US6703718B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wind turbine controller
Assignee: Wind Resource LLC
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Filing: 2001-10-12
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Granted: 2004-03-09
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Expires: 2021-10-12
Abstract
Abstract A wind turbine with a permanent magnet alternator that uses a boost mode controller to improve performance at low and high wind speeds. The boost mode controller also allows the permanent magnet alternator to be slowed so that the wind turbine can be stall controlled. A rectifier bridge circuit includes a power electronic switching device on each phase to selectively short the voltage on that phase. The duty cycle of the switching devices is controlled to give the desired wind turbine performance. The switching frequency of the power electronic switches is continuously modulated at low wind speeds in order to minimize tonal acoustic emissions. The controller simplifies the design of the wind turbine by accomplishing the necessary control functions without adding additional complexity to the wind turbine. This improves the cost-effectiveness of the wind turbine. The improvement in cost-effectiveness allows the wind turbine to be economically utilized at a location with a lower wind speed than previous wind turbine designs allowed.
Inventors
- 👤 David Gregory Calley
- 👤 Harrison Marden Knowler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:26
CPC Classifications
F; F03; F03D; F03D7/00; F03D7/02; F03D7/0256; F03D9/00; F03D9/20; F03D9/25; H; H02; H02P; H02P9/00; H02P9/14; H02P9/26; H02P9/30; H02P9/305; F05; F05B; F05B2220/00; F05B2220/70; F05B2220/706; F05B2220/7068; F05B2270/00; F05B2270/30; F05B2270/327; H02P2101/00; H02P2101/15; Y; Y02; Y02E; Y02E10/00; Y02E10/70; Y02E10/72
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
133 words
A wind turbine comprising: a rotor with at least one blade; an permanent magnet alternator with a rotating portion attached to said rotor for rotation therewith and an armature that generates alternating current electricity when said rotating portion turns, wherein said armature has an internal inductance; a rectifier for converting said AC electricity from said armature into a DC voltage; a power circuit operatively coupled to said rectifier for selectively shorting the AC voltage from said armature so as to store electrical energy within said internal inductance of said armature; and an inverter for converting said DC voltage to AC voltage suitable for connection to a utility grid wherein said power circuit boosts said DC voltage to a level sufficient to allow said inverter to operate without a boost function within said inverter.
Claim 2
Dependent Claim
133 words
A wind turbine comprising: a rotor with at least one blade; an permanent magnet alternator with a rotating portion attached to said rotor for rotation therewith and an armature that generates alternating current electricity when said rotating portion turns, wherein said armature has an internal inductance; a rectifier for converting said AC electricity from said armature into a DC voltage; a power circuit operatively coupled to said rectifier for selectively shorting the AC voltage from said armature so as to store electrical energy within said internal inductance of said armature; and an inverter for converting said DC voltage to AC voltage suitable for connection to a utility grid wherein said power circuit boosts said DC voltage to a level sufficient to allow said inverter to operate without a boost function within said inverter.
Claim 3
Dependent Claim
32 words
The wind turbine of claim 1 further comprising a controller that senses the rotational speed of said rotor and adjusts the duty cycle of said power circuit based upon said rotational speed.
Claim 4
Dependent Claim
15 words
The wind turbine of claim 2 further comprising a battery electrically connected to said rectifier.
Claim 5
Dependent Claim
54 words
The wind turbine of claim 3 wherein said controller momentarily shorts the AC voltage from said armature thereby causing an inductive voltage spike in said internal inductance of said armature sufficient to cause current to flow into said battery when said rotational speed is at a lower end of the range of generating speeds.
Claim 6
Dependent Claim
33 words
The wind turbine of claim 3 wherein said controller senses the charge in said battery and adjusts the duty cycle of said power circuit based upon said rotational speed and said battery charge.
Claim 7
Dependent Claim
60 words
The wind turbine of claim 1 wherein said power circuit has a selectable duty cycle, and wherein said wind turbine further comprises a controller that senses the rotational speed of said blade and increases the duty cycle of said power circuit when said rotational speed reaches a predetermined level, thereby causing said blade to enter a condition of aerodynamic stall.
Claim 8
Dependent Claim
28 words
The wind turbine of claim 1 wherein said power circuit has a switching frequency and said switching frequency is modulated in order to minimize tonal acoustic noise emission.
Claim 9
Dependent Claim
46 words
A wind turbine comprising: a blade; a permanent magnet alternator operatively connected to said blade wherein said alternator generates electricity when said blade rotates; a controller for operating said alternator at variable speed and for controlling the power output from said wind turbine by aerodynamic stall.
Claim 10
Dependent Claim
46 words
A wind turbine comprising: a blade; a permanent magnet alternator operatively connected to said blade wherein said alternator generates electricity when said blade rotates; a controller for operating said alternator at variable speed and for controlling the power output from said wind turbine by aerodynamic stall.
Claim 11
Dependent Claim
41 words
The wind turbine of claim 8 wherein said controller senses the rotational speed of said blade and slows said alternator when said blade turns at a predetermined speed in order to causes said blade to enter a state of aerodynamic stall.
Claim 12
Dependent Claim
85 words
The wind turbine of claim 8 wherein said alternator comprises a rotating portion attached to said blade for rotation therewith and an armature that generates alternating current electricity when said rotating portion turns, wherein said armature has an internal inductance; a rectifier for converting said AC electricity from said armature into a DC voltage; and a power circuit operatively coupled to said rectifier for selectively shorting the AC voltage from said armature so as to store electrical energy within said internal inductance of said armature.
Claim 13
Dependent Claim
40 words
The wind turbine of claim 10 wherein said controller selects a duty cycle for said power circuit that causes said wind turbine to operate at variable speed and that controls the power output from said wind turbine by aerodynamic stall.
Claim 14
Dependent Claim
44 words
The wind turbine of claim 11 wherein said controller senses the rotational speed of said blade and increases the duty cycle of said power circuit when said rotational speed reaches a predetermined level, thereby causing said blade to enter a condition of aerodynamic stall.
Claim 15
Dependent Claim
134 words
A wind turbine comprising: a rotor with at least one blade; a permanent magnet alternator with a rotating portion attached to said rotor for rotation therewith and an armature that generates alternating current electricity when said rotating portion turns, wherein said armature has an internal inductance; a rectifier for converting said AC electricity from said armature into a DC voltage; a power circuit with a selectable duty cycle operatively coupled to said rectifier for selectively shorting the AC voltage from said armature so as to store electrical energy within said internal inductance of said armature; and a controller that senses the rotational speed of said blade and increases the duty cycle of said power circuit when said rotational speed reaches a predetermined level, thereby causing said blade to enter a condition of aerodynamic stall.
Claim 16
Dependent Claim
134 words
A wind turbine comprising: a rotor with at least one blade; a permanent magnet alternator with a rotating portion attached to said rotor for rotation therewith and an armature that generates alternating current electricity when said rotating portion turns, wherein said armature has an internal inductance; a rectifier for converting said AC electricity from said armature into a DC voltage; a power circuit with a selectable duty cycle operatively coupled to said rectifier for selectively shorting the AC voltage from said armature so as to store electrical energy within said internal inductance of said armature; and a controller that senses the rotational speed of said blade and increases the duty cycle of said power circuit when said rotational speed reaches a predetermined level, thereby causing said blade to enter a condition of aerodynamic stall.
References Cited (Backward Citations)
US1142538A
Cited
US2152576A
Cited
US4427897A
Cited
US4435646A
Cited
US4498017A
Cited
US4651017A
Cited
US4695736A
Cited
US4825139A
Cited
US4908565A
Cited
US5083039B1
Cited
US5083039A
Cited
US5225712A
Cited
US5579217A
Cited
US5172310A
Cited
US5289041A
Cited
US5187427A
Cited
US5566061A
Cited
US5663631A
Cited
US5652485A
Cited
US5798632A
Cited
US5798631A
Cited
US6175217B1
Cited
US5946202A
Cited
US5793625A
Cited
US6285090B1
Cited
US5907192A
Cited
US6137187A
Cited
DE19817412A1
Cited
US6353307B1
Cited
US6072302A
Cited
US6359421B1
Cited
US6144190A
Cited
US6181111B1
Cited
US6275012B1
Cited
US6239996B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-03-09 | 2007-09-08 | 2008-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-03-09 | 2011-09-08 | 2012-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-03-09 | 2015-09-08 | 2016-03-09 | $7700.00 | Window Closed / Lapsed |