Yaw system for yaw control based on control signals
By introducing a controller and an independent brake power supply into the yaw control system of a wind turbine, the impact of grid changes on the yaw system was resolved, achieving stability and durability of the yaw system and ensuring the reliability of the yaw function.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- VESTAS WIND SYSTEMS AS
- Filing Date
- 2021-05-06
- Publication Date
- 2026-07-28
AI Technical Summary
Existing wind turbine yaw systems cannot effectively control changes in grid voltage and frequency, leading to unstable yaw motor torque, which may cause overload or wear and affect yaw capability.
By introducing a controller into the yaw control system, the yaw function is selectively delayed using grid condition signals, and an independent power supply is provided to the brake to ensure proper disengagement during extreme voltage changes, thus avoiding braking torque interference.
It improves the stability and durability of the yaw system, reduces wear on the yaw motor and brake, and ensures reliable operation of the yaw system when the power grid changes.
Smart Images
Figure CN115836158B_ABST
Abstract
Description
Technical Field
[0001] This invention generally relates to wind turbines and yaw control of such wind turbines. Background Technology
[0002] Modern utility-scale wind turbines are typically equipped with an active yaw control system. This system moves the nacelle of the wind turbine and ensures that the nacelle and rotor face the wind during power generation. This ensures efficient use of the wind turbine based on wind conditions.
[0003] Common types of active yaw control systems involve the use of electro- or hydraulic drive systems with multiple active actuators coupled to the nacelle of the wind turbine to move the nacelle at an angle relative to the tower in an azimuth angle. Typically, the nacelle is mounted on the tower via roller or sliding yaw bearings to allow for smooth yaw. A yaw braking system may also be provided to hold the nacelle at a specific azimuth angle position. Each yaw actuator may individually include a yaw motor, and the motors collectively drive gear elements for nacelle movement. Multiple yaw actuators, typically mounted to the nacelle with corresponding motors and output gear elements, are positioned to mesh with a large gear or geared drive typically mounted to the tower. The actuators may be arranged around the bottom of the nacelle to operate together under the guidance of a yaw controller to provide the desired yaw control. Typically, the motors of the yaw actuators may be equipped with electro-mechanical brakes.
[0004] Active yaw control systems are controlled by a suitable controller, which may be, for example, part of a larger wind turbine control system. The controller's task is to operate various yaw actuators and move the nacelle to a commanded yaw position, or to move the nacelle to maintain zero heading relative to the relative wind direction. Yaw control implemented by the controller typically operates based on the variable nature of the wind to cope with changing wind conditions, while keeping the activation of the yaw actuators at an acceptable level to minimize wear. Furthermore, external conditions other than wind variations are also considered for wind turbine control.
[0005] For example, to ensure a stable power grid, wind turbines must comply with national grid compliance requirements. One of those requirements stipulates that wind turbines must cease power generation when specific voltage and frequency changes occur in the grid. These voltage changes can range from -20% to +36% of the nominal voltage. Typically, more extreme changes last for shorter periods, such as seconds or sometimes minutes.
[0006] For continuous operation in response to grid changes, actual voltage variations can be as high as + / - 13%. For example, Table 1 is an exemplary table of grid change compliance parameters used to control the power generation of a wind turbine experiencing changing grid conditions.
[0007] Exceeding +36% for a maximum of 0.15 seconds
[0008] +25% to +36% for a maximum of 2 seconds
[0009] +16% to +25% for a maximum of 60 seconds
[0010] +13% to +16% for a maximum of 1800 seconds
[0011] +13% to -13% persistent
[0012] -13% to -15% (maximum 180 seconds)
[0013] -15% to -20% (maximum 12 seconds)
[0014] Table 1
[0015] Besides wind turbine operational compliance, variations in grid voltage and frequency can also adversely affect the operation of yaw control systems, particularly the yaw drive. In wind turbines with yaw drives or drive systems using electric yaw drives (such as asynchronous induction motors), the motors are typically supplied with power directly affected by these grid voltage and frequency variations. Yaw motors are also usually equipped with electromechanical brakes. These yaw brakes require power to disengage their braking function. Such power for the brakes is typically fed directly from the motor junction box as AC or DC power via a rectifier. Therefore, the motor brakes are also affected by grid variations.
[0016] Typically, electric motors and their brakes are designed to operate within a voltage variation range of + / -10%. Outside this range, they may not function properly. For example, an electric motor may be able to withstand short bursts of overvoltage, but in overvoltage situations, due to the higher torque of the yaw motor, there is a risk of yaw system overload during gusts. Conversely, in the case of undervoltage supply involving the yaw system, there is a risk of insufficient yaw capability due to the lower torque output of the yaw motor.
[0017] Furthermore, another problem arising in power variation scenarios is that many yaw motor brakes will fail to disengage properly under voltage variations below -10%. As a result, in the worst-case scenario, a large portion of the generated yaw motor torque will be used to overcome the braking torque from the improperly disengaged brakes. This leads to a significant reduction in the system's yaw capability. The improperly disengaged brakes will wear prematurely when driven by the yaw motor. Furthermore, the yaw motor and the rest of the yaw system may be overloaded in this situation.
[0018] Therefore, there is a need for improved systems and methods that can detect changes in the power grid associated with wind turbines and operate and control the yaw system based on the detected changes. Summary of the Invention
[0019] In one embodiment of the invention, the wind turbine includes a nacelle mounted on a tower to provide power to the power grid. The wind turbine has a yaw system with one or more yaw motors operable to provide yaw functionality to the wind turbine and to move the nacelle about the tower. A controller is coupled to the yaw system for controlling the operation of the yaw motors during the yaw function. A control signal reflecting grid conditions is provided to the controller, and the controller is configured to evaluate the control signal and selectively delay the yaw function for a period of time based on the control signal, and to continue the yaw function after the delay period. For example, the controller can use a suitable range of grid variations (such as voltage or frequency) for performing the yaw function. The controller compares the control signal to the range of grid variations and selectively delays the yaw function based on the comparison. If the control signal is outside the range of grid variations, the yaw function may be delayed. This delay may be a time delay.
[0020] In one embodiment, the controller is also configured to periodically compare the control signal with the range of grid variation over time when it determines that the control signal is outside the range of grid variation. If the control signal indicates that grid conditions are within acceptable limits, this allows the yaw function to continue.
[0021] In another embodiment, even if the control signal indicates that the grid conditions are not within acceptable limits, a time delay can be used to perform the yaw function if sufficient time has elapsed. For this purpose, the controller can use a time limit and is configured to determine whether the delay of the yaw function exceeds the time limit, and if the delay exceeds the time limit, the yaw function will continue.
[0022] In another embodiment, the yaw system includes one or more brakes for interacting with a yaw motor and a separate power supply for the brakes. A controller uses a brake control signal that reflects the power supply for the brakes. The controller is configured to evaluate the brake control signal and selectively delay the yaw function based on the brake control signal. For example, the brake control signal may reflect whether the brake power supply is operational. If the brake power supply is not operational, the yaw function is selectively delayed. Attached Figure Description
[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the embodiments of the invention.
[0024] Figure 1This is a perspective view of an exemplary wind turbine according to an embodiment of the present invention, the wind turbine including a nacelle and a rotor.
[0025] Figure 2 yes Figure 1 A partial front view of a portion of the rotor, showing the blades attached to the rotor hub.
[0026] Figure 3 It is used for Figure 1 A cross-sectional view of a portion of the yaw system of a wind turbine.
[0027] Figure 3A It is used for Figure 1 A perspective view of the various yaw drive components of the yaw system of a wind turbine.
[0028] Figure 3B Is it like this? Figure 3A A perspective view of the yaw motor and braking element of the exemplary yaw drive shown.
[0029] Figure 4 This is a schematic diagram of a yaw control system used to control the yaw motor to provide yaw function in a wind turbine.
[0030] Figure 5 This is a schematic diagram of an exemplary wind turbine control system that implements a yaw control system.
[0031] Figure 6 This is a schematic diagram of an exemplary wind turbine control system that implements a yaw control system according to an embodiment of the present invention.
[0032] Figure 7 This is a flowchart of a yaw control system according to an embodiment of the present invention. Detailed Implementation
[0033] Figure 1 An exemplary wind turbine 10 capable of yaw control according to an embodiment of the present invention is illustrated. The wind turbine 10 includes a tower 12, a nacelle 14 disposed at the apex of the tower 12, and a rotor 16 of a generator operatively coupled to the nacelle 14. In addition to the generator, the nacelle 14 typically houses various components necessary for converting wind energy into electrical energy, as well as for operating and optimizing the performance of the wind turbine 10. The tower 12 supports the loads presented by the nacelle 14, the rotor 16, and other wind turbine components housed within the nacelle 14. The nacelle 14 rotates clockwise and counterclockwise about the tower 12 under the control of a yaw system as discussed herein. The tower 12 of the wind turbine 10 elevates the nacelle 14 and the rotor 16 to a height above ground level, allowing the rotor 16 to rotate freely and at which airflow has lower turbulence and higher velocity.
[0034] The rotor 16 includes a hub 18 and one or more (e.g., three) blades 20 attached to the hub 18 at circumferentially distributed locations around it. The blades 20 project radially outward from the hub 18 and are configured to interact with the passing airflow to generate a rotational force that causes the hub 18 to rotate about its longitudinal axis. This rotational energy is transmitted to a generator housed within the nacelle 14 and converted into electrical energy. To optimize the performance of the wind turbine 10, the pitch of the blades 20 is adjusted by a pitch control system in response to wind speed and other operating conditions.
[0035] Figure 2 A perspective view is presented showing the nacelle 14 partially cut open or disassembled to expose the structures housed within. A main shaft extending from the rotor 16 into the nacelle 14 is held in place by a main bearing support 32, which supports the weight of the rotor 16 and transfers the load on the rotor 16 to the tower 12. The main shaft is operatively coupled to a gearbox 34 that transmits its rotation to a generator 36. The electrical energy generated by the generator 36 can be supplied to a power grid (not shown) or an energy storage system (not shown) for later release to the grid, as understood by those skilled in the art. The yaw system of the present invention, as discussed herein, moves the nacelle, enabling efficient generation of electricity based on wind conditions. In this way, the wind turbine 10 can utilize the kinetic energy of the wind to generate electricity. The nacelle 14 may also house other equipment (not shown) for operating the wind turbine 10, such as hydraulic pumps, hydraulic accumulators, cooling systems, controllers, sensors, batteries, communication equipment, etc.
[0036] The weight of the nacelle 14, including the components housed therein, can be supported by a load-bearing structure 38. The load-bearing structure 38 may include the outer shell of the nacelle 14 and one or more additional structural components (such as frames or latticework), as well as a gear housing that operatively connects the load of the nacelle 14 to the tower 12 via a yaw bearing 42. (See also...) Figure 3 The yaw bearing 42 is configured to allow the nacelle 14 to rotate for air intake and exhaust via the yaw system. The hub 18 may accommodate at least a portion of the pitch system, which includes one or more pitch actuators, each including an actuator (e.g., a hydraulic cylinder, an electric actuator, a mechanical actuator, etc.) configured to provide pitch force and, as needed, rotate the position or pitch of the corresponding blade 20 about the pitch bearing 22 of the rotor 16.
[0037] Figure 3 The illustration shows a cross-sectional view of the yaw system 40 used to adjust the cabin yaw. (Refer to...) Figure 3 The nacelle 14 is rotatably supported on the yaw gear 41, which itself is supported at the top of the tower 12. For ease of illustration, the nacelle 14 is... Figure 3The nacelle is shown as a single representative block, but in reality, it is a much larger structure, as will be understood by those skilled in the art. The yaw gear 41 includes a yaw bearing 42 on which the nacelle 14 is mounted, thus enabling it to rotate about the tower 12 and the gear 41. The yaw bearing 42 can be any type of bearing suitable for this high-load application; for example, a sliding yaw bearing or a roller yaw bearing can be used, both of which are well known to those skilled in the art.
[0038] The rotational movement of the nacelle is driven by one or more yaw drives or drive actuators 44. For simplicity, Figure 3 Only a single drive 44 is shown, but several drives are typically provided to deliver the high levels of torque required to rotate the nacelle mass. For example, Figure 3A An example of multiple yaw actuators 44 arranged in a circular pattern around a yaw gear 41 is illustrated. Each yaw actuator 44 may include a yaw motor component 46 that can be mounted to the nacelle. For example, the yaw actuator 44 may be mounted on a major structural component such as the nacelle floor or underframe. The yaw actuator also includes a yaw gear or pinion 48 that meshes with the gear teeth 50 of the yaw gear 41 for yaw control. A portion of the transmission in the yaw gear 48 of the yaw actuator will include a suitable reduction gear to convert the high-speed rotation of the yaw motor component 46 into a low-speed rotation of the yaw gear 41. Typically, the yaw motor 46 will be an AC motor, and the reduction gear will allow the nacelle to take several minutes to complete one full revolution on the tower.
[0039] The yaw drive 44 also includes a brake 52, which is an electromechanical brake for providing braking functionality to the yaw drive 44. The brake 52 operates to provide braking to the yaw motor 46 or to maintain inertial loads during operation. In one embodiment, the brake 52 is a de-energized brake that applies braking to the motor to create an inertial load when no power is applied. When power is applied, the braking force or function is removed, and the yaw motor 46 and the coupled yaw gear 48 are free to rotate. The brake 52 can also prevent nacelle rotation by providing a torque in the opposite direction to the rotational torque exerted due to wind forces.
[0040] Additional braking systems can be implemented for nacelle braking if necessary. For example, a wind turbine can utilize a yaw system including a mechanical yaw brake 60, such as... Figure 3As shown. The yaw brake 60 includes a braking surface provided by a brake ring or disc 62 associated with the tower 12 and one or more brake calipers 64 associated with the nacelle 14. The brake calipers 64 can act in a normally compliant manner to apply braking force to the brake ring 62 in order to hold the nacelle 14 in a position where torque is removed from the yaw actuator 44. This mechanical yaw brake 60 can be hydraulically or electrically driven. In other embodiments, the yaw system does not incorporate a yaw brake 60 and relies on brake 52.
[0041] In one exemplary embodiment of the invention, the yaw system 40 is combined with a yaw control system 66 to provide monitoring and control of the activity of the yaw drive 44 based on power grid conditions. (See reference) Figure 3 The yaw control system 46 may include a yaw controller 70 and a wind direction sensor 72. It should be noted that the yaw controller 70 may be implemented as follows: Figure 4 The image shows a portion of the main wind turbine controller. Figure 4 This is a schematic diagram of an exemplary yaw control system 66, illustrating a wind turbine controller 80 and an optional separate yaw controller 70. Specifically, the yaw controller 70 can be implemented as a dedicated or separate controller, including the processing power, memory, and input / output functions required to implement the present invention. Alternatively, the yaw control / controller and its functions according to the present invention can be implemented as part of the main wind turbine controller or control unit 80. Therefore, the present invention is not limited to the physical location of the necessary yaw controller in the wind turbine, and thus controllers 70, 80 are referred to as addressing various situations.
[0042] Wind sensor 72 provides relative wind direction measurements to yaw controllers 70 and 80, and yaw controllers 70 and 80 in turn provide control signals 73 to each of the yaw actuators 44. The yaw system 40 may also incorporate a monitoring system (such as position sensor 74) for determining the position of the yaw gear. (Reference) Figure 4The wind turbine controller 80 or a separate yaw controller 70 is connected to the power grid 104 to obtain one or more control signals 105 reflecting the grid conditions. For example, the control signals 105 may include information or data about grid voltage or frequency conditions and changes. Drive control signals are provided by controllers 70, 80 to the linked drive 44. Typically, the yaw motor 46 will be operable to run at a single speed, so the control signal 73 will therefore activate the yaw drive and motor with an ON signal to make them run at a single speed and clockwise (CW) or counterclockwise (CCW), or activate the yaw drive and motor with an OFF or STOP control signal to deactivate the yaw drive. It should be noted that while single-speed yaw is common, a system may also use more than one yaw speed, and a system may also use a variable yaw speed depending on operating conditions.
[0043] Figure 5 The illustration shows a schematic diagram of a larger exemplary control system 90 that can be used to control a wind turbine 10. The control system 90 can be configured to implement embodiments of the invention to achieve desired yaw control. The control system 90 includes a wind turbine controller 80 communicating with a wind sensor 72, a pitch system 94, and a yaw system 40 coupled to a nacelle 14 (e.g., Figure 3 (as shown) and a supervisory controller 92. The supervisory controller 92 can be configured to implement a system-wide control strategy for a group of wind turbines 10 (e.g., a wind farm), which optimizes the collective performance of the wind turbines 10, such as maximizing the power production of the group of wind turbines and minimizing overall maintenance. The yaw system 40 can be controlled by the wind turbine controller 80 or by a separate yaw controller 70 to control the direction in which the nacelle 14 is pointed. As is known for wind turbine control, the pitch system 94 can be configured to collectively or independently adjust the pitch of the blades 20 in response to pitch command signals received from the wind turbine controller 80. Controllers 70, 80 use data from the power grid 104 for yaw control according to the invention.
[0044] According to one aspect of the invention, the yaw system monitors power grid conditions (such as grid voltage or frequency conditions) and provides control of the yaw function based on the determined grid voltage and / or frequency conditions. More specifically, the yaw system selectively delays or prevents yaw under extreme voltage and frequency conditions to ensure more appropriate and accurate yaw function and to ensure proper operation of various components (particularly the drive motor of the yaw system). Specifically, refer to... Figure 6The illustration shows a yaw control system 40a for implementing an embodiment of the present invention. The components of the control system 40a for controlling the yaw function of the wind turbine 10 use similar reference numerals (such as controllers 70, 80) where applicable, as those used in the yaw system described herein. The yaw control system 40a incorporates a power supply (represented as system power supply 100) suitable for powering various components. The wind turbine may also have a backup power supply 102, which can be used to operate the wind turbine and yaw system 40a in the absence of system power supply 100.
[0045] According to one feature of the invention, the system power supply 100 or the backup power supply 102 may be connected to the wind turbine controller 80 or the yaw controller 70, depending on the location where the functions of the invention are implemented. As described above, the invention can be implemented through the operation of the wind turbine controller or through the separate yaw controller 70. Figure 6 The illustration shows the control of various yaw motors 46 via a separate yaw controller 70; however, those skilled in the art will understand that if the yaw controller functionality is implemented in the wind turbine controller, then such yaw motors 46 can also be directly connected to the wind turbine controller 80 for control.
[0046] According to one feature of the invention, such as Figure 5 As shown, the yaw system 40a is connected to the power grid 104 to receive control signals and various data from the power grid. Specifically, one or more power grid sensors 106 can be configured as follows: Figure 6 As illustrated, one or more control signals 108 are provided to reflect grid conditions such as grid voltage or grid frequency, in order to control the yaw function based on changing grid conditions. A grid sensor 106 and the corresponding control signal 108 can be provided to the wind turbine controller. In various systems, the wind turbine controller is typically coupled to the grid to receive such data and / or control signals based on grid conditions.
[0047] In one embodiment of the invention, if a mains voltage is sensed and sensor 106 indicates that mains conditions are changing and therefore the mains conditions and changes may be outside an acceptable range, the yaw function can be selectively delayed. Sensor signals or other signals reflect mains conditions, such as the mains voltage, and one or more signals are provided to a controller, which can then evaluate the signal. That is, controllers 70, 80 can evaluate the mains condition signal or other signal and will selectively delay the yaw motor 46, and yaw will not occur when the mains condition is present. The mains condition signal or other control signal can be compared to the range of mains changes in mains operation, and if the signal is outside the range of mains changes, the yaw function can be delayed. In particular, if the mains voltage is outside the acceptable range for yaw according to the invention, the yaw can be selectively delayed for a few seconds based on control signal 108 (such as the sensed voltage), or it can be delayed for up to a few minutes. In one embodiment of the invention, the yaw can be selectively delayed for a preset delay time. An acceptable operating range for mains voltage according to the invention can be between -13% and +16%. However, those skilled in the art will understand that such an acceptable range can vary reasonably based on the specific components of the wind turbine and the yaw system.
[0048] According to one aspect of the invention, a maximum time limit (such as a maximum of 180 seconds) can be used for the delay of the yaw function. For example, when it is determined that the control signal is outside the range of grid variation, the controller can be further configured to periodically compare the control signal with the range of grid variation over time and determine whether the delay of the yaw function exceeds the time limit. If the delay exceeds the time limit or after such a maximum time limit has passed, the yaw function can be resumed, even if the sensed control signal 108 is still outside the acceptable range. To delay the yaw function, the various yaw motors 46 will not be powered through the wind turbine controller 80 or the yaw controller 70, or more precisely, will receive a stop control signal.
[0049] According to another feature of the invention, the braking element 52 of the yaw system is separate from the power grid or other power system 100, 102 used to supply power to the yaw system. Specifically, the yaw control 40a (e.g., Figure 6(As shown) A separate brake power supply 110 is provided for the brake 52 of each of the yaw motors 46. Specifically, the brake 52 is powered independently of the system power supply or grid power supply that can be used to power the various yaw motors 46. In one embodiment of the invention, the brake 52 is powered separately by a common regulated power supply 110 (such as, for example, a 24-volt DC power supply). This regulated power supply 110 will be able to maintain the voltage power signal to the brake 52 within a stable range of approximately + / -10% for controlling the brake during extreme voltage changes on the grid. In that way, the invention ensures that the brake will properly disengage during extreme grid voltage changes. Therefore, the motor torque used to provide the yaw function will not have to overcome the braking torque as in current systems (where the braking function is adversely affected by grid changes). This results in improved yaw capability and a longer wear life for the brake 52 and the yaw motors 46. Furthermore, the various other components of the yaw motors and yaw system will not be overloaded.
[0050] Those skilled in the art will understand that other stable power supplies can be implemented. Furthermore, the + / -10% range can also be adjusted based on the operating characteristics of the brake 52. For example, a larger or smaller voltage stability range can be used.
[0051] According to another feature of the invention, the yaw control system including yaw controllers 70, 80 is configured to control the yaw function based on the ability to provide sufficient braking. A brake control signal 112 reflecting the power supply 110 is provided to the controllers 70, 80. For example, signal 112 may reflect whether the brake power supply is operating. For this purpose, the brake power supply 110 is coupled to the yaw controllers 70, 80 via appropriate connections to provide the brake control signal 112. The appropriate controllers 70, 80 monitor or evaluate the brake power supply 110 and / or the control signal 112 or other data regarding the operation of the braking element 52 associated with the yaw function. Based on this evaluation, such as determining that the brake power supply 110 is not operating, the yaw controllers 70, 80 will selectively delay the yaw function and prevent the yaw motor 46 from operating.
[0052] Therefore, the yaw control system of the present invention, whether via the wind turbine controller 80 or the separate yaw controller 70, will monitor grid conditions (such as via control signal 108) and will also monitor yaw components (such as via brake power supply 110 and control signal 112) to make a decision about when the yaw function is appropriate or whether it should be delayed. The present invention selectively delays yaw in situations where extreme voltage and frequency scenarios may occur. Furthermore, if the brake 52 malfunctions, such as in the event of a failure in brake power supply 110, the yaw function can be selectively delayed or otherwise prevented.
[0053] and Figure 6 The diagram illustrates system 40a, which incorporates a controller that senses the mains voltage for actuation of the yaw function and a separate brake power supply for the yaw motor brake, each of which can be implemented independently. For example, if brake 52 is not operated via a separate brake power supply 110, control of the yaw function can still be achieved through yaw controllers 70, 80 to utilize an acceptable range of mains voltage variations for the brake. For instance, if the brake fails to disengage properly at voltages below -10% and the brake is powered by the mains, the acceptable range in which yaw controllers 70, 80 operate will be taken into account. For example, an acceptable limit for mains voltage variation could then be set between -10% and +10% or some other upper limit, as long as the mains voltage variation does not continue to fall below the operating voltage at which brake 52 would be damaged.
[0054] Furthermore, embodiments of the present invention can monitor only the brake power supply 110 that affects or delays the yaw function, independently of changes in the power grid.
[0055] In some cases, such as Figure 6 As shown, the backup power unit 102 can be connected to various components, including the wind turbine controller 80 shown or a separate yaw controller 70. The backup power system 102 can be an external backup generator.
[0056] As will be understood by those skilled in the art, the wind turbine controller 80 or controller 70 described herein will include the necessary elements (such as a processor and memory) for running a control program to implement the present invention. Such memory may, for example, store suitable ranges of grid variations to which control signals 105, 108 from the grid can be compared to see if the yaw function should be delayed as described herein. For example, certain acceptable operating ranges reflecting variations with nominal grid parameters (such as grid voltage) may be stored for comparison with one or more control signals in a control scheme. As discussed herein, an exemplary range may be -13% to +16% of the nominal grid voltage for evaluating whether the yaw function should be executed or delayed. Other ranges may also be used.
[0057] Figure 7 An embodiment of the program flow of the yaw controllers 70 and 80 according to an embodiment of the present invention is illustrated. When the yaw control system issues a yaw command, power grid conditions can be assessed, and the protocol can begin at block 120. Figure 7 In the illustrated embodiment, the voltage is evaluated. However, the grid frequency can also be evaluated based on control signal 108 and compared with a suitable range or other metric.
[0058] refer to Figure 7 At block 122, a determination is made regarding whether the mains voltage is within an acceptable range. Control signals 108 received by controllers 70 and 80 can be evaluated. For example, based on the sensed mains voltage, it can be evaluated or tested by comparing it to a range (as described above, such as -13% to +16% of the nominal mains voltage). If the mains voltage is not within this range or is outside this range, the yaw function can be delayed at 126 and the controller will not operate the yaw motor to move the nacelle. The comparison of the control signals with suitable condition ranges can be performed periodically. For example, based on loop path 127, the system can periodically or cyclically check the mains voltage relative to an acceptable range. Once the mains voltage is within an acceptable range, the yaw function can, for example, follow path 129 and can continue at 130, as discussed herein.
[0059] In one embodiment of the invention, a time limit for the yaw function delay can be implemented. If the time limit function is implemented, after determining at 122 that the grid voltage is outside the acceptable range, it can be further determined at 124 whether the time limit has elapsed. If the time limit has not been reached, the yaw function delay will be implemented at 126. As the control loop for the yaw function delay continues in loop 127, the time limit can be continuously checked if the grid voltage remains outside the acceptable range. If the time limit has been reached or a set amount of time has elapsed, the yaw function can continue at 126, even if the grid voltage is outside the acceptable range. Figure 7 As shown.
[0060] If the grid voltage is within an acceptable range, i.e., "yes" at 122, the yaw function can continue at 130, such as via the indicated path 129. In an alternative embodiment of the invention, the brake can be provided by, for example... Figure 6 The independent brake power supply 110 shown is powered, and the power supply can be monitored. In this case, controllers 70 and 80 can be configured to determine the operating state of the independent brake power supply, even if the mains voltage is acceptable or within an acceptable range. (Reference) Figure 7 At block 128, controllers 70 and 80 can check the brake power supply. If the brake power supply is operational, the yaw function can continue at 130. However, if the brake power supply is not operational, the yaw function can be delayed at 126.
[0061] In an alternative embodiment of the invention incorporating a separate brake power supply for brake 52, the functions of controllers 70, 80 and the evaluation of the brake power supply at block 128 can occur independently in a control flow separate from the evaluation of power grid changes. In that case, the function of the brakes through their power supply can be evaluated at 128 before the yaw command or function is executed, such as evaluating the control signal 112 reflecting power supply 110. If the power supply is not operating, as reflected by control signal 112, the brakes will not have power. In this case, the yaw function can be delayed at 126. Those skilled in the art will understand that... Figure 7 If necessary, the function can be implemented in controllers 70 and 80 to achieve the control of the mentioned yaw function.
[0062] Therefore, the invention, in its broader aspects, is not limited to the specific details, representative devices and methods, and the illustrative examples shown and described. Thus, deviations from these details may be made without departing from the spirit or scope of the applicant's general inventive concept.
Claims
1. A wind turbine (10) comprising a nacelle (14) mounted on a tower (12) to supply power to a power grid (104), the wind turbine (10) comprising: A yaw system including at least one yaw motor (46) operable to provide yaw function to the wind turbine (10) and move the nacelle (14) about the tower (12); A controller (70, 80) is connected to the yaw system to control the operation of the at least one yaw motor (46) in the yaw function; Control signals (108) reflecting the grid conditions of the grid (104) are provided to the controllers (70, 80). The controllers (70, 80) are configured to evaluate the control signal (108) and selectively delay the yaw function based on the control signal (108), and continue the yaw function after the delay period expires. The yaw system further includes at least one brake (52) for braking the at least one yaw motor (46) and a separate power supply (110) for the at least one brake. A brake control signal (112) reflecting the power supply for the at least one brake is provided to the controller (70, 80). The controllers (70, 80) are also configured to evaluate the brake control signal (112) and selectively delay the yaw function based on the brake control signal (112), and The brake control signal (112) reflects whether the power supply (110) is operating, and The controllers (70, 80) are also configured to evaluate the brake control signal (112) and selectively delay the yaw function if the power supply (110) is not operating.
2. The wind turbine (10) according to claim 1, wherein, The controllers (70, 80) include a range of grid variations associated with the grid (104), and the controllers (70, 80) compare the control signal (108) with the range of grid variations and selectively delay the yaw function based on the comparison.
3. The wind turbine (10) according to claim 2, wherein, If the control signal (108) is outside the range of the power grid variation, the yaw function is delayed.
4. The wind turbine (10) according to any one of claims 1-3, wherein, The control signal (108) provided to the controller (70, 80) reflects the grid voltage of the power grid (104).
5. The wind turbine (10) according to any one of claims 1-3, wherein, The controllers (70, 80) are also configured to periodically compare the control signal (108) with the power grid variation range over time when they determine that the control signal (108) is outside the power grid variation range.
6. The wind turbine (10) according to any one of claims 1-3, wherein, The yaw function is selectively delayed by a preset delay time.
7. The wind turbine (10) according to any one of claims 1-3, wherein the controller (70, 80) includes a time limit, and the controller (70, 80) is configured to determine whether the delay of the yaw function exceeds the time limit, and if the delay exceeds the time limit, to continue the yaw function.
8. A method for controlling a wind turbine (10) having a nacelle (14) mounted on a tower (12) to supply power to a power grid (104), the method comprising: The operation includes a yaw system comprising at least one yaw motor (46) operable to provide yaw function to the wind turbine (10) and to move the nacelle (14) about the tower (12); Provide control signals (108) that reflect the grid conditions of the power grid (104); The control signal (108) is evaluated and the yaw function is selectively delayed based on the control signal, and the yaw function continues after the delay period expires. The yaw system further includes at least one brake (52) for interacting with the at least one yaw motor (46) and a separate power supply (110) for the at least one brake. The method further includes: providing a brake control signal (112) reflecting the power supply (110) for the at least one brake; evaluating the brake control signal (112); and selectively delaying the yaw function based on the brake control signal (112). The brake control signal (112) reflects whether the power supply (110) is operating. The method also includes evaluating the brake control signal (112) and selectively delaying the yaw function if the power supply (110) is not operating.
9. The method according to claim 8, further comprising: The control signal (108) is compared with the range of grid changes, and if the control signal (108) is outside the range of grid changes, the yaw function is selectively delayed.
10. The method of claim 9, further comprising: When it is determined that the control signal (108) is outside the range of the power grid variation, the control signal (108) is compared with the range of the power grid variation periodically over time.
11. The method according to any one of claims 8-10, further comprising: The controllers (70, 80) include a time limit, and the controllers (70, 80) are configured to determine whether the delay of the yaw function exceeds the time limit, and if the delay exceeds the time limit, to continue the yaw function.
12. A controller (70, 80) for controlling the yaw function of a wind turbine (10), the wind turbine (10) including a nacelle (14) mounted on a tower (12) to supply power to a power grid (104), and a yaw system including at least one yaw motor (46) operable to move the nacelle (14) about the tower (12), the controller (70, 80) being configured to: The operation of the at least one yaw motor (46) is controlled in the yaw function to move the cabin (14). Receives control signals (108) reflecting the grid conditions of the power grid (104); and The control signal (108) is evaluated, and the yaw function is selectively delayed based on the control signal (108), and the yaw function continues after the delay period expires. in, The controllers (70, 80) are also configured to: Receives a brake control signal (112) reflecting the power supply of at least one brake (52) for braking the at least one yaw motor (46), and Evaluate the brake control signal (112) and selectively delay the yaw function based on the brake control signal (112), and The brake control signal (112) reflects whether the power supply (110) is operating, and the controllers (70, 80) are also configured to evaluate the brake control signal (112) and selectively delay the yaw function if the power supply (110) is not operating.