The present disclosure relates in general to wind turbines, and more
particularly to electrical systems for wind turbines having a reduced uptower footprint
as compared to existing electrical systems.
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
[0003] In modern wind turbines, the electrical energy is typically transmitted to an
electrical grid via an electrical system. Various elements of the electrical system may
be located within the nacelle. However, as the size and power-generating capability
of wind turbines increases to meet growing demand, space within the nacelle is
increasingly consumed by the drivetrain components. This, in turn, typically limits
the amount of space available for the electrical system within the nacelle. As a result,
a need exists to accommodate portions of the electrical system within the reduced
amount of available free space within the nacelle.
[0004] Thus, the art is continuously seeking new and improved electrical systems
having a reduced footprint. Accordingly, the present disclosure is directed to
electrical systems having redistributed components within and around the wind
turbine so as to minimize the amount of free space within the nacelle occupied by
elements of the electrical system by reducing the overall footprint of the electrical system.
BRIEF DESCRIPTION
[0005] 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.
[0006] In one aspect, the present disclosure is directed to an electrical system for a
wind turbine. The electrical system may include a generator housing located in a
nacelle of the wind turbine. A generator may be disposed within the generator
housing. The generator may include a stator and a rotor. The stator and/or the rotor
may be operably coupled to at least one generator output connection. The electrical
system may also include a plurality of electrical subsystems including a plurality of
electrical subsystem assemblies. At least one electrical subsystem assembly may be
integrated with the generator housing. The electrical subsystem assembly(s) may also
be operably coupled between the stator and/or the rotor and the generator output
connection(s). The plurality of electrical subsystems may include a stator switch
subsystem, a power converter subsystem, and/or a generator step-up transformer.
[0007] In an embodiment, the electrical subsystem assembly(s) integrated with the
generator housing may include a stator switch of the stator switch subsystem and/or a
rotor-inductor assembly of the power converter subsystem.
[0008] In an additional embodiment, the stator switch may be operably coupled
in-line between the generator output connection and the stator. The generator output
connection may be coupled to the generator step-up transformer.
[0009] In a further embodiment, the electrical subsystem assembly(s) integrated
with the generator housing may include the stator switch of the stator switch
subsystem and the rotor-inductor assembly of the power converter subsystem.
[0010] In an embodiment, the generator housing may be coupled to a bedplate
support frame of the wind turbine, with the bedplate support frame defining a recess
between the generator housing and a surface of the bedplate support frame. In such
embodiments, the electrical subsystem assembly(s) may be positioned at least
partially within the recess. [0011] In an additional embodiment, the nacelle may define a clearance between an inner surface of a wall of the nacelle and the generator housing. Accordingly, in
such embodiments, the electrical subsystem assembly(s) may be positioned at least
partially within the clearance.
[0012] In a further embodiment, the electrical subsystem assembly(s) may be
electrically grounded by the generator housing.
[0013] In an embodiment, the stator switch subsystem may be absent of a stator
grounding switch.
[0014] In another aspect, the present disclosure is directed to a method for
reducing an uptower footprint of an electrical system of a wind turbine. The method
may include disposing a generator within a nacelle of the wind turbine. The
generator includes a stator and a rotor disposed within a generator housing. Further,
the stator and/or the rotor may be operably coupled to at least one generator output
connection. The method may also include positioning a power converter subsystem
in a converter cabinet located within the nacelle. The power converter subsystem may
be operably coupled to the generator. Further, the method may include integrating a
stator switch of a stator switch subsystem with the generator housing. Additionally,
the method may include operably coupling the stator switch to the stator or the rotor
of the generator and the generator output connection(s). Moreover, the method may
also include coupling the generator output connection(s) of the generator to a
transformer.
[0015] In an embodiment, the method may further include retrofitting an existing
electrical system of the wind turbine to reduce the overall footprint thereof. Wherein
integrating the stator switch permits a reduction in the surface area of the electrical
system and/or a number of electrical subsystem cabinets relative to an electrical
system nominal design.
[0016] In an additional embodiment, integrating the stator switch may include
electrically grounding the stator switch with the generator housing. Further, the
integration may include eliminating a stator grounding switch of the stator switch
subsystem.
[0017] In a further embodiment, the method may include integrating a rotorinductor assembly of the power converter subsystem with the generator housing. The
method may also include integrating a voltage feedback assembly of the power converter subsystem with a generator step-up transformer. Integrating the voltage
feedback assembly and the rotor-inductor assembly may permit a reduction in the
surface area of the converter cabinet.
[0018] In an embodiment, integrating the stator switch with the generator housing
may permit at least one of a reduction in a gauge and a reduction in the number of
electrical systems cables positioned within the nacelle.
[0019] In an additional embodiment, the wind turbine may include a bedplate
support frame positioned within the nacelle. The generator housing may be coupled
to the bedplate support frame, and the bedplate support frame may define a recess
between generator housing and a surface of the bedplate support frame. The method
may also include positioning the stator switch subsystem component and/or a power
converter subsystem component at least partially within the recess.
[0020] In yet another aspect, the present disclosure is directed to a wind turbine.
The wind turbine may include a tower, a nacelle mounted atop the tower, and a rotor
mounted to the nacelle. The rotor may include a rotatable hub having a plurality of
rotor blades secured thereto. The wind turbine may also include an electrical system
disposed within the nacelle. The electrical system may include a generator located in
a nacelle of the wind turbine. The generator includes a stator and a rotor housed
within a generator housing. The stator and/or the rotor may be operably coupled to at
least one generator output connection. The electrical system may also include a
plurality of electrical subsystems including a plurality of electrical subsystem
assemblies. The electrical subsystems may include a stator switch subsystem
operably coupled to the generator. The electrical subsystems may also include a
power converter subsystem positioned in a converter cabinet within the nacelle. The
power converter subsystem may be operably coupled to the generator. Additionally,
the electrical subsystems may include a generator step-of transformer positioned
within the nacelle and operably coupled to the stator switch subsystem and the power
converter subsystem. Further, the stator switch and/or the power converter subsystem
assembly may be integrated with the generator housing and may be operably coupled
between the stator or the rotor and the generator output connection. It should be
understood that the wind turbine may further include any of the features described
herein [0021] 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
[0022] 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:
[0023] FIG. 1 illustrates a perspective view of one embodiment of a wind turbine
according to the present disclosure;
[0024] FIG. 2 illustrates a perspective, internal view of one embodiment of a
nacelle of a wind turbine according to the present disclosure;
[0025] FIG. 3 illustrates a simplified cross-sectional view of one embodiment of a
nacelle of the wind turbine according to the present disclosure;
[0026] FIG. 4 illustrates a simplified schematic diagram of an electrical system of
the wind turbine according to the present disclosure;
[0027] FIG. 5 illustrates an embodiment of the electrical system of FIG. 4
according to the present disclosure; and
[0028] FIG. 6 illustrates a flow diagram of one embodiment of a method for
reducing an uptower footprint of an electrical system of a wind turbine 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] 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.
[0032] 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.
[0033] 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.
[0034] Generally, the present disclosure is directed to an electrical system for a
wind turbine having a reduced footprint uptower. In particular, the present disclosure
includes an electrical system which may integrate one or more electrical subsystem
assemblies with the generator housing. For example, a stator switch of the stator
switch subsystem may be incorporated with the generator housing. By incorporating
the stator switch with the generator housing, the number and/or size of electrical
system cabinets located uptower may be reduced. In other words, by incorporating
the stator switch with the generator housing, the stator switch may be incorporated
into the space party occupied by the generator housing and thus a separate electrical system cabinet may not be required to house the stator switch. Additionally,
integrating the electrical subsystem assembly with the generator housing may
preclude the need for various components of the electrical system. For example, by
incorporating the stator switch with the generator housing, the stator grounding switch
of the stator switch subsystem may be eliminated.
[0035] 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) of an electrical system 150
positioned within the nacelle 106 to permit electrical energy to be produced.
[0036] Referring now to FIGS. 2 and 3, a simplified, internal view and a crosssectional view of one embodiment of the nacelle 106, of the wind turbine 100 shown
in FIG. 1 are 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. The rotor shaft 122 may, in turn, be
rotatably coupled to a high-speed shaft 124 of the generator 118 through an optional
gearbox 126 connected to a bedplate support frame 136. 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 with a plurality of gears 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.
[0037] The electrical system 150 may include the generator 118 disposed within a
generator housing 120. The generator housing 120 may be located within the nacelle
106 of the wind turbine 100. For example, as shown, an inner surface 128 of a wall of
the nacelle 106 may define a clearance 140 about the generator housing 120.
Additionally, as shown in FIG. 3, the generator 118 may be coupled to the bedplate
support frame 136 of the wind turbine 100. The bedplate support frame 136 may
define a recess 138 between the generator housing 120 and a surface of the bedplate
support frame 136.
[0038] Referring now to FIGS. 4 and 5, schematic diagrams of embodiments of
the electrical system 150 in accordance with the present disclosure are depicted. In an
embodiment, the electrical system 150 may include various components for
converting the kinetic energy of the rotor 108 into an electrical output in an acceptable
form to a connected electrical grid. For example, in an embodiment, the generator
118 may be a doubly-fed induction generator (DFIG). It should be appreciated that
while an electrical system 150 utilizing a DFIG generator is presented herein as an
exemplary embodiment, the present disclosure is not limited to such embodiments and
may include electrical systems 150 utilizing any other suitable electrical generator
and/or assemblage of electrical subsystems.
[0039] In an embodiment, the generator 118 may include a rotor 132 and a stator
130 operably coupled to a step-up transformer 178. As shown particularly in FIG. 5,
the stator 130 may be coupled to the step-up transform 178 via a stator bus 166.
Additionally, the rotor 132 may be coupled to the transformer via a rotor bus 170 and
a power converter subsystem 168. In such a configuration, the stator bus 166 may
provide an output multiphase power (e.g. three-phase power) from the stator 130 of
the generator 118, and the rotor bus 170 may provide an output multiphase power
(e.g. three-phase power) of the rotor 132 of the generator 118. Additionally, the
power converter subsystem 168 may include a rotor side converter 172 which may be
coupled to the generator 118 via the rotor bus 170. The rotor side converter 172 may
be coupled to a line side converter 174 of the power converter subsystem 168 which,
in turn, may be coupled to a line side bus 176. Additionally, as shown in FIG. 4, the power converter subsystem 168 may include a rotor-inductor assembly 162 and a
voltage feedback assembly 164. It should be appreciated that the power converter
subsystem 168 may be disposed within a converter cabinet 148 located within the
nacelle 106.
[0040] In an embodiment, the rotor side converter 172 and the line side converter
174 may be configured for normal operating mode in a three-phase, pulse width
modulation (PWM) arrangement using insulated gate bipolar transistors (IGBTs) as
switching devices. Other suitable switching devices may be used, such as insulated
gate commuted thyristors, MOSFETs, bipolar transistors, silicone controlled
rectifier’s, and/or other suitable switching devices. The rotor side converter 172 and
the line side converter 174 may be coupled via a DC link 173 across which may be a
DC link capacitor 175.

WHAT IS CLAIMED IS:
1. An electrical system for a wind turbine, the electrical system
comprising:
a generator located in a nacelle of the wind turbine, the generator comprising a
stator and a rotor housed within a generator housing, at least one of the stator and the
rotor being operably coupled to at least one generator output connection; and
a plurality of electrical subsystems comprising a plurality of electrical
subsystem assemblies, at least one electrical subsystem assembly being integrated
with the generator housing, the at least one electrical subsystem assembly being
operably coupled between the stator or the rotor and the at least one generator output
connection, the plurality of electrical subsystems comprising a stator switch
subsystem, a power converter subsystem, and a generator step-up transformer.
2. The electrical system of claim 1, wherein the at least one electrical
subsystem assembly integrated with the generator housing comprises at least one of a
stator switch of the stator switch subsystem and a rotor-inductor assembly of the
power converter subsystem.
3. The electrical system of claim 2, wherein the stator switch is operably
coupled between the at least one generator output connection and the stator, and
wherein the at least one generator output connection is coupled to the generator stepup transformer.
4. The electrical system of claim 2, wherein the at least one electrical
subsystem assembly integrated with the generator housing comprises the stator switch
of the stator switch subsystem and the rotor-inductor assembly of the power converter
subsystem.
5. The electrical system of claim 1, wherein the generator housing is
coupled to a bedplate support frame of the wind turbine, wherein the bedplate support
frame defines a recess between the generator housing and a surface of the bedplate
support frame, wherein the at least one electrical subsystem assembly is positioned at
least partially within the recess.
6. The electrical system of claim 1, wherein the nacelle defines a
clearance between an inner surface of a wall of the nacelle and the generator housing, wherein the at least one electrical subsystem assembly is positioned at least partially
within the clearance.
7. The electrical system of claim 1, wherein the at least one electrical
subsystem assembly is electrically grounded by the generator housing.
8. The electrical system of claim 7, wherein the stator switch subsystem
is absent of a stator grounding switch.
9. A method for reducing an uptower footprint of an electrical system of a
wind turbine, the method comprising:
disposing a generator in a nacelle of the wind turbine, the generator having a
stator and a rotor housed within a generator housing, at least one of the stator and the
rotor being operably coupled to at least one generator output connection;
positioning a power converter subsystem in a converter cabinet located within
the nacelle, the power converter subsystem being operably coupled to the generator;
integrating a stator switch of a stator switch subsystem with the generator
housing;
operably coupling the stator switch between the stator and the at least one
generator output connection; and
coupling the at least one generator output connection of the generator to a
transformer.
10. The method of claim 9, further comprising:
retrofitting an existing electrical system of the wind turbine to reduce the
overall footprint thereof, wherein integrating the stator switch permits at least one of a
reduction in the surface area of the electrical system and a number electrical
subsystem cabinets relative to an electrical system nominal design.
11. The method of claim 10, wherein integrating the stator switch
comprises:
electrically grounding the stator switch with the generator housing; and
eliminating a stator grounding switch of the stator switch subsystem.
12. The method of claim 10, further comprising: wherein integrating the
stator switch with the generator housing permits at least one of a reduction in a gauge
and a reduction in the number of electrical system cables positioned within the
nacelle 13. The method of claim 9, further comprising:
integrating a rotor-inductor assembly of the power converter subsystem with
the generator housing; and
integrating a voltage feedback assembly of the power converter subsystem
with a generator step-up transformer, wherein integrating the voltage feedback
assembly and the rotor-inductor assembly permits a reduction in the surface area of
the converter cabinet.
14. The method of claim 9, wherein the wind turbine further comprises a
bedplate support frame positioned within the nacelle, wherein the generator housing is
coupled to a bedplate support frame, wherein the bedplate support frame defines a
recess between the generator housing and a surface of the bedplate support frame; the
method further comprising:
positioning at least one of the stator switch and a power converter subsystem
assembly at least partially within the recess.
15. A wind turbine, comprising:
a tower;
a nacelle mounted atop the tower;
a rotor mounted to the nacelle, the rotor comprising a rotatable hub having a
plurality of rotor blades secured thereto; and
an electrical system disposed within the nacelle, the electrical system
comprising:
a generator located in the nacelle, the generator comprising a stator and
a rotor housed within a generator housing, at least one of the stator and the
rotor being operably coupled to at least one generator output connection,
a plurality of electrical subsystems comprising a plurality of electrical
subsystem assemblies, the plurality of electrical subsystems comprising:
a stator switch subsystem being operably coupled to the
generator,
a power converter subsystem positioned in a converter cabinet
within the nacelle, the power converter subsystem being operably
coupled to the generator, and a transformer positioned within the nacelle and operably
coupled to the stator switch subsystem and the power converter
subsystem; and
at least one of a stator switch and a power converter subsystem
assembly being integrated with the generator housing and being operably
coupled between the stator or the rotor and the at least one generator output
connection.
16. The system of claim 15, further comprising:
a voltage feedback assembly of the power converter subsystem integrated with
the generator transformer.
17. The system of claim 15, wherein the generator is coupled to the step-up
transformer.
18. The system of 15, wherein the power converter subsystem component
integrated with the generator housing comprises a rotor-inductor assembly of a power
converter subsystem.
19. The system of claim 15, wherein the wind turbine further comprises a
bedplate support frame positioned within the nacelle, wherein the generator housing is
coupled to a bedplate support frame, wherein the bedplate support frame defines a
recess between the generator housing and a surface of the bedplate support frame; and
the at least one of the stator switch and the power converter subsystem component is
positioned at least partially within the recess.
20. The system of claim 15, wherein the stator switch subsystem is absent
of a stator grounding switch.