 2, wherein said zero sequence filter includes a plurality of capacitive elements.
Claim 10
Dependent Claim
38 words
The apparatus of claim 8, wherein each of said plurality of capacitive elements is connected to one of stator windings and each of said stator windings is connected to at least one of said plurality of capacitive elements.
Claim 11
Dependent Claim
14 words
The apparatus of claim 9, wherein said stator windings consists of three stator windings.
Claim 12
Dependent Claim
16 words
The apparatus of claim 10, wherein said plurality of capacitive elements consists of three capacitive elements.
Claim 13
Dependent Claim
13 words
The apparatus of claim 1, wherein said energy storage device includes a capacitor.
Claim 14
Dependent Claim
40 words
The apparatus of claim 1, including an electric energy source connectable to said energy storage device, said electric energy source being capable of charging said energy storage device when said electric energy source is connected to said energy storage device.
Claim 15
Dependent Claim
59 words
The apparatus of claim 1, including actuator control means for actuating said switch means to connect and disconnect said energy storage device and said stator windings in a manner that creates electric excitation signals having a first characteristic that is not passable through said filter and electric power signals having a second characteristic that is passable through said filter.
Claim 16
Dependent Claim
56 words
The apparatus of claim 14, wherein said actuator control means includes energy sensing means connected to said energy storage device for sensing energy level stored in said energy storage device and actuating said switch means to produce said electric power signals when the energy level of said energy storage device is above a target energy level.
Claim 17
Dependent Claim
42 words
The apparatus of claim 14, wherein said actuator control means includes angular velocity sensing means for measuring angular velocity of said rotor and actuating said switch means that produces electric excitation signals having a frequency that maximizes the production of electric energy.
Claim 18
Independent Claim
125 words
A method of producing and delivering electrical energy to a load, comprising the steps of: generating electrical energy with a variable angular velocity rotating rotor that is magnetically coupled to a plurality of stator windings; storing said electrical energy; tapping the electrical energy stored to create electric excitation signals having a first characteristic on a plurality of conductors that are connected respectively to said stator windings; tapping the electrical energy stored to create electric power signals having a second characteristic distinct from said first characteristic on at least one of said conductors; and connecting the load electrically to the conductor or conductors that has or have said electric power signals via a filter that passes said electric power signals and blocks said electric excitation signals.
Claim 19
Independent Claim
125 words
A method of producing and delivering electrical energy to a load, comprising the steps of: generating electrical energy with a variable angular velocity rotating rotor that is magnetically coupled to a plurality of stator windings; storing said electrical energy; tapping the electrical energy stored to create electric excitation signals having a first characteristic on a plurality of conductors that are connected respectively to said stator windings; tapping the electrical energy stored to create electric power signals having a second characteristic distinct from said first characteristic on at least one of said conductors; and connecting the load electrically to the conductor or conductors that has or have said electric power signals via a filter that passes said electric power signals and blocks said electric excitation signals.
Claim 20
Dependent Claim
24 words
The method of claim 17, including the step of creating said electric excitation signals to have the first characteristic of being in positive sequence.
Claim 21
Dependent Claim
25 words
The method of claim 18, including the step of creating said electrical excitation signals with a frequency that is adjustable within an excitation frequency range.
Claim 22
Dependent Claim
36 words
The method of claim 19, including the step of adjusting the frequency of the excitation signals within the excitation range to maximize the electrical energy generated for an angular velocity at which the rotor is rotating.
Claim 23
Dependent Claim
57 words
The method of claim 20, including the steps of measuring angular velocity of the rotating rotor, determining an optimum frequency for the excitation signals that will cause the rotating rotor interacting with the stator windings to generate maximum electrical energy at the angular velocity measured, and adjusting the frequency of the excitation signals to that optimum frequency.
Claim 24
Dependent Claim
58 words
The method of claim 21, including the steps of determining empirically a gamut of optimum frequencies in said excitation frequency range that will cause the rotating rotor interacting with the stator windings to generate maximum electrical energy at a variety of angular velocities, and selecting the optimum frequency from the gamut that corresponds to the angular velocity measured.
Claim 25
Dependent Claim
48 words
The method of claim 17, including the steps of establishing a target level for the stored energy that is sufficient to provide the electric excitation signals necessary to interact with the rotating rotor to generate the electrical energy and maintaining the electrical energy stored at the target level.
Claim 26
Dependent Claim
32 words
The method of claim 23, including the steps of measuring the electrical energy stored and adjusting the electric power signals to deliver excess electrical energy over the target level to the load.
Claim 27
Dependent Claim
58 words
The method of claim 24, including the steps of creating said electric excitation signals to have the first characteristics of being in positive sequence and with a frequency that is adjustable within an excitation frequency range, and creating said electric power signals to have the second characteristic include a frequency that is not in said excitation frequency range.
Claim 28
Dependent Claim
38 words
The method of claim 25, including the step of creating said electric power signals on more than one of said conductors to have the second characteristic also include said electric power signals being in phase with each other.
Claim 29
Dependent Claim
39 words
The method of claim 26, including the step of creating said electric power signals to have the second characteristic also include said electric power signals having the same magnitude on each of the conductors that has electric power signals.
Claim 30
Dependent Claim
40 words
The method of claim 27, including the steps of connecting said stator windings in a star configuration and providing said filter to have a higher impedance in said excitation frequency range than at the frequency of the electric power signal.
Claim 31
Dependent Claim
28 words
The method of claim 27, including the step of providing said filter to have a higher impedance in said excitation frequency range than impedances in the stator windings.
Claim 32
Dependent Claim
43 words
The method of claim 28, including the steps of connecting the load to the conductors that have electric power signals at a node that is common to the conductors and positioning an impedance producing device between each of the conductors and the node.
Claim 33
Dependent Claim
25 words
The method of claim 30, including the step of using an inductor for the impedance producing device between each of the conductors and the node.
Claim 34
Dependent Claim
25 words
The method of claim 30, including the step of using a capacitor for the impedance producing device between each of the conductors and the node.
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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) | 2001-08-24 | 2002-02-23 | 2002-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-24 | 2006-02-23 | 2006-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-24 | 2010-02-23 | 2010-08-25 | $7700.00 | Window Closed / Lapsed |