Hub system limit load control method and system under single-blade stall condition

Abstract

The application discloses a kind of single-blade card paddle working condition under wheel hub system limit load control method and system, this method is when wind turbine generator set normal operation detects whether blade is in card paddle state, when detecting card paddle failure, shutdown action is carried out, wind turbine generator set first enters load dynamic balance control mode, then calculates the current yaw error in shutdown process, yaw control is carried out to wind turbine generator set based on yaw error, so that wind turbine generator set is far away from directly facing wind direction, reduce the wind load of wind turbine generator set, and then reduce generator speed, when the load of wheel hub system of wind turbine generator set is less than preset threshold, wind turbine generator set carries out unified variable pitch rate feathering control, so that the load of wheel hub system meets design requirement, improve the safety of unit, and then reduce the design cost of wheel hub system.

Description

Technical Field

[0001] This invention relates to the technical field of load control under jammed propeller conditions, and in particular to a method, system, storage medium, and computing device for controlling the ultimate load of a hub system under single-blade jammed propeller conditions. Background Technology

[0002] The loads on wind turbine generators mainly come from gravity, inertial, and aerodynamic loads. These are the primary factors affecting the operating status of wind turbine generators and the basis for their operation control. Loads not only relate to the safety of the generator set but also directly impact the strength of its components.

[0003] As the wind power industry enters the era of grid parity, wind turbine generators are gradually undergoing technological innovation and cost reduction optimization towards larger rotors, longer blades, and lighter towers. From the turbine design and development stage, the operating load is a key factor determining the strength of the turbine's subsystems and components. How to operate the turbine at a lower load level is the foundation for cost reduction and optimization in wind turbine generators.

[0004] Currently, the main design basis for wind turbine generator sets is the IEC standard. This standard evaluates and analyzes various complex operating conditions that the entire machine may encounter. During the overall design phase, it is essential to ensure that the unit meets the load requirements of all extreme and fatigue conditions throughout its service life. However, extreme operating conditions of wind turbine generator sets are generally accompanied by unit failures, such as grid outages, pitch failures, and unit overspeed. Among these pitch failures, there is a condition where a single blade may become stuck. Under this condition, any one of the three blades of the wind turbine generator set may become stuck, causing aerodynamic imbalance among the three blades of the unit. This can easily lead to a sudden increase in load on the yaw system and hub system, thereby affecting the overall operating status of the unit.

[0005] Current jammed propeller conditions typically involve a shutdown operation, but the control methods for the unit during shutdown are complex and varied. Generally, an emergency shutdown is initiated, during which pitch control is applied to the two non-jammed propeller blades. Existing load control technology for jammed propeller conditions uses pitch control based on the pitch motor's current, but this places higher demands on the pitch motor's hardware, increasing its development costs.

[0006] Existing load control technologies for jammed propellers include separate control of non-jammed propeller blades. However, this requires shielding the hardware safety chain of the non-jammed propeller blades, which carries certain risks. When controlling a non-jammed propeller blade separately during a single blade jamming process, it cannot be guaranteed that the non-jammed propeller blade will not trigger a pitch change fault.

[0007] Existing load control technologies for stuck propeller conditions include pitch control based on the fore-and-aft displacement of the nacelle during shutdown, switching the pitch rate at the maximum fore-and-aft displacement in both the positive and negative directions. However, the blade unbalanced load is significant under stuck propeller conditions, and frequent switching of the pitch rate may exacerbate this unbalanced load. Furthermore, the reliability of pitch control depends on the accuracy of the data from the fore-and-aft displacement sensors. Summary of the Invention

[0008] The primary objective of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a safe and reliable method for controlling the ultimate load of the hub system under single-blade jammed propeller conditions. By controlling the pitch of the unjammed propeller blades and the yaw control of the unit, the load on the hub system is reduced, the safety of the unit is improved, and the design cost of the hub system is reduced.

[0009] The second objective of this invention is to provide a hub system ultimate load control system for single-blade impeller jamming conditions.

[0010] A third objective of this invention is to provide a storage medium.

[0011] A fourth objective of this invention is to provide a computing device.

[0012] The first objective of this invention is achieved through the following technical solution: a method for controlling the ultimate load of a hub system under single-blade jamming conditions. This method involves detecting whether the blade is jammed during normal operation of the wind turbine generator set. Upon detection of a jamming fault, a shutdown is initiated. The wind turbine generator set first enters a dynamic load balance control mode. Then, during the shutdown process, the current yaw error is calculated. Based on the yaw error, yaw control is applied to the wind turbine generator set, causing it to move away from the wind direction, reducing the wind load on the wind turbine generator set, and consequently reducing the generator speed. When the load on the hub system of the wind turbine generator set is less than a preset threshold, the wind turbine generator set performs uniform pitch rate feathering control, ensuring that the load on the hub system meets design requirements, thereby reducing the design cost of the hub system.

[0013] Furthermore, the method for controlling the ultimate load of the hub system under single-blade jamming conditions includes the following steps:

[0014] 1) Diagnosis of single-blade jamming fault;

[0015] When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T or when the pitch system communication flag is 0, the wind turbine will report a jamming fault for the corresponding blade; otherwise, there is no single blade jamming fault.

[0016] 2) Load dynamic balance control mode;

[0017] When a jammed blade is detected, the wind turbine is shut down and enters a dynamic load balance control mode. By measuring the load changes in the hub system, the non-jammed blades are adjusted to perform corresponding pitch changes, so that the load in the hub system is in a dynamic balance process.

[0018] 3) Perform yaw control based on yaw error;

[0019] When the wind turbine is in the load dynamic balance mode, the current yaw error of the wind turbine is calculated, and yaw control is performed on the wind turbine based on the yaw error to make the unit move away from the wind direction. When the yaw error of the wind turbine is greater than the preset threshold, the wind turbine stops yawing.

[0020] 4) Wind turbine generator sets with uniform speed feathering;

[0021] During the yaw control process of the wind turbine generator, the load on the hub system gradually decreases. When the load on the hub system is lower than the preset threshold, the non-clamped blades of the wind turbine generator feather at a uniform pitch rate.

[0022] Furthermore, in step 1), under normal operating conditions of the wind turbine generator set, a propeller jamming fault logic judgment is required to monitor whether the three blades of the wind turbine generator set are in a propeller jamming state. When the wind turbine generator set is in normal operating conditions, its pitch system calculates the pitch rate of the three blades. Let the pitch rate of blade 1 be V1, the pitch rate of blade 2 be V2, and the pitch rate of blade 3 be V3. When the pitch rate V1 of blade 1 is less than the propeller jamming rate threshold V1′, blade 1 is in a propeller jamming state. When the pitch rate V2 of blade 2 is less than the propeller jamming rate threshold V2′, blade 2 is in a propeller jamming state. When the pitch rate V3 of blade 3 is less than the propeller jamming rate threshold V3′, blade 3 is in a propeller jamming state. Finally, the pitch system outputs the corresponding pitch system communication flags C1, C2, and C3 of the three blades to the main control PLC. When the communication flag is 1, it indicates that the pitch system communication is normal. When the communication flag is 0, it indicates that the pitch system communication is abnormal.

[0023] Furthermore, in step 2), stress sensors need to be installed at the blade root positions of the three blades, and then the blade root load measured by the stress sensors is transformed to obtain the load in the hub coordinate system, i.e., the hub system load.

[0024] Furthermore, the stress sensor converts the deformation of the strain gauge into a resistance or voltage output with a linear or arbitrary functional relationship. Let the distance from the predetermined root position P1 of blade 1 to the blade root position be X1, the distance from the predetermined root position P2 of blade 2 to the blade root position be X2, and the distance from the predetermined root position P3 of blade 3 to the blade root position be X3. The predetermined root positions P1, P2, and P3 of the three blades are the actual installation positions of the stress sensor. The distances X1, X2, and X3 from the predetermined positions to the blade root positions are the distances from the sensor positions to the blade roots. X1, X2, and X3 need to be calibrated according to the actual site conditions.

[0025] Furthermore, the blade root load measured by the stress sensor needs to be processed through a high-pass filter, and then the hub system load is calculated through coordinate transformation; the coordinate transformation relationship is as follows:

[0026] M hub =cosθ*M y1 +cos(θ+2π / 3)*M y2 +cos(θ+4π / 3)*M y3

[0027] In the formula, M hub M represents the load on the wheel hub system in the Y direction at the center of the wheel hub in the wheel hub coordinate system. y1 M is the root load measured for blade 1. y2 M is the root load measured for blade 2. y3 θ is the blade root load measured for blade 3, and θ is the impeller azimuth angle.

[0028] Furthermore, based on the strength requirements of existing wind turbine components, the corresponding hub system load design threshold Q is obtained. z Based on the wind speed W condition for the single-blade jamming condition described in the IEC standard, determine the maximum load M of the hub system under the wind speed W condition. max According to the load M of the hub system under turbulent wind conditions hub Based on the changing pattern, load control thresholds M for three stages are set. h1 M h2 M h3 The load control thresholds for these three stages are related to the shutdown process time and wind speed during the jamming condition. Different load control thresholds for different stages require different pitch rates. When the wind turbine enters shutdown due to a jamming fault, the hub system load M is calculated based on the current operating state. hub Perform dynamic load balance control when M hub ≤M h1 At that time, the pitch rate of the pitch system is set to V1″, when M h1 <Mhub ≤M h2 At that time, the pitch rate of the pitch system is set to V2″, when M h2 <M hub ≤M h3 At that time, the pitch rate of the pitch system is set to V3″, when M h3 <M hub At that time, the pitch rate of the pitch system was set to V4″.

[0029] Furthermore, in step 3), after the wind turbine generator enters shutdown, it undergoes a dynamic load balancing control process. This process reduces the unbalanced load on the wind turbine generator and extends its shutdown time. After the wind turbine generator stops, the actual on-site yaw rate V is set. yaw During the yaw maneuver, the wind turbine calculates the actual yaw error E. yaw When the wind turbine is facing the wind direction, E yaw The value is 0. When the wind turbine performs a yaw maneuver, the direction of the yaw error is defined according to the yaw direction of the wind turbine. When the yaw error E is 0, the direction of the yaw error is defined as 0. yaw Greater than the yaw error threshold E yawmax At that time, the wind turbine stopped yawing, where the yaw error threshold E yawmax This is the condition for terminating the yaw action of a wind turbine generator.

[0030] Furthermore, in step 4), the wind turbine performs a yaw maneuver. If during or after the yaw maneuver, the calculated hub system load M of the wind turbine... hub Less than M h1 When the wind turbine's non-clamped blades are in a constant pitch rate V1″, they will feather until the wind turbine reaches the feathering angle and stops.

[0031] The second objective of this invention is achieved through the following technical solution: a hub system ultimate load control system for single-blade jamming conditions, used to implement the above-mentioned hub system ultimate load control method for single-blade jamming conditions, comprising:

[0032] The single-blade jamming fault detection module is used to determine whether a single-blade jamming fault exists. When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T or the pitch system communication flag is 0, the wind turbine generator will report the jamming fault of the corresponding blade; otherwise, there is no single-blade jamming fault.

[0033] The load dynamic balance control module is used to execute the load dynamic balance control mode. When a blade jamming fault is detected, the wind turbine generator will shut down and enter the load dynamic balance control mode. By measuring the load changes of the hub system, the non-jammed blades will be adjusted to perform corresponding pitch actions, so that the hub system load is in a dynamic balance process.

[0034] The yaw control module performs yaw control on the wind turbine generator based on the calculated current yaw error of the wind turbine generator, so that the generator moves away from the wind direction. When the yaw error of the wind turbine generator exceeds a preset threshold, the wind turbine generator stops yawing.

[0035] The feathering control module, based on the calculated hub system load, controls the non-clamped blades of the wind turbine to feather at a uniform pitch rate.

[0036] The third objective of this invention is achieved through the following technical solution: a storage medium storing a program, which, when executed by a processor, implements the above-mentioned method for controlling the ultimate load of a hub system under single-blade jamming conditions.

[0037] The fourth objective of this invention is achieved through the following technical solution: a computing device, including a processor and a memory for storing processor-executable programs, wherein when the processor executes the program stored in the memory, it implements the above-mentioned method for controlling the ultimate load of the hub system under single-blade jamming conditions.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] 1. This invention improves the control strategy based on the existing single-blade propeller load control method, without adding requirements to the original yaw system hardware configuration of the unit, thus avoiding increased hardware development costs.

[0040] 2. Regarding the existing load control for propeller jamming conditions, this invention, based on the existing unit hardware configuration, stops the unit after a single blade propeller jamming fault is triggered, and performs pitch control and torque control during the shutdown process, without imposing higher design requirements on the yaw motor.

[0041] 3. Regarding the existing load control for propeller jamming conditions, this invention proposes to first perform dynamic load balancing control after entering shutdown, and then perform yaw control, so that the unit moves away from the wind direction directly in front, which can greatly reduce wind load, thereby reducing generator speed and reducing the ultimate load of the hub system.

[0042] 4. This invention controls the shutdown logic for propeller jamming faults separately, without affecting the shutdown logic for other unit faults. Furthermore, the fault level of propeller jamming faults will not trigger the safety chain fault level, ensuring the safety of the unit and preventing the execution of the highest level shutdown logic.

[0043] 5. Regarding the existing load control for jammed blade conditions, this invention does not affect the pitch fault settings of the safety chain in the main control system. When a single blade jamming fault is triggered, pitch control is performed separately on the non-jammed blades, but it will not affect the triggering of other pitch faults on the non-jammed blades, thus avoiding the impact on the unit's safety chain fault alarm and preventing any impact on the overall safety of the unit.

[0044] 6. This invention performs dynamic load balance control based on the hub system load obtained by coordinate system transformation, avoiding a sudden increase in the unbalanced load of the unit after shutdown, which would lead to a sharp increase in the ultimate load of the hub system and damage the strength of the hub system components. In addition, it can reserve a period of time for the unit's yaw action, avoiding the unit stopping too quickly and thus being unable to reach a large yaw position.

[0045] 7. The present invention adds yaw control logic during the shutdown process, so that the unbalanced load of the unit under high wind speed conditions can be gradually reduced by yaw control, thereby reducing the unbalanced load of the unit. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the method of the present invention.

[0047] Figure 2 This is the timing diagram of the load on hub My.

[0048] Figure 3 This is a time series diagram of wind direction deviation.

[0049] Figure 4 This is a schematic diagram of the coordinate system for the wheel hub system.

[0050] Figure 5 This is an architecture diagram of the system of the present invention. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0052] Example 1

[0053] like Figure 1As shown in the figure, this embodiment discloses a method for controlling the ultimate load of a hub system under single-blade jamming conditions. This method detects whether the blade is jammed during normal operation of the wind turbine generator. When a jamming fault is detected, a shutdown is initiated. The wind turbine generator first enters a dynamic load balance control mode. Then, during the shutdown process, the current yaw error is calculated, and yaw control is applied to the wind turbine generator based on the yaw error, causing the wind turbine generator to move away from the wind direction, reducing the wind load on the wind turbine generator, and thus reducing the generator speed. When the hub system load of the wind turbine generator is less than a preset threshold, the wind turbine generator performs uniform pitch rate feathering control, ensuring that the hub system load meets design requirements, thereby reducing the design cost of the hub system. The method includes the following steps:

[0054] 1) Diagnosis of single-blade jamming fault;

[0055] During normal operation of a wind turbine generator, a pitch jamming fault logic check is required to monitor whether any of the three blades are jammed. When the wind turbine is operating normally, its pitch system calculates the pitch rates of the three blades. Let V1 be the pitch rate of blade 1, V2 be the pitch rate of blade 2, and V3 be the pitch rate of blade 3. When the pitch rate V1 of blade 1 is less than the jamming rate threshold V1′, blade 1 is jammed. Similarly, when the pitch rate V2 of blade 2 is less than the jamming rate threshold V2′, blade 2 is jammed. When the pitch rate V3 of blade 3 is less than the jamming rate threshold V3′, blade 3 is in a jamming state. Finally, the pitch system outputs the corresponding pitch system communication flags C1, C2, and C3 of the three blades to the main control PLC. When the communication flag is 1, it indicates that the pitch system communication is normal. When the communication flag is 0, it indicates that the pitch system communication is abnormal. When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T, or when the pitch system communication flag is 0, the wind turbine reports a jamming fault of the corresponding blade. Otherwise, there is no single blade jamming fault.

[0056] 2) Load dynamic balance control mode;

[0057] When a propeller jamming fault is detected, the wind turbine generator is shut down and enters a dynamic load balance control mode. By measuring the load changes in the hub system, the non-jammed blades are adjusted to perform corresponding pitch changes, so that the hub system load is in a dynamic balance process. In this process, stress sensors need to be installed at the blade root positions of three blades. Then, the blade root load measured by the stress sensors is transformed to obtain the load in the hub coordinate system, i.e., the hub system load.

[0058] The stress sensor converts the deformation of the strain gauge into a linear or arbitrary functional relationship of resistance or voltage output. Let X1 be the distance between the predetermined position P1 of blade 1 and the blade root position, X2 be the distance between the predetermined position P2 of blade 2 and the blade root position, and X3 be the distance between the predetermined position P3 of blade 3 and the blade root position. The predetermined positions P1, P2, and P3 of the three blades are the actual installation positions of the stress sensor. The distances X1, X2, and X3 between the predetermined positions and the blade root positions are the distances from the sensor positions to the blade roots. X1, X2, and X3 need to be calibrated according to the actual site conditions.

[0059] The blade root load measured by the stress sensor needs to be processed through a high-pass filter, and then the hub system load is calculated through coordinate transformation; the coordinate transformation relationship is as follows:

[0060] M hub =cosθ*M y1 +cos(θ+2π / 3)*M y2 +cos(θ+4π / 3)*M y3

[0061] In the formula, M hub M represents the load on the wheel hub system in the Y direction at the center of the wheel hub in the wheel hub coordinate system. y1 M is the root load measured for blade 1. y2 M is the root load measured for blade 2. y3 The blade root load is measured for blade 3, and θ is the impeller azimuth angle. The Y direction refers to the Y direction in the hub coordinate system. Figure 4 As shown, F XN F is the thrust in the direction of the incoming wind speed. YN F is the thrust perpendicular to the direction of the transmission chain. ZN M is the force perpendicular to the XY plane. XN M YN M ZN The bending moment is generated by forces in three directions.

[0062] The corresponding hub system load design threshold Q is obtained based on the strength requirements of existing wind turbine components. z Based on the wind speed W condition for the single-blade jamming condition described in the IEC standard, determine the maximum load M of the hub system under the wind speed W condition. max According to the load M of the hub system under turbulent wind conditions hub Based on the changing pattern, load control thresholds M for three stages are set. h1 M h2 M h3The load control thresholds for these three stages are related to the shutdown process time and wind speed during the jamming condition. Different load control thresholds for different stages require different pitch rates. When the wind turbine enters shutdown due to a jamming fault, the hub system load M is calculated based on the current operating state. hub Perform dynamic load balance control when M hub ≤M h1 At that time, the pitch rate of the pitch system is set to V1″, when M h1 <M hub ≤M h2 At that time, the pitch rate of the pitch system is set to V2″, when M h2 <M hub ≤M h3 At that time, the pitch rate of the pitch system is set to V3″, when M h3 <M hub At that time, the pitch rate of the pitch system is set to V4″. For example... Figure 2 As shown, when the wind turbine enters the shutdown state, the wind turbine enters the load dynamic balance control mode. The load of the hub system will slowly reach the peak value and fluctuate near the peak value to avoid excessive extreme load.

[0063] 3) Perform yaw control based on yaw error;

[0064] After the wind turbine generator enters shutdown, it undergoes a dynamic load balancing control process. This process reduces the unbalanced load on the wind turbine generator and extends the shutdown time. Considering the low yaw rate in the actual field, the dynamic load balancing control in step 2) is a necessary control measure. After the wind turbine generator stops, the actual field yaw rate V is set. yaw During the yaw maneuver, the wind turbine calculates the actual yaw error E. yaw When the wind turbine is facing the wind direction, E yaw The value is 0. When the wind turbine performs a yaw maneuver, the direction of the yaw error is defined according to the yaw direction of the wind turbine. When the yaw error E is 0, the direction of the yaw error is defined as 0. yaw Greater than the yaw error threshold E yawmax At that time, the wind turbine stopped yawing, where the yaw error threshold E yawmax This is the condition for terminating the yaw action of a wind turbine generator. For example... Figure 3 As shown, when the wind turbine starts to yaw, the yaw rate is slow. When the yaw action lasts for 20 seconds, the wind direction deviation of the unit changes significantly. As the yaw action continues, the wind direction deviation continues to increase.

[0065] 4) Wind turbine generator sets with uniform speed feathering;

[0066] When a wind turbine performs a yaw maneuver, if during or after the yaw maneuver, the calculated hub system load M of the wind turbine... hub Less than M h1 When the wind turbine's non-clamped blades are in a constant pitch rate V1″, they will feather until the wind turbine reaches the feathering angle and stops.

[0067] Example 2

[0068] This embodiment discloses a hub system ultimate load control system for single-blade jamming conditions, used to implement the hub system ultimate load control method for single-blade jamming conditions described in Embodiment 1, such as... Figure 5 As shown, the system includes the following functional modules:

[0069] The single-blade jamming fault detection module is used to determine whether a single-blade jamming fault exists. When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T or the pitch system communication flag is 0, the wind turbine generator will report the jamming fault of the corresponding blade; otherwise, there is no single-blade jamming fault.

[0070] The load dynamic balance control module is used to execute the load dynamic balance control mode. When a blade jamming fault is detected, the wind turbine generator will shut down and enter the load dynamic balance control mode. By measuring the load changes of the hub system, the non-jammed blades will be adjusted to perform corresponding pitch actions, so that the hub system load is in a dynamic balance process.

[0071] The yaw control module performs yaw control on the wind turbine generator based on the calculated current yaw error of the wind turbine generator, so that the generator moves away from the wind direction. When the yaw error of the wind turbine generator exceeds a preset threshold, the wind turbine generator stops yawing.

[0072] The feathering control module, based on the calculated hub system load, controls the non-clamped blades of the wind turbine to feather at a uniform pitch rate.

[0073] Example 3

[0074] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, it implements the hub system ultimate load control method under single-blade jamming conditions as described in Embodiment 1.

[0075] The storage medium in this embodiment can be a disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), USB flash drive, portable hard drive, etc.

[0076] Example 4

[0077] This embodiment discloses a computing device, including a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the hub system ultimate load control method under single-blade jamming conditions described in Embodiment 1.

[0078] The computing device described in this embodiment may be a desktop computer, laptop computer, smartphone, PDA handheld terminal, tablet computer, programmable logic controller (PLC), or other terminal device with processor function.

[0079] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for controlling the ultimate load of a hub system under single-blade jamming conditions, characterized in that, This method involves detecting blade jamming during normal wind turbine operation. Upon detection of a jamming fault, a shutdown is initiated. The wind turbine first enters a dynamic load balancing control mode. During shutdown, the current yaw error is calculated, and yaw control is applied based on this error to move the turbine away from the wind direction, reducing wind load and consequently lowering generator speed. Once the hub system load falls below a preset threshold, uniform pitch control is applied to ensure the hub system load meets design requirements, thereby reducing hub system design costs. The method includes the following steps: 1) Diagnosis of single-blade jamming fault; When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T or when the pitch system communication flag is 0, the wind turbine will report a jamming fault for the corresponding blade; otherwise, there is no single blade jamming fault. 2) Load dynamic balance control mode; When a jammed blade is detected, the wind turbine is shut down and enters a dynamic load balance control mode. By measuring the load changes in the hub system, the non-jammed blades are adjusted to perform corresponding pitch changes, so that the load in the hub system is in a dynamic balance process. Stress sensors need to be installed at the blade root positions of the three blades. Then, the blade root load measured by the stress sensors is transformed to obtain the load in the hub coordinate system, i.e., the hub system load. The blade root load measured by the stress sensor needs to be processed through a high-pass filter, and then the hub system load is calculated through coordinate transformation; the coordinate transformation relationship is as follows: M hub =cosθ*M y1 +cos(θ+2π / 3)*M y2 )cos(θ+4π / 3)*M y3 In the formula, M hub M represents the load on the wheel hub system in the Y direction at the center of the wheel hub in the wheel hub coordinate system. y1 M is the root load measured for blade 1. y2 M is the root load measured for blade 2. y3 The blade root load is measured for blade 3, and θ is the impeller azimuth angle. The corresponding hub system load design threshold Q is obtained based on the strength requirements of existing wind turbine components. z Based on the wind speed W condition for the single-blade jamming condition described in the IEC standard, determine the maximum load M of the hub system under the wind speed W condition. max According to the load M of the hub system under turbulent wind conditions hub Based on the changing pattern, load control thresholds M for three stages are set. h1 M h2 M h3 The load control thresholds for these three stages are related to the shutdown process time and wind speed during the jamming condition. Different load control thresholds for different stages require different pitch rates. When the wind turbine enters shutdown due to a jamming fault, the hub system load M is calculated based on the current operating state. hub Perform dynamic load balance control when M hub ≤M h1 At that time, the pitch rate of the pitch system is set to V1″, when M h1 <M hub ≤M h2 At that time, the pitch rate of the pitch system is set to V2″, when M h2 <M hub ≤M h3 At that time, the pitch rate of the pitch system is set to V3″, when M h3 <M hub At that time, the pitch rate of the pitch system is set to V4″; 3) Perform yaw control based on yaw error; When the wind turbine is in the load dynamic balance mode, the current yaw error of the wind turbine is calculated, and yaw control is performed on the wind turbine based on the yaw error to make the unit move away from the wind direction. When the yaw error of the wind turbine is greater than the preset threshold, the wind turbine stops yawing. 4) Wind turbine generator sets with uniform speed feathering; During the yaw control process of the wind turbine generator, the load on the hub system gradually decreases. When the load on the hub system is lower than the preset threshold, the non-clamped blades of the wind turbine generator feather at a uniform pitch rate.

2. The method for controlling the ultimate load of a hub system under single-blade jamming conditions according to claim 1, characterized in that, In step 1), under normal operating conditions of the wind turbine generator set, a propeller jamming fault logic judgment is required to monitor whether the three blades of the wind turbine generator set are in a propeller jamming state. When the wind turbine generator set is in normal operating conditions, its pitch system calculates the pitch rate of the three blades. Let the pitch rate of blade 1 be V1, the pitch rate of blade 2 be V2, and the pitch rate of blade 3 be V3. When the pitch rate V1 of blade 1 is less than the propeller jamming rate threshold V1′, blade 1 is in a propeller jamming state. When the pitch rate V2 of blade 2 is less than the propeller jamming rate threshold V2′, blade 2 is in a propeller jamming state. When the pitch rate V3 of blade 3 is less than the propeller jamming rate threshold V3′, blade 3 is in a propeller jamming state. Finally, the pitch system outputs the corresponding pitch system communication flags C1, C2, and C3 of the three blades to the main control PLC. When the communication flag is 1, it indicates that the pitch system communication is normal. When the communication flag is 0, it indicates that the pitch system communication is abnormal.

3. The method for controlling the ultimate load of a hub system under single-blade jamming conditions according to claim 2, characterized in that, The stress sensor converts the deformation of the strain gauge into a linear or arbitrary functional relationship of resistance or voltage output. Let X1 be the distance between the predetermined position P1 of blade 1 and the blade root position, X2 be the distance between the predetermined position P2 of blade 2 and the blade root position, and X3 be the distance between the predetermined position P3 of blade 3 and the blade root position. The predetermined positions P1, P2, and P3 of the three blades are the actual installation positions of the stress sensor. The distances X1, X2, and X3 between the predetermined positions and the blade root positions are the distances from the sensor positions to the blade roots. X1, X2, and X3 need to be calibrated according to the actual site conditions.

4. The method for controlling the ultimate load of a hub system under single-blade jamming conditions according to claim 3, characterized in that, In step 3), after the wind turbine generator enters the shutdown process, it is in the load dynamic balance control process. This process can reduce the unbalanced load of the wind turbine generator and extend the shutdown time of the wind turbine generator. After the wind turbine generator is shut down, set the actual on-site yaw rate V. yaw During the yaw maneuver, the wind turbine calculates the actual yaw error E. yaw When the wind turbine is facing the wind direction, E yaw The value is 0. When the wind turbine performs a yaw maneuver, the direction of the yaw error is defined according to the yaw direction of the wind turbine. When the yaw error E is 0, the direction of the yaw error is defined as 0. yaw Greater than the yaw error threshold E yawmax At that time, the wind turbine stopped yawing, where the yaw error threshold E yawmax This is the condition for terminating the yaw action of a wind turbine generator.

5. The method for controlling the ultimate load of a hub system under single-blade jamming conditions according to claim 4, characterized in that, In step 4), the wind turbine performs a yaw maneuver. If during or after the yaw maneuver, the calculated hub system load M of the wind turbine... hub Less than M h1 When the wind turbine's non-clamped blades are in a constant pitch rate V1″, they will feather until the wind turbine reaches the feathering angle and stops.

6. A hub system ultimate load control system for single-blade impeller jamming, characterized in that, The method for controlling the ultimate load of a hub system under single-blade jamming conditions as described in any one of claims 1 to 5 includes: The single-blade jamming fault detection module is used to determine whether a single-blade jamming fault exists. When the pitch rate of any blade is less than the jamming rate threshold and continues for a preset time T or the pitch system communication flag is 0, the wind turbine generator will report the jamming fault of the corresponding blade; otherwise, there is no single-blade jamming fault. The load dynamic balance control module is used to execute the load dynamic balance control mode. When a blade jamming fault is detected, the wind turbine generator will shut down and enter the load dynamic balance control mode. By measuring the load changes of the hub system, the non-jammed blades will be adjusted to perform corresponding pitch actions, so that the hub system load is in a dynamic balance process. The yaw control module performs yaw control on the wind turbine generator based on the calculated current yaw error of the wind turbine generator, so that the generator moves away from the wind direction. When the yaw error of the wind turbine generator exceeds a preset threshold, the wind turbine generator stops yawing. The feathering control module, based on the calculated hub system load, controls the non-clamped blades of the wind turbine to feather at a uniform pitch rate.

Images