U.S. patent application number 12/961322 was filed with the patent office on 2011-09-15 for system, device, and method for noise-based operation of wind turbines.
Invention is credited to Friedrich Loh, Mahesh A. Morjaria, Benoit P. Petitjean.
Application Number | 20110223006 12/961322 |
Document ID | / |
Family ID | 44560162 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110223006 |
Kind Code |
A1 |
Loh; Friedrich ; et
al. |
September 15, 2011 |
SYSTEM, DEVICE, AND METHOD FOR NOISE-BASED OPERATION OF WIND
TURBINES
Abstract
A method for use in operating a plurality of wind turbines is
provided. An aggregate noise level at one or more geographic
positions is calculated. The aggregate noise level is compared to a
target noise level associated with the geographic position. When
the aggregate noise level differs substantially from the target
noise level, an operational adjustment is transmitted to at least
one wind turbine controller. When the aggregate noise level is
greater than the target noise level, such an operational adjustment
may lead to a decrease in the aggregate noise level. Conversely,
when the aggregate noise level is less than the target noise level,
such an operational adjustment may lead to an increase in the
aggregate noise level, facilitating an increase in the overall
power output of the wind turbines.
Inventors: |
Loh; Friedrich; (Salzbergen,
DE) ; Petitjean; Benoit P.; (Rheine, DE) ;
Morjaria; Mahesh A.; (Marietta, GA) |
Family ID: |
44560162 |
Appl. No.: |
12/961322 |
Filed: |
December 6, 2010 |
Current U.S.
Class: |
415/118 ;
415/119 |
Current CPC
Class: |
Y02E 10/72 20130101;
F03D 7/0224 20130101; F05B 2270/333 20130101; F03D 7/048 20130101;
F03D 7/0296 20130101; Y02E 10/723 20130101 |
Class at
Publication: |
415/118 ;
415/119 |
International
Class: |
F04D 29/00 20060101
F04D029/00; F04D 29/66 20060101 F04D029/66 |
Claims
1. A system for use in operating a plurality of wind turbines, the
system comprising: a plurality of wind turbine controllers, each
wind turbine controller of the plurality of wind turbine
controllers operatively coupled to a wind turbine of a plurality of
wind turbines; and, a site controller coupled in communication with
the plurality of wind turbine controllers and configured to:
determine an aggregate noise level at a geographic position based
on a plurality of noise levels associated with the plurality of
wind turbines; compare the aggregate noise level to a target noise
level associated with the geographic position; and, when the
aggregate noise level exceeds the target noise level, transmit an
operational adjustment to a first wind turbine controller of the
plurality of wind turbine controllers, wherein the first wind
turbine controller is operatively coupled to a first wind turbine,
and a noise level associated with the first wind turbine is reduced
when the first wind turbine controller applies the operational
adjustment.
2. A system in accordance with claim 1, wherein the site controller
is configured to determine the aggregate noise level at least in
part by: receiving a first noise level associated with the first
wind turbine from the first wind turbine controller; and,
calculating a second noise level at the geographic position based
at least in part on the first noise level and a distance between
the geographic position and the first wind turbine.
3. A system in accordance with claim 2, wherein the first wind
turbine controller is configured to calculate the noise level based
on at least one of a rotor blade geometry, a rotor blade surface
roughness, a wind speed, a wind direction, a rotor blade tip speed,
a rotor blade pitch angle, and an operational state of the first
wind turbine.
4. A system in accordance with claim 1, wherein the site controller
is configured to determine the aggregate noise level at least in
part by calculating a noise level associated with the first wind
turbine.
5. A system in accordance with claim 1, further comprising one or
more audio sensors configured to provide a noise level measurement,
wherein the site controller is configured to determine the
aggregate noise level at least in part by sampling the noise level
measurements provided by the audio sensors.
6. A system in accordance with claim 1, wherein the target noise
level is a maximum noise level associated with the geographic
position, and the operational adjustment is calculated by the site
controller to reduce the noise level at the geographic position
substantially to the maximum noise level.
7. A system in accordance with claim 1, wherein the operational
adjustment is a first operational adjustment, and when the
aggregate noise level is below the target noise level, the site
controller is configured to transmit a second operational
adjustment to the first wind turbine controller, wherein the noise
level associated with the first wind turbine and a power output
associated with the first wind turbine are increased when the first
wind turbine controller applies the second operational
adjustment.
8. A system in accordance with claim 1, wherein the aggregate noise
level is a first aggregate noise level at a first geographic
position that is associated with a first target noise level, and
the site controller is further configured to: calculate the first
aggregate noise level based on a noise level and a distance from
the first geographic position that are associated with each wind
turbine of the plurality of wind turbines; calculate a second
aggregate noise level at a second geographic position that is
associated with a second target noise level, wherein the second
aggregate noise level is based on a noise level and a distance from
the second geographic position that are associated with each wind
turbine of the plurality of wind turbines; and, when the second
aggregate noise level exceeds the second target noise level,
transmit an operational adjustment to at least one wind turbine of
the plurality of wind turbines.
9. A device for use in operating a plurality of wind turbines, the
device comprising: a memory device configured to store a target
noise level associated with a geographic position; a processor
coupled to the memory device and programmed to: determine an
aggregate noise level at the geographic position, the aggregate
noise level representing a combination of noise levels associated
with a plurality of wind turbines; and, compare the aggregate noise
level to the target noise level; and, a communication interface
coupled to the processor and configured to transmit an operational
adjustment to at least a first wind turbine controller of the
plurality of wind turbine controllers when the aggregate noise
level differs substantially from the target noise level, the first
wind turbine controller operatively coupled to a first wind
turbine, wherein the difference between the aggregate noise level
and the target noise level decreases when the first wind turbine
controller applies the operational adjustment to the first wind
turbine.
10. A device in accordance with claim 9, wherein the communication
interface is further configured to receive a noise level from the
first wind turbine controller, and the processor is programmed to
determine the aggregate noise level based at least in part on the
received noise level.
11. A device in accordance with claim 9, wherein the communication
interface is further configured to receive one or more operating
parameters from the first wind turbine controller, and the
processor is further programmed to: calculate a noise level
associated with the first wind turbine based on the operating
parameters; and, determine the aggregate noise level based at least
in part on the calculated noise level.
12. A device in accordance with claim 9, wherein the communication
interface is configured to transmit an operational adjustment to
the first wind turbine controller by transmitting to the first wind
turbine controller a desired maximum noise level associated with
the first wind turbine.
13. A device in accordance with claim 9, wherein the communication
interface is configured to transmit an operational adjustment to
the first wind turbine controller by transmitting to the first wind
turbine controller at least one of a rotor blade pitch angle, a
maximum rotor blade speed, a maximum torque, and a maximum power
output level.
14. A device in accordance with claim 9, wherein the operational
adjustment is a first operational adjustment, and the communication
interface is further configured to transmit a second operational
adjustment to a second wind turbine controller that is operatively
coupled to a second wind turbine when the aggregate noise level
differs substantially from the target noise level.
15. A device in accordance with claim 9, wherein the aggregate
noise level is a first aggregate noise level at a first geographic
position that is associated with a first target noise level, and
the processor is further programmed to: determine a second
aggregate noise level at a second geographic position that is
associated with a second target noise level; and, compare the
second aggregate noise level to the second target noise level,
wherein the communication interface is further configured to
transmit an operational adjustment to at least one wind turbine of
the plurality of wind turbines when the second aggregate noise
level differs substantially from the second target noise level.
16. One or more computer readable storage media having
computer-executable instructions embodied thereon, wherein when
executed by at least one processor, the computer-executable
instructions cause the processor to: calculate an aggregate noise
level at a geographic position; compare the aggregate noise level
to a target noise level associated with the geographic position;
and, transmit an operational adjustment to at least one wind
turbine controller when the aggregate noise level differs
substantially from the target noise level, wherein the difference
between the aggregate noise level and the target noise level
decreases when the first wind turbine controller applies the
operational adjustment to a first wind turbine.
17. One or more computer readable storage media in accordance with
claim 14, wherein the computer-executable instructions cause the
processor to calculate the aggregate noise level based at least in
part on a plurality of noise level measurements, each noise level
measurement of the plurality of noise level measurements
corresponding to a geographic position.
18. One or more computer readable storage media in accordance with
claim 15, wherein each noise level measurement of the plurality of
noise level measurements further corresponds to a direction, and
the computer-executable instructions cause the processor to
calculate the aggregate noise level based further on the direction
associated with each noise level measurement.
19. One or more computer readable storage media in accordance with
claim 14, wherein the aggregate noise level is a first aggregate
noise level at a first geographic position associated with a first
target noise level, and when executed by the processor, the
computer-executable instructions further cause the processor to:
calculate a second aggregate noise level at a second geographic
position; compare the second aggregate noise level to a second
target noise level associated with the geographic position; and
determine the operational adjustment based on a first difference
between the first aggregate noise level and the first target noise
level, and a second difference between the second aggregate noise
level and the second target noise level.
20. One or more computer readable storage media in accordance with
claim 14, wherein the computer-executable instructions cause the
processor to transmit the operational adjustment by transmitting a
desired maximum noise level associated with the first wind turbine.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter described herein relates generally to
operating wind turbines and, more particularly, to automatically
adjusting the operation of one or more wind turbines based on a
comparison of an aggregate noise level to a target noise level.
[0002] Wind turbines utilize wind energy to generate or produce
electrical power. Operation of one or more wind turbines within a
site produces noise that may be audible at locations adjacent the
site. Because such noise may be considered a nuisance, maximum
noise levels may be imposed.
[0003] An operator of a wind farm may operate one or more wind
turbines at a less than full level of operation (e.g., power
output) in the interest of compliance with noise level
restrictions. However, selecting a level of operation that ensures
the noise level stays below a maximum level may have a significant
negative effect on the output of the wind farm. Further, adjusting
the level of operation based on changing conditions, such as wind
turbine outages and weather conditions, requires continually
monitoring such conditions and manually applying adjustments to
wind turbines. Such manual effort delays adjustment and increases
the expense of operating a wind turbine site.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, a system for use in operating a plurality of
wind turbines is provided. The system includes a plurality of wind
turbine controllers. Each wind turbine controller is operatively
coupled to a wind turbine of a plurality of wind turbines. The
system also includes a site controller that is coupled in
communication with the plurality of wind turbine controllers and
configured to determine an aggregate noise level at a geographic
position based on a plurality of noise levels associated with the
plurality of wind turbines. The site controller is also configured
to compare the aggregate noise level to a target noise level
associated with the geographic position. When the aggregate noise
level exceeds the target noise level, the site controller is
configured to transmit an operational adjustment to a first wind
turbine controller of the plurality of wind turbine controllers.
The first wind turbine controller is operatively coupled to a first
wind turbine, and a noise level associated with the first wind
turbine is reduced when the first wind turbine controller applies
the operational adjustment
[0005] In another aspect, a device for use in operating a plurality
of wind turbines is provided. The device includes a memory device
that is configured to store a target noise level associated with a
geographic position. The device also includes a processor that is
coupled to the memory device and programmed to determine an
aggregate noise level at the geographic position. The aggregate
noise level represents a combination of noise levels associated
with a plurality of wind turbines. The processor is also programmed
to compare the aggregate noise level to the target noise level. The
device also includes a communication interface that is coupled to
the processor and configured to transmit an operational adjustment
to at least a first wind turbine controller of the plurality of
wind turbine controllers when the aggregate noise level differs
substantially from the target noise level. The first wind turbine
controller is operatively coupled to a first wind turbine, and the
difference between the aggregate noise level and the target noise
level decreases when the first wind turbine controller applies the
operational adjustment to the first wind turbine.
[0006] In yet another aspect, one or more computer readable storage
media having computer-executable instructions embodied thereon are
provided. When executed by at least one processor, the
computer-executable instructions cause the processor to calculate
an aggregate noise level at a geographic position, to compare the
aggregate noise level to a target noise level associated with the
geographic position, and to transmit an operational adjustment to
at least one wind turbine controller when the aggregate noise level
differs substantially from the target noise level. The difference
between the aggregate noise level and the target noise level
decreases when the first wind turbine controller applies the
operational adjustment to a first wind turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an exemplary wind
turbine.
[0008] FIG. 2 is a block diagram illustrating an exemplary wind
turbine controller for use with the wind turbine shown in FIG.
1.
[0009] FIG. 3 is a block diagram illustrating an exemplary
computing device.
[0010] FIG. 4 is a block diagram illustrating an exemplary system
for use in operating one or more wind turbines, such as the wind
turbine shown in FIG. 1.
[0011] FIG. 5 is a flowchart of an exemplary method for use in
operating one or more wind turbines using the system shown in FIG.
4.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The embodiments described herein facilitate operating one or
more wind turbines in a site by automatically responding to noise
levels within or near the site. Noise levels may be determined by
direct measurement and/or by calculating noise levels based on wind
turbine characteristics (e.g., wind turbine dimensions, blade
geometry, and/or blade surface roughness) and/or operating
conditions (e.g., wind speed and/or wind direction). When an
aggregate noise level, representing noise from multiple wind
turbines within a site, deviates substantially from a target noise
level, an operational adjustment may be transmitted to one or more
wind turbine controllers that are coupled to the wind turbines.
[0013] A target noise level may include, without limitation, a
noise level defined by a regulation (e.g., enacted by a
municipality or other government body), by a contractual or
property-based obligation, or by a preference of an operator of a
wind turbine site. For example, the target noise level associated
with a geographic position may be a maximum noise level defined for
a type of property (e.g., residential, commercial, or recreational)
corresponding to the geographic position.
[0014] In some embodiments, in response to an aggregate noise level
above the target noise level, an operational adjustment is
calculated to reduce the aggregate noise level, facilitating
compliance with the target noise level. In other embodiments, in
response to an aggregate noise level below the target noise level,
an operational adjustment is calculated to permit increasing the
aggregate noise level, facilitating increasing the power output of
the site.
[0015] Embodiments are described herein with reference to
geographic positions. As used herein the term "geographic position"
refers to a point in a two-dimensional or three-dimensional space.
For example, a geographic position may be expressed in two
dimensions as a latitude and a longitude, or in three dimensions as
a latitude, a longitude, and an elevation.
[0016] An exemplary technical effect of the methods, system, and
apparatus described herein includes at least one of: (a)
calculating an aggregate noise level at one or more geographic
positions; (b) comparing the aggregate noise level to a target
noise level associated with the geographic position; and (c)
transmitting an operational adjustment to at least one wind turbine
controller when the aggregate noise level differs substantially
from the target noise level.
[0017] FIG. 1 is a perspective view of an exemplary wind turbine
100. Wind turbine 100 includes a nacelle 102 that houses a
generator (not shown in FIG. 1). Nacelle 102 is mounted on a tower
104 (only a portion of tower 104 is shown in FIG. 1). Tower 104 may
have any suitable height that facilitates operation of wind turbine
100 as described herein. In an exemplary embodiment, wind turbine
100 also includes a rotor 106 that includes three rotor blades 108
coupled to a rotating hub 110. Alternatively, wind turbine 100 may
include any number of rotor blades 108 that enable operation of
wind turbine 100 as described herein. In an exemplary embodiment,
wind turbine 100 includes a gearbox (not shown) that is rotatably
coupled to rotor 106 and to the generator.
[0018] In some embodiments, wind turbine 100 includes one or more
sensors 120 and/or control devices 135 (shown in FIG. 2). Sensors
120 sense or detect wind turbine operating conditions. For example,
sensor(s) 120 may include a wind speed and/or a direction sensor
(e.g., an anemometer), an ambient air temperature sensor, an air
density sensor, an atmospheric pressure sensor, a humidity sensor,
a power output sensor, a blade pitch sensor, a turbine speed
sensor, a gear ratio sensor, and/or any sensor suitable for use
with wind turbine 100. Each sensor 120 is located according to its
function. For example, an anemometer may be positioned on an
outside surface of nacelle 102, such that the anemometer is exposed
to air surrounding wind turbine 100. Each sensor 120 generates and
transmits one or more signals corresponding to a detected operating
condition. For example, an anemometer transmits a signal indicating
a wind speed and/or a wind direction. Moreover, each sensor 120 may
transmit a signal continuously, periodically, or only once, for
example, though other signal timings are also contemplated.
Furthermore, each sensor 120 may transmit a signal either in an
analog form or in a digital form.
[0019] Control devices 135 are configured to control an operation
of wind turbine 100 and may include, without limitation, a brake, a
relay, a motor, a solenoid, and/or a servomechanism. A control
device 135 may adjust a physical configuration of wind turbine 100,
such as an angle or pitch of rotor blades 108 and/or an orientation
of nacelle 102 or rotor 106 with respect to tower 104.
[0020] FIG. 2 is a block diagram illustrating an exemplary wind
turbine controller 200 for use with wind turbine 100. Wind turbine
controller 200 includes a processor 205 for executing instructions
and a memory device 210 configured to store data, such as
computer-executable instructions and operating parameters.
[0021] Wind turbine controller 200 also includes a communication
interface 215. Communication interface 215 is configured to be
coupled in signal communication with one or more remote devices,
such as another wind turbine controller 200 and/or a computing
device (shown in FIG. 3).
[0022] In some embodiments, wind turbine controller 200 includes
one or more sensor interfaces 220. Sensor interface 220 is
configured to be communicatively coupled to one or more sensors
120, such as a first sensor 125 and a second sensor 130, and may be
configured to receive one or more signals from each sensor 120.
Sensor interface 220 facilitates monitoring and/or operating wind
turbine 100. For example, wind turbine controller 200 may monitor
operating conditions (e.g., wind speed, wind direction, rotor
speed, and/or power output) of wind turbine 100 based on signals
provided by sensors 120. In an exemplary embodiment, processor 205
executes one or more monitoring software applications and/or
control software applications. A software application may produce
one or more operating parameters that indicate an operating
condition, and memory device 210 may be configured to store the
operating parameters. For example, a history of operating
parameters may be stored in memory device 210.
[0023] In some embodiments, wind turbine controller 200 also
includes a control interface 225, which is configured to be
communicatively coupled to one or more control devices 135, such as
a first control device 140 and a second control device 145. In one
embodiment, wind turbine control interface 225 is configured to
operate control device 135 including a brake to prevent rotor 106
(shown in FIG. 1) from rotating. In addition, or in the
alternative, wind turbine control interface 225 may operate a
control device 135 including a blade pitch servomechanism to adjust
one or more rotor blades 108 (shown in FIG. 1) to a desired and/or
predetermined pitch. The brake and the blade pitch servomechanism
may be operated by the same control device 135 or a first control
device 135 and a second control device 135. In some embodiments,
wind turbine controller 200 is configured to operate control
devices 135 to achieve a desired noise level and/or a desired power
output.
[0024] FIG. 3 is a block diagram illustrating an exemplary
computing device 300. Computing device 300 includes a processor 305
for executing instructions. In some embodiments, executable
instructions are stored in a memory device 310. Memory device 310
is any device allowing information, such as executable instructions
and/or other data, to be stored and retrieved.
[0025] In some embodiments, computing device 300 includes at least
one presentation device 315 for presenting information to user 320.
Presentation device 315 is any component capable of conveying
information to user 320. Presentation device 315 may include,
without limitation, a display device (e.g., a liquid crystal
display (LCD), organic light emitting diode (OLED) display, or
"electronic ink" display) and/or an audio output device (e.g., a
speaker or headphones). In some embodiments, presentation device
315 includes an output adapter, such as a video adapter and/or an
audio adapter. An output adapter is operatively coupled to
processor 305 and configured to be operatively coupled to an output
device, such as a display device or an audio output device.
[0026] In some embodiments, computing device 300 includes an input
device 325 for receiving input from user 320. Input device 325 may
include, for example, a keyboard, a pointing device, a mouse, a
stylus, a touch sensitive panel (e.g., a touch pad or a touch
screen), a gyroscope, an accelerometer, a position detector, and/or
an audio input device. A single component, such as a touch screen,
may function as both an output device of presentation device 315
and input device 325. Computing device 300 also includes a
communication interface 330, which is configured to be
communicatively coupled to one or more wind turbine controllers 200
and/or one or more other computing devices 300.
[0027] Stored in memory device 310 are, for example, computer
readable instructions for determining and responding to noise
levels, providing a user interface to user 320 via presentation
device 315, and/or receiving and processing input (e.g., target
noise levels) from input device 325. In addition, or alternatively,
memory device 310 may be configured to store target noise levels,
measured noise levels, calculated noise levels, and/or any other
data suitable for use with the methods described herein.
[0028] FIG. 4 is a block diagram illustrating an exemplary system
400 for use in operating one or more wind turbines 100. System 400
includes a network 405. For example, network 405 may include,
without limitation, the Internet, a local area network (LAN), a
wide area network (WAN), a wireless LAN (WLAN), a mesh network,
and/or a virtual private network (VPN).
[0029] In an exemplary embodiment, a wind turbine site 410 includes
a plurality of wind turbines 100, each of which includes a wind
turbine controller 200. One or more computing devices 300 (shown in
FIG. 3), such as a site controller 415, are configured to be
coupled in signal communication with wind turbine controllers 200
via network 405.
[0030] In an exemplary embodiment, site controller 415 is
positioned at wind turbine site 410. Alternatively, site controller
415 may be positioned outside wind turbine site 410. For example,
site controller 415 may be communicatively coupled to wind turbine
controllers 200 at a plurality of wind turbine sites 410.
[0031] Each of site controller 415 and wind turbine controller 200
includes a processor, as shown in FIGS. 2 and 3. A processor may
include a processing unit, such as, without limitation, an
integrated circuit (IC), an application specific integrated circuit
(ASIC), a microcomputer, a programmable logic controller (PLC),
and/or any other programmable circuit. A processor may include
multiple processing units (e.g., in a multi-core configuration).
Each of site controller 415 and wind turbine controller 200 is
configurable to perform the operations described herein by
programming the corresponding processor. For example, a processor
may be programmed by encoding an operation as one or more
executable instructions and providing the executable instructions
to the processor in a memory device (also shown in FIGS. 2 and 3)
that is coupled to the processor. A memory device may include,
without limitation, one or more random access memory (RAM) devices,
one or more storage devices, and/or one or more computer readable
media.
[0032] In some embodiments, one or more audio sensors 420 are
coupled in communication with site controller 415. Audio sensors
420 are configured to provide a noise level measurement indicating
an intensity of noise at a corresponding geographic position. For
example, audio sensors 420 may be configured to indicate a sound
pressure level (SPL). In one embodiment, sensors 120 of one or more
wind turbines 100 include an audio sensor 420. Audio sensors 420
may include omnidirectional microphones. Alternatively, or in
addition, audio sensors 420 may include directional microphones
that are configured to provide a noise level measurement and a
direction associated with a noise level measurement. For example,
an audio sensor 420 may provide noise level measurements associated
with a plurality of directions (e.g., each of the cardinal
directions and one or more directions therebetween) at a single
geographic position.
[0033] In an exemplary embodiment, system 400 enables operation of
wind turbines 100 such that an aggregate noise level does not
exceed target noise levels associated with a first geographic
position 425 and a second geographic position 430. System 400 may
further enable operation of wind turbines 100 such that power
output of site 410 is optimized within the bounds of the target
noise levels.
[0034] FIG. 5 is a flowchart of an exemplary method 500 for use in
operating one or more wind turbines 100 using system 400 (shown in
FIG. 4). Referring to FIGS. 4 and 5, in an exemplary embodiment,
site controller 415 determines 505 noise levels associated with
wind turbines 100 and/or audio sensors 420. For example, site
controller 415 may determine 505 a noise level produced by a wind
turbine 100 at a geographic position associated with the wind
turbine 100 and/or a noise level measured at one or more geographic
positions associated with audio sensors 420. Measured noise levels
may optionally be associated with directions. In addition, or
alternatively, noise levels may be determined 505 by predicting or
estimating the noise level of a wind turbine 100 based on
previously recorded noise level measurements, as described in more
detail below.
[0035] In one embodiment, a wind turbine controller 200 is
configured to calculate a noise level produced by the corresponding
wind turbine 100 based on one or more wind turbine characteristics
(e.g., wind turbine dimensions, rotor dimensions, rotor blade
geometry, and/or rotor blade solidity), one or more operating
parameters (e.g., wind speed, wind direction, rotor speed, rotor
blade tip speed, rotor blade pitch angle, thrust loading, and/or
power output), and/or an operational state (e.g., disabled,
curtailed, or normal) of a wind turbine 100. Wind turbine
controller 200 transmits the calculated noise level to site
controller 415. In another embodiment, wind turbine controller 200
transmits the wind turbine characteristics, operating parameters,
and/or operational state to site controller 415, and site
controller 415 calculates the noise level produced by wind turbine
100.
[0036] A determination 505 of noise level based on such data may be
performed using a transfer function or a reference table (also
known as a "lookup table"). In one embodiment, wind turbine 100, or
a similar wind turbine, is monitored with a plurality of audio
sensors 420 (e.g., arranged in a circle centered about wind turbine
100) while wind turbine 100 is operating, and noise level
measurements from audio sensors 420 are correlated with wind
turbine characteristics, operating parameters, and/or operational
states. A transfer function or a reference table may be created
based on these correlations and stored at wind turbine controller
200, such that noise levels produced by wind turbine 100 may be
determined 505 subsequently based on known wind turbine
characteristics, operating parameters, and/or operational
states.
[0037] Whether performed by wind turbine controller 200 or site
controller 415, calculating a noise level produced by a wind
turbine 100 provides a noise level associated with a corresponding
geographic position. In addition, or alternatively, audio sensors
420 may provide noise level measurements indicating a noise level
associated with a geographic position and, optionally, with a
plurality of directions. In some embodiments, an audio sensor 420
is included as a sensor 120 of one or more wind turbines 100. The
noise level associated with a wind turbine 100 may be determined
505 based at least in part on noise level measurements, such as
noise level measurements associated with a direction pointing
approximately toward (e.g., within 5, 10, or 20 degrees of) wind
turbine 100.
[0038] Site controller 415 determines 510 an aggregate noise level
at one or more geographic positions, such as first geographic
position 425 and second geographic position 430 based on the
calculated and/or measured noise levels. When measured noise levels
are used, the aggregate noise level may be determined 510 based
further on a direction associated with noise level measurement.
[0039] In an exemplary embodiment, the aggregate noise level at
first geographic position 425 is determined 510 based at least in
part on each of the noise levels and a distance between first
geographic position 425 and a geographic position associated with
each noise level. Such an embodiment facilitates accounting for the
attenuation of noise over a distance. The aggregate noise level may
be further based on a wind direction, the presence of obstacles
(e.g., structures and/or natural features) between first geographic
position 425 and a geographic position associated with each noise
level, and/or any other factors affecting the propagation of noise.
In one embodiment, the aggregate noise level is determined 510 at
least in part by using the method described in ISO 9613-2,
"Acoustics--Attenuation of sound during propagation outdoors--Part
2: General method of calculation."
[0040] Site controller 415 compares 515 the calculated aggregate
noise level to a target noise level associated with the geographic
position. For example, the aggregate noise level and the target
noise level may be expressed as an intensity or sound pressure
level (SPL), expressed in decibels (dB). In some embodiments, site
controller 415 compares 515 the aggregate noise level to a target
noise level that is selected based on a predetermined schedule. For
example, a schedule may define target noise levels for a geographic
position based on a time of day, a day of the week, and/or a time
of year. In one embodiment, a schedule defines a first target noise
level for a geographic position during daytime hours (e.g., 8 a.m.
to 8 p.m.) and a second target noise level for the geographic
position during nighttime hours (e.g., 8 p.m. to 8 a.m.).
[0041] If the aggregate noise level differs substantially from the
target noise level, site controller 415 calculates 520 a desired
maximum noise level for one or more wind turbines 100. In an
exemplary embodiment, the aggregate noise level is considered to
differ substantially from the target noise level if the aggregate
noise level exceeds the target noise level or if the aggregate
noise level is less than the target noise level by more than a
predetermined threshold value. The threshold value may be defined
in absolute (e.g., 2 db, 3 dB, or 5 dB) or relative (e.g., 3%, 5%,
or 10%) terms.
[0042] Such a determination 510 and comparison 515 may be performed
for each target noise level. In an exemplary embodiment, when
target noise levels are defined for multiple geographic positions,
calculating 520 the desired maximum noise level for a wind turbine
100 may include applying a minimum function to a current value and
a previous value. For example, if a desired maximum noise level of
50 dB is calculated 520 for a first wind turbine 435 with regard to
first geographic position 425, and a desired maximum noise level of
48 dB is calculated 520 for first wind turbine 435 with regard to
second geographic position 430, the effective desired maximum noise
level for first wind turbine 435 would be min(50, 48)=48 dB. In
contrast, if a desired maximum noise level of 51 dB was calculated
520 with regard to second geographic position 430, the effective
desired maximum noise level for first wind turbine 435 would be
min(50,51)=50 dB.
[0043] Based on the desired maximum noise level associated with a
wind turbine 100, site controller 415 determines 525 an operational
adjustment. In one embodiment, determining 525 an operational
adjustment includes transmitting the desired maximum noise level
associated with a wind turbine 100 to a corresponding wind turbine
controller 200. In such an embodiment, wind turbine controller 200
is configured to adjust operating parameters of wind turbine 100 to
achieve the desired maximum noise level. For example, wind turbine
controller 200 may adjust operating parameters based on the desired
maximum noise level and a predetermined transfer function or
reference table. In another embodiment, site controller 415 is
configured to determine one or more operating parameters (e.g., a
rotor blade pitch angle, a maximum rotor blade speed, a maximum
torque, and/or a maximum power output level) for wind turbine 100
and transmit to wind turbine controller 200 an operational
adjustment that includes the determined operating parameters.
[0044] Operational adjustments may be determined 525 such that a
difference between the aggregate noise level and the target noise
level decreases when the operational adjustment is applied. When
the aggregate noise level exceeds the target noise level at a
geographic position, an operational adjustment may be determined
525 to reduce the aggregate noise level at the geographic position
substantially to or below the target noise level. When the
aggregate noise level is substantially below the target noise level
an operational adjustment may be determined 525 to allow a higher
noise level, enabling an increase in power output.
[0045] Site controller transmits 530 an operational adjustment to
at least one wind turbine controller 200. When wind turbine
controller 200 applies the operational adjustment to a wind turbine
100, the difference between the aggregate noise level and the
target noise level decreases. For example, when the aggregate noise
level exceeds the target noise level, wind turbine controller 200
may apply the operational adjustment such that a noise level
produced by wind turbine 100 and, accordingly, the aggregate noise
level, decrease.
[0046] In some embodiments, noise levels are evaluated based at
least in part on audio frequency. In such an embodiment, measured
and/or calculated noise levels may indicate an intensity of noise
over a range of frequencies. Comparing 515 the aggregate noise
level to the target noise level may include weighting frequency
ranges of the aggregate noise level and the target noise level
based on a model of human hearing. For example, noise near 1
kilohertz (kHz) may be weighted more heavily than noise near 10 kHz
is weighted. In one embodiment, A-weighting and/or ITU-R 468 noise
weighting is applied to the noise levels.
[0047] Method 500 may be performed repeatedly (e.g., continuously,
periodically, or upon request), enabling continual adjustment to
operation of wind turbines 100 in site 410. For example, as the
wind direction changes, the aggregate noise level at second
geographic position 430 may increase, while the aggregate noise
level at first geographic position 425 decreases. Accordingly,
operational adjustments may be determined 525 and transmitted 530
to ensure the target noise level at second geographic position 430
is not exceeded.
[0048] Similarly, if a wind turbine, such as first wind turbine
435, is disabled for maintenance or repair, or is operated at a
reduced level of operation for any reason, the aggregate noise
level decreases, and site controller 415 may automatically increase
a desired maximum noise level associated with a second wind turbine
440 and a third wind turbine 445, such that the power output of
second wind turbine 440 and third wind turbine 445 is increased.
When first wind turbine 435 is activated again, noise produced by
first wind turbine 435 is reflected in the aggregate noise level,
and site controller 415 may adjust the desired maximum noise level
of second wind turbine 440 and third wind turbine 445 downward to
ensure compliance with the target noise levels.
[0049] Embodiments provided herein facilitate automatically and
continually adjusting the operation of wind turbines based on a
calculated aggregate noise level at one or more geographic
positions that are associated with a target noise level. Aggregate
noise levels may be calculated based on calculated and/or measured
noise levels associated with wind turbines and/or audio sensors in
a site. Adjusting wind turbine operation as described herein
enables an operator of a wind turbine site to optimize power output
while ensuring compliance with noise regulations and other
obligations. Further, the methods described herein facilitate
automatically applying noise-based operational adjustments to wind
turbines without the delay and expense of manual intervention.
[0050] The methods described herein may be encoded as executable
instructions embodied in a computer readable storage medium
including, without limitation, a memory device of a computing
device. Such instructions, when executed by a processor, cause the
processor to perform at least a portion of the methods described
herein.
[0051] Exemplary embodiments of a wind turbine control system are
described above in detail. The system, devices, wind turbine, and
included assemblies are not limited to the specific embodiments
described herein, but rather each component may be utilized
independently and separately from other components described
herein.
[0052] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal language of the claims.
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