System and method for adjusting reactive power response of a wind turbine in the event of a communication failure

Abstract

The invention relates to a system and method of adjusting a reactive power response of a wind turbine upon a communication failure, in particular a method comprising receiving, via one or more turbine level controllers, an indication of at least one of a loss of communication between the one or more turbine level controllers and a farm level controller, a detection of an absence of reactive power regulation by the farm level controller, or a reactive power command of the farm level controller being equal to or higher than a saturation threshold during a transition between a baseline operating mode and a reactive power mode, the reactive power mode being characterized by reactive power generation only. Upon receiving the indication, the method comprises adjusting a reactive power response of one or more reactive power regulators of the one or more turbine level controllers in order to avoid an overshoot reactive power event or an undershoot reactive power event at an interconnection point.

Description

Technical Field

[0001] This disclosure generally relates to systems and methods for controlling a wind farm having one or more wind turbines, and more particularly to systems and methods for adjusting the reactive power response of one or more wind turbines in a wind farm to provide a smooth transition during communication failures, when reactive power control functionality is disabled by a field-level controller, and / or during transitions between a baseline power mode and a reactive power mode while reactive power command saturation is in effect. Background Technology

[0002] Wind power is considered one of the cleanest and most environmentally friendly energy sources available today, and wind turbines have received increasing attention in this regard. Existing power distribution systems (e.g., power grids) can be utilized to distribute power from renewable energy sources such as wind by employing control systems and methods that coordinate the power generated by renewable energy sources, the power demand on the power distribution system, and the power consumed, based on the inherently different operating states of renewable energy. For example, the operating state of a wind turbine can vary based on wind speed or the absence of wind.

[0003] Wind power does not always have a constant power output, but can include variations; therefore, operators of distribution systems must take this into account. One consequence is that distribution and transmission networks have become more difficult to manage. This also involves resonance management in distribution systems (including wind turbines). Like conventional power plants, wind farms or wind farms should be managed or controlled to provide stable power to the power grid (e.g., with constant voltage and frequency, minimal disturbances, and low harmonic emissions) to ensure reliable and proper power delivery.

[0004] Accordingly, modern wind farms have a field-level controller communicatively coupled to the turbine-level controller of each wind turbine in the wind farm. More specifically, the field-level controller manages each of the individual turbine-level controllers to achieve the desired active and reactive power outputs. Furthermore, to achieve fast reactive power response, the power control loop between the field-level controller and the turbine-level controller is tuned to account for each other's response times. This is exacerbated when the power converters in the wind farm are configured to connect to a weak power grid. Accordingly, the field-level controller generally includes an active setting for reactive power feedforward functionality. This function is typically used in applications with requirements for rapid field-level voltage regulation.

[0005] However, if communication is lost between the field-level controller and one or more of the turbine-level controllers, or if the reactive power regulation functionality of the field-level controller is disabled, the corresponding wind turbine is configured to operate in "autonomous mode." Consequently, the turbine-level control loop is no longer coupled to the field-level controller. As a result, reactive power overshoot / undershoot events may occur at the common coupling point (e.g., turbine output) when the reference changes, or when switching back and forth between normal mode and reactive power-only mode. Furthermore, after communication is restored, the controller may cause the same reactive power undershoot / overshoot response during field-level undersaturation during switching back and forth between normal mode and reactive power-only mode.

[0006] In light of the foregoing, the following systems and methods will be favored in the art for adjusting the reactive power response of a wind farm to provide a smooth transition during communication failures, when reactive power control functionality is disabled by the field-level controller, and / or during transitions between baseline power modes and reactive power modes while reactive power command saturation is present. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the description which follows, or will be obvious from the description, or may be learned by practicing exemplary embodiments of the present disclosure.

[0008] In one aspect, this disclosure relates to a method for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point. The wind farm is controlled by a farm-level controller. Furthermore, each of the multiple wind turbines has a turbine-level controller communicatively coupled to the farm-level controller. The method includes receiving, via one or more of the turbine-level controllers, an indication of at least one of the following: loss of communication between one or more of the turbine-level controllers and the farm-level controller; detection of the absence of reactive power regulation by the farm-level controller; or a reactive power command of the farm-level controller being equal to or higher than a saturation threshold during a transition between a baseline operating mode and a reactive power mode characterized by generating only reactive power. Upon receiving this indication, the method includes adjusting the reactive power response of one or more reactive power regulators of one or more of the turbine-level controllers to avoid overshoot or undershoot reactive power events at the interconnection point.

[0009] In one embodiment, adjusting the reactive power response of one or more reactive power conditioners in one or more turbine stage controllers may include adjusting the gain of one or more reactive power conditioners and / or disabling the feedforward function of one or more reactive power conditioners. In such an embodiment, disabling the feedforward function of one or more reactive power conditioners may include generating a disable signal via one or more turbine stage controllers to disable the feedforward function of one or more converter controllers of a plurality of wind turbines, and sending the disable signal via one or more turbine stage controllers to one or more converter controllers to disable the feedforward function.

[0010] In a particular embodiment, a disable signal-guided converter controller slows down the reactive power response of one or more reactive power regulators by disabling the feedforward branches of one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

[0011] In another embodiment, the disable signal can be a Boolean signal. In such an embodiment, the method may include setting the Boolean signal to a true state upon receiving the indication, wherein the Boolean signal was set to a false state before receiving the indication. In an additional embodiment, the Boolean signal remains set to a true state for a predetermined time limit before being automatically reset to a false state. For example, in such an embodiment, the predetermined time limit is less than approximately 100 seconds.

[0012] In several embodiments, the method may further include determining a communication loss by observing one or more reference communication updates via one or more turbine-level controllers. In another embodiment, the method may include determining whether reactive power regulation in the field-level controller is disabled by observing the validity of a reactive power command sent by the field-level controller. Furthermore, in embodiments, the method may include determining whether the reactive power command of the field-level controller is equal to or higher than a saturation threshold by comparing the reactive power command of the field-level controller with the maximum available reactive power at one of a plurality of wind turbines via one or more turbine-level controllers.

[0013] In an embodiment, the method may include enabling the feedforward function of one or more reactive power regulators via one or more turbine-level controllers after at least one of the following: communication loss recovery, reactive power regulation in the field-level controller is enabled, or the reactive power command is less than a saturation threshold during the transition between the baseline operating mode and the reactive power mode.

[0014] In another aspect, this disclosure relates to a system for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point. The system includes a field-level controller and multiple turbine-level controllers communicatively coupled to the field-level controller. Each of the multiple turbine-level controllers includes at least one processor. One or more processors are configured to perform operations including, but not limited to, receiving via one or more of the multiple turbine-level controllers an indication of at least one of the following: loss of communication between one or more of the multiple turbine-level controllers and the field-level controller; detecting the absence of reactive power regulation by the field-level controller or a reactive power command of the field-level controller equal to or higher than a saturation threshold during a transition between a baseline operating mode and a reactive power mode characterized by generating only reactive power; and adjusting the reactive power response of one or more reactive power regulators of one or more of the multiple turbine-level controllers to avoid overshoot or undershoot reactive power events at the interconnection point. It should be understood that the system may further include any of the additional features described herein.

[0015] Technical Solution 1. A method for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point, the wind farm being controlled by a field-level controller, each of the multiple wind turbines having a turbine-level controller communicatively coupled to the field-level controller, the method comprising: The system receives, via one or more of the turbine stage controllers, an indication of at least one of the following: loss of communication between the turbine stage controller and the field stage controller; detection of no reactive power regulation by the field stage controller; or a reactive power command from the field stage controller equal to or higher than a saturation threshold during the transition between a baseline operating mode and a reactive power mode, wherein the reactive power mode is characterized by generating only reactive power; and Upon receiving the instruction, the reactive power response of one or more reactive power regulators of the turbine stage controller is adjusted to avoid overshoot or undershoot reactive power events at the interconnection point.

[0016] Technical Solution 2. The method according to Technical Solution 1, wherein adjusting the reactive power response of one or more reactive power regulators of the turbine stage controller further includes adjusting one or more gains of the one or more reactive power regulators or disabling at least one of the feedforward function of the one or more reactive power regulators.

[0017] Technical Solution 3. The method according to Technical Solution 2, wherein disabling the feedforward function of the one or more reactive power regulators further includes: A disable signal is generated via one or more of the turbine stage controllers to disable the feedforward function for one or more converter controllers of the plurality of wind turbines; and The disable signal is sent to one or more of the turbine stage controllers to disable the feedforward function.

[0018] Technical Solution 4. The method according to Technical Solution 3, wherein the disable signal instructs the one or more converter controllers to slow down their reactive power response by disabling the feedforward branches of the one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

[0019] Technical Solution 5. The method according to Technical Solution 3, wherein the disable signal includes a Boolean signal, and the method further includes setting the Boolean signal to a true state upon receiving the instruction, wherein the Boolean signal is set to a false state before receiving the instruction.

[0020] Technical Solution 6. The method according to Technical Solution 5, wherein, before automatically resetting to the false state, the Boolean signal is still set to the true state for a predetermined time limit.

[0021] Technical Solution 7. The method according to Technical Solution 6, wherein the predetermined time limit is less than approximately 100 seconds.

[0022] Technical Solution 8. The method according to Technical Solution 1 further includes determining at least one of the following: observing one or more reference communication updates via one or more of the turbine stage controllers to determine whether the reactive power regulation in the field stage controller is disabled or enabled by observing the validity of a reactive power command sent by the field stage controller.

[0023] Technical Solution 9. The method according to Technical Solution 1 further includes determining whether the reactive power command of the field-level controller is equal to or higher than the saturation threshold during the transition between the baseline operating mode and the reactive power mode by comparing the reactive power command of the field-level controller with the maximum available reactive power at one of the plurality of wind turbines via one or more of the turbine-level controllers.

[0024] Technical Solution 10. The method according to Technical Solution 2 further includes enabling the feedforward function of the one or more reactive power regulators via one or more of the turbine stage controllers after the communication loss is recovered, the reactive power regulation in the field-level controller is enabled, or the reactive power command is less than at least one of the saturation thresholds during the transition between the baseline operating mode and the reactive power mode.

[0025] Technical Solution 11. A system for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point, the system comprising: Field-level controller; A plurality of turbine-stage controllers communicatively coupled to the field-stage controller, each of the plurality of turbine-stage controllers including at least one processor configured to perform operations including: The system receives, via one or more of the plurality of turbine stage controllers, an indication of at least one of the following: loss of communication between one or more of the plurality of turbine stage controllers and the field-level controller; detection of no reactive power regulation performed by the field-level controller; or a reactive power command of the field-level controller being equal to or higher than a saturation threshold during the transition between a baseline operating mode and a reactive power mode, wherein the reactive power mode is characterized by generating only reactive power; and Upon receiving the instruction, the reactive power response of one or more reactive power regulators of one or more of the plurality of turbine stage controllers is adjusted to avoid overshoot or undershoot reactive power events at the interconnection point.

[0026] Technical Solution 12. The system according to Technical Solution 11, wherein adjusting the reactive power response of one or more reactive power regulators of one or more of the plurality of turbine stage controllers further includes adjusting one or more gains of the one or more reactive power regulators or disabling at least one of the feedforward functions of the one or more reactive power regulators.

[0027] Technical Solution 13. The system according to Technical Solution 12, wherein disabling the feedforward function of the one or more reactive power regulators further includes: A disable signal is generated via one or more of the plurality of turbine stage controllers to disable the feedforward function for one or more converter controllers of the plurality of wind turbines; and The disable signal is sent to one or more converter controllers via one or more of the plurality of turbine stage controllers to disable the feedforward function.

[0028] Technical Solution 14. The system according to Technical Solution 13, wherein the disable signal instructs the one or more converter controllers to slow down their reactive power response by disabling the feedforward branches of the one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

[0029] Technical Solution 15. The system according to Technical Solution 13, wherein the disable signal includes a Boolean signal, and the operation further includes setting the Boolean signal to a true state upon receiving the instruction, wherein the Boolean signal is set to a false state before receiving the instruction.

[0030] Technical Solution 16. The system according to Technical Solution 15, wherein, before being automatically reset to the false state, the Boolean signal is still set to the true state for a predetermined time limit.

[0031] Technical Solution 17. The system according to Technical Solution 16, wherein the predetermined time limit is less than approximately 100 seconds.

[0032] Technical Solution 18. The system according to Technical Solution 11, wherein the operation further includes determining at least one of the following: observing one or more reference communication updates via one or more of the plurality of turbine stage controllers to determine whether the reactive power regulation in the field stage controller is disabled or enabled by observing the validity of a reactive power command sent by the field stage controller.

[0033] Technical Solution 19. The system according to Technical Solution 11, wherein the operation further includes determining whether the reactive power command of the field-level controller is equal to or higher than the saturation threshold by comparing the reactive power command of the field-level controller with the maximum available reactive power via one or more of the plurality of turbine-level controllers.

[0034] Technical Solution 20. The system according to Technical Solution 12, wherein the operation further includes enabling the feedforward function of the one or more reactive power regulators via one or more of the plurality of turbine-level controllers after the communication loss is recovered, the reactive power regulation in the field-level controller is enabled, or the reactive power command is less than at least one of the saturation thresholds during the transition between the baseline operating mode and the reactive power mode.

[0035] Variations and modifications can be made to these exemplary aspects of this disclosure. These and other features, aspects, and advantages of the various embodiments will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the related principles. Attached Figure Description

[0036] A detailed discussion of embodiments for those skilled in the art is set forth in this specification with reference to the accompanying drawings, wherein: Figure 1 The illustration shows a perspective view of a portion of a wind turbine according to an exemplary embodiment of the present disclosure; Figure 2 The diagram is suitable for use with Figure 1 A schematic diagram of a wind turbine electric power system according to an exemplary embodiment of the present disclosure, used in conjunction with a wind turbine, is shown. Figure 3 The figure shows a schematic diagram of a wind farm electric power system according to an exemplary embodiment of the present disclosure; Figure 4 The figure shows a block diagram of a controller according to an exemplary embodiment of the present disclosure; Figure 5 The figure shows a flowchart of one embodiment of a method for controlling a wind field according to the present disclosure; Figure 6 The figure shows a schematic diagram of an embodiment of a system for controlling a wind field according to the present disclosure. Detailed Implementation

[0037] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of interpretation rather than limitation of the present disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from its scope or spirit. For example, features partially illustrated or described as one embodiment can be used with another embodiment to produce yet another embodiment. Thus, it is intended that the present disclosure cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0038] Generally, this disclosure relates to systems and methods for adjusting the reactive power response of a wind farm to provide a smooth transition during communication failures. Specifically, this disclosure provides adjustment of the reactive power regulator response of one or more turbine-level controllers when the output of the farm-level controller is saturated or lost due to communication failure. In embodiments, for example, the response change can be achieved by adjusting the gain of one or more power regulators or disabling the reactive power regulator feedforward of the power converter during these conditions, for example, to slow down the turbine response and avoid overshoot and undershoot conditions. Detection of these specific scenarios is performed by one or more turbine-level controllers. Upon detection of these scenarios, one or more turbine-level controllers are configured to send commands to one or more power converters to disable the reactive power regulator feedforward. Additionally, when one or more wind turbines recover from these conditions, one or more turbine-level controllers are configured to send commands to re-enable the feedforward.

[0039] Now refer to the attached diagram, Figure 1 A perspective view depicting one embodiment of a wind turbine 10 according to the present disclosure is shown. As illustrated, the wind turbine 10 generally includes: a tower 12 extending from a support surface (not shown); a nacelle 14 mounted on the tower 12; and a rotor 16 coupled to the nacelle 14. The rotor 16 includes a rotatable hub 18 and at least one rotor blade 20 coupled to and extending outward from the hub 18. For example, in the illustrated embodiment, the rotor 16 includes three rotor blades 20. However, in alternative embodiments, the rotor 16 may include more or fewer than three rotor blades 20. Each rotor blade 20 may be spaced around the hub 18 to facilitate rotation of the rotor 16 so that kinetic energy can be converted from wind into usable mechanical energy and subsequently into electrical energy. For example, the hub 18 may be rotatably coupled to an electric generator 28 located within the nacelle 14. Figure 2 ), to allow the generation of electrical energy.

[0040] Now for reference Figure 2The diagram illustrates a wind turbine power system 100, which includes a wind turbine 10 and an associated power system 102. When wind impacts rotor blades 20, the blades convert wind energy into mechanical rotational torque that rotatably drives a low-speed shaft 22. The low-speed shaft 22 is configured to drive a gearbox 24 (if present), which subsequently increases the low-speed rotational speed of the low-speed shaft 22 to drive a high-speed shaft 26 at the increased speed. The high-speed shaft 26 is substantially rotatably coupled to a generator 28 (such as a doubly-fed induction generator or a DFIG) to rotatably drive a generator rotor 30. A rotating magnetic field can be induced by the generator rotor 30, and a voltage can be induced within the generator stator 32, which is magnetically coupled to the generator rotor 30. The associated electrical power can be transmitted from the generator stator 32 to a primary three-winding converter 34, which is connected to the power grid at an interconnection point (POI) 56 via a grid circuit breaker 36. Therefore, the main converter 34 increases the voltage amplitude of the electrical power, so that the converted electrical power can be further transmitted to the power grid.

[0041] Additionally, as shown, generator 28 can be electrically coupled to bidirectional power converter 38, which includes a rotor-side converter 40 connected to a line-side converter 42 via a regulated DC link 44. The rotor-side converter 40 converts AC power supplied from generator rotor 30 into DC power and supplies DC power to DC link 44. The line-side converter 42 converts the DC power on DC link 44 into AC output power suitable for the power grid. Thus, AC power from power converter 38 can be combined with power from generator stator 32 to provide multiphase power (e.g., three-phase power) with a frequency substantially maintained at the power grid frequency (e.g., 50 Hz / 60 Hz).

[0042] In some configurations, the power system 102 may include a turbine stage controller 224 (in Figure 3 (As shown in the diagram). The turbine stage controller 224 can be a control device, such as... Figure 4 The controller shown and described.

[0043] The illustrated three-winding converter 34 can have: (1) a 33 kV medium voltage (MV) primary winding 33 connected to the power grid; (2) a 6 to 13.8 kV MV secondary winding 35 connected to the generator stator 32; and (3) a 690 to 900 V low voltage (LV) tertiary winding 37 connected to the line-side power converter 42.

[0044] Special reference Figure 3The illustration shows a schematic diagram of one embodiment of a wind farm 200 according to the present disclosure. More specifically, as shown, the wind farm 200 can include a plurality of wind turbines 10 connected to a power grid via a point of interest (POI) 56. In one embodiment, the wind farm 200 can include a plurality of clusters 204 of wind turbines 10. Thus, a wind turbine power system 100 including wind turbines 10 can be arranged in a predetermined geographical location and electrically connected together to form the wind farm 200.

[0045] The electrical power associated with each wind turbine power system 100 can be transmitted to the main line 206 via one or more cluster lines 220. Each wind turbine power system 100 can be connected to or disconnected from one or more cluster lines 220 via one or more switches 222 or circuit breakers. Furthermore, as shown, each cluster 204 of the wind turbines 10 can be connected to individual converters 214, 216, 218 via switches 208, 210, 212 to increase the voltage amplitude of the electrical power from each cluster 204, allowing the converted power to be further transmitted to the power grid. Additionally, as shown, converters 214, 216, 218 can be connected to the main line 206, which combines the voltages from each cluster 204 before transmitting power to the grid via POI 56. POI 56 can be a circuit breaker, switch, or other known method of connecting to the power grid.

[0046] Each wind turbine power system 100 may include a turbine stage controller 224 and a voltage regulator 228 (i.e., a wind turbine terminal voltage regulator). Accordingly, the voltage regulator 228 regulates the voltage output by each wind turbine power system 100. Furthermore, the voltage regulator 228 may be part of or in electrical communication with the turbine stage controller 224 or the field stage controller 226. Therefore, the field stage controller 226 and / or (one or more) turbine stage controllers 224 may transmit voltage regulator gain commands (V... CMD The power is delivered to one or more of the voltage regulators 228, which in turn determines the amount of power distributed to the POI 56 via the cluster line 220.

[0047] As described herein, one or more turbine stage controllers 224 can be configured to control components of the respective wind turbine power system 100 (including switch 222 or voltage regulator 228) and / or implement some or all of the method steps as described herein. One or more turbine stage controllers 224 can be located on or within each wind turbine 10, or can be positioned remotely from each wind turbine 10. One or more turbine stage controllers 224 can be part of or included with one or more other controllers associated with the wind turbine power system 100 and / or wind farm 200.

[0048] Similarly, wind farm 200 may include one or more controllers, such as a field-level controller 226. Field-level controller 226 may be configured to control components of wind farm 200 (including switches 208, 210, and 212, voltage regulator 228), communicate with one or more other controllers (such as turbine-level controller 224), and / or implement some or all of the method steps as described herein. Field-level controller 226 may be located within or off a geographical area of ​​wind farm 200. Field-level controller 226 may be part of or included with one or more other controllers associated with or off wind farm 200 and / or wind turbine power system 100. Each of cluster 204, wind turbine power system 100, or turbine-level controller 224 may be communicatively coupled to field-level controller 226.

[0049] The field-level controller 226 is capable of generating and sending control signals, at least in part, based on the power required at POI 56, to the turbine-level controller 224 to operate switch 222 to connect or disconnect one or more wind turbine power systems 100 from cluster line 220. The field-level controller 226 is also capable of generating and sending control signals, at least in part, based on the power required at POI 56, to the voltage regulator 228 to operate or control the voltage regulator 228 and control the amount of power delivered from the wind turbine power system(s) 100 to POI 56 via cluster line 220.

[0050] In another embodiment, the field-level controller 226 is capable of generating control signals based at least in part on the power required at POI 56 and / or at least in part on the characteristics of the wind farm 200, (one or more) wind turbine power system 100 and / or wind turbine 10, and sending the control signals to switches 208, 210 and / or 212 and / or voltage regulator 228 to regulate the power delivered to POI 56.

[0051] Now for reference Figure 4The diagram illustrates a block diagram of a controller 300 according to an exemplary embodiment of the present disclosure. As shown, the controller 300 can be a turbine-level controller 224 or a field-level controller 226. Furthermore, as shown, the controller 300 can include one or more processors 402 configured to perform various computer-implemented functions (e.g., performing methods, steps, operations, etc. and storing relevant data as disclosed herein) and associated memory(s). The memory(s) 304 may also store data related to certain characteristics of the wind farm 200, the wind turbine power system(s) 100, and / or the characteristics of the wind turbine 10.

[0052] Additionally, the controller 300 may include a communication module 306 to facilitate communication between the controller and various components of the wind farm 200, the field-level controller 226, and / or one or more wind turbine power systems 100, including communication between the field-level controller 226 and one or more turbine-level controllers 224. Furthermore, the communication module 306 may include a sensor interface 308 (e.g., one or more analog-to-digital converters) to allow signals transmitted from one or more sensors 310, 312, and 314 to be converted into signals that can be understood and processed by the processor 402. Thus, in this embodiment, sensors 310, 312, and 314 can be used to measure, determine, or collect data regarding the characteristics of the wind farm 200, one or more wind turbine power systems 100, and / or the wind turbine 10.

[0053] Still referencing Figure 4 The controller 300 may also include a user interface 316. The user interface 316 may have various configurations and may house or contain control devices. The user interface 316 may also be located within or away from the wind farm 200 or any part thereof. The user interface 316 may also include an input element 318. In an embodiment, the input element 318 may be, for example, a capacitive touchscreen. In such an embodiment, the input element 318 may allow selective activation, adjustment, or control of the field-level controller 226 and / or one or more turbine-level controllers 224, as well as any timer features or other user-adjustable inputs. One or more of a variety of electrical, mechanical, or electromechanical input devices (including rotary dials, buttons, and touchpads) may also be used individually or in combination as the input element 318. In another embodiment, the user interface 316 may include a display element, such as a digital or analog display designed to provide operational feedback to the user.

[0054] It should be understood that sensors 310, 312, and 314 can be communicatively coupled to communication module 306 using any suitable device. For example, sensors 310, 312, and 314 can be coupled to sensor interface 308 via a wired connection. However, in other embodiments, sensors 310, 312, and 314 can be coupled to sensor interface 308 via a wireless connection, such as by using any suitable wireless communication protocol known in the art. Accordingly, processor 402 can be configured to receive one or more signals from sensors 310, 312, and 314. In further embodiments, sensors 310, 312, and 314 can be part of or included with one or more of one or more associated other controllers in wind farm 200 and / or wind turbine power system 100. Furthermore, in embodiments, sensors 310, 312, and 314 can also be located within a geographic area of ​​wind farm 200 or any part thereof, or can be located remotely from wind farm 200 or any part thereof.

[0055] It should also be understood that sensors 310, 312, and 314 can be any number or type of voltage and / or current sensors that can be employed within the wind turbine power system 100 and at any location. For example, the sensors can be current transformers, shunt sensors, Rogowski coils, Hall effect current sensors, miniature inertial measurement units (MIMUs) or the like, and / or any other suitable voltage or current sensor currently known or later developed in the art. Consequently, one or more controllers (such as wind farm controller 226 and / or one or more turbine stage controllers 224) are configured to receive one or more voltage and / or current feedback signals from sensors 310, 312, and 314.

[0056] As used herein, the term "processor" refers not only to integrated circuits included in a computer as understood in the art, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits (ASICs), and other programmable circuits. One or more processors 402 are also configured to compute advanced control algorithms and transmit them to a wide variety of Ethernet-based or serial protocols (Modbus, OPC, CAN, etc.). Additionally, one or more memory devices 304 may generally include one or more memory elements (including, but not limited to, computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, CD-ROMs, magneto-optical disks (MODs), DVDs, and / or other suitable memory elements). Such memory devices 140 may generally be configured to store suitable computer-readable instructions that, when implemented by one or more processors 402, configure the controller to perform the various functions described herein.

[0057] Now for reference Figure 5 and Figure 6 The figures illustrate a method 400 and a system 500 according to the present disclosure for controlling a wind field having multiple wind turbines electrically connected to a power grid at interconnection points. More specifically, Figure 5 The diagram illustrates a flowchart of one embodiment of the method 400 for controlling a wind field according to the present disclosure, while Figure 6 The figure is a schematic diagram of one embodiment of a system 500 for controlling a wind field according to the present disclosure. Generally, method 400 and system 500 will be referred herein with reference to wind turbine 10, wind turbine power system 100, wind field 200, and... Figure 1-4 The various controllers illustrated herein are used to describe this. However, it should be appreciated that the disclosed method 400 and system 500 can be implemented using wind turbines and wind farms with any other suitable configuration.

[0058] In addition, although Figure 5 The steps are depicted in a specific order for illustration and discussion purposes, but the methods discussed herein are not limited to any particular order or arrangement. Those skilled in the art will recognize using the disclosure provided herein that the various steps of the methods disclosed herein can be omitted, rearranged, combined, and / or modified in various ways without departing from the scope of this disclosure.

[0059] Special reference Figure 5As shown at (402), method 400 includes receiving, via one or more of the turbine stage controllers 224, a communication loss between one or more of the turbine stage controllers 224 and the field stage controllers 226, detecting the absence of reactive power regulation by the field stage controllers 226, and / or a reactive power command from the field stage controllers 226 equal to or higher than a saturation threshold during transitions between (e.g., back and forth) a baseline operating mode and a reactive power mode. As used herein, a reactive power mode may be characterized by generating only reactive power during this mode. Thus, in several embodiments, method 400 may include determining a communication loss by observing one or more reference communication updates via one or more of the turbine stage controllers 224. In another embodiment, method 400 may include determining whether reactive power regulation in the field stage controllers 226 is disabled or enabled by observing the validity of a reactive power command sent by the field stage controllers 226. Furthermore, in an embodiment, method 400 may include determining whether the reactive power command of the field level controller 226 is equal to or higher than a saturation threshold by comparing the reactive power command of the field level controller 226 with the maximum available reactive power via one or more turbine level controllers 224.

[0060] Upon receiving the instruction, as shown at (404), method 400 includes adjusting the reactive power response of one or more reactive power regulators in one or more of the turbine stage controllers 224 to avoid overshoot or undershoot reactive power events at POI 56.

[0061] Now for reference Figure 6The diagram illustrates a control diagram of a system 500 for controlling a wind farm 200 according to this disclosure, further illustrating the details of the method 400 described herein. More specifically, as shown, the system 500 may generally include a field-level controller 226 and a turbine-level controller 224, each having a converter controller 225 (only one of which is shown) for controlling a power converter 38. Thus, as shown, each of the converter controllers(s) ... Furthermore, as shown, comparator 510 is configured to compare reactive power reference 516, reactive power command 518, and reactive power feedback signal 520. The output 524 is then used by reactive power regulator 502 in conjunction with reactive power feedforward function 526, which can be enabled or disabled via various switches as shown.

[0062] Therefore, in embodiments, adjusting the reactive power response of one or more reactive power conditioners 502 may include adjusting the gain of one or more of the reactive power conditioners 502 or disabling the feedforward function 526 of one or more of the reactive power conditioners 502 in converter controllers 225. For example, in such embodiments, as shown, disabling the feedforward function 526 may include generating a disable signal 528 (e.g., QregffDsb) by turbine stage controller 224 and sending the disable signal 528 to converter controllers 225 to disable the feedforward function 526 therein. Thus, in a particular embodiment, the disable signal 528 instructs converter controllers 225 to slow down its reactive power response by disabling the feedforward branch 532 of one or more reactive power conditioners 502, thereby effectively providing a smooth reactive power response.

[0063] In an additional embodiment, as shown, one or more converter controllers 225 are further configured to enable feedforward function 526 of reactive power conditioner 502 after communication loss recovery and / or reactive power command is less than a saturation threshold. For example, in an embodiment, one or more converter controllers 225 are further configured to enable feedforward function 526 by generating an enable signal 530 (e.g., QregffEnb) and sending the enable signal 530 to one or more reactive power conditioners 502.

[0064] In certain embodiments, for example, the disable signal 528 and enable signal 530 may be Boolean signals. In such an embodiment, upon receiving an indication related to communication loss and / or saturation of the field-level controller 226, the system 500 is configured to set the Boolean signal to a true state, wherein the Boolean signal was set to a false state prior to receiving the indication. In an additional embodiment, the Boolean signal remains set to a true state for a predetermined time limit before being automatically reset to a false state. For example, in such an embodiment, the predetermined time limit is less than approximately 100 seconds.

[0065] Therefore, it is still recommended to refer to Figure 6 One or more reactive power regulators 502 are configured to generate an output 534 that may be limited via limiters 504 having defined maximum and minimum values ​​(e.g., VregRefmax and VregRefmin). The output 536 from limiter 504 can then be compared with a power ramp voltage boost value 538 via comparator 512 to generate a voltage command 540. Thus, as shown, the voltage command 540 can be compared with a voltage feedback signal 522 via comparator 514. The output 542 from comparator 514 can then be used by AC voltage regulator 508 with a grid strength signal 544. Accordingly, the output 546 from AC voltage regulator 508 may also be limited via limiters 506 having defined maximum and minimum values ​​(e.g., Vregmax and Vregmin). Therefore, the output from limiter 506 corresponds to a reactive current command 548 for power converter 38.

[0066] Various aspects and embodiments of the present invention are defined by the following numbered clauses: Clause 1. A method for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point, the wind farm being controlled by a field-level controller, each of the multiple wind turbines having a turbine-level controller communicatively coupled to the field-level controller, the method comprising: The system receives, via one or more turbine-level controllers, an indication of at least one of the following: loss of communication between the turbine-level controller and the field-level controller; detection of no reactive power regulation by the field-level controller; or a reactive power command from the field-level controller equal to or higher than a saturation threshold during the transition between a baseline operating mode and a reactive power mode, wherein the reactive power mode is characterized by generating only reactive power; and Upon receiving an instruction, the reactive power response of one or more reactive power regulators of the turbine stage controller is adjusted to avoid overshoot or undershoot reactive power events at the interconnection point.

[0067] Clause 2. The method of Clause 1, wherein adjusting the reactive power response of one or more reactive power regulators of the turbine stage controller further comprises adjusting one or more gains of one or more reactive power regulators or disabling at least one of the feedforward functions of one or more reactive power regulators.

[0068] Clause 3. Any method described in the foregoing clauses, wherein disabling the feedforward function of one or more reactive power regulators further includes: A disable signal is generated via one or more turbine stage controllers to disable the feedforward function of one or more converter controllers of multiple wind turbines; and A disable signal is sent to one or more converter controllers via one or more turbine stage controllers to disable the feedforward function.

[0069] Clause 4. Any method described in the foregoing clauses, wherein a disable signal instructs one or more converter controllers to slow their reactive power response by disabling the feedforward branches of one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

[0070] Clause 5. Any method in the foregoing clauses, wherein the disabled signal includes a Boolean signal, the method further comprising setting the Boolean signal to a true state upon receiving an instruction, wherein the Boolean signal is set to a false state prior to receiving the instruction.

[0071] Clause 6. Any method described in the foregoing clauses, wherein the Boolean signal remains set to true for a predetermined time limit before being automatically reset to false.

[0072] Clause 7. Any method described in the foregoing clauses, wherein the predetermined time limit is less than approximately 100 seconds.

[0073] Clause 8. Any of the methods described in the foregoing clauses further includes at least one of determining communication loss by observing one or more reference communication updates via one or more turbine-level controllers and determining whether reactive power regulation in the field-level controller is disabled or enabled by observing the validity of reactive power commands sent by the field-level controller.

[0074] Clause 9. Any method described in the foregoing clauses further includes determining whether the reactive power command of the field-level controller is equal to or higher than a saturation threshold during the transition between baseline operating mode and reactive power mode by comparing the reactive power command of the field-level controller with the maximum available reactive power at one of the plurality of wind turbines via one or more turbine-level controllers.

[0075] Clause 10. Any of the methods described in the foregoing clauses further includes enabling the feedforward function of one or more reactive power regulators via one or more turbine-level controllers after at least one of communication loss recovery, reactive power regulation in the field-level controller is enabled, or the reactive power command is less than a saturation threshold during the transition between the baseline operating mode and the reactive power mode.

[0076] Clause 11. A system for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point, the system comprising: Field-level controller; Multiple turbine-level controllers communicatively coupled to a field-level controller, each of the multiple turbine-level controllers including at least one processor, the at least one processor being configured to perform operations including: The system receives, via one or more of a plurality of turbine-level controllers, an indication of at least one of the following: loss of communication between one or more of the turbine-level controllers and the field-level controller; detection of no reactive power regulation by the field-level controller; or a reactive power command of the field-level controller being equal to or higher than a saturation threshold during the transition between a baseline operating mode and a reactive power mode, wherein the reactive power mode is characterized by generating only reactive power; and Upon receiving this instruction, the reactive power response of one or more reactive power regulators in one or more of the multiple turbine stage controllers is adjusted to avoid overshoot or undershoot reactive power events at the interconnection point.

[0077] Clause 12. The system of Clause 11, wherein adjusting the reactive power response of one or more reactive power regulators of one or more of the plurality of turbine stage controllers further includes adjusting one or more gains of one or more reactive power regulators or disabling at least one of the feedforward functions of one or more reactive power regulators.

[0078] Clause 13. For systems described in Clauses 11-12, disabling the feedforward function of one or more reactive power regulators further includes: A disable signal is generated via one or more of a plurality of turbine stage controllers to disable the feedforward function of one or more converter controllers of the plurality of wind turbines; and A disable signal is sent to one or more converter controllers via one or more of the multiple turbine stage controllers to disable the feedforward function.

[0079] Clause 14. Systems of Clauses 11-13, wherein a disable signal instructs one or more converter controllers to slow their reactive power response by disabling the feedforward branches of one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

[0080] Clause 15. The system of Clauses 11-14, wherein the disabled signal includes a Boolean signal, the method further comprising setting the Boolean signal to a true state upon receiving an instruction, wherein the Boolean signal is set to a false state prior to receiving the instruction.

[0081] Clause 16. The system of Clauses 11-15, wherein a Boolean signal remains set to true for a predetermined time limit before being automatically reset to false.

[0082] Clause 17. Systems of Clauses 11-16, wherein the predetermined time limit is less than approximately 100 seconds.

[0083] Clause 18. The system of Clauses 11-17, wherein operation further includes determining communication loss by observing one or more reference communication updates via one or more of a plurality of turbine-level controllers and determining whether reactive power regulation in the field-level controller is disabled or enabled by observing the validity of reactive power commands sent by the field-level controller.

[0084] Clause 19. The system of Clauses 11-18, wherein operation further includes determining whether the reactive power command of the field-level controller is equal to or higher than a saturation threshold by comparing the reactive power command of the field-level controller with the maximum available reactive power via one or more of a plurality of turbine-level controllers.

[0085] Clause 20. The system of Clauses 11-19, wherein the operation further includes enabling the feedforward function of one or more reactive power regulators via one or more of a plurality of turbine-level controllers after at least one of communication loss recovery, reactive power regulation in the field-level controller is enabled, or the reactive power command is less than a saturation threshold during the transition between the baseline operating mode and the reactive power mode.

[0086] This written description uses examples to disclose the invention (including the best mode) and also enables any person skilled in the art to practice the invention (including making and using any device or system and performing any incorporated method). The scope of patentability of the invention is defined by the claims and may include other examples that would occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they comprise structural elements that are not different from the literal language of the claims, or if they comprise equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A method for controlling a wind farm having a plurality of wind turbines electrically connected to a power grid at an interconnection point, the wind farm being controlled by a field-level controller, each of the plurality of wind turbines having a turbine-level controller communicatively coupled to the field-level controller, the method comprising: The system receives an indication via one or more of the turbine stage controllers that a communication loss between the turbine stage controller and the field stage controller is received, that no reactive power regulation is detected by the field stage controller, or that the reactive power command of the field stage controller is equal to or higher than a saturation threshold during the transition between a baseline operating mode and a reactive power mode, wherein the reactive power mode is characterized by generating only reactive power. as well as Upon receiving the instruction, the reactive power response of one or more reactive power regulators of the turbine stage controller is adjusted to avoid overshoot or undershoot reactive power events at the interconnection point; The adjustment of the reactive power response of one or more reactive power regulators of the turbine stage controller further includes adjusting one or more gains of the one or more reactive power regulators or disabling at least one of the feedforward functions of the one or more reactive power regulators.

2. The method of claim 1, wherein, Disabling the feedforward function of the one or more reactive power regulators further includes: A disable signal is generated via one or more of the turbine stage controllers to disable the feedforward function for one or more converter controllers of the plurality of wind turbines; and The disable signal is sent to one or more of the turbine stage controllers to disable the feedforward function.

3. The method of claim 2, wherein, The disable signal instructs the one or more converter controllers to slow down their reactive power response by disabling the feedforward branches of the one or more reactive power regulators, thereby effectively providing a smooth reactive power response.

4. The method according to claim 2, wherein, The disabled signal includes a Boolean signal, and the method further includes setting the Boolean signal to a true state upon receiving the instruction, wherein the Boolean signal is set to a false state before receiving the instruction.

5. The method according to claim 4, wherein, Before being automatically reset to the false state, the Boolean signal remains set to the true state for a predetermined time limit.

6. The method according to claim 5, wherein, The predetermined time limit is less than 100 seconds.

7. The method of claim 1, further comprising determining, by observing one or more reference communication updates via one or more of the turbine stage controllers, whether the communication loss is determined to be disabled or enabled by observing the validity of a reactive power command sent by the field stage controller.

8. The method of claim 1, further comprising determining whether the reactive power command of the field-level controller is equal to or higher than the saturation threshold during the transition between the baseline operating mode and the reactive power mode by comparing the reactive power command of the field-level controller with the maximum available reactive power at one of the plurality of wind turbines via one or more of the turbine-level controllers.

9. The method of claim 1, further comprising enabling the feedforward function of the one or more reactive power regulators via one or more of the turbine-level controllers after the communication loss is recovered, the reactive power regulation in the field-level controller is enabled, or the reactive power command is less than at least one of the saturation thresholds during the transition between the baseline operating mode and the reactive power mode.

10. A system for controlling a wind farm having multiple wind turbines electrically connected to a power grid at an interconnection point, the system comprising: Field-level controller; A plurality of turbine-level controllers communicatively coupled to the field-level controller, each of the plurality of turbine-level controllers including at least one processor, the at least one processor being configured to perform the method according to any one of claims 1 to 9.

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