U.S. patent application number 16/684771 was filed with the patent office on 2021-05-20 for system and method for controlling a wind farm.
The applicant listed for this patent is General Electric Company. Invention is credited to Alev Akbulut, Patrick Hammel Hart, Charles Joseph Kosuth, Alina Fatima Moosvi, Christoph Schulten, Enno Ubben.
Application Number | 20210148332 16/684771 |
Document ID | / |
Family ID | 1000005565051 |
Filed Date | 2021-05-20 |
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United States Patent
Application |
20210148332 |
Kind Code |
A1 |
Kosuth; Charles Joseph ; et
al. |
May 20, 2021 |
SYSTEM AND METHOD FOR CONTROLLING A WIND FARM
Abstract
A system and method are provided for controlling a wind farm.
Accordingly, a demand signal is received from the electrical grid.
The farm-level controller also receives a plurality of capability
metrics from each wind turbines, which include, at least, a
steady-state power availability, a transient power availability and
a responsive capability of each wind turbine. The farm-level
controller determines a power production capability profile for
each wind turbine and determines the availability of each wind
turbine to meet at least a portion of the demand signal based on
the power production capability profiles. The farm-level controller
also determines which portion of the demand signal to be satisfied
by each wind turbine based on the availability and the power
production capability for each wind turbine.
Inventors: |
Kosuth; Charles Joseph;
(Albany, NY) ; Hart; Patrick Hammel; (Ballston
Lake, NY) ; Moosvi; Alina Fatima; (Ballston Spa,
NY) ; Ubben; Enno; (Steinfurt, DE) ; Schulten;
Christoph; (Salzbergen, DE) ; Akbulut; Alev;
(Rheine, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Family ID: |
1000005565051 |
Appl. No.: |
16/684771 |
Filed: |
November 15, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 3/38 20130101; F03D
9/257 20170201; F03D 7/028 20130101 |
International
Class: |
F03D 7/02 20060101
F03D007/02; F03D 9/25 20060101 F03D009/25; H02J 3/38 20060101
H02J003/38 |
Claims
1. A method for controlling a wind farm connected to an electrical
grid, the wind farm having a plurality of wind turbines, the method
comprising: receiving, with a farm-level controller of the wind
farm, a demand signal from the electrical grid; receiving, with the
farm-level controller, a plurality of capability metrics from each
of the plurality of wind turbines, the plurality of capability
metrics include at least a steady-state power availability, a
transient power characteristic, and a responsive capability of each
wind turbine; determining, with the farm-level controller, a power
production capability profile for each of the plurality of wind
turbines by analyzing the plurality of capability metrics for each
of the plurality of wind turbines; determining, with the farm-level
controller, the availability of each of the plurality of wind
turbines to meet at least a portion of the demand signal based on
the power production capability profiles; determining, with the
farm-level controller, which portion of the demand signal to be
satisfied by each of the plurality of wind turbines based on the
availability and the power production capability profile for each
of the plurality of wind turbines, the determination comprising:
determining, with the farm-level controller, an anticipated portion
of the demand signal to be satisfied by the steady-state power
availability for each of the plurality of wind turbines;
determining, with the farm-level controller, an anticipated portion
of the demand signal to be satisfied by the transient power
characteristic for each of the plurality of wind turbines, and
determining, with the farm-level controller, a remaining portion of
the demand signal to be satisfied by a change in an operating state
of each of the plurality of wind turbines; generating, with the
farm-level controller, a power production command for each of the
plurality of wind turbines; and transmitting the power production
commands to the plurality of wind turbines so as to control a power
output of each of the plurality of wind turbines.
2. The method of claim 1, further comprising: receiving, with the
farm-level controller, data indicative of an environmental
condition acting upon the wind farm; receiving, with the farm-level
controller, data indicative of an operational condition of the
electrical grid; determining, with the farm-level controller, a
desired wind-farm operating state based on the environmental
condition and the operational condition of the electrical grid; and
determining, with the farm-level controller, a weighting factor for
each of the plurality of capability metrics received from each of
the plurality of wind turbines based on the desired wind farm
operating state, wherein determining the power production
capability profile for each wind turbine further comprises applying
the weighting factor to the received plurality of capability
metrics.
3. The method of claim 2, further comprising: filtering, with the
farm-level controller, at least one capability metric of the
plurality of capability metrics for at least one wind-farm
operating state so as to preclude consideration of the at least one
capability metric.
4. The method of claim 1, wherein determining the availability of
each of the plurality of wind turbines to meet at least the portion
of the demand signal further comprises: determining, with the
farm-level controller, a capability metric limit for each of the
plurality of capability metrics from each of the plurality of wind
turbines; and verifying, with the farm-level controller, that the
power production command complies with each of the corresponding
capability metric limits.
5. (canceled)
6. The method of claim 1, wherein the change in the operating state
is based on a rise time capability for each of the plurality of
wind turbines.
7. The method of claim 1, wherein determining the power production
capability profile for each of the plurality of wind turbines
further comprises simultaneously considering the plurality of
capability metrics from each of the plurality of wind turbines.
8. The method of claim 7, wherein the transient power
characteristic is based at least on a transient power availability
and a transient energy availability for each of the plurality of
wind turbines.
9. The method of claim 8, wherein the transient energy availability
is an amount of kinetic energy of a rotor of each wind turbine of
the plurality of wind turbines.
10. The method of claim 9, wherein the transient power
characteristic further comprises a transient energy discharge
efficiency for each of the plurality of wind turbines.
11. The method of claim 1, further comprising: receiving, with a
turbine controller, the transmitted power production command for a
respective wind turbine of the plurality of wind turbines;
filtering, with the turbine controller, the received power
production command based on an internal prioritization, wherein the
received power command defines a required power production for the
wind turbine; determining, with the turbine controller, a portion
of the required power production to be satisfied by each of a
plurality of wind turbine capabilities, wherein the plurality of
wind turbine capabilities include at least the steady-state power
availability, the transient power characteristic, and the
responsive capability of the wind turbine; and changing at least
one wind turbine operating state so as to satisfy the required
power production.
12. A system for controlling a wind farm, the system comprising: a
plurality of wind turbines operably coupled to an electrical grid;
and a farm-level controller communicatively coupled to the
plurality of wind turbines and to the electrical grid, the
farm-level controller comprising at least one processor configured
to perform a plurality of operations, the plurality of operations
comprising: receiving, with a farm-level controller of the wind
farm, a demand signal from the electrical grid; receiving, with the
farm-level controller, a plurality of capability metrics from each
of the plurality of wind turbines, the plurality of capability
metrics include at least a steady-state power availability, a
transient power characteristic, and a responsive capability of each
wind turbine; determining, with the farm-level controller, a power
production capability profile for each of the plurality of wind
turbines by analyzing the plurality of capability metrics for each
of the plurality of wind turbines; determining, with the farm-level
controller, the availability of each of the plurality of wind
turbines to meet at least a portion of the demand signal based on
the power production capability profiles; determining, with the
farm-level controller, which portion of the demand signal to be
satisfied by each of the plurality of wind turbines based on the
availability and the power production capability profile for each
of the plurality of wind turbines, the determination comprising:
determining an anticipated portion of the demand signal to be
satisfied by the steady-state power availability for each of the
plurality of wind turbines, determining an anticipated portion of
the demand signal to be satisfied by the transient power
characteristic for each of the plurality of wind turbines, and
determining a remaining portion of the demand signal to be
satisfied by a change in an operating state of each of the
plurality of wind turbines; generating, with the farm-level
controller, a power production command for each of the plurality of
wind turbines; and transmitting the power production commands to
the plurality of wind turbines so as to control a power output of
each of the plurality of wind turbines.
13. The system of claim 12, wherein the system further comprises at
least one environmental sensor and wherein the plurality of
operations further comprises: receiving data indicative of an
environmental condition acting upon the wind farm; receiving data
indicative of an operational condition of the electrical grid;
determining a desired wind-farm operating state based on the
environmental condition and the operational condition of the
electrical grid; and determining a weighting factor for each of the
plurality of capability metrics received from each of the plurality
of wind turbines based on the desired wind-farm operating state,
wherein determining the power production capability profile for
each wind turbine further comprises applying the weighting factor
to the received plurality of capability metrics.
14. The system of claim 12, wherein the plurality of operations
further comprises: determining a capability metric limit for each
of the plurality of capability metrics from each of the plurality
of wind turbines; and verifying that the power production command
complies with each of the corresponding capability metric
limits.
15. (canceled)
16. The system of claim 12, wherein the change in the operating
state is based on a rise time capability for each of the plurality
of wind turbines.
17. The system of claim 12, wherein the process of determining the
power production capability profile for each of the plurality of
wind turbines further comprises simultaneously considering the
plurality of capability metrics from each of the plurality of wind
turbines.
18. The system of claim 17, wherein the transient power
characteristic is based at least on a transient power availability
and a transient energy availability for each of the plurality of
wind turbines.
19. The system of claim 18, wherein the transient energy
availability is an amount of kinetic energy of a rotor of each wind
turbine of the plurality of wind turbines.
20. The system of claim 12, further comprising: a plurality of
turbine controllers communicatively coupled to a corresponding wind
turbine of the plurality of wind turbines, the turbine controller
comprising at least one processor configured to perform a plurality
of operations, the plurality of operations comprising: receiving,
with a turbine controller of the plurality of turbine controllers,
the transmitted power production command for a respective wind
turbine of the plurality of wind turbines; filtering, with the
turbine controller, the received power production command based on
an internal prioritization, wherein the received power production
command defines a required power production for the wind turbine;
determining, with the wind turbine controller, a portion of the
required power production to be satisfied by each of a plurality of
wind turbine capabilities, wherein the plurality of wind turbine
capabilities include at least the steady-state power availability,
the transient power characteristic, and the responsive capability
of the wind turbine; and changing at least one wind turbine
operating state so as to satisfy the required power production.
Description
FIELD
[0001] The present disclosure relates in general to wind farms, and
more particularly to systems and methods for controlling wind farms
based on a plurality of capability metrics of a plurality of wind
turbines.
BACKGROUND
[0002] Wind power is considered one of the cleanest, most
environmentally friendly energy sources presently available, and
wind turbines have gained increased attention in this regard. A
modern wind turbine typically includes a tower, a generator, a
gearbox, a nacelle, and one or more rotor blades. The nacelle
includes a rotor assembly coupled to the gearbox and to the
generator. The rotor assembly and the gearbox are mounted on a
bedplate support frame located within the nacelle. The one or more
rotor blades capture kinetic energy of wind using known airfoil
principles. The rotor blades transmit the kinetic energy in the
form of rotational energy so as to turn a shaft coupling the rotor
blades to a gearbox, or if a gearbox is not used, directly to the
generator. The generator then converts the mechanical energy to
electrical energy and the electrical energy may be transmitted to a
converter and/or a transformer housed within the tower and
subsequently deployed to a utility grid. Modern wind power
generation systems typically take the form of a wind farm having
multiple such wind turbine generators that are operable to supply
power to a transmission system providing power to an electrical
grid.
[0003] These wind turbine generators and wind farms are typically
designed to deliver power to the electrical grid. Generally, wind
turbines are optimized to provide steady-state power in response to
a relatively constant wind. Optimally, this power is delivered to
an electrical grid which is also stable. Traditionally, wind
turbines are not particularly well-suited to aid the electrical
grid in responding to transient conditions, such as, a sudden
failure of generation, line fault or connection of a large load.
However, as more power generated by wind turbines is interfaced
through the utility system, it would be desirable for wind turbines
to also contribute to the electrical grid's response to the
transient conditions in order to stabilize the power system.
[0004] In order to respond to transient conditions, it may be
desirable to utilize transient energy which may be available in the
wind turbines, and by extension the wind farm. However, different
environmental and/or mechanical conditions may exist at individual
wind turbines within the wind farm. As a result of these
differences, the power production capabilities of the various
turbines may differ from turbine to turbine. As such, it may be
desirable to tailor the demands placed on each wind turbine in
responding to the transient conditions.
[0005] Thus, the art is continuously seeking new and improved
systems to control the wind farm and tailor the demands placed on
any individual wind turbine. Accordingly, the present disclosure is
directed to systems and methods for controlling a wind turbine so
as to establish power production commands for the individual wind
turbines based on the capabilities of the individual turbines.
BRIEF DESCRIPTION
[0006] Aspects and advantages of the invention will be set forth in
part in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0007] In one aspect, the present disclosure is directed to a
method for controlling a wind farm connected to an electrical grid.
The wind farm may have a plurality of wind turbines. The method may
include determining, via a farm-level controller of the wind farm,
a demand signal from the electrical grid. The method may include
receiving, with the farm-level controller, a plurality of
capability metrics from each of the plurality of wind turbines. The
plurality of capability metrics may include at least a steady-state
power availability, a transient power characteristic, and/or a
responsive capability of each wind turbine. The method may also
include determining, with the farm-level controller, a power
production capability profile for each of the plurality of wind
turbines by analyzing the plurality of capability metrics for each
of the plurality of wind turbines. The method may include
determining, with the farm-level controller, the ability of each of
the plurality of wind turbines to meet at least a portion of the
demand signal based on the power production capability profile. The
method may further include determining, with the farm-level
controller, which portion of the demand signal may be satisfied by
each of the plurality of wind turbines based on the availability
and the power production capability profile for each of the
plurality of wind turbines. The method may include generating, with
the farm-level controller, a power production command for each of
the plurality of wind turbines. Additionally, the method may
include transmitting the power production command to the plurality
of wind turbines so as to control a power output of each of the
plurality of wind turbines.
[0008] In an embodiment, the method may also include receiving,
with the farm-level controller, data indicative of an environmental
condition acting upon the wind farm. The method may include
receiving, with the farm-level controller, data indicative of an
operational condition of the electrical grid. The method may also
include determining, with the farm-level controller, a desired
wind-farm operating state based on the environmental condition and
the operational condition of the electrical grid. Additionally, the
method may include determining, with the farm-level controller, a
weighting factor for each of the plurality of capability metrics
received from each the plurality of wind turbines based on the
desired wind farm operating state. Determining the power production
capability profile for each wind turbine may also include applying
the weighting factor to the received plurality of capability
metrics.
[0009] In a further embodiment, the method may include filtering,
with the farm-level controller, at least one capability metric of
the plurality of capably metrics for at least one wind-farm
operating state so as to preclude consideration of the at least one
capability metric during non-applicable operating states of the
wind farm.
[0010] In an embodiment, determining the availability of each of
the plurality of wind turbines to meet at least the portion of the
demand signal may further include determining, with the farm-level
controller, a capability metric limit for each of the plurality of
capability metrics from each of the plurality of wind turbines. The
method may also include verifying, with the farm-level controller,
that the power production commands complies with each of the
corresponding capability metric limits
[0011] In an additional embodiment, determining which portion of
the demand signal to be satisfied by each of the plurality wind
turbines may also include determining, with the farm-level
controller, an anticipated portion of the demand signal to be
satisfied by the steady-state power availability for each of the
plurality wind turbines. The method may include determining, with
the farm-level controller, an anticipated portion of the demand
signal to be satisfied by the transient power characteristic for
each of the plurality of wind turbines. Further, the method may
include determining, with the farm-level controller, a remaining
portion of the demand signal to be satisfied by a change in an
operating state of each of the plurality wind turbines.
[0012] In a further embodiment, the change in the operating state
may be based on a rise time capability for each of the plurality
wind turbines.
[0013] In yet a further embodiment, determining the power
production capability profile for each of the plurality of wind
turbines may also include simultaneously considering the plurality
of capability metrics from each of the plurality of wind
turbines.
[0014] In an embodiment, the transient power characteristic may be
based at least on a transient power availability and a transient
energy availability for each of the plurality of wind turbines.
[0015] In an additional embodiment, the transient energy
availability may be a kinetic energy of a rotor of each wind
turbine of the plurality of wind turbines.
[0016] In an embodiment, the transient power characteristic may
also be based on an energy discharge efficiency for each of the
plurality of wind turbines.
[0017] In an embodiment, the method may also include receiving,
with a turbine controller, the transmitted power command for a
respective wind turbine of the plurality of wind turbines. The
method may include filtering, with the turbine controller, the
received power command based on an internal prioritization, wherein
the received power command defines a required power production for
the wind turbine. The method may further include determining, with
the turbine controller, a portion of the required power production
to be satisfied by each of a plurality of wind turbine
capabilities. The plurality of wind turbine capabilities include,
at least, the steady-state power availability, the transient power
characteristic, and the responsive capability of the wind turbine.
The method may also include changing at least one wind turbine
operating state so as to satisfy the required power production.
[0018] In another aspect, the present disclosure is directed to a
system for controlling a wind farm. The system may include a
plurality of wind turbines operably coupled to electrical grid. The
system may also include a farm-level controller communicatively
coupled to the plurality wind turbines and to the electrical grid.
The farm-level controller may include at least one processor
configured to perform a plurality of operations. The plurality of
operations may include receiving, with the farm-level controller, a
demand signal from the electrical grid. The operations may include
receiving, with the farm-level controller, a plurality of
capability metrics from each of the plurality of wind turbines. The
plurality of capability metrics may include at least a steady-state
power availability, a transient power characteristic, and a
responsive capability for each wind turbine. Additionally, the
plurality of operations may include determining, with the
farm-level controller, a power production capability profile for
each of the plurality of wind turbines by analyzing the plurality
of capability metrics for each of the plurality of wind turbines.
The plurality of operations may include determining, with the
farm-level controller, the availability of each of the plurality of
wind turbines to meet at least a portion of the demand signal based
on the power production capability profile. The plurality of
operations may include determining, with the farm-level controller,
which portion of the demand signal to be satisfied by each of the
plurality of wind turbines based on the availability and the power
production capability profile for each of the plurality of wind
turbines. The plurality of operations may further include
generating, with the farm-level controller, a power production
command for each of the plurality wind turbines. The plurality of
operations may further include transmitting the power production
command to the plurality of wind turbine so as to control a power
output of each of the plurality of wind turbines. It should be
understood that the system may further include any of the
additional steps and/or features described herein.
[0019] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0021] FIG. 1 illustrates a perspective view of one embodiment of a
wind turbine according to the present disclosure;
[0022] FIG. 2 illustrates a perspective, internal view of one
embodiment of a nacelle of a wind turbine according to the present
disclosure;
[0023] FIG. 3 illustrates a schematic diagram of one embodiment of
a wind farm having a plurality of wind turbines according to the
present disclosure;
[0024] FIG. 4 illustrates a schematic diagram of one embodiment of
a farm controller and a turbine controller for use with the wind
farm as shown in FIG. 2;
[0025] FIG. 5 illustrates a schematic diagram of one embodiment of
a control logic of a system for operating a wind farm according to
the present disclosure;
[0026] FIG. 6 illustrates a schematic diagram of a portion of the
control logic of FIG. 5 particularly illustrating an embodiment of
the control logic for interpreting a demand signal from the
electrical grid according to the present disclosure;
[0027] FIG. 7 illustrates a schematic diagram of a portion of the
control logic of FIG. 5 particularly illustrating an embodiment of
the control logic for determining a portion of the demand signal to
be met by each turbine according to the present disclosure; and
[0028] FIG. 8 illustrates a flow diagram of one embodiment of a
method for controlling a wind farm connected to an electrical grid
according to the present disclosure.
[0029] Repeat use of reference characters in the present
specification and drawings is intended to represent the same or
analogous features or elements of the present invention.
DETAILED DESCRIPTION
[0030] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0031] As used herein, the terms "first", "second", and "third" may
be used interchangeably to distinguish one component from another
and are not intended to signify location or importance of the
individual components.
[0032] The terms "coupled," "fixed," "attached to," and the like
refer to both direct coupling, fixing, or attaching, as well as
indirect coupling, fixing, or attaching through one or more
intermediate components or features, unless otherwise specified
herein.
[0033] Approximating language, as used herein throughout the
specification and claims, is applied to modify any quantitative
representation that could permissibly vary without resulting in a
change in the basic function to which it is related. Accordingly, a
value modified by a term or terms, such as "about",
"approximately", and "substantially", are not to be limited to the
precise value specified. In at least some instances, the
approximating language may correspond to the precision of an
instrument for measuring the value, or the precision of the methods
or machines for constructing or manufacturing the components and/or
systems. For example, the approximating language may refer to being
within a 10 percent margin.
[0034] Here and throughout the specification and claims, range
limitations are combined and interchanged, such ranges are
identified and include all the sub-ranges contained therein unless
context or language indicates otherwise. For example, all ranges
disclosed herein are inclusive of the endpoints, and the endpoints
are independently combinable with each other.
[0035] Generally, the present disclosure is directed to systems and
methods for controlling a wind farm connected to an electrical
grid. In particular, the present disclosure may include a system
and method which may facilitate tailoring the power production of
the various wind turbines of the wind farm in order to account for
varying environmental and/or mechanical conditions throughout the
wind farm. Specifically, the present disclosure may include
receiving a demand signal from the electrical grid. The farm-level
controller may then determine how much of the demand signal may be
met by the steady-state power production of the wind farm. The
farm-level controller may then determine how much of the remaining
demand signal may be satisfied through an available transient power
and energy. The amount of the demand signal which remains after
portions are satisfied by the steady-state power and the transient
power and/or energy may necessitate a required response from at
least one turbine of the wind farm.
[0036] In order to meet the demand signal, the farm-level
controller may also receive a plurality of capability metrics from
each of the wind turbines. The plurality of capability metrics may
include data indicative of at least a steady-state power
availability, a transient power characteristic, and/or a
responsiveness capability for each wind turbine. Based on the
inputs received, the farm-level controller may determine a power
production capability profile for each of the wind turbines by
analyzing the plurality of capability metrics for each wind
turbine. The farm-level controller may then determine the
availability of each of the wind turbines to meet at least a
portion of the demand signal based on these power production
capability profiles. Based on the availability and the power
production capability profile, the farm-level controller may then
determine which portions of the demand signal are to be satisfied
by each wind turbine. The farm-level controller may then generate
and transmit a power production command for each of the wind
turbines so as to control a power output of each of the wind
turbines.
[0037] It should be appreciated that tailoring the production
commands for each wind turbine of the wind farm may permit the more
efficient operation of the wind farm. For example, the power
production capability profile for a first turbine may indicate that
the turbine is able to supply a large quantity of transient power
to the electrical grid without slowing the rotor to an unacceptable
degree. In contrast, the power production profile for a second
turbine may indicate that any attempt to harvest transient energy
from the second turbine may result in a slowing of the rotor to
such a degree that the steady-state power production for the second
turbine is negatively affected. In such a scenario, the farm-level
controller may direct that transient energy be harvested from the
first turbine in addition to the steady-state power, while only
steady-state power is to be produced by the second turbine. As
such, the overall power production of the wind farm may remain
stable through a transient grid condition.
[0038] Referring now to the drawings, FIG. 1 illustrates a
perspective view of one embodiment of a wind turbine 100 according
to the present disclosure. As shown, the wind turbine 100 generally
includes a tower 102 extending from a support surface 104, a
nacelle 106, mounted on the tower 102, and a rotor 108 coupled to
the nacelle 106. The rotor 108 includes a rotatable hub 110 and at
least one rotor blade 112 coupled to and extending outwardly from
the hub 110. For example, in the illustrated embodiment, the rotor
108 includes three rotor blades 112. However, in an alternative
embodiment, the rotor 108 may include more or less than three rotor
blades 112. Each rotor blade 112 may be spaced about the hub 110 to
facilitate rotating the rotor 108 to enable kinetic energy to be
transferred from the wind into usable mechanical energy, and
subsequently, electrical energy. For instance, the hub 110 may be
rotatably coupled to an electric generator 118 (FIG. 2) positioned
within the nacelle 106 to permit electrical energy to be
produced.
[0039] The wind turbine 100 may also include a turbine controller
202 (FIG. 3) centralized within the nacelle 106. However, in other
embodiments, the turbine controller 202 may be located within any
other component of the wind turbine 100 or at a location outside
the wind turbine. Further, the turbine controller 202 may be
communicatively coupled to any number of the components of the wind
turbine 100 in order to control the components. As such, the
turbine controller 202 may include a computer or other suitable
processing unit. Thus, in several embodiments, the turbine
controller 202 may include suitable computer-readable instructions
that, when implemented, configure the turbine controller 202 to
perform various different functions, such as receiving,
transmitting and/or executing wind turbine control signals.
[0040] Referring now to FIG. 2, a simplified, internal view of one
embodiment of the nacelle 106 of the wind turbine 100 shown in FIG.
1 is illustrated. As shown, the generator 118 may be coupled to the
rotor 108 for producing electrical power from the rotational energy
generated by the rotor 108. For example, as shown in the
illustrated embodiment, the rotor 108 may include a rotor shaft 122
coupled to the hub 110 for rotation therewith. The rotor shaft 122
may be rotatably supported by a main bearing 144. The rotor shaft
122 may, in turn, be rotatably coupled to a high-speed shaft 124 of
the generator 118 through a gearbox 126 connected to a bedplate
support frame 136 by one or more torque arms 142. As is generally
understood, the rotor shaft 122 may provide a low-speed,
high-torque input to the gearbox 126 in response to rotation of the
rotor blades 112 and the hub 110. The gearbox 126 may then be
configured to convert the low-speed, high-torque input to a
high-speed, low-torque output to drive the high-speed shaft 124
and, thus, the generator 118. In an embodiment, the gearbox 126 may
be configured with multiple gear ratios so as to produce varying
rotational speeds of the high-speed shaft for a given low-speed
input, or vice versa.
[0041] Each rotor blade 112 may also include a pitch control
mechanism 120 configured to rotate each rotor blade 112 about its
pitch axis 116. The pitch control mechanism 120 may include a pitch
controller 150 configured to receive at least one pitch setpoint
command from the turbine controller 202. Further, each pitch
control mechanism 120 may include a pitch drive motor 128 (e.g.,
any suitable electric, hydraulic, or pneumatic motor), a pitch
drive gearbox 130, and a pitch drive pinion 132. In such
embodiments, the pitch drive motor 128 may be coupled to the pitch
drive gearbox 130 so that the pitch drive motor 128 imparts
mechanical force to the pitch drive gearbox 130. Similarly, the
pitch drive gearbox 130 may be coupled to the pitch drive pinion
132 for rotation therewith. The pitch drive pinion 132 may, in
turn, be in rotational engagement with a pitch bearing 134 coupled
between the hub 110 and a corresponding rotor blade 112 such that
rotation of the pitch drive pinion 132 causes rotation of the pitch
bearing 134. Thus, in such embodiments, rotation of the pitch drive
motor 128 drives the pitch drive gearbox 130 and the pitch drive
pinion 132, thereby rotating the pitch bearing 134 and the rotor
blade(s) 112 about the pitch axis 116. Similarly, the wind turbine
100 may include one or more yaw drive mechanisms 138
communicatively coupled to the turbine controller 202, with each
yaw drive mechanism(s) 138 being configured to change the angle of
the nacelle 106 relative to the wind (e.g., by engaging a yaw
bearing 140 of the wind turbine 100).
[0042] The rotation of each rotor blade 112 about its pitch axis
116 by its respective pitch control mechanism 120 may establish a
pitch angle for each of the rotor blades 112. In an embodiment, the
pitch angle may be an angular deviation from a zero-pitch
location.
[0043] Still referring to FIG. 2, one or more sensors 156, 158, 160
may be provided on the wind turbine 100 to monitor the performance
of the wind turbine 100 and/or environmental conditions affecting
the wind turbine 100. It should also be appreciated that, as used
herein, the term "monitor" and variations thereof indicates that
the various sensors of the wind turbine 100 may be configured to
provide a direct measurement of the parameters being monitored or
an indirect measurement of such parameters. Thus, the sensors
described herein may, for example, be used to generate signals
relating to the parameter being monitored, which can then be
utilized by the turbine controller 202 to determine the condition
of the wind turbine 100.
[0044] Referring now to FIG. 3, a schematic view of a wind farm 152
controlled according to the system and method of the present
disclosure is illustrated. As shown, the wind from 152 may include
a plurality of the wind turbines 100 described herein and a
farm-level controller 200. For example, as shown in the illustrated
embodiment, the wind farm 152 may include twelve wind turbines 100.
However, in other embodiments, the wind farm 152 may include any
other number of wind turbines 100, such as less than twelve wind
turbines 100 or greater than twelve wind turbines 100. In one
embodiment, the turbine controller(s) 202 of the turbine(s) 100 may
be communicatively coupled to the farm-level controller 200 through
a wired connection, such as by connecting the turbine controller(s)
202 through suitable communicative links 154 (e.g., a suitable
cable). Alternatively, the turbine controller(s) 202 may be
communicatively coupled to the farm-level controller 200 through a
wireless connection, such as by using any suitable wireless
communications protocol known in the art. In addition, the
farm-level controller 200 may be generally configured similar to
the turbine controller 202 for each of the individual wind turbines
100 within the wind farm 152.
[0045] In several embodiments, the wind turbines 100 of the wind
farm 152 may include a plurality of sensors for monitoring various
operational data of the wind turbine(s) 100 and/or one or more when
parameters of the wind farm 152. For example, as shown, each of the
wind turbines 100 includes an environmental sensor 156 configured
for gathering data indicative of at least one environmental
condition. The environmental sensor 156 may be operably coupled to
the farm-level controller 200 and to the turbine controller 202.
Thus, in an embodiment, the environmental sensor(s) 156 may, for
example, be a wind vane, an anemometer, a lidar sensor,
thermometer, barometer, or other suitable sensor. The data gathered
by the environmental sensor(s) 156 may include measures of wind
speed, wind direction, wind shear, wind gust, wind veer,
atmospheric pressure, and/or temperature. In at least one
embodiment, the environmental sensor(s) 156 may be mounted to the
nacelle 106 at a location downwind of the rotor 108. The
environmental sensor(s) 156 may, in alternative embodiments, be
coupled to, or integrated with, the rotor 108. It should be
appreciated that the environmental sensor(s) 156 may include a
network of sensors and may be positioned away from the turbine(s)
100. It should be appreciated that environmental conditions may
vary significantly across a wind farm 152. Thus, the environmental
sensor(s) 156 may allow for the local environmental conditions,
such as local wind speed, at each wind turbine 100 to be monitored
individually by the respective turbine controllers 202 and
collectively by the farm-level controller 200.
[0046] Referring still to FIG. 3, in an embodiment, the farm-level
controller 200 may also be operably coupled to at least one grid
sensor 160. The grid sensor(s) 160 may be operably coupled to an
electrical power grid. The grid sensor(s) 160 may be configured to
detect data indicative of a transient grid condition. The data
indicative of the transient grid condition may be interpreted by
the farm-level controller 200 as a demand signal from the
electrical grid.
[0047] In addition to the environmental sensor(s) 156, the wind
turbine 100 may also include one or more turbine condition sensors
158. The turbine condition sensor 158 may, for example, be
configured to monitor electrical properties of the output of the
generator 118 of the wind turbine(s) 100, such as current sensors,
voltage sensors temperature sensors, or power sensors that monitor
power output directly based on current and voltage
measurements.
[0048] In at least one embodiment, the turbine condition sensor(s)
158 may include any other sensors that may be utilized to monitor
the operating state of the wind turbine(s) 100. More specifically,
the turbine condition sensor(s) 158 may be a rotational speed
sensor operably coupled to the turbine controller(s) 202. The
turbine condition sensor(s) 158 may be directed at the rotor shaft
122 of the wind turbine 100. The turbine condition sensor(s) 158
may gather data indicative of the rotational speed of the rotor
shaft 122, and thus the rotor 108. The turbine condition sensor(s)
158 may, in an embodiment, be an analog tachometer, a D.C.
tachometer, an A.C. tachometer, a digital tachometer, a contact
tachometer a non-contact tachometer, or a time and frequency
tachometer.
[0049] In an additional embodiment, the turbine condition sensor(s)
158 may be a pitch sensor. As such, the turbine controller(s) 202
may receive a pitch setpoint indication for the rotor 108 of the
wind turbine 100 via turbine condition sensor(s) 158 operably
coupled to the pitch control mechanism 120. The turbine
controller(s) 202 may consider the pitch setpoint indication in
light of the environmental condition so as to determine whether the
pitch of the rotor 108 is an operating state which may be changed
to satisfy a required power production. It should also be further
appreciated that the wind turbines 100 in the wind farm 152 may
include any other suitable sensor known in the art for measuring
and/or monitoring when parameters and/or wind turbine operational
data.
[0050] Referring now to FIGS. 4-7, schematic diagrams of multiple
embodiments of a system 300 for controlling the wind farm 152
according to the present disclosure are presented. As shown
particularly in FIG. 4, a schematic diagram of one embodiment of
suitable components that may be included within the farm-level
controller 200 and the turbine controller 202 is illustrated. For
example, as shown, the controllers 200, 202 may include one or more
processor(s) 206 and associated memory device(s) 208 configured to
perform a variety of computer-implemented functions (e.g.,
performing the methods, steps, calculations and the like and
storing relevant data as disclosed herein). Additionally, the
controllers 200, 202 may also include a communications module 210
to facilitate communications between the controllers 200, 202 and
the various components of the turbine(s) 100. Further, the
communications module 210 may include a sensor interface 212 (e.g.,
one or more analog-to-digital converters) to permit signals
transmitted from one or more sensors 156, 158, 160 to be converted
into signals that can be understood and processed by the processors
206. It should be appreciated that the sensors 156, 158, 160 may be
communicatively coupled to the communications module 210 using any
suitable means. For example, as shown in FIG. 4, the sensors 156,
158, 160 are coupled to the sensor interface 212 via a wired
connection. However, in other embodiments, the sensors 156, 158,
160 may be coupled to the sensor interface 212 via a wireless
connection, such as by using any suitable wireless communications
protocol known in the art. Additionally, the communications module
210 may also be operably coupled to an operating state control
module 214 configured to change at least one wind turbine operating
state.
[0051] As used herein, the term "processor" refers not only to
integrated circuits referred to in the art as being included in a
computer, but also refers to a controller, a microcontroller, a
microcomputer, a programmable logic controller (PLC), an
application specific integrated circuit, and other programmable
circuits. Additionally, the memory device(s) 208 may generally
comprise memory element(s) including, but not limited to, computer
readable medium (e.g., random access memory (RAM)), computer
readable non-volatile medium (e.g., a flash memory), a floppy disk,
a compact disc-read only memory (CD-ROM), a magneto-optical disk
(MOD), a digital versatile disc (DVD) and/or other suitable memory
elements. Such memory device(s) 208 may generally be configured to
store suitable computer-readable instructions that, when
implemented by the processor(s) 206, configure the controller 202
to perform various functions including, but not limited to,
detecting an approach of the current condition to a
current-dependent limit and affecting a speed of the generator 118
so as to alter a rotor-stator balance of the generator 118 such
that the current-dependent limit is not exceeded and the wind
turbine 100 can operate at a rated power, as described herein, as
well as various other suitable computer-implemented functions.
[0052] Referring particularly to FIG. 5, in an embodiment, the
farm-level controller 200 of the system 300 may be configured to
receive a demand signal 302 from the electrical grid. In certain
embodiments, the demand signal 302 may include a requirement from
the electrical grid that the wind farm 152 provide a specified
power output in response to a transient condition of the electrical
grid.
[0053] In an embodiment, as shown in FIG. 5, the farm-level
controller 200 may also be configured to receive a plurality of
capability metrics 304 from each of the plurality of wind turbines
100. To that end, the turbine controller(s) 202 may communicate to
the farm-level controller 200 a plurality of capability metrics
304, which include at least a steady-state power availability 306,
a transient power characteristic 308, and a responsive capability
310 for each wind turbine 100 of the wind farm 152.
[0054] In an embodiment, the wind farm 152 may have a steady-state
power availability 306. This steady-state power availability 306
may reflect the active power production for the wind farm 152 for
the currently prevailing environmental conditions. Each wind
turbine 100 of the wind farm 152 may also have a steady-state power
availability 306 (reflected in FIG. 7 by the subscript "(i)"). The
steady-state power availability 306 for each wind turbine 100 may
indicate the ability of the wind turbine 100 to continue providing
an indicated power production for the currently prevailing
environmental conditions. In other words, the steady-state power
availability 306 may reflect a relatively unchanging power
production over a specified time interval. It should be appreciated
that the steady-state power availability 306 for the various wind
turbines 100 may differ from wind turbine to wind turbine. This
variation may be due to differences in the environmental conditions
at various locations across the wind farm and/or differences in the
operating states of the wind turbines 100.
[0055] As particularly depicted in FIGS. 5 and 7, the transient
power characteristic 308 may reflect and ability of the wind
turbine(s) 100 to respond to a transient condition in the
electrical grid. The transient power characteristic 308 may, in at
least one embodiment, be based at least on a transient power
availability 312 and a transient energy availability 314 for each
of the plurality of wind turbines 100.
[0056] In at least one embodiment, the transient energy
availability 314 may be an indication of the kinetic energy of the
rotor 108 of the wind turbine(s) 100. In such an embodiment, the
rotor 108 serves as a flywheel storing rotational energy until
required for the driving of the generator 118. The rotational
inertia of the rotor 108 may permit the rotor 108 to continue
revolving and driving the generator 118 for a calculable period
following a decrease in the effective wind velocity acting upon the
wind turbine(s) 100. This may allow the wind turbine(s) 100 to
continue producing a steady-state power during periods of
fluctuating wind speeds. Additionally, the kinetic energy of the
rotor 108 may be harvested in order to increase the rotational
speed of the rotor shaft 122 in excess of that which would
otherwise be achievable in direct response to the currently
prevailing environmental conditions. In an embodiment, this may be
accomplished by increasing the torque of the generator 118. So long
as the increased torque does not exceed the rotational inertia of
the rotor 108, the increase in torque may result in a higher
rotational speed of the high-speed shaft 124 and thus a higher
power output. However, the harvesting of the kinetic energy may
also serve to slow the rotor. If the increase in torque is too
great or is applied for too great a duration, the rotor 108 may
slow to such a degree that the wind turbine(s) 100 become incapable
of producing a required steady-state power. As such, increasing
power production utilizing the stored kinetic energy may be a
transitory process limited by the amount of kinetic energy stored
in the rotor 108 and the degree to which the torque of the
generator 118 is increased.
[0057] In an embodiment, the transient power availability 312 may
be an indication of the accessibility of the kinetic energy of the
rotor 108 for the power production by the generator 118. The
transient power availability 312 may be a hardware limit affecting
the rate at which kinetic energy may be harvested from the rotor
108 and converted to electrical power. For example, recognizing
that harvesting the kinetic energy of the rotor 108 to produce
electrical power may result in an increase in the rotational speed
of the high-speed shaft 124, a maximally acceptable rotational
speed of the high-speed shaft 124 may serve to limit the rate at
which the kinetic energy of the rotor may be discharged. In other
words, in an exemplary embodiment, the kinetic energy of rotor 108
may be sufficient to be converted into a certain amount of
electrical power, but the hardware of the wind turbine(s) 100 may
limit this production to a fraction of that amount per time
interval. In such an exemplary embodiment, the transient power
availability 312 may limit the transient power characteristic 308
to fraction per time interval.
[0058] It should be appreciated that in at least one embodiment,
the transient power availability 312 may be greater than the
transient energy availability 314. In other words, the rate at
which the kinetic energy of the rotor 108 may be converted into
electrical power may exceed the amount of kinetic energy stored in
the rotor 108 and converting the kinetic energy to electrical power
may rapidly decelerate the rotor 108. In such an embodiment, the
transient power characteristic 308 may be limited by the transient
energy availability 314 rather than the transient power
availability 312 as discussed previously.
[0059] Referring still to FIGS. 5 and 7, in an embodiment, the
transient power characteristic 308 may also include a transient
energy discharge efficiency 316. The transient energy discharge
efficiency 316 may be a measure of efficiency with which the
kinetic energy of the rotor 108 is converted into electrical power
by the generator 118 and transmitted to the electrical grid. The
transient energy discharge efficiency 316 may, for example, be
affected by the physical characteristics of the generator 118, the
transformer, the converter, cabling, the gearbox 126, and/or any
other component of the wind turbine(s) 100.
[0060] In an embodiment, the responsive capability 310 may reflect
and ability of the wind turbine(s) 100 to respond to a power
production command 332 from the farm-level controller 200. The
ability of the wind turbine(s) 100 to respond to a power production
command 332 may correspond to a turbine operating state, a
mechanical limit, an environmental condition, or a combination
thereof. For example, in an embodiment wherein the wind turbine(s)
100 is operating in a de-powered state due to a wind velocity
exceeding a limit for the wind turbine(s) 100, the wind turbine(s)
100 may lack the ability to increase the steady-state power
production of the generator 118, as doing so may pose an
unacceptable risk to the wind turbine(s) 100. Similarly, a wind
speed may be insufficient to drive an increase in the rotational
speed of the rotor 108 of the wind turbine(s) 100. As such, the
response of the wind turbine(s) 100 to a power production commands
may be curtailed. In an alternative embodiment, a mechanical
condition of the wind turbine(s), such as a fault in the pitch
control mechanism 120, may preclude an optimal response to the
power command. Alternatively, the responsive capability 310 may
indicate that the wind turbine(s) 100 is readily able to positively
respond the power production command and is thus able to increase
the power output of the generator 118. It should be appreciated
that turbine(s) 100 with higher responsiveness may be prioritized
to support changes in power setpoints.
[0061] Referring again to FIGS. 4-7, in an embodiment, such as
particularly depicted in FIG. 6, the farm-level controller 200 of
the system 300 may be configured to determine the amount of the
demand signal 302 which may be satisfied by the steady-state power
availability 306 of the wind farm 152. This determination may
establish the steady-state power requirement 318 of the demand
signal 302. The farm-level controller 200 may subtract the
steady-state power availability 306 from the demand signal 302 in
order to derive the transient power requirement 320 of the demand
signal 302. Additionally, the farm-level controller 200 may
subtract both the steady-state power availability 306 and the
transient power characteristic 308 in order to derive the required
response of the wind farm 152. In other words, the system 300 may
seek to meet the demand signal 302 first using the available
steady-state power. The system 300 may then seek to meet whatever
portion of the demand signal 302 remains in excess of the
steady-state power availability 306 with the transient power.
Finally, the system 300 may seek to meet the remaining portion, if
any, of the demand signal 302 by generating a response within the
wind farm 152. The response may, for example, include increasing
the steady-state power production of the wind turbine(s) 100.
[0062] As shown at 324 of FIG. 5, the farm-level controller 200 of
the system 300 may be configured to determine a power production
capability profile for each of the wind turbine(s) 100. The
farm-level controller 200 may analyze the plurality of capability
metrics 304 for each of the wind turbines 100 of the wind farm 152.
The power production capability profiles may indicate an initial
capability of the wind turbine(s) 100 to respond to the demand
signal 302. It should be appreciated that the power production
capability profiles may indicate that certain wind turbines 100 may
be better situated to respond to the steady-state power requirement
318, while other wind turbines 100 may be better situated to
respond to the transient power requirement 320.
[0063] In at least one embodiment, the farm-level controller 200 of
the system 300 may be configured to determine a power production
capability profile for each of the wind turbine(s) 100 by
simultaneously considering the plurality of capability metrics 304.
Considering multiple capability metrics 304 simultaneously allows
for nonlinear distribution methodologies, which may allow available
transient power to be utilized more efficiently. In turn, this may
yield a longer discharge duration for the transient power
characteristic 308 in other words, by considering multiple
capability metrics 304 simultaneously, the farm-level controller
200 may avoid overtaxing a first wind turbine 100 while at the same
time under utilizing a second wind turbine 100. Thus, the overall
efficiency of the response of the wind farm 152 to a demand signal
302 may be increased.
[0064] Referring still to 324 of FIG. 5, in an embodiment, the
farm-level controller 200 of the system 300 may be configured to
apply a weighting factor to the received plurality of capability
metrics 304 in order to determine the power production capability
profile for each wind turbine 100. In order to determine the
weighting factor, the farm-level controller 200 may be configured
to receive data indicative of an environmental condition 326 acting
upon the wind farm 152 via the environmental sensor(s) 156. The
environmental condition 326 may be an average environmental
condition acting on the entirety of the wind farm 152 or,
alternatively, may be selected by the farm-level controller 200
from a plurality of environmental conditions acting at different
locations across the wind farm 152. The farm-level controller 200
may also be configured to receive data indicative of a grid
condition 328 of the electrical grid via the grid sensor(s) 160.
The grid condition 328 may reflect the operational condition of the
electrical grid. For example, the grid sensor(s) 160 may detect a
grid condition indicating a relatively stable electrical grid, a
grid experiencing a high-load condition, a grid experiencing
frequent, minor transient events, and/or a grid experiencing a
relatively significant transient condition, such as an unexpected
shutdown of a connected power plant.
[0065] In an embodiment, the farm-level controller 200 may
determine a desired wind-farm operating state based on the
environmental condition 326 and the grid condition 328. For
example, based on the currently prevailing environmental condition
326 and grid condition 328, the farm-level controller 200 may
determine that the wind farm 152 should be optimized for
steady-state power production at the expense of storing kinetic, or
inertial, energy throughout the wind farm 152. Alternatively, the
farm-level controller 200 may, elect to prioritize inertial energy
storage so as to position the wind farm 152 to be better able to
respond to transient conditions in the electrical grid. In such an
embodiment, the speed of the rotors 108 of the wind turbine(s) 100
may be permitted to increase in response to the environmental
condition 326 while the torque of the generator 118 may be
decreased resulting in a storage of kinetic energy in the rotors
108. It should be appreciated that the wind-farm operating state
may not be a binary choice between prioritizing steady-state power
and the storing of kinetic energy, but rather, may be a combination
thereof.
[0066] In an embodiment, the system 300 may direct the
establishment of the desired wind-farm operating state via the
farm-level controller 200 applying the weighting factor to the
plurality of capability metrics 304. The weighting factors may,
thus alter the power production capability profile for each wind
turbine 100. For example, in an embodiment wherein it may be
desirable to increase the stored kinetic energy of the rotor(s)
108, the farm-level controller 200 may apply a weighting factor to
the transient power characteristic 308 which serves to effectively
reduce the amount of transient power which may be available to meet
the transient power requirement 320. Thus, because the computed
amount of the transient power characteristic 308 may be less than
the amount of transient power which may actually be available in
the wind farm 152, the wind farm 152 may store additional kinetic
energy in the wind turbine(s) 100.
[0067] In at least one embodiment, the farm-level controller 200
may filter at least one capability metric of the plurality of
capability metrics 304 for at least one wind-farm operating state.
Filtering the capability metrics 304 may preclude consideration of
the at least one capability metric during non-applicable operating
states of the wind farm 152. By filtering the plurality of
capability metrics 304, the farm-level controller 200 may prevent
interference between capability metrics during certain operating
states wherein one of the capability metrics may not be relevant.
For example, in a scenario wherein the grid conditions are
relatively stable, the farm-level controller 200 may filter the
transient power characteristic 308 from the capability metrics 304.
In such a situation, the farm-level controller 200 may not consider
the transient power characteristic 308 as a capability of the wind
turbine(s) 100 to meet the demand signal 302. However, should the
grid sensor 160 detect an under-frequency event that may require an
inertial response from the wind farm 152, the farm-level controller
200 may stop filtering the transient power characteristic 308 so
that the transient power characteristic 308 may be utilized to
satisfy a portion of the demand signal 302.
[0068] As shown at 330 of FIG. 5, the farm-level controller 200 of
the system 300 may be configured to determine the availability of
each of the wind turbines 100 to meet, at least a portion, of the
demand signal 302 based on the power production capability
profiles. For example, the power production capability profile for
one of the wind turbines 100 may indicate that the wind turbine 100
does not have the capability to satisfy any portion of the
transient power requirement 320. This inability may be due to
conditions at the wind turbine 100 and/or the weighting discussed
previously.
[0069] In at least one embodiment, the farm-level controller 200
may also determine a capability metric limit for each of the
plurality of capability metrics 304 from the wind turbine(s) 100.
The farm-level controller 200 may then verify that any power
production commands 332 to the wind turbine(s) 100 comply with each
of the corresponding capability metric limits. For example, in an
embodiment, the hardware configuration of the wind turbine(s) 100
may limit the power production of the wind turbine(s) 100 to a
maximal output. In such an embodiment, the farm-level controller
200 may verify that meeting the required response 322 will not
drive the wind turbine(s) 100 to exceed the maximal output limit.
Alternatively, in an embodiment, the wind turbine(s) 100 may
require the rotor 108 to have a certain inertia, or speed, in order
to effectively respond to the prevailing environmental conditions
326. In such an embodiment, the farm-level controller 200 may
verify that meeting the required response 322 will not slow the
rotor 108 to such a degree as to violate the minimum speed limit
for the rotor 108.
[0070] As shown at 334 of FIG. 5, the farm-level controller 200 of
the system 300 may be configured to determining which portion of
the demand signal 302 is to be satisfied by each of the plurality
of wind turbines 100 based on the availability and the power
production capability profile for each of the plurality of wind
turbines 100. This determination may include determining an
anticipated portion of the demand signal 302 to be satisfied by the
steady-state power availability 306 for each of the plurality of
wind turbines 100. As particularly illustrated in FIG. 7, the
farm-level controller 200 may divide, at 336, the steady-state
power availability 306 for a first wind turbine 100 by the
steady-state power availability 306 for the wind farm 152. The
farm-level controller 200 may then multiply, at 338, the resultant
value by the steady-state power requirement 318 in order to yield
the portion of the steady-state power requirement 318 to be
satisfied by the first wind turbine 100. The farm-level controller
200 may, in at least one embodiment, perform the same calculation
simultaneously for the remainder of the wind turbines 100 of the
wind farm 152.
[0071] Referring still to FIG. 7, the farm-level controller 200 may
determine the portion of the demand signal 302 to be met by the
transient power characteristic 308 of each wind turbine 100 of the
wind farm 152. In order to make this determination, the farm-level
controller 200 may divide, at 340, the transient power
characteristic 308 for the first wind turbine 100 by the transient
power characteristic 308 for the wind farm. The farm-level
controller 200 may then multiply, at 342, the resultant value by
the transient power requirement 320 in order to yield the portion
of the transient power requirement 320 to be satisfied by the first
wind turbine 100. The farm-level controller 200 may, in at least
one embodiment, perform the same calculation simultaneously for the
remainder of the wind turbines 100 of the wind farm 152.
[0072] Referring still to FIG. 7, the farm-level controller 200 may
determine the portion of the demand signal to be met by the
response capability 310 of each wind turbine 100 of the wind farm
152. In order to make this determination, farm-level controller 200
may divide, at 344, a value representing the response capability
310, such as rise time capability, for the first wind turbine 100
by a value representing the response capability 310 for the wind
farm. The farm-level controller 200 may then multiply, at 346, the
resultant value by the required response 322 in order to yield the
portion of the required response 322 to be satisfied by the first
wind turbine 100. The farm-level controller 200 may, in at least
one embodiment, perform the same calculation simultaneously for the
remainder of the wind turbines 100 of the wind farm 152.
[0073] Referring generally to FIGS. 4-7, in an embodiment, the
farm-level controller 200 of the system 300 may be configured to
combine, at 348, the various portions of the demand signal 302 to
be satisfied by a single wind turbine 100 and generate a power
production command 332 for each wind turbine 100 of the wind farm
152. The single, combined power production command 332 for each
wind turbine 100 may define a required power production for the
wind turbine 100. The power production command 332 may be based on
the portions of the demand signal to be satisfied by the particular
wind turbine 100, which in turn may be based on the availability of
the particular wind turbine 100 and the capability of the
particular wind turbine 100 to provide the required power
production. However, the power production command 332 transmitted
to the wind turbine(s) 100 may not specify which portions of the
required power production may be satisfied by at least the
steady-state power availability 306, the transient power
characteristic 308, and the responsive capability 310 for the wind
turbine(s) 100. As such, it should be appreciated that, utilizing a
single combined power command 332 may permit a turbine-level
regulation of the power production based on an internal
prioritization of the wind turbine(s) 100. It should be further
appreciated that the generation of the power production command 332
may occur cyclically at a rate of less than once every 100
milliseconds, for example at a rate of once every 40 milliseconds
or less.
[0074] As shown at 350 of FIG. 5, in an embodiment, the turbine
controller(s) 202 of the system 300 may be configured to receive
the transmitted power command 332 for a respective wind turbine 100
of the wind farm 152. As shown at 352, in an embodiment, the
turbine controller(s) 202 may filter the received power command
332, which defines the required power production for the wind
turbine 100, based on an internal prioritization for the wind
turbine(s) 100.
[0075] As shown at 354, in an embodiment, the turbine controller(s)
202 may determine a portion of the required power production to be
satisfied by each of a plurality of wind turbine capabilities. The
plurality of wind turbine capabilities include, at least, the
steady-state power availability 306, the transient power
characteristic 308, and the responsive capability 310 of the wind
turbine 100. Based on this determination, the turbine controller(s)
202 may select an operating condition of the wind turbine 100 for
adjustment. In an embodiment, the turbine controller(s) 202 may
balance the various inputs received from the turbine condition
sensor(s) 158 concerning the operation of the wind turbine(s) 100
and the environmental condition 326 in order to select an optimal
operating parameter for adjustment. It should be appreciated,
however, that the turbine controller(s) 202 may, in consideration
of the various inputs, determine that the wind turbine(s) 100 is
unable to satisfy the power production requirement and may report
thus to the farm-level controller 200.
[0076] As shown at 356 of FIG. 5, the turbine controller(s) 202 may
also be configured to change at least one wind turbine operating
state so as to satisfy the required power production. In an
embodiment, the turbine controller(s) 202 may transmit a command
signal to the operating state control module 214 so as to affect a
change in at least one aspect of the wind turbine operating
state.
[0077] In an exemplary embodiment, the turbine controller(s) 202
may select the pitch of the rotor blades 112 as the operating
parameter to be adjusted so as to affect the shaft speed of the
generator 118 and thereby increase (or decrease) the power
production of the wind turbine(s) 100. To that end, the turbine
controller 204 may generate and transmit a pitch setpoint command
to the pitch controller 150 of the pitch control mechanism 120. The
pitch setpoint command may instruct the pitch control mechanism 120
to pitch at least one of the rotor blades 112 of the rotor(s) 108
of the wind turbine 100 so as to accelerate the rotor(s) 108 of the
wind turbine(s) 100 for the determined environmental condition 226.
An acceleration of the rotor(s) 108 may result in the acceleration
of the rotor shaft 122, the high-speed shaft 124, and the generator
118, in turn. It should be appreciated that such an adjustment may
not be commanded if the wind turbine 100 is operating in a
de-powered state based on a wind velocity exceeding a limit.
[0078] In an alternative embodiment, the turbine controller(s) 202
may select the torque of the generator as the operating parameter
to be adjusted in order to increase the torque and harvest a
portion of the transient energy 314 of the rotor(s) 108 by
converting the transient energy 314 into an electrical power
production of the generator 118. To that end, the turbine
controller(s) 202 may generate and transmit a torque command to the
converter instructing the converter to increase the torque of the
generator 118, thereby slowing the rotational speed of the rotor(s)
108.
[0079] Referring now to FIG. 8, a flow diagram of one embodiment of
a method 400 for controlling a wind farm is illustrated. The method
400 may be implemented using, for instance, the system 300 of the
present disclosure discussed above with references to FIGS. 1-7.
FIG. 8 depicts steps performed in a particular order for purposes
of illustration and discussion. Those of ordinary skill in the art,
using the disclosures provided herein, will understand that various
steps of the method 400, or any of the methods disclosed herein,
may be adapted, modified, rearranged, performed simultaneously, or
modified in various ways without deviating from the scope of the
present disclosure.
[0080] As shown at (402), the method 400 may include receiving,
with a farm-level controller of the wind farm, a demand signal from
the electrical grid. As shown at (404), the method 400 may include
receiving, with the farm-level controller, a plurality of
capability metrics from each of the plurality of wind turbines. The
plurality of capability metrics include at least a steady-state
power availability, a transient power characteristic, and a
responsive capability for each wind turbine. As shown at (406), the
method 400 may include determining, with the farm-level controller,
a power production capability profile for each of the plurality of
wind turbines by analyzing the plurality of capability metrics for
each of the plurality of wind turbines. As shown at (408), the
method 400 may include determining, with the farm-level controller,
the availability of each of the plurality of wind turbines to meet
at least a portion of the demand signal based on the power
production capability profiles. As shown at (410), the method 400
may include determining, with the farm-level controller, which
portion of the demand signal to be satisfied by each of the
plurality of wind turbines based on the availability and the power
production capability profile for each of the plurality of wind
turbines. Additionally, as shown at (412), the method 400 may
include generating, with the farm-level controller, a power
production commands for each of the plurality of wind turbines. As
shown at (414), the method 400 may include transmitting the power
production commands to the plurality of wind turbines so as to
control a power output of each of the plurality wind turbines.
[0081] Furthermore, the skilled artisan will recognize the
interchangeability of various features from different embodiments.
Similarly, the various method steps and features described, as well
as other known equivalents for each such methods and feature, can
be mixed and matched by one of ordinary skill in this art to
construct additional systems and techniques in accordance with
principles of this disclosure. Of course, it is to be understood
that not necessarily all such objects or advantages described above
may be achieved in accordance with any particular embodiment. Thus,
for example, those skilled in the art will recognize that the
systems and techniques described herein may be embodied or carried
out in a manner that achieves or optimizes one advantage or group
of advantages as taught herein without necessarily achieving other
objects or advantages as may be taught or suggested herein.
[0082] 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 include 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 languages of the claims.
[0083] Further aspects of the invention are provided by the subject
matter of the following clauses:
[0084] Clause 1. A method for controlling a wind farm connected to
an electrical grid, the wind farm having a plurality of wind
turbines, the method comprising receiving, with a farm-level
controller of the wind farm, a demand signal from the electrical
grid; receiving, with the farm-level controller, a plurality of
capability metrics from each of the plurality of wind turbines, the
plurality of capability metrics include at least a steady-state
power availability, a transient power availability and a responsive
capability of each wind turbine; determining, with the farm-level
controller, a power production capability profile for each of the
plurality of wind turbines by analyzing the plurality of capability
metrics for each of the plurality of wind turbines; determining,
with the farm-level controller, the availability of each of the
plurality of wind turbines to meet at least a portion of the demand
signal based on the power production capability profiles;
determining, with the farm-level controller, which portion of the
demand signal to be satisfied by each of the plurality of wind
turbines based on the availability and the power production
capability profile for each of the plurality of wind turbines;
generating, with the farm-level controller, a power production
command for each of the plurality of wind turbines; and
transmitting the power production commands to the plurality of wind
turbines so as to control a power output of each of the plurality
of wind turbines.
[0085] Clause 2. The method of any preceding clause, further
comprising receiving, with the farm-level controller, data
indicative of an environmental condition acting upon the wind farm;
receiving, with the farm-level controller, data indicative of an
operational condition of the electrical grid; determining, with the
farm-level controller, a desired wind-farm operating state based on
the environmental condition and the operational condition of the
electrical grid; and determining, with the farm-level controller, a
weighting factor for each of the plurality of capability metrics
received from each of the plurality of wind turbines based on the
desired wind farm operating state, wherein determining the power
production capability profile for each wind turbine further
comprises applying the weighting factor to the received plurality
of capability metrics.
[0086] Clause 3. The method of any preceding clause, further
comprising: filtering, with the farm-level controller, at least one
capability metric of the plurality of capability metrics for at
least one wind-farm operating state so as to preclude consideration
of the at least one capability metric during non-applicable
operating states of the wind farm.
[0087] Clause 4. The method of any preceding clause, wherein
determining the availability of each of the plurality of wind
turbines to meet at least the portion of the demand signal further
comprises: determining, with the farm-level controller, a
capability metric limit for each of the plurality of capability
metrics from each of the plurality of wind turbines; and verifying,
with the farm-level controller, that the power production command
complies with each of the corresponding capability metric
limits.
[0088] Clause 5. The method of any preceding clause, wherein
determining which portion of the demand signal to be satisfied by
each of the plurality of wind turbines further comprises:
determining, with the farm-level controller, an anticipated portion
of the demand signal to be satisfied by the steady-state power
availability for each of the plurality of wind turbines;
determining, with the farm-level controller, an anticipated portion
of the demand signal to be satisfied by the transient power
availability for each of the plurality of wind turbines; and
determining, with the farm-level controller, a remaining portion of
the demand signal to be satisfied by a change in an operating state
of each of the plurality of wind turbines.
[0089] Clause 6. The method of any preceding clause, wherein the
change in the operating state is based on a rise time capability
for each of the plurality of wind turbines.
[0090] Clause 7. The method of any preceding clause, wherein
determining the power production capability profile for each of the
plurality of wind turbines further comprises simultaneously
considering the plurality of capability metrics from each of the
plurality of wind turbines.
[0091] Clause 8. The method of any preceding clause, wherein the
transient power availability is based on a transient energy
availability and an energy discharge efficiency for each of the
plurality of wind turbines.
[0092] Clause 9. The method of any preceding clause, wherein the
transient energy availability is a kinetic energy of a rotor of
each wind turbine of the plurality of wind turbines.
[0093] Clause 10. The method of any preceding clause, further
comprising: receiving, with a turbine controller, the transmitted
power command for a respective wind turbine of the plurality of
wind turbines; filtering, with the turbine controller, the received
power command based on an internal prioritization, wherein the
received power command defines a required power production for the
wind turbine; determining, with the wind turbine controller, a
portion of the required power production to be satisfied by each of
a plurality of wind turbine capabilities, wherein the plurality of
wind turbine capabilities include at least the steady-state power
availability, the transient power availability, and the responsive
capability of the wind turbine; and changing at least one wind
turbine operating state so as to satisfy the required power
production.
[0094] Clause 11. The method of any preceding clause, wherein
generating the power production command for each of the plurality
of wind turbines further comprises generating the power production
command for each of the plurality of wind turbines at least every
40 ms.
[0095] Clause 12. A system for controlling a wind turbine farm, the
system comprising: a plurality of wind turbines operably coupled to
an electrical grid; and a farm-level controller communicatively
coupled to the plurality of wind turbines and to the electrical
grid, the farm-level controller comprising at least one processor
configured to perform a plurality of operations, the plurality of
operations comprising: receiving, with a farm-level controller of
the wind farm, a demand signal from the electrical grid, receiving,
with the farm-level controller, a plurality of capability metrics
from each of the plurality of wind turbines, the plurality of
capability metrics include at least a steady-state power
availability, a transient power availability and a responsive
capability of each wind turbine; determining, with the farm-level
controller, a power production capability profile for each of the
plurality of wind turbines by analyzing the plurality of capability
metrics for each of the plurality of wind turbine; determining,
with the farm-level controller, the availability of each of the
plurality of wind turbines to meet at least a portion of the demand
signal based on the power production capability profiles;
determining, with the farm-level controller, which portion of the
demand signal to be satisfied by each of the plurality of wind
turbines based on the availability and the power production
capability profile for each of the plurality of wind turbines;
generating, with the farm-level controller, a power production
command for each of the plurality of wind turbines; and
transmitting the power production commands to the plurality of wind
turbines so as to control a power output of each of the plurality
of wind turbines.
[0096] Clause 13. The system of any preceding clause, wherein the
system further comprises at least one environmental sensor and
wherein the plurality of operations further comprises: receiving,
with the farm-level controller, data indicative of an environmental
condition acting upon the wind farm; receiving, with the farm-level
controller, data indicative of an operational condition of the
electrical grid; determining, with the farm-level controller, a
desired wind-farm operating state based on the environmental
condition and the operational condition of the electrical grid; and
determining, with the farm-level controller, a weighting factor for
each of the plurality of capability metrics received from each of
the plurality of wind turbines based on the desired wind farm
operating state, wherein determining the power production
capability profile for each wind turbine further comprises applying
the weighting factor to the received plurality of capability
metrics.
[0097] Clause 14. The system of any preceding clause, wherein the
plurality of operations further comprises: determining, with the
farm-level controller, a capability metric limit for each of the
plurality of capability metrics from each of the plurality of wind
turbines; and verifying, with the farm-level controller, that the
power production command complies with each of the corresponding
capability metric limits.
[0098] Clause 15. The system of any preceding clause, wherein the
plurality of operations further comprises: determining, with the
farm-level controller, an anticipated portion of the demand signal
to be satisfied by the steady-state power availability for each of
the plurality of wind turbines; determining, with the farm-level
controller, an anticipated portion of the demand signal to be
satisfied by the transient power availability for each of the
plurality of wind turbines; and determining, with the farm-level
controller, a remaining portion of the demand signal to be
satisfied by a change in an operating state of each of the
plurality of wind turbines.
[0099] Clause 16. The system of any preceding clause, wherein the
change in the operating state is based on a rise time capability
for each of the plurality of wind turbines.
[0100] Clause 17. The system of any preceding clause claim 15,
wherein the process of determining the power production capability
profile for each of the plurality of wind turbines further
comprises simultaneously considering the plurality of capability
metrics from each of the plurality of wind turbines.
[0101] Clause 18. The system of any preceding clause, wherein the
transient power availability is based on a transient energy
availability and an energy discharge efficiency for each of the
plurality of wind turbines.
[0102] Clause 19. The system of any preceding clause, wherein the
transient energy availability is a kinetic energy of a rotor of
each wind turbine of the plurality of wind turbines.
[0103] Clause 20. The system of any preceding clause 12, further
comprising: a plurality of turbine controllers communicatively
coupled to a corresponding wind turbine of the plurality of wind
turbines, the turbine controller comprising at least one processor
configured to perform a plurality of operations, the plurality of
operations comprising: receiving, with a turbine controller, the
transmitted power command for a respective wind turbine of the
plurality of wind turbines; filtering, with the turbine controller,
the received power command based on an internal prioritization,
wherein the received power command defines a required power
production for the wind turbine; determining, with the wind turbine
controller, a portion of the required power production to be
satisfied by each of a plurality of wind turbine capabilities,
wherein the plurality of wind turbine capabilities include at least
the steady-state power availability, the transient power
availability, and the responsive capability of the wind turbine;
and changing at least one wind turbine operating state so as to
satisfy the required power production.
* * * * *