U.S. patent application number 12/206878 was filed with the patent office on 2010-03-11 for backup power system for cryo-cooled elements in wind turbines.
This patent application is currently assigned to General Electric Company. Invention is credited to James W. Bray, Patrick L. Jansen, Evangelos T. Laskarls, Kirubaharan Sivasubramaniam.
Application Number | 20100058806 12/206878 |
Document ID | / |
Family ID | 41466835 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100058806 |
Kind Code |
A1 |
Jansen; Patrick L. ; et
al. |
March 11, 2010 |
BACKUP POWER SYSTEM FOR CRYO-COOLED ELEMENTS IN WIND TURBINES
Abstract
A cooling system is provided for supplying cryogenic cooling
fluid to a thermal load. The system includes a cryogenic
refrigeration system, a cryogenic cooling fluid coupled to the
thermal load, and a primary power supply for providing power to the
cryogenic refrigeration system. A backup power supply provides
power to the cryogenic refrigeration system in the event that the
primary power supply is unable to provide sufficient power to the
cryogenic refrigeration system.
Inventors: |
Jansen; Patrick L.; (Scotia,
NY) ; Laskarls; Evangelos T.; (Schenectady, NY)
; Bray; James W.; (Niskayuna, NY) ;
Sivasubramaniam; Kirubaharan; (Clifton Park, NY) |
Correspondence
Address: |
GE ENERGY GENERAL ELECTRIC;C/O ERNEST G. CUSICK
ONE RIVER ROAD, BLD. 43, ROOM 225
SCHENECTADY
NY
12345
US
|
Assignee: |
General Electric Company
|
Family ID: |
41466835 |
Appl. No.: |
12/206878 |
Filed: |
September 9, 2008 |
Current U.S.
Class: |
62/657 |
Current CPC
Class: |
F25B 2500/06 20130101;
F25B 27/00 20130101; F03D 9/11 20160501; F03D 9/257 20170201; F03D
80/60 20160501; F03D 9/007 20130101; Y02E 10/72 20130101 |
Class at
Publication: |
62/657 |
International
Class: |
F25J 3/00 20060101
F25J003/00 |
Claims
1. A cooling system for providing cryogenic cooling fluid to a
thermal load, said system comprising: a cryogenic refrigeration
system; a cryogenic cooling fluid coupled to said thermal load; a
primary power supply for providing power to said cryogenic
refrigeration system; and a backup power supply for providing power
to said cryogenic refrigeration system in the event that said
primary power supply is unable to provide sufficient power to said
cryogenic refrigeration system.
2. The cooling system of claim 1, wherein said thermal load is, at
least one of, an electrical generator and a power converter.
3. The cooling system of claim 1, wherein said thermal load
comprises a part of a wind turbine.
4. The cooling system of claim 1, wherein said thermal load
comprises at least one superconducting generator in a wind
turbine.
5. The cooling system of claim 1, wherein said thermal load
comprises at least one superconducting generator in a wind turbine,
and said backup power supply is located within or near said wind
turbine.
6. The cooling system of claim 1, wherein said thermal load
comprises a plurality of superconducting generators in a plurality
of wind turbines, said plurality of wind turbines comprising a wind
farm; and said backup power supply located within or near said wind
farm.
7. The cooling system of claim 1, wherein said backup power supply
is chosen from at least one or combinations of, an electrical
generator, a microturbine, a fuel cell, a solar panel, and a
battery.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to backup power systems, and
specifically to backup power systems used to power cryogenically
cooled elements in a wind turbine.
[0002] Recently, wind turbines have received increased attention as
an environmentally safe and relatively inexpensive alternative
energy source with zero green house gas (GHG) emissions. With this
growing interest, considerable efforts have been made to develop
wind turbines that are reliable and efficient.
[0003] Generally, wind turbines use the wind to generate
electricity. The wind turns one or more blades connected to a hub,
where the blades and hub can comprise a rotor. The spin of the
blades caused by the wind spins a shaft connected to the rotor,
which connects to a generator that generates electricity.
Specifically, the rotor is mounted within a housing or nacelle,
which is positioned on top of a truss or tubular tower. Utility
grade wind turbines (e.g., wind turbines designed to provide
electrical power to a utility grid) can have large rotors (e.g., 30
or more meters in diameter). Blades on these rotors transform wind
energy into a rotational torque or force that drives one or more
generators, rotationally coupled to the rotor through a gearbox.
The gearbox may be used to step up the inherently low rotational
speed of the turbine rotor for the generator to efficiently convert
mechanical energy to electrical energy, which is provided to a
utility grid. Some turbines utilize generators that are directly
coupled to the rotor without using a gearbox.
[0004] To improve the efficiency and performance of a wind turbine,
superconducting generators can be used, but require a cryogenic
cooling system that maintains the low temperatures required by
superconducting field coils. If the cryogenic cooling system loses
power for an extended time (e.g., greater than about three hours),
the cryo-coolant can warm up to the point where boil-off may occur.
The loss of coolant normally requires service personnel to recharge
the cryo-system. In addition, the warming of the cryogenic cooling
system can add considerable cool-down time (e.g. twelve hours to
three days) to the overall downtime of the wind turbine.
BRIEF SUMMARY OF THE INVENTION
[0005] A cooling system is provided for supplying cryogenic cooling
fluid to a thermal load. The system includes a cryogenic
refrigeration system, a cryogenic cooling fluid coupled to the
thermal load, and a primary power supply for providing power to the
cryogenic refrigeration system. A backup power supply provides
power to the cryogenic refrigeration system in the event that the
primary power supply is unable to provide sufficient power to the
cryogenic refrigeration system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a block diagram illustration of one embodiment of
the present invention showing an electrical system of a wind
turbine generator that incorporates a backup power system.
DETAILED DESCRIPTION OF THE INVENTION
[0007] FIG. 1 is a block diagram of one embodiment of an electrical
system 100 of a wind turbine generator incorporating a backup power
system. The example of FIG. 1 provides specific voltages that are
typical for wind turbine generators in the 1.5 MW class for use in
the United States. Other similar voltages can be used for 50 Hz
wind turbine generators. In general, higher voltages are used for
higher power ratings and lower voltages are used for lower power
ratings. However, the overall architecture is applicable for many
different types and sizes of wind turbines with the same and/or
different voltages.
[0008] Generator 110 provides AC power to the power grid as well as
to other components of wind turbine electrical system 100. In one
embodiment, generator 110 provides 575 V (which is the rated
voltage of the generator); however, any voltage can be provided.
The power generated by generator 110 is provided to a wind farm
substation or other facility for collecting power generated by
multiple wind turbine generators via power converter 115, which may
also provide power to low voltage distribution panel (LVDP)
120.
[0009] In one embodiment, LVDP 120 includes a transformer to
transform the 575 V power received from generator 110 to 120 V, 230
V and 400 V power for use throughout the wind turbine (150
designates 120 volt systems, 160 designates 230 volt systems and
170 designates 400 volt systems, respectively). Other and/or
additional power supply levels can be provided as desired. The wind
turbine generator systems connected to LVDP 120 include, for
example, the pitch system controls and motors, the yaw system
controls and motors, various lubrication and cooling systems,
electrical receptacles and lights, heaters and miscellaneous
equipment. In general, the various sub-systems needing electrical
power (e.g., cryogenic cooling system 135, turbine controller 140,
turbine communications server 180, etc.) can be powered via LVDP
120, but the specific connections from LVDP 120 to the various
sub-systems are not shown in FIG. 1 for clarity.
[0010] In one embodiment, LVDP 120 is connected to backup power
supply 130. The backup power supply 130 provides power to one or
more sub-systems in the event that LVDP 120 is unable to provide
the required power. Backup power supply 130 can be any type of
dispatchable or interruptible power supply, for example, a battery
system, a photovoltaic system or any other power storage system
known in the art. In other embodiments, backup power supply 130 can
comprise a backup generator, which may include liquid or gas fueled
electrical generators, fuel cells, solar panels, batteries, or any
other power storage system known in the art.
[0011] The backup power supply can also provide power to a
cryogenic cooling system 135. The backup power supply 130 can be
connected directly to cryogenic cooling system 135 and any other
sub-system, or it may be connected indirectly to various
sub-systems through LVDP 120, or combinations thereof. For example,
power converter 11 5 may also contain cryogenic components and can
be connected to cryogenic cooling system 135.
[0012] Some wind turbines can incorporate one or more
superconducting electrical generators 110. Cryogenic cooling system
135 maintains the low temperatures required by the superconducting
field coils in generator 110. The cooling system 135 requires a
continuous and reliable source of power to maintain the temperature
of the field coils. If the cryogenic cooling system 135 loses power
for an extended time (e.g., greater than about three hours), the
cryo-coolant can warm up to the point where boil-off may occur. The
loss of coolant normally requires service personnel to recharge the
cryo-system. In addition, the warming of the cryogenic cooling
system can add considerable cool-down time (e.g. twelve hours to
three days) to the overall downtime of the wind turbine.
[0013] The backup power supply 130, which is connected to cryogenic
cooling system 135, maintains the necessary power to cryogenic
cooling system 135. The possibility for cryo-coolant boil-off, the
associated maintenance and down-time can also be reduced or
eliminated.
[0014] In one embodiment of the current invention, where a single
wind turbine needs a backup power supply 135, the size of the
backup power generator could be about five to twenty kilowatts. In
other embodiments of the present invention, where a wind farm
incorporates one or more backup power supplies, one backup power
supply could service multiple wind turbines or all of the wind
turbines. In this example, the backup generator could be sized in
the range of about 500 to 2,000 kW. In all the examples above, the
backup power supply could be sized below or above the given ranges,
as required by the specific application.
[0015] In additional aspects of the present invention, the backup
power supply could be connected with the main power supply via an
automatic or controllable transfer switch. In automatic
configurations, the transfer switch could be configured to
automatically switch in the backup power supply upon loss of main
power. The transfer switch may also have a predetermined delay to
avoid premature switching due to very short voltage transients. In
one example, the transfer switch could be configured to switch over
to backup power if main power is lost for greater than five
seconds. This time period could be shorter or longer based on the
needs of the specific application.
[0016] Other sub-systems in the wind turbine can also be powered by
backup power supply 130 in the event of a power loss. Turbine
communications server (TCS) 180 can be coupled to receive power
from backup power supply 130, either directly or indirectly. TCS
180 may also be coupled with wind farm network 190 to provide data
to a remote device, for example, a server device that interacts
with multiple TCSs in a wind farm. TCS 180 is coupled with turbine
controller 140 as well as other components (coupling not
illustrated in FIG. 1 for reasons of simplicity) to provide control
and data acquisition operations.
[0017] TCS 180 can also be coupled with database 185, which stores
data acquired from the components of the wind turbine. In one
embodiment, TCS 180 acquires real time and historical data from
wind turbine controllers and other devices within wind turbine 100
using a real time interrupt driven database manager. TCS 180 also
performs secondary data processing, alarming, configuration
management and data compression, stores or archives data in a real
time and historical database in database 185.
[0018] TCS 180 also serves real time data to single or multiple
SCADA master using a real time SCADA protocol over wind farm
network 190. TCS 180 further serves historical data to a central
database using ODBC protocol and provides a user and configuration
interface via an embedded browser. TCS 180 can either be an
independent hardware device (e.g., a computer system or other
electronic device) that interfaces and communicates with turbine
controller 140 or the functionality of TCS 180 may be implemented
in the turbine controller 140.
[0019] In additional aspects of the present invention, the backup
power supply for the cryogenic cooling system could be replaced
with or used in conjunction with a large cold-storage reservoir.
The reservoir could be comprised of a liquid cryogenic medium
(e.g., liquid helium, etc.) or a cooled block of dense matter.
[0020] While the invention has been described in connection with
what is presently considered to be one of the most practical and
preferred embodiments, it is to be understood that the invention is
not to be limited to the disclosed embodiments, but on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims.
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