SYSTEMS AND METHODS OF COORDINATED YAW CONTROL OF MULTIPLE WIND TURBINES

Abstract

Systems and methods of autonomous farm-level control and optimization of wind turbines are provided. Exemplary embodiments comprise a site controller running on a site server. The site controller collects and analyzes yaw control data of a plurality of wind turbines and wind direction data relating to the plurality of wind turbines. The site server determines collective wind direction across an area occupied by the plurality of wind turbines and sends yaw control signals including desired nacelle yaw position instructions to the plurality of wind turbines. The site controller performs wake modeling analysis and determines desired nacelle positions of one or more of the plurality of wind turbines. The desired nacelle yaw position instructions systematically correct static yaw misalignment for all of the plurality of wind turbines. Embodiments of the disclosure provide means to perform whole site or partial site level controls of the yaw controllers of a utility scale wind turbine farm. The overall effect of the coordinated yaw control of wind turbines across the whole or partial site is intended to keep the wake loss of the wind turbines from the upstream wind turbines to the minimum and to maximize the production of turbines that are not waking other turbines.

Claims

1. A method of autonomous farm-level control and optimization of wind turbines comprising: collecting and analyzing yaw control data of one or more of a plurality of wind turbines each of the plurality of wind turbines including a tower and a nacelle mounted to the top of the tower; collecting and analyzing wind direction data across an area occupied by the plurality of wind turbines and determining a collective wind direction across the area; collecting and analyzing power production data of one or more of the plurality of wind turbines and determining whether the one or more of the plurality of wind turbines is capturing maximum power; determining desired nacelle yaw positions of a nacelle relative to its respective tower of one or more of the plurality of wind turbines; and sending yaw control signals including instructions for the desired nacelle yaw positions of the nacelle relative to its respective tower to one or more of the plurality of wind turbines based upon analysis of the yaw control data, wind direction data, and power production data.

2. The method of claim 1 further comprising determining which of the plurality of wind turbines are upstream wind turbines and assigning the upstream wind turbines desired nacelle yaw positions of the nacelle relative to its respective tower such that downstream wind turbines increase power production.

3. The method of claim 1 wherein if one or more of the plurality of wind turbines is not in optimal yaw position because of yaw misalignment, yaw misalignment errors are calculated at individual turbine level and offset corrections are sent to one or more of the plurality of wind turbines such that the offset corrections correct the yaw misalignment.

4. The method of claim 3 further comprising regularly eliminating yaw zero error or yaw misalignment of one or more of the plurality of wind turbines.

5. The method of claim 1 further comprising predicting a change in wind direction for one of the plurality of wind turbines from the collected and analyzed wind direction data from other wind turbines of the plurality of wind turbines such that one or more of the plurality of wind turbines moves into desired nacelle yaw position in advance of the change in wind direction.

6. The method of claim 5 further comprising sending instructions to the one of the plurality of wind turbines for desired nacelle yaw position in advance of the predicted change in wind direction.

7. The method of claim 3 wherein the instructions for the desired nacelle yaw positions of the nacelle relative to its respective tower are calculated based on the offset corrections.

8. The method of claim 1 further comprising learning from operational data, thereby improving predictions of effects of wake steering.

9. An autonomous system for improving energy extraction of a plurality of wind turbines, each of the plurality of wind turbines including a tower and a nacelle mounted to the top of the tower, comprising: a site controller running on a site server, the site controller collecting and analyzing yaw control data of a plurality of wind turbines and wind direction data relating to the plurality of wind turbines, the site server determining collective wind direction across an area occupied by the plurality of wind turbines and sending yaw control signals including desired nacelle yaw position of a nacelle relative to its respective tower.

10. The system of claim 9 further comprising an edge device configured to be communicatively coupled to a turbine control unit, the edge device supplying yaw control data to the site controller and receiving the yaw control signals from the site controller.

11. The system of claim 9 wherein the site server is in communication with a cloud system collecting yaw control data from the plurality of wind turbines and performing data analytics and model optimization and providing optimization instructions to the site controller.

12. The system of claim 9 wherein the site controller performs wake modeling analysis and determines desired nacelle yaw positions of one or more of the plurality of wind turbines, and wherein the desired nacelle yaw position instructions systematically correct static yaw misalignment for all of the plurality of wind turbines.

13. The system of claim 9 wherein the site controller determines which of the plurality of wind turbines are upstream wind turbines and assigns upstream wind turbines the desired nacelle yaw positions of a nacelle relative to its respective tower such that downstream wind turbines increase power production.

14. The system of claim 9 wherein the site controller determines which of the plurality of wind turbines are upstream wind turbines and derates the upstream wind turbines such that downstream wind turbines increase power production.

15. The system of claim 9 wherein the site controller determines the collective wind direction in real time.

16. The system of claim 9 wherein the site controller receives data from one or more of: Metmast, LiDar, RADAR, a weather forecast, or a metrological/fluid dynamics simulation.

17. The system of claim 9 wherein the site controller tracks high frequency yaw control data history and power production data history.

18. The system of claim 9 wherein the site controller determines whether one or more of the plurality of wind turbines is capturing maximum power.

19. The system of claim 18 wherein if the site controller determines that one or more of the plurality of wind turbines is not in optimal yaw position because of yaw misalignment, the site controller calculates yaw misalignment errors at individual turbine level and sends offset corrections to one or more retrofit data communication and processing units such that the offset corrections correct the yaw misalignment.

20. The system of claim 9 wherein the site controller predicts a change in wind direction for one of the plurality of wind turbines from the collected and analyzed wind direction data from other wind turbines of the plurality of wind turbines such that one or more of the plurality of wind turbines moves into desired nacelle yaw position in advance of the change in wind direction.

21. The system of claim 20 wherein the site controller sends instructions to the one of the plurality of wind turbines for desired nacelle yaw position in advance of the predicted change in wind direction.

22. The system of claim 9 wherein the site controller learns from its operational data, thereby improving its ability to predict effects of wake steering.

23. A method of autonomous farm-level control and optimization of wind turbines comprising: collecting and analyzing yaw control data of one or more of a plurality of wind turbines; collecting and analyzing wind direction data across an area occupied by the plurality of wind turbines and determining a collective wind direction across the area; collecting and analyzing power production data of one or more of the plurality of wind turbines and determining whether the one or more of the plurality of wind turbines is capturing maximum power; determining desired nacelle yaw positions of one or more of the plurality of wind turbines; and sending yaw control signals including instructions for the desired nacelle yaw positions to one or more of the plurality of wind turbines based upon analysis of the yaw control data, wind direction data, and power production data; and predicting a change in wind direction for one of the plurality of wind turbines from the collected and analyzed wind direction data from other wind turbines of the plurality of wind turbines such that one or more of the plurality of wind turbines moves into desired nacelle yaw position in advance of the change in wind direction.

24. The method of claim 23 further comprising sending instructions to the one of the plurality of wind turbines for desired nacelle yaw position in advance of the predicted change in wind direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The foregoing and other objects of the disclosure will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which:

[0023] FIG. 1 is a perspective view of an exemplary embodiment of a wind plant in accordance with the present disclosure;

[0024] FIG. 2A is a side view of an exemplary embodiment of a wind turbine nacelle showing an exemplary additional SW module in accordance with the present disclosure;

[0025] FIG. 2B is a side view of an exemplary embodiment of a wind turbine nacelle showing an exemplary retrofit system for a wind turbine including a retrofit data communication and processing unit installed between the existing wind direction sensor and the turbine control unit in accordance with the present disclosure;

[0026] FIG. 3 is a perspective view of an exemplary system for controlling group or wind farm level yaw control behavior and improving energy extraction at a wind plant in accordance with the present disclosure;

[0027] FIG. 4 is a schematic of an exemplary system for controlling group or wind farm level yaw control behavior and improving energy extraction at a wind plant in accordance with the present disclosure;

[0028] FIG. 5 is a schematic of an exemplary method of controlling group or wind farm level yaw control behavior and improving energy extraction at a wind plant in accordance with the present disclosure;

[0029] FIG. 6 is a side view and top view of an exemplary method of dynamic yaw optimization in accordance with the present disclosure;

[0030] FIG. 7 is a side view, top view, and power curve plot showing an exemplary method of correcting static yaw misalignment errors in accordance with the present disclosure;

[0031] FIG. 8 is a schematic showing an exemplary wake steering method in accordance with the present disclosure;

[0032] FIG. 9 is a schematic showing an exemplary method of utilizing social wind information across multiple turbines in accordance with the present disclosure; and

[0033] FIG. 10 is a block diagram showing an exemplary embodiment of the internal structure of a computer in which various embodiments of the disclosure may be implemented.

DETAILED DESCRIPTION

[0034] In the following paragraphs, embodiments will be described in detail by way of example with reference to the accompanying drawings, which are not drawn to scale, and the illustrated components are not necessarily drawn proportionately to one another. Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than as limitations of the present disclosure. As used herein, the “present disclosure” refers to any one of the embodiments described herein, and any equivalents. Furthermore, reference to various aspects of the disclosure throughout this document does not mean that all claimed embodiments or methods must include the referenced aspects.

[0035] Embodiments of the present disclosure provide methods and systems for improving the energy extraction of wind plants. An exemplary wind farm 1 is shown in FIG. 1. A wind farm or wind plant 1 includes a plurality of wind turbines 10. Each wind turbine 10 has a tower 11 and a rotor 12 and a nacelle 14 mounted to the top of the tower 11 along with a yaw bearing 9. The rotor 12 has a plurality of rotor blades 16 coupled to and extending from a rotor hub 15. The rotor hub 15 is rotatably coupled to an electric generator 17 via the main shaft 3. FIGS. 2A and 2B illustrate the major components in the nacelle 14. Various mechanical, electrical and computer systems, including but not limited to, the electric generator 17, a gearbox 19, a yaw motor 7, and a turbine control unit 24, may be housed in the nacelle 14. A retrofit data communication and processing unit 23, described in more detail herein, may be added to the wind turbine 10.

[0036] Exemplary methods and systems for controlling group or wind farm level yaw control behavior at a wind plant improve plant performance by making improvements at four levels. At the turbine level, disclosed systems provide more accurate relative wind direction measurement and improve responsiveness of turbine yaw control with additional dynamic yaw control tuning optimization based on the high-speed turbine wind direction sensor history. At site level, systems and methods eliminate yaw zero error or yaw misalignment regularly online in a higher frequency at seconds to minutes based on environmental conditions such as air density, temperature and turbulence.

[0037] Once improved, individual turbine yaw control accuracy and performance consider neighboring turbines' measured wind directions to come up with the wind direction flow across a group of turbines 10 or a whole farm 1. Fourth, based on the overall farm level wind speed and the accurate yaw positions across the group of wind turbines 10 or the wind farm 1, the systems deploy a wake steering model such as the NREL FLORIS model. This controls the upstream turbines at the moment to yaw away from wind enough for the downstream turbines to achieve higher production, thereby improving the overall group or farm level power production as a whole. This four-level methodology improves the farm level production to about 3-5% AEP. The final control output at system level is the desired turbine nacelle direction. It should be noted that there could be multiple opportunities to guide the turbine to point to the directions the group or wind farm level controller desires.

[0038] With reference to FIGS. 2A-5, an exemplary system 2 and method 3 for improving energy extraction of a plurality of wind turbines 10 will now be described. The system 2 has a coordinated yaw controller 20 that provides control of multiple wind turbines 10. In exemplary embodiments, the coordinated yaw controller 20 is a site level edge device such as an edge computer or sits in the cloud 8 and collects and analyzes yaw control data from the wind turbines 10. More particularly, coordinated yaw controller 20 is a wind turbine group or wind farm level control system implemented in the edge computer or in the cloud 8 that collects high speed wind direction and yaw control inputs and outputs data. It also sends out the yaw control signals to each turbine control unit 24 via an extra control module or unit.

[0039] Exemplary implementations could have portions of control systems or processes on edge or cloud computing. Wind plant network communication could be wired or wireless. A GUI and/or wizard-like user interface 25 may be provided for monitoring and controlling the system 2 remotely. The GUI at the wind plant may include real-time feedback on system behavior and on/off control. A cloud GUI is read-only and may be slightly behind real time, displaying the cumulative benefit.

[0040] In exemplary embodiments, the coordinated yaw controller 20 determines the collective wind direction across the area 6 of the wind farm 1, also at wind turbine group or wind farm level. The coordinated yaw controller 20 collects the turbine yaw control inputs and outputs high frequency data while monitoring how each wind turbine yaw control behaves. It may send out a yaw bias signal to help the turbine yaw control to achieve better accuracy and response time. The coordinated yaw controller analyzes the high frequency power data to determine how much the yaw misalignment is present for each turbine at current time and send a correction offset signal to each wind turbine 10.

[0041] Referring to FIG. 2A, the individual wind turbines 10 could be controlled by any suitable extra controller. One approach is to use the original turbine control software and add a new module inside, e.g., an additional SW module 13 inside the turbine control unit. In exemplary embodiments, the SW module 13 receives the yaw bias command from the coordinated yaw controller in the edge computer or cloud and drives the wind turbine 10 to the position at the speed the coordinated yaw controller 20 desires.

[0042] Alternatively, as shown in FIG. 2B, each individual wind turbine could be equipped with a retrofit data communication and processing unit 23 as part of a retrofit system 4 as described in U.S. Pat. No. 11,313,351, issued Apr. 26, 2022, which is hereby incorporated by reference herein in its entirety. The retrofit data communication and processing unit 23 receives nacelle yaw position commands and other signals from the coordinated yaw controller 20 and the technology feeds fictitious yaw error and wind speed signals to the turbine control unit 24 and measures the response. This hardware may be installed on the turbine 10 to enable far level yaw control for the turbine and to provide accurate timely data regarding the nacelle yaw position and measured wind conditions at the turbine to the system.

[0043] Additional modules or components could be provided to generate the same improved yaw control performance other than additional hardware inputs or control SW inputs from the edge computer or cloud, such as from additional measurement hardware such as Metmast, LiDAR or RADAR. Also, a turbine control unit software modification could be performed to implement the required controls instead of relying on add-on hardware such as a retrofit data communication and processing unit 23. Advantageously, disclosed systems allow for a decentralized analysis implementation (true swarm computing) implemented on each turbine with all turbines talking to each other. In other words, multiple wind turbines “collaborate” to maximize plant performance.

[0044] Turning now to FIG. 4, an exemplary system 2 operates in a closed loop, and the coordinated yaw controller 20 drives an autonomous fix cycle 28. The fix cycle 28 includes improving or fixing 110 turbine yaw control, fixing 120 group wind tracking, fixing 130 wake interaction, and closing 140 the loop on wind farm power. As discussed in more detail herein, the turbine yaw control fix 110 could be by dynamic yaw control 112 and/or yaw misalignment correction 114. At a group level, the group wind tracking fix 120 is by collective yaw control 122. The wake interaction fix 130 may be by a wake steering model 132.

[0045] FIG. 5 illustrates an exemplary closed-loop method 3 for improving energy extraction of a plurality of wind turbines. The basic loop or cycle substantially tracks the fix cycle 28 as described above. As shown in the basic loop, the fundamental functions are dynamic yaw control 112, yaw misalignment correction 114, collective yaw control 122, and wake steering 132. Outside the loop the advantageous results associated with the fundamental functions are shown. Dynamic yaw control 112 improves yaw control 30 and optimizes 32 the precision and speed of the turbines. More particularly, as shown in FIG. 6, dynamic yaw optimization minimizes average yaw error and moves the turbine 10 when it makes the most sense to do so, thereby reducing unnecessary yawing. Yaw misalignment correction 114 fixes 32 wind direction measurement and improves 34 measurement accuracy.

[0046] Collective yaw control 122 utilizes 36 social wind information across multiple turbines. As best seen in FIG. 9, the wind turbines 10 “talk” to each other to provide a more accurate picture of large-scale, site-level wind characteristics, avoiding unnecessary yaw motions and improving output. Collective yaw optimization determines the overall wind field and aligns turbines 10 to it. With reference to FIGS. 5 and 9, collective yaw control 122 and wake steering 132 optimize 38 nacelle direction. Wake steering 132 also reduces 40 wake interaction and minimizes 42 wake losses. Exemplary embodiments may focus on wake steering with a simplified collective yaw process and/or refine collective yaw optimization and measure its impact on the instrumented turbines separately. The improved output can either be independent or combined with wake steering, depending on the magnitude of plant wake losses.

[0047] In operation, exemplary methods 3 perform the following steps. They collect wind characteristic data from wind turbine sensors 22. The disclosed methods determine bias (yaw misalignment) of each measurement and perform yaw misalignment correction 114 in an automated and regular fashion. They determine the wind flow direction through the wind plant 1 using these measurements and appropriate models. Condition specific adjustments are possible depending on wind direction and wind speed. Exemplary methods determine the desired nacelle yaw positions 38 for each turbine based on the wake modeling to maximize the performance of the whole group or farm 1 as a function of time. They send positions to the wind turbines 10 such that the turbines move in a dynamically optimum way to improve production of energy or reduce mechanical loads on the turbine structure and components.

[0048] To improve yaw control accuracy and response at the turbine level, either the yaw control system settings are optimized or an additional controls input is added to the original feedback loop of the turbine yaw control. Such additional input can be an additional bias over the wind direction sensor signal or additional controls output of the coordinated yaw controller 20. In exemplary embodiments, these changes are based on the optimization separately done with a simulated model based on high frequency historic yaw control data at a site level edge computer or in the cloud.

[0049] Operations include tracking the high frequency yaw control and power production data history of the turbines 10 in the wind plant 1 and yaw control resulting nacelle direction. The coordinated yaw controller 20 determines if each wind turbine 10 is yawing the rotor 12 into the wind to capture the highest power. As best seen in FIG. 7, if it determines that a wind turbine 10 is not in optimal yaw position, then a yaw misalignment error 44 is calculated and applied to the turbine yaw control as an offset correction regularly at second, minutes or hours to account for environmental impacts.

[0050] When individual turbine yaw control accuracy and performance is corrected and improved, neighboring turbines' measured wind directions are analyzed to determine the wind direction flow across a group of turbines 10 or a whole wind farm 1. The site level coordinated yaw controller 20 tracks the wind direction sensed across a group of neighboring wind turbines 10 to identify the collective wind direction across the region all these turbines occupy. The local consensus wind direction is determined using all available information at site level. The wind direction changes across this region are determined in real time and support the yaw control at farm level to perform proper wake steering.

[0051] Based on the overall farm level wind speed and the accurate yaw positions across the group of wind turbines or the wind farm, a wake steering model may be performed, as shown in FIG. 8. This typically is done at site level. The coordinated yaw controller 20 determines which are the upstream turbines across the group or wind farm 1 and assign them desired nacelle yaw positions based on the simulated model prediction. Then it checks the power produced with downstream turbines to determine if the turbine desired nacelle yaw position dialed in upstream has induced the desired results downstream. If the results are not as predicted, the coordinated yaw controller 20 revises the turbine desired nacelle yaw position to try to increase the power improvement effect downstream based on a feedback algorithm. In some circumstances, the coordinated yaw controller 20 intentionally misaligns upstream turbines, which can provide a net power benefit by mitigating harmful wake effects. Advantageously, wake steering results in increased power output and lifetime extension.

[0052] The wake steering and farm level yaw control could also be used to mitigate downstream turbine mechanical loading instead of to increase energy production. In exemplary embodiments, the farm or group level control could use more than wake steering to help the turbine interaction, such as purposefully derating the upstream turbines to achieve a similar wake reduction effect downstream. Exemplary embodiments utilize a calibrated wake steering model, optimizing a wind plant using bins of wind speed, wind direction, and nacelle TI present in a large amount of 10-minute SCADA data. Optimum yaw position values are computed for all turbines in all bins, and both the total wake losses and the recoverable wake losses are estimated.

[0053] FIG. 10 shows an exemplary internal structure of a computer 1250 in which various embodiments of the present disclosure may be implemented. For example, the computer 1250 may act as a coordinated yaw controller 20. The computer 1250 contains a system bus 1279, where a bus is a set of hardware lines used for data transfer among the components of a computer or processing system. Bus 1279 is essentially a shared conduit that connects different elements of a computer system (e.g., processor, disk storage, memory, input/output ports, network ports, etc.) that enables the transfer of information between the elements. Attached to system bus 1279 is I/O device interface 1282 for connecting various input and output devices (e.g., sensors, transducers, keyboard, mouse, displays, printers, speakers, etc.) to the computer 1250. Network interface 1286 allows the computer 1250 to connect to various other devices attached to a network (e.g., wind farm system 130, SCADA system, wind farm controller, individual turbine control units, weather condition sensors, data acquisition system etc.).

[0054] Memory 1090 provides volatile storage for computer software instructions 1292 (e.g., instructions for the processes/calculations described above, for example, receiving operating state information from the wind farm system and sensor data from the blade sensors to calculate cyclic loads, the processes for cycle counting, calculating the cyclic loads, determining the cyclic loading's effect on the life span of a wind turbine or specific component thereof, the bending moment calculations and calibration calculations) and data 1294 used to implement an embodiment of the present disclosure. Disk storage 1295 provides non-volatile storage for computer software instructions 1292 and data 1294 used to implement an embodiment of the present disclosure. Central processor unit 1284 is also attached to system bus 1279 and provides for the execution of computer instructions.

[0055] In an exemplary embodiment, the processor routines 1292 (e.g., instructions for the processes/calculations described above) and data 1094 are a computer program product (generally referenced 1292), including a computer readable medium (e.g., a removable storage medium such as one or more DVD-ROMs, CD-ROMs, diskettes, tapes, etc.) that provides at least a portion of the software instructions for the invention system. Computer program product 1292 can be installed by any suitable software installation procedure, as is well known in the art.

[0056] In another embodiment, at least a portion of the software instructions may also be downloaded over a cable, communication and/or wireless connection. Further, the present embodiments may be implemented in a variety of computer architectures. The computer of FIG. 10 is for purposes of illustration and not limitation of the present disclosure. In some embodiments of the present disclosure, the data analysis and augmented control system may function as a computer to perform aspects of the present disclosure.

[0057] Thus, it is seen that systems and methods of coordinated yaw control of multiple wind turbines are provided. It should be understood that the example embodiments described above may be implemented in many different ways. In some instances, the various methods and machines described herein may each be implemented by a physical, virtual or hybrid general purpose computer having a central processor, memory, disk or other mass storage, communication interface(s), input/output (I/O) device(s), and other peripherals. The general purpose computer is transformed into the machines that execute the methods described above, for example, by loading software instructions into a data processor, and then causing execution of the instructions to carry out the functions described, herein. Embodiments may therefore typically be implemented in hardware, firmware, software, or any combination thereof.

[0058] While embodiments of the disclosure have been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. For example, the disclosed augmented control is described in the context of wind farms and wind turbines, but may be applied to augment control of other turbines, such underwater turbines.