WIND TURBINE SYSTEM CONTROL TECHNICAL FIELD
The invention relates to control of multiple wind turbine generators. ' More particularly, the invention relates to control and data acquisition in a wind farm having multiple wind turbine generators.
BACKGROUND
Historically, wind turbines have been very small contributors to overall power generation to supply electrical grids. The low unit ratings (<100 kW) and the uncertain availability of wind sources caused wind turbine generators affect negligible when power grid operators considered the security of the grid. However, wind turbine generators with ratings of 1.5 MW or more are now available. Furthermore, many power generation developers are installing wind farms having one hundred or more wind turbine generators. The "block" of power available from wind farms with 1.5 MW wind turbine generators is comparable to a modern gas turbine generator. Accordingly, wind turbine generators are increasingly feasible sources of power for the power grid.
One requirement for efficient power production in a wind farm is collection of data. Current data collection systems are typically based upon a continuously functioning single central data collection architecture with limited capability for intelligent processing and storage of data at each wind turbine, meteorological mast or at the substation. This type of architecture is susceptible to the central data collecting system failing to store and archive the data being produced by the devices in the wind farm if faults occur in the wind farm network infrastructure. For example, the loss of the connectivity between the supervisory command and data acquisition (SCADA) master device and wind turbines could result in loss of operational data and fault records from the wind turbines.
SUMMARY

A supervisory command and farm is described. The SCAD
ata acquisition (SCADA) system to manage a wind system includes a plurality of turbine communication

servers (TCSs) within wind turbines of the wind farm. The TCSs collect data from

the turbines, store a first subset
of the data locally and transmit the first subset of data

according to non-real-time inte vals. The TCSs also transmit a second subset of data

over a wind farm network to
provide approximately real-time data and store the

second subset of data until si ccessfully transferred. The SCADA system further

includes a server coupled to
X)mmunicate with the plurality of TCSs to provide

signals to control the wind tui bines, the server being further to store data received

from the plurality of TCSs and
o perform database management on the received data.

BRIEF DESCRIPTION OF T£ E DRAWINGS

The invention is illustrated by figures of the accompanying similar elements.
way of example, and not by way of limitation, in the drawings in which like reference numerals refer to



Figure 1 is a block diagram turbine generator.
one embodiment of an electrical system of a wind

Figure 2 is a block diagram of me embodiment of a wind farm.
Figure 3 is a flow diagram of < ne embodiment of data acquisition and processing by a wind turbine in a wind farm.
Figure 4 is a flow diagram of one embodiment of data acquisition and processing by a server coupled to multiple wind turbines, substations and/or meteorological sites in a wind farm.

DETAILED DESCRIPTION
The techniques described herein collect data for use, for example,
in allow a wind turbine generator wind farm systems to for generator control. In one embodiment, a

combination master-slave supervisory command and data acquisition (SCADA) architecture together with distributed databases local to the data producing device within a wind farm provide functionality for real-time monitoring and control as well as user visualization, historical data archiving and reporting, configuration management, secondary data processing, fault logging, alarming and/or remote user access. In one embodiment, the architecture provides approximately real-time monitoring and control of wind farm devices both locally and remotely while also facilitating archiving of operational data of individual wind turbines as well as totalized wind farm data.
In one embodiment, the architecture utilizes a client device within wind turbines, wind farm meteorological masts and/or wind farm substations to provide a communications interface (real-time and file transfer) between the devices and a wind farm local area network (LAN) or remote host. The architecture further provides real time data logging and processing, data historian, access to data via servers and database storage and management functionality. The system can use, for example, a real time, event driven database management system in each intelligent device and a host master station.
The system design can also support integration and a single user configuration interface for additional wind farm applications such as curtailment, power applications such as power factor control, condition monitoring systems and operational forecasting systems. In one embodiment, integrated into the system is a electric utility gateway that provides connectivity options to electric utility SCADA master stations using native protocols. This gateway can also include a database that allows multiple database partitioning and multiple independent master station capabilities. The master-slave architecture can also allow central single point of configuration for complex data management and communications system management.
Previous wind farm control architectures have been based upon a continuously functioning single central data collection architecture with limited capability for intelligent processing and storage of data at each wind turbine, meteorological mast

and/or at the substation. This collecting system failing to sto in the .wind farm if faults oo example, standard master slav distributed SQL database wit between the SCADA master Network) could result in loss turbine.
type of architecture was susceptible to the central data and archive the data being produced by the devices urred in the wind farm network infrastructure. For architectures used in a wind farm and without a n each wind turbine, the loss of the connectivity d wind turbines, the wind farm LAN (Local Area f operational data and fault records from the wind

Being based upon a single architecture (i.e., single SCA additional independent SCAD components of a wind farm meteorological sites) and secon architectures support remote m the SCADA master.
Figure 1 is a block diagram o turbine generator. The exampl-for wind turbine generators in similar voltages can be used f< voltages are used for higher j power ratings. However, the types and sizes of wind turbine;
ce tral monitoring, control and central data collection )A Master), previous systems could not support masters (i.e., SCADA devices within the various for example, wind turbines, substations and/or ary databases within the wind farm, nor could these nitoring, control and data collection independent of
one embodiment of an .electrical system of a wind of Figure 1 provides specific voltages that are typical e 1.5 MW class for use in the United States. Other 50 Hz wind turbine generators. In general, higher wer ratings and lower voltages are used for lower verall architecture is applicable for many different with the same and/or different voltages.

Generator 110 provides AC wind turbine electrical system V (which is the rated voltage o: The power generated by generi facility for collecting powei Generator 110 also provides described above with respect (LVDP) 120.
po\j/er to the power grid as well as to other components of )0. In one embodiment, generator 110 provides 575 the generator); however, any voltage can be provided, or 110 is provided to a wind farm substation or other generated by multiple wind turbine generators, ower to power converter 115, which operates as o Figure 2, and to low voltage distribution panel

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 (120 V systems 150, 230 V systems 160 and 400 V.systems 170, 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 one embodiment, LVDP 120 provides power to turbine controller 140 through uninterruptible power supply (UPS) 130. 'UPS 130 provides power to turbine controller 140 in the event that LVDP 120 is unable to provide necessary power to turbine controller 140. UPS 130 can be any type of uninterruptible power supply, for example, a battery system, a photovoltaic system or any other power storage system known in the art. In one embodiment, UPS 130 does not have sufficient capacity to energize all of the electrical loads served by LVDP 120.
Turbine communications server (TCS) 180 is coupled to receive power from UPS 130. TCS 180 is also 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 Figure 1 for reasons of simplicity) to provide control and data acquisition operations.
TCS 180 is further coupled with database 185, which stored data acquired from the components of wind turbine 100. 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.

TCS 180 also serves real time time SCADA protocol over historical data to a central database configuration interface via an independent hardware device ( interfaces and communicates w 180 may be implemented in the turbine
ata to single or multiple SCADA master using a real ind farm network 190. TCS 180 further serves using ODBC protocol and provides a user and embedded browser. TCS 180 can either be an , a computer system or other electronic device) that th turbine controller 140 or the functionality of TCS controller 140.

Figure 2 is a block diagram of include any number of wind ti the wind farm are interconnect
ne embodiment of a wind farm. The wind farm can bines, meteorological sites, etc. The components of d by wind farm network 200, which can be any type

of network (e.g., local-area network, wide-area network, wired connections and/or

wireless connections) known ii

the art using any network protocol (e.g., known in

the art. Meteorological site 210 gen command and acquisition unit
meteorological site 210 inch meteorological data to be usec wind farm. In one embodiment, wind speed and direction fron speed, temperature, and atmosj heric pressure, and/or tower configurations cai erally
includes one or more sensors 212, meteorological (MCAU) 214 and database 216. In one embodiment, des a tower with multiple sensors 212 to gather in the control of the wind turbine generators of the the tower includes sensors to monitor horizontal at least four levels above the ground, vertical wind :. hi alternate embodiments, other sensor be used.

hi one embodiment, MCAU 2 operates as a SCADA slave de communicates with a SCADA Imaster system for the wind farm, hi event-driven data logging and in database 216. Data stored period for historical data archi
4 is coupled with sensors 212 and database 216 and ice. As described in greater detail below, MCAU 214 device to provide a control and data acquisition one embodiment, MACU 214 operates as a real-time, recessing device that causes acquired data to be stored in database 216 can be maintained for an extended ng, reporting and/or other purposes.

In one embodiment, MCAU 214 includes a database manager that performs secondary data processing in addition to real-time, event-driven data logging. The secondary processing can include, for example, alarming, configuration management and/or data compression. In one embodiment, database 216 is a Structured Query Language (SQL) database; however, any database language and/or protocol can be used. Use of SQL databases in known in the art.
Data stored in database 216 is periodically transmitted to a server with an associated database over wind farm network 200. In one embodiment, the various databases interact via the ODBC application program interface (API); however, other interfaces could also be used. Various versions of the ODBC Manager are available from Microsoft Corporation of Redmond, Washington.
Substation site 220 generally includes meters and relays 222, substation command and acquisition unit (SCAU) 226, database 228 and utility gateway 224. Utility gateway 224 provides an interface to an external network (utility network 280) that can be used, for example, by a utility company or other entity that controls a utility grid to communicate with components of the wind farm. Alternatively, utility gateway 224 can be located at a site other than substation site 220.
Meters and relays 222 can be any combination of meters and relays known in the art for use at a substation. Meters and relays 22 provide an interface between generators of the wind farm and utility grid 280 as well as monitoring functionality related to power delivery.
In one embodiment, SCAU 224 includes a database manager that performs real-time, event-driven data logging alarming, configuration management, data compression and/or other data management functions. In one embodiment, database 228 is a SQL database; however, any database language and/or protocol can be used. Data stored in database 228 is periodically transmitted to a server with an associated database over wind farm network 200. In one embodiment, the various databases interact via the ODBC API; however, other interfaces could also be used.

The wind farm of Figure 2 is ill of simplicity of explanation, that can be similar or different i
strated with two wind turbines (230,240) for reasons \Vind farms can include any number of wind turbines design and/or power delivery.

Wind turbines 230 and 240 gerieri (TCS) 234 and 244, databases controllers 238 and 248. Genejrators turbine 230 and 240, respectiv known in the art suitable for w and 248 are coupled with ger generators using any control
tecl iniques
•ally include turbine command and acquisition units 236 and 246 generators 232 and 242 and turbine 232 and 242 are connected to a shaft of wind ly and are driven by wind forces. Any generator id turbine use can be used. Turbine controllers 238 ,rators 232 and 242, respectively, and control the known in the art.

In one embodiment, TCSs 234 perform real-time, event-driven data compression and/or other databases 236 and 246 are SQ protocol can be used. Data store i to a server with an associatec embodiment, the various data1 interfaces could also be used.
and 244 include database manager applications that data logging alarming, configuration management, data management functions. In one embodiment, databases; however, any database language and/or in databases 236 and 246 is periodically transmitted database over wind farm network 200. In one ases interact via the ODBC API; however, other

Server site 250 includes SCAD network 200. SCADA master SCAU 226, TCS 234 and TCS .operator interfaces, alarming, co acquires historical data from stored in databases 216, 228, 2 protocols.
SCADA master device 252 is a
master device 252 that is coupled with wind farm svice 252 acquires real-time data from MCAU 214,
44 using a real-time acquisition engine and provides
itrol interfaces, etc. SCADA master device 252 also AU 214, SCAU 226, TCS 234 and TCS 244 (as
6 and 246, respectively) using, for example, ODBC
so coupled with network database 256 that provides

storage of data acquired by SC./UDA master device 252. Network interface 254 is

coupled with SCADA master d
rice 252 to provide an interface to external network
260. External network 260 cajn be any network external to the wind farm, for
example, the Internet, or a corporate intranet. Remote device 270 is coupled with external network 260 and is configured to communicate with SCADA master device 252.
In one embodiment, use of a real time, event driven database management systems and SQL databases within each wind turbine, meteorological mast and/or substation provides that there is no loss of data that is being acquired from controllers, relays, meters and other intelligent electronic devices being used within the wind farm. In one embodiment, use of a distributed database together with secondary data processing functions provides capability for data compression and database management techniques within each wind turbine, meteorological mast and/or wind farm substation.
In one embodiment, use of a real time communication protocol together with a non-real-time LAN protocol between the SCADA master and the wind turbines' assists in providing real time monitoring and control data is acquired independently from historical data from wind turbines, providing a system operator the ability to view near real time wind turbine status on an operator console and has prompt confirmation of wind turbine control actions that are initiated from the SCADA master. In one embodiment, the architecture also facilitates multiple independent master stations either within the wind farm and/or external to the wind farm.
While not illustrated in Figure 2, a wind farm can be logically or physically divided into multiple "parks" that include one or more wind turbines. Data that is gathered can be processed and/or presented in terms of parks as well as the wind farm as a whole or individual wind turbines.
Figure 3 is a flow diagram of one embodiment of data acquisition and processing by a wind turbine in a wind farm. Data is gathered from sensor and/or components of a wind farm device, 310. The wind farm device can be, for example, a wind turbine having a generator, a substation, or a meteorological site having a mast with various sensors.

The specific data gathered by device in which it is included, be gathered: wind turbine controller etc. An another example, in a n horizontal wind speed and/or di rection temperature, and/or atmospheric pressure,
I'or
the local SCADA master varies depending on the example, in a wind turbine, the following data can state, wind speed, energy levels, and/or alarms, eteorological site the following data can be gathered: and multiple elevations, vertical wind speed, etc.

A first subset of the data is trans server or other data collectkn communications medium. In on a SCADA protocol, which is kn real-time transmission of data database until successfully transmitted
mitted in real time, 320. The data is transmitted to a device using a wind farm network or other embodiment, the real-time data is transmitted using n in the art; however, any protocol that allows for an be used. The data is maintained in the local to the server.

A second subset of the data is st( local database is a historical SQ any type of information can be device that gathers data at the site, substation) operates as a S device. The local SCADA master wind farm SCADA master devi control location.
red in a local database, 330. In one embodiment, the database; however, any database protocol as well as tored in the local database. In one embodiment, the farm device (e.g., wind turbine, meteorological DADA master device with respect to the wind farm device operates as a slave device with respect to a e, that can be located, for example, at a wind farm

In one embodiment, the local da time sufficient to bridge anticipa transmitted. For example, data 48 hours while a server can st periods can be used based on, foi
abases each have capacity to store data locally for a ed unavailability of a server to which the data will be sollected from a wind farm device can be stored for re data in a database for two months. Other time example, operating conditions, etc.

The local SCADA master can database, 340. Data from the network, 350. The data that is
p rform data processing on the data stored in the local local database is transmitted over the wind farm stored in the local database until transmitted to the

server. The data can be transmitted at the end of predetermined periods of time, in response to requests from the server or in response to predetermined conditions.
In one embodiment, data is transmitted from local SCADA masters at a relatively high degree of time resolution (e.g., approximately real time, each second, each two. seconds, or at a sub-second resolution) and at a relatively low degree of time resolution (e.g., several seconds, minutes). For a wind turbine, data gathered at the relatively high degree of time resolution can include, for example, real power production, reactive power production, wind speed, energy subtotal, total energy gathered, etc. Wind turbine data can further include generator rotational speed, generator temperature, gearbox temperature, ambient temperature, wind direction, power factor phase voltage and phase current for each phase, production time, etc.
For a meteorological site, the data gathered at a relatively high degree of time resolution can be vertical and horizontal wind speeds, wind direction, temperature and air pressure. For a substation, the data gathered can include total active energy our from the substation, total reactive energy out from the substation, total active energy into the substation, total reactive energy into the substation, etc. Additional and/or different data can also be gathered.
Figure 4 is a flow diagram of one embodiment of data acquisition and processing by a server coupled to multiple wind turbines, substations and/or meteorological sites-in a wind farm. Data is received from the wind farm devices, 410. Real-time data is received on a continuous basis as the data is provided by the wind turbines, substations, meteorological sites, etc. As mentioned above, the real-time data can be received using a SCADA protocol, or any other appropriate protocol. Data is also • gathered periodically as described above.
The data received by the server is processed and command operations can be issued, 420. Processing of the data can be performed in any manner known in the art. The commands issued by the server, or other device coupled with the server, can be used to control individual wind turbines, groups of wind turbines, as well as other devices coupled to the wind farm network.
The server, or a workstation cou >led with the server, provides the data received via a command and control interface, [30. In one embodiment, the interface is a graphical user interface (GUI); however, any type of user interface can be provided. The interface can be used to receive user input, 440, as well as to provide data to a user. Commands to one or more wind farm components can be generated based on the user input. The commands are transmitted to one or more target devices, 450, over the wind farm network.

The server, or a workstation or < processing including generatio indications, if generated, can be
ther device coupled with the server, can provide data i of alarms based on the received data. Alarm transmitted to remote devices and/or displayed via the

user interface, 460. The device (s) to which alarms are transmitted can communicate via the wind farm network or vi i a network external to the wind farm network.
Reference in the specification tc "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in o tie embodiment" in various places in the specification

are not necessarily all referring

:o the same embodiment.



In the foregoing specification specific embodiments thereof.
the invention has been described with reference to It will, however, be evident that various modifications

and changes can be made therejto without departing from the broader spirit and scope

of the invention. The specific!

ition and drawings are, accordingly, to be regarded in

an illustrative rather than a restjictive sense.

CLAIMS
What is claimed is:
1. A system for managing a wind farm having a plurality of wind turbines
comprising:
a Supervisory Command and Data Acquisition (SCADA) element (234, 244) at each wind turbine to collect data from the respective wind turbines (230,240);
a SCADA element (214) at each of one or more meteorological sites (210) to collect meteorological data;
a SCADA element (226) at each of one or more substations (220) electrically connected with the plurality of wind turbines (230,240); and
a server (252) coupled to communicate with the wind turbine, meteorological, and substation SCADA elements (226,234,244,214) to receive and to store data received from the elements at predetermined intervals and to perform database management on the received data, the server further to gather and maintain current and historical data as to the inputs, operating conditions, and outputs of the plurality of wind turbines.
2. The system of claim 1, wherein the gathered data comprises wind speed and
energy production gathered from each wind turbine according to a first predetermined
interval, meteorological data gathered from each meteorological site according to a
second predetermined interval and substation data including power production each
'substation.
3. The system of claim 1, wherein the gathered data comprises power, reactive
power, wind speed, energy subtotal, and total energy data gathered according to a first
time interval.
4. The system of claim 3, wherein the gathered data further comprises generator
rotational speed, generator temperature, gearbox temperature, ambient temperature,

ih phase energy production, and production time.
wind speed, wind direction, real and phase current for eacl

power, reactive power, power factor, phase voltage



5. The system of claim 2, gathered from each wind turbine temperature, and air pressure,
vherein the gathered data comprises controller state vertical and horizontal wind speeds, wind direction,. total active energy out from the substation, total

reactive energy out from the su ^station, total active energy into the substation, and total reactive energy into the substation.
6. The system of claim 1, wherein the wind farm is organized into parks for reporting and management purposes and the gathered data comprises energy produced by each park.

7. The system of claim 6, wherein the data for each park comprises an

operational status of one or more turbines in the park, total real power produced in the park, total reactive power produped in the park, and/or a power factor for the park.
8. The system of claim 1, (further comprising a configuration database (256) for the wind farm to store information describing a current configuration of .systems elements to be used during system initialization comprising information describing the current configuration of ijhe wind farm including the wind turbine SCADA elements in the wind farm.

9. The system of claim
the configuration information further comprising:
information describing each w nd turbine of the wind farm, including for each such turbine data source informatioi describing how'source data from the turbine is to be mapped to fields in a system ds tabase.

10. The system of claim 1 wind turbine data to report av power production over the tin window for each wind turbine
farther comprising processing logic (252) to process :rage power production over a time window, expected e window, and/or production efficiency over the time n the wind farm.