A wind turbine variable pitch control method, system and storage medium

Abstract

The application relates to the technical field of wind turbine generator set control, in particular to a wind turbine variable pitch control method and system and a storage medium, the method comprises the following steps: acquiring a wind speed signal, and comparing the wind speed signal with a preset wind speed signal to obtain corresponding variable pitch operation information; periodically acquiring a centralized pitch angle filter value and a generator speed deviation value; obtaining a variable pitch PID pitch angle demand value according to the centralized pitch angle filter value and the generator speed deviation value; obtaining a variable pitch control demand value according to the variable pitch PID pitch angle demand value and a preset variable pitch demand value; and generating and sending a corresponding variable pitch control signal every time the variable pitch control demand value is acquired. The application has the advantages that the centralized pitch angle filter value and the generator speed deviation value can be processed by a PID control system to obtain a corresponding variable pitch control demand value, the variable pitch control demand value can be accurately calculated, and the variable pitch control process of the wind turbine generator set can be controlled in real time.

Description

Technical Field

[0001] This application relates to the technical field of wind turbine generator control, and in particular to a wind turbine pitch control method, system and storage medium. Background Technology

[0002] Wind power generation is an emerging interdisciplinary field. Currently, wind power generation is developing very rapidly. In order to maximize the power generation of wind power, the pitch angle of the wind turbine is usually changed to adjust the control of the wind turbine generator set, thereby increasing the power generation of the wind turbine generator set.

[0003] In order to improve the power generation of wind turbine generators, the relevant schemes obtain the current rotational speed of the wind turbine, calculate the rotational speed deviation based on the current rotational speed, and then calculate the required pitch angle based on the pitch control parameters, adjustment coefficients and rotational speed deviation.

[0004] However, since the pitch angle requirement is obtained based on the current rotational speed of the wind turbine, which depends on the actual wind speed, when the wind speed is too high or too low, the calculated pitch angle requirement will have a large error. Summary of the Invention

[0005] To improve the accuracy of obtaining the pitch control angle, this application provides a wind turbine pitch control method, system, and storage medium.

[0006] In a first aspect, this application provides a wind turbine pitch control method, which adopts the following technical solution:

[0007] A method for controlling the pitch of a wind turbine includes the following steps:

[0008] In normal operating mode:

[0009] The system acquires wind speed signals and compares them with preset wind speed signals to obtain corresponding pitch control operation information; whenever pitch control operation information is acquired, the system enters pitch control operation mode.

[0010] In pitch control mode:

[0011] Periodically obtain the concentrated pitch angle filter value and the generator speed deviation value;

[0012] The required pitch angle for pitch control (PID) is obtained based on the concentrated pitch angle filter value and the generator speed deviation value.

[0013] The pitch control requirement value is obtained based on the pitch PID pitch angle requirement value and the preset pitch requirement value.

[0014] Whenever a pitch control requirement value is obtained, the corresponding pitch control signal is generated and sent out, and the normal operation mode is entered.

[0015] In some embodiments, the periodic acquisition of the concentrated pitch angle filter value includes the following steps:

[0016] Periodically acquire blade pitch angle measurements, which include measurements of the first blade, the second blade, and the third blade.

[0017] The average value of the concentrated pitch angle measurement is obtained based on the measurement values ​​of the first blade, the second blade, and the third blade; the concentrated pitch angle filter value is obtained based on the average value of the concentrated pitch angle measurement using a pitch angle filter.

[0018] In some embodiments, periodically acquiring the generator speed deviation value includes the following steps:

[0019] Obtain the generator speed filter value;

[0020] The first temporary speed value is obtained based on the generator speed filter value and the preset speed target value;

[0021] The difference between the first temporary speed value and the preset speed offset value is used as the generator speed deviation value.

[0022] In some embodiments, obtaining the generator speed filter value includes the following steps:

[0023] Regularly obtain generator speed measurements;

[0024] The first filtered speed is obtained based on the measured generator speed value, and the current generator power is obtained from the first filtered speed; the current generator power is compared with the preset optimal power.

[0025] If the current generator power is greater than the preset optimal power, a control signal for entering normal operation mode is generated and issued, and a generator speed filter value is generated based on a notch filter.

[0026] In some embodiments, obtaining the required pitch angle (PID) value based on the concentrated pitch angle filter value and the generator speed deviation value includes the following steps:

[0027] The control adjustment parameters are obtained based on the concentrated pitch angle filter value, and the control adjustment parameters include proportional parameters, integral parameters and derivative parameters;

[0028] The ratio data is obtained based on the product of the comparison parameters and the preset gain parameters;

[0029] Based on the proportional data, integral parameters, and derivative parameters, the pitch angle requirement value of the pitch PID controller is obtained.

[0030] In some embodiments, obtaining the control adjustment parameters based on the concentrated pitch angle filter value includes the following steps:

[0031] Obtain the control adjustment interpolation table, and based on the concentrated pitch angle filter value, obtain the control adjustment parameters corresponding to the concentrated pitch angle filter value from the control adjustment interpolation table.

[0032] In some embodiments, obtaining the pitch control requirement value based on the pitch PID pitch angle requirement value and a preset pitch requirement value includes the following steps:

[0033] The first temporary calculated value is obtained based on the sum of the pitch angle requirement value of the PID and the estimated pitch requirement value.

[0034] Based on the first temporary calculated value, obtain the pitch position limit data;

[0035] The pitch control requirement value is obtained based on the pitch position limit data, the preset pitch rate limit, and the pitch acceleration limit.

[0036] In some embodiments, obtaining the pitch position constraint data based on the first temporary calculated value includes the following steps:

[0037] Obtain limiting pitch angle data, which includes power pitch angle values ​​that characterize the minimum pitch angle value under rated power and wind deviation pitch angle values ​​that characterize the minimum pitch angle under the same wind deviation.

[0038] Based on the first temporary calculated value, the power pitch angle value, and the wind deviation pitch angle value, the pitch position constraint data is obtained.

[0039] Secondly, this application provides a wind turbine pitch control system, which adopts the following technical solution:

[0040] A wind turbine pitch control system includes a wind speed acquisition module, a wind speed processing module, a data acquisition module, a first processing module, a second processing module, and an execution module; wherein,

[0041] In normal operating mode:

[0042] The wind speed acquisition module is used to acquire wind speed signals and compare the wind speed signals with preset wind speed signals to obtain corresponding pitch operation information.

[0043] The wind speed processing module is used to enter the pitch operation mode whenever pitch operation information is obtained;

[0044] In pitch control mode:

[0045] The data acquisition module is used to periodically acquire the concentrated pitch angle filter value and the generator speed deviation value;

[0046] The first processing module is used to obtain the pitch angle requirement value of the variable pitch angle (PID) based on the centralized pitch angle filter value and the generator speed deviation value.

[0047] The second processing module is used to obtain the pitch control requirement value based on the pitch PID pitch angle requirement value and the preset pitch requirement value.

[0048] The execution module is used to generate and send out the corresponding pitch control signal and enter the normal operation mode whenever a pitch control demand value is obtained.

[0049] Thirdly, this application provides a storage medium, which adopts the following technical solution:

[0050] A storage medium storing at least one instruction, at least one program, a code set, or an instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to implement the wind turbine pitch control method.

[0051] The wind turbine pitch control method, system, and storage medium provided in this application compare the acquired wind speed signal with a preset wind speed signal to obtain pitch operation information in real time. This enables the wind turbine to obtain the information that needs to be pitched in a timely manner, acquire the wind speed signal in real time, and then reasonably calculate the signal that needs to be pitched. The PID control system processes the concentrated pitch angle filter value and the generator speed deviation value to obtain the corresponding pitch control requirement value, thereby accurately calculating the pitch control requirement value and controlling the pitch control process of the wind turbine in real time. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the overall steps in an embodiment of this application;

[0053] Figure 2 This is a schematic diagram showing the relationship between wind speed and rotational speed within the operating range;

[0054] Figure 3 This is a control block diagram for the concentrated pitch angle filter value;

[0055] Figure 4 This is a schematic diagram illustrating the steps for concentrating the pitch angle filtering value;

[0056] Figure 5 This is the control block diagram for the required pitch angle value of the variable pitch PID controller;

[0057] Figure 6 This is a schematic diagram illustrating the steps involved in determining the generator speed deviation value.

[0058] Figure 7 This is the control block diagram for the generator speed filter value;

[0059] Figure 8 This is a schematic diagram illustrating the steps involved in filtering generator speed values.

[0060] Figure 9 This is a schematic diagram illustrating the steps involved in determining the required pitch angle using a variable pitch PID controller.

[0061] Figure 10 This is a control block diagram showing the pitch control demand values;

[0062] Figure 11 This is a schematic diagram illustrating the steps involved in setting pitch control requirements. Detailed Implementation

[0063] To better understand the purpose, technical solutions, and advantages of this application, it has been described and illustrated below with reference to the accompanying drawings and embodiments. However, those skilled in the art should understand that this application can be implemented without these details. In some cases, to avoid obscuring various aspects of this application due to unnecessary description, well-known methods, processes, systems, components, and / or circuits already described at a higher level will not be elaborated upon. It will be apparent to those skilled in the art that various modifications can be made to the embodiments disclosed in this application, and the general principles defined in this application can be applied to other embodiments and application scenarios without departing from the principles and scope of this application. Therefore, this application is not limited to the illustrated embodiments, but conforms to the broadest scope consistent with the scope of protection claimed in this application.

[0064] This application discloses a wind turbine pitch control method.

[0065] A wind turbine pitch control method is applied in a wind turbine control system, which includes a terminal parameter acquisition device, a terminal server, and a main control system. Specifically, the wind turbine control system uses the terminal parameter acquisition device to measure characteristic parameters and other state parameters, enabling the terminal server to obtain the current operating state of the main control system. The current operating state of the main control system indicates that the wind turbine is generating electricity. The operating states mainly include normal operation and pitch control operation. Therefore, the main control system has two modes: a normal operation mode corresponding to the normal operation mode and a pitch control operation mode corresponding to the pitch control operation mode. In normal operation mode, the terminal server controls the wind turbine blades to rotate under wind speed, enabling the wind turbine to generate electricity. In pitch control operation mode, the terminal server controls the wind turbine blades to change their pitch angle relative to the ground, thereby achieving higher power generation. When the terminal server receives pitch parameter information, it controls the main control system to switch from normal operation mode to pitch control operation mode.

[0066] like Figure 1 As shown, after the wind turbine is started, it automatically enters the normal operation mode, which includes the following steps:

[0067] S100 acquires wind speed signals and compares them with preset wind speed signals to obtain corresponding pitch control operation information.

[0068] The S200 enters pitch operation mode whenever it receives pitch operation information.

[0069] Among them, the wind speed signal represents the current wind speed magnitude. The preset wind speed signal represents the minimum wind speed magnitude at which the main control system needs to perform pitch control. The pitch control information represents the information sent by the terminal server to the main control system. When the main control system receives this pitch control information, it will switch from the current normal operation state to the pitch control operation state.

[0070] Wind turbines include grid-connected turbines. Grid connection refers to the process where, during power generation, the generator's transmission and communication lines are integrated into the power grid, and these lines are connected to the grid for power exchange. For grid-connected turbines, due to varying external wind speed signals, the turbine needs to reach the cut-in wind speed to operate. The cut-in wind speed, specific to grid-connected turbines, refers to the minimum wind speed required for grid connection and power generation. Below this speed, the turbine automatically shuts down. However, when the wind speed signal reaches the cut-out wind speed, which represents the maximum wind speed at which the turbine can generate power, the turbine will disconnect from the grid, shutting down and ceasing power generation. The cut-in speed is related to the aerodynamic performance of the blades.

[0071] Specifically, when this cut-out wind speed is reached, the generator can generate electricity continuously and stably. The cut-out wind speed is related to the blades and the unit load. If the cut-out wind speed is reached but the generator does not cut out, there may be risks of tower collapse, impeller runaway, and other accidents. The starting power consumption is generally less than the power generation at the cut-in wind speed.

[0072] It should be noted that wind turbines operate in four different ranges as they move from the cut-in wind speed to the cut-out wind speed.

[0073] Combination Figure 2 The operating range refers to the period when the generator speed of the wind turbine is between N1 and N4, i.e., when the outside wind speed is between Vin and Vout. The wind turbine operates within this range. Vin represents the minimum wind speed available for power generation (cut-in wind speed), and Vout represents the maximum wind speed (cut-out wind speed). Within the operating range, the wind turbine also operates in normal operation and pitch control mode. As shown in the figure, segment BC represents the optimal tip ratio, where the blade pitch angle is maintained at the minimum, enabling maximum wind energy capture.

[0074] Since the main control system enters the pitch control operation state, it is in pitch control mode. The main control system needs to obtain the characteristic parameters and other status parameters measured by the equipment based on the terminal parameters, so as to realize the change of the pitch angle between the wind turbine blades and the ground. Therefore, when the main control system is in pitch control mode, the specific steps include: S300, periodically obtaining the centralized pitch angle filter value and the generator speed deviation value.

[0075] The concentrated pitch angle filter value represents the angle between the wind turbine blades and the wind turbine's plane of rotation after processing. The generator speed deviation value is used to characterize the speed influence value of the PID control of the wind turbine unit.

[0076] Specifically, the concentrated pitch angle filter value and the generator speed deviation value are obtained periodically. This periodicity means that the values ​​are obtained within the same time interval. The specific time interval can be set according to the wind speed situation in a certain period of time. If the wind speed is greater than the cut-in wind speed for a long period of time, the corresponding time interval can be set to be larger. If the wind speed is greater than the cut-in wind speed for a short period of time, the corresponding time interval can be set to be smaller.

[0077] For example, if the current wind speed is greater than the cut-in wind speed for 10 minutes within a period A, the time interval can be set to 0.5 seconds. If the current wind speed is greater than the cut-in wind speed for 30 minutes within a period B, the time interval can be set to 5 seconds.

[0078] It should be noted that the concentrated pitch angle filter value and the generator speed deviation value are obtained by the terminal parameter acquisition device, and the terminal parameter acquisition device sends the concentrated pitch angle filter value and the generator speed deviation value to the terminal server for subsequent processing of the values.

[0079] S400 obtains the required pitch angle value for pitch control PID based on the concentrated pitch angle filter value and the generator speed deviation value.

[0080] In a wind power system, the required pitch angle (PID) value refers to the control signal calculated using a PID algorithm to control the blade pitch angle and maximize wind energy utilization. Specifically, the PID algorithm calculates the difference between the actual and target pitch angles and outputs a corresponding control signal to adjust the pitch angle, bringing the actual pitch angle closer to the target value. This process requires setting the target pitch angle, typically determined by the system designer based on actual conditions. Setting this value involves multiple factors, such as wind speed, wind direction, and sensor measurement errors, and requires experimental testing to determine the optimal setting.

[0081] S500 obtains the pitch control requirement value based on the pitch angle requirement value of the pitch PID and the preset pitch requirement value.

[0082] The preset pitch requirement value is the additional pitch requirement, which can be set according to the set offset value of the wind turbine.

[0083] Specifically, the process of obtaining the pitch control demand value generally involves the following steps: calculating the deviation between the pitch angle demand value of the pitch PID controller and the preset pitch demand value, i.e., the error; and determining the output value of the PID controller, i.e., the pitch control demand value, based on the error value and the proportional, integral, and derivative parameters.

[0084] The pitch control requirement value mentioned here is automatically generated by the pitch PID control system. The specific calculation formula can be selected in Simulink, and then the corresponding pitch control requirement value is obtained based on the proportional, integral, and derivative parameters. The specific calculation formula can be used as follows, or other formulas can be set.

[0085] Pitch control demand value = Kp*e + Ki*K∑e + Kd*Δe

[0086] Where Kp is the proportional parameter, Ki is the integral parameter, Kd is the differential parameter, e is the current error, Δe is the difference between the current error and the previous error, and ∑e is the integral of the error, that is, the cumulative sum of the error over time.

[0087] The pitch control requirements are translated into actionable signals or commands, such as adjusting the pitch angle or controlling the pitch motor. It is important to note that different wind turbine models and operating conditions may require different proportional, integral, and derivative parameters to achieve optimal control. Furthermore, experimentation and debugging are necessary to verify the system's performance and stability.

[0088] S600 generates and sends out the corresponding pitch control signal and enters normal operation mode whenever it obtains the pitch control requirement value.

[0089] When the system receives pitch control requirements, it typically generates corresponding pitch control signals and sends them to the pitch actuator or other relevant equipment. These signals may include instructions to adjust the pitch angle, or to turn the pitch motor on or off. Simultaneously, the system enters normal operation mode, monitoring and adjusting generator speed, power output, and pitch control requirements in real time based on current conditions and environmental factors to ensure stable operation of the wind power system and maximize power generation.

[0090] Reference Figure 3 and Figure 4 In another embodiment, the terminal parameter acquisition device includes a pitch angle measuring instrument, an amplification element, an execution element, a pitch angle filter, and a pitch angle output element. The pitch angle measuring instrument measures the pitch angle of the corresponding blade on the wind turbine, and then outputs a corresponding concentrated pitch angle filter value through the output element. This enables the terminal server to obtain a more accurate concentrated pitch angle filter value. Therefore, periodically acquiring the concentrated pitch angle filter value specifically includes the following steps:

[0091] S310 periodically acquires blade pitch angle measurements, including measurements of the first blade, the second blade, and the third blade.

[0092] S320 obtains the average value of the concentrated pitch angle measurement based on the measurement values ​​of the first blade, the second blade, and the third blade.

[0093] S330 obtains the concentrated pitch angle filtered value based on the average value of the concentrated pitch angle measurement and the pitch angle filter.

[0094] The measurement of the first blade represents the pitch angle measurement of the first blade of the wind turbine. The measurement of the second blade represents the pitch angle measurement of the second blade of the wind turbine. The measurement of the third blade represents the pitch angle measurement of the third blade of the wind turbine. The average pitch angle measurement is used to represent the average pitch angle value of the three blades of the wind turbine.

[0095] Specifically, the blade pitch angle is measured by measuring the first, second, and third blades using a pitch angle measuring instrument. The pitch angle can be measured separately for each of the three blades of the wind turbine. The measurement method involves using cameras positioned around the wind turbine to capture real-time images of the turbine, obtaining initial and target images. The initial image corresponds to the initial pitch angle. The measured blade pitch angle is obtained by extracting images from both the initial and target images. Image extraction is a current technology and will not be elaborated upon further.

[0096] Specifically, the method for obtaining the average value of the concentrated pitch angle measurement is as follows: the amplification element receives the measurement values ​​of the first blade, the second blade, and the third blade obtained by the pitch angle measuring instrument. The amplification factor of the amplification element is 1 / 3, thereby causing the amplification element to output the average value of the measurement values ​​of the first blade, the second blade, and the third blade, and input the average value of the concentrated pitch angle measurement to the execution element.

[0097] Furthermore, the specific method for obtaining the concentrated pitch angle filter value is as follows: when the actuator receives the average value of the concentrated pitch angle measurement, it transmits the average value of the concentrated pitch angle measurement to the pitch angle filter. Since the blade pitch angle measurement value is obtained periodically, there will be multiple sets of different numerical signals. The pitch angle filter directly filters out some numerical signals that cause instability in the entire control by means of the average value of the concentrated pitch angle measurement, thereby enabling the pitch angle output element to output some stable concentrated pitch angle filter values.

[0098] It should be noted that commonly used filters include first-order low-pass filters, second-order low-pass filters, etc., and each filter has a different transfer function. The pitch angle filter mentioned here selects an appropriate transfer function based on the actual needs. In this embodiment, a second-order filter transfer function is selected to filter out unstable numerical signals.

[0099] Since the transfer function of a second-order filter specifically meets the requirements of the wind turbine control system, a second-order filter is selected. Because the transfer functions of second-order filters are existing technologies, they will not be elaborated upon here. Furthermore, the control system selection utilizes Simulink in MATLAB to set up the control block diagram; therefore, it is only necessary to select the appropriate transfer function as the filter's transfer function based on the acquired data.

[0100] Reference Figure 5 and Figure 6In another embodiment, the terminal parameter acquisition device includes a speed acquisition system, a first comparison element, a second comparison element, and a deviation value output element. The speed acquisition system acquires the corresponding generator speed filter value, and then the first and second comparison elements process the value, and the deviation value output element outputs the corresponding generator speed deviation value. This enables the terminal server to obtain a more accurate generator speed deviation value. Therefore, periodically acquiring the generator speed deviation value specifically includes the following steps:

[0101] S340, obtain the generator speed filter value.

[0102] S350 obtains the first temporary speed value based on the generator speed filter value and the preset speed target value.

[0103] S360 uses the difference between the first temporary speed value and the preset speed offset value as the generator speed deviation value.

[0104] The generator speed filter value refers to the value obtained after filtering the generator speed. Specifically, generator speed is usually affected by various factors that cause fluctuations, such as mechanical vibration and load changes. To obtain a more stable and accurate speed value, filtering algorithms can be used to process the raw data. There are many filtering methods, commonly including low-pass filtering, band-pass filtering, and median filtering. The choice of different filtering methods depends on the application scenario and specific requirements. In this embodiment, a speed acquisition system is used to obtain the corresponding generator speed filter value.

[0105] Furthermore, the preset target speed value refers to the desired generator speed set within a control system. Typically, the control system monitors and receives feedback on the speed, adjusting parameters such as output torque or traction force to make the actual speed as close as possible to the preset target value. Setting the preset target speed value requires considering various factors, such as load variations and environmental conditions, to meet user needs and ensure normal generator operation. In practical applications, algorithms such as PID control can be used to achieve the control of the preset target speed value.

[0106] The first temporary speed value mentioned here refers to the temporary speed value before the generator reaches normal operation during startup. During generator startup, due to the inertia of mechanical components and the electrical system, the generator speed gradually increases until it reaches the speed required for normal operation. To ensure safe generator operation, a first temporary speed value is typically set. When the actual speed reaches this value, corresponding control logic is executed to ensure smooth and reliable generator operation. The specific setting of the first temporary speed value needs to consider factors such as the generator's design parameters and operating environment to ensure that the generator can be quickly and stably brought to normal operating status during startup.

[0107] The preset speed offset value refers to an offset value obtained by fine-tuning the preset target speed value based on actual conditions in some control systems to achieve better control performance. In practical applications, due to various factors such as load changes and mechanical losses, the actual speed may differ from the preset target value. In such cases, the preset speed offset value can be set to adjust the actual speed, achieving a more accurate and stable control effect. The specific setting of the preset speed offset value needs to consider factors such as the generator's characteristics and operating environment, and requires testing and verification to determine the optimal offset value.

[0108] Specifically, the generator speed filter value is obtained based on the speed acquisition system. The first comparison element subtracts the obtained generator speed filter value from the preset speed target value and then inputs the resulting first temporary speed value into the second comparison element. The second comparison element subtracts the first temporary speed value from the preset speed offset value to obtain the generator speed deviation value and inputs the generator speed deviation value into the deviation value output element for subsequent processing.

[0109] It should be noted that the preset target speed value and the preset speed offset value are set in advance based on the specific situation.

[0110] Reference Figure 7 and Figure 8 In another embodiment, the speed acquisition system includes a speed measuring instrument, a low-pass filter, a first notch filter, a second notch filter, and a speed output element. The speed measuring instrument measures the corresponding generator speed on the wind turbine, and then outputs the corresponding generator speed filter value through the speed output element. This enables the terminal server to obtain a more accurate generator speed filter value. Obtaining the generator speed filter value includes the following steps:

[0111] S341, periodically obtain generator speed measurement values.

[0112] S342, obtain the first filtered speed based on the generator speed measurement value, and obtain the current generator power from the first filtered speed.

[0113] S343 compares the current generator power with the preset optimal power.

[0114] S344: If the current generator power is greater than the preset optimal power, generate and send a control signal to enter the normal operation mode and generate a generator speed filter value based on the notch filter.

[0115] The generator speed measurement refers to the value obtained by real-time monitoring of the generator speed through sensors and other devices. The first filtered speed is the filtered result obtained after filtering the generator speed signal, aiming to smooth the signal curve and eliminate noise and fluctuations. The current generator power refers to the actual power generated by the generator during operation. The preset optimal power refers to the target power value set in the control system, usually set by the system designer based on actual conditions. The control signal refers to the signal output by the terminal server used to adjust the generator power and speed; adjusting the control signal can achieve the effect of the actual power approaching the preset optimal power.

[0116] Specifically, the speed measuring instrument periodically acquires generator speed measurements and sends these measurements to a low-pass filter. The low-pass filter processes the acquired generator speed measurements, followed by a notch filter to obtain the first filtered speed. The terminal server uses the first filtered speed to obtain the current generator power and compares it with a preset optimal power. If the current generator power is greater than the preset optimal power, a control signal to enter normal operation mode is generated and sent, along with a generator speed filter value generated based on the notch filter.

[0117] The transfer functions selected for the low-pass filter and notch filter mentioned here are chosen based on actual conditions, and will not be set individually here. They can be the same as the transfer function selected for the pitch angle filter, or a first-order transfer function can be selected according to the actual situation.

[0118] Reference Figure 5 and Figure 9 In another embodiment, the terminal parameter acquisition device further includes a proportional parameter controller, an integral parameter controller, a derivative parameter controller, a third comparator element, and a pitch PID controller. Specifically, obtaining the required pitch angle value for the pitch PID controller based on the lumped pitch angle filter value and the generator speed deviation value includes the following steps:

[0119] S410 obtains control parameters based on the concentrated pitch angle filter value. The control parameters include proportional parameters, integral parameters, and derivative parameters.

[0120] S420 obtains the ratio data based on the product of the comparison parameter and the preset gain parameter.

[0121] The S430 obtains the required pitch angle value of the pitch PID controller based on proportional data, integral parameters, and derivative parameters.

[0122] The proportional, integral, and derivative parameters are three crucial parameters in a PID controller, used to adjust the response speed and control accuracy of the control algorithm. Specifically: the proportional parameter adjusts the relationship between the control output and the deviation; when a deviation exists between the actual and target values, the proportional parameter adjusts proportionally to calculate the corresponding control output. The integral parameter eliminates steady-state errors by accumulating deviations over a long period and adjusting based on the accumulated deviations, ensuring the actual value eventually approaches the target value. The derivative parameter eliminates transient errors; when the deviation changes, the derivative parameter adjusts proportionally to calculate the corresponding control output, enabling the system to recover to the target state more quickly.

[0123] In this embodiment, the proportional parameter controller obtains the proportional parameter, the integral parameter controller obtains the integral parameter, and the derivative parameter controller obtains the derivative parameter. The third comparator obtains the proportional data based on the product of the comparator parameter and the preset gain parameter. The proportional data, integral parameter, and derivative parameter are all input to the pitch PID controller, thereby causing the pitch PID controller to output the pitch PID pitch angle requirement value.

[0124] In another embodiment, to improve the speed of acquiring proportional, integral, and derivative parameters, a corresponding adjustment difference table is prepared in advance. Using the acquired concentrated pitch angle filter value, the corresponding proportional, integral, and derivative parameters are selected from the adjustment difference table. Obtaining the control adjustment parameters based on the concentrated pitch angle filter value specifically includes the following steps:

[0125] S411, Obtain the control adjustment interpolation table.

[0126] S412: Obtain the control adjustment parameters corresponding to the concentrated pitch angle filter value from the control adjustment interpolation table based on the concentrated pitch angle filter value.

[0127] Specifically, the control and adjustment interpolation table can be obtained from past practical results or by prediction based on past practical results.

[0128] Reference Figure 10 The terminal parameter acquisition device also includes a fourth comparator, a pitch position limiting system, a pitch rate limiting system, and a pitch acceleration limiting system.

[0129] The pitch control requirement value is obtained based on the pitch angle requirement value of the PID controller and the preset pitch requirement value, including the following steps:

[0130] S510 obtains the first temporary calculated value based on the sum of the pitch angle requirement value of the pitch control PID and the estimated pitch requirement value.

[0131] S520 obtains pitch position limit data based on the first temporary calculated value.

[0132] The S530 obtains pitch control requirements based on pitch position limit data, preset pitch rate limit, and pitch acceleration limit.

[0133] In the step of obtaining the first temporary calculated value based on the sum of the pitch angle requirement value of the pitch controller and the estimated pitch requirement value, it is necessary to add the pitch angle requirement value of the pitch controller obtained from the PID controller and the estimated pitch requirement value, and make fine adjustments according to the actual situation to obtain a temporary calculated value, which is used to calculate the pitch position limit data in the subsequent calculation.

[0134] Furthermore, in the step of obtaining pitch position limit data based on the first temporary calculation value, the pitch position limit data is calculated based on the first temporary calculation value, mechanical structure parameters, and the set pitch angle range. This data includes the upper and lower limits of the permissible pitch angle to ensure that the pitch actuator does not exceed the acceptable angle range.

[0135] Furthermore, in the step of obtaining the pitch control requirement value based on pitch position constraint data, preset pitch rate constraint, and pitch acceleration constraint, the final pitch control requirement value needs to be calculated based on factors such as pitch position constraint data, preset pitch rate constraint, and pitch acceleration constraint. The calculation method involves multiple parameters and constraints, and the specific calculation method needs to be adjusted and optimized according to the actual situation to ensure the performance and stability of the pitch control system.

[0136] It should be specifically explained here that the fourth comparator receives the pitch angle requirement value (PID) and the estimated pitch requirement value, and obtains a first temporary calculated value based on the sum of the PID pitch angle requirement value and the estimated pitch requirement value. This first temporary calculated value then passes sequentially through the pitch position limiting system, the pitch rate limiting system, and the pitch acceleration limiting system, until it is input to the terminal server as the pitch control requirement value. The terminal server receives the pitch control requirement value and controls the first, second, and third blades of the wind turbine to rotate by the corresponding angles, thereby achieving pitch control of the entire wind turbine.

[0137] Reference Figure 11 In another embodiment, the pitch position limiting system includes a minimum pitch angle acquisition element and a minimum pitch angle element for wind deviation, and acquires pitch position limiting data based on a first temporary calculated value, including the following steps:

[0138] S521, Obtain the limiting pitch angle data, which includes the power pitch angle value representing the minimum pitch angle value under rated power and the wind deviation pitch angle value representing the minimum pitch angle under the same wind deviation.

[0139] S522, obtain pitch position constraint data based on the first temporary calculated value, power pitch angle value, and wind deviation pitch angle value.

[0140] It should be noted that the minimum pitch angle acquisition element obtains the power pitch angle value of the minimum pitch angle, while the minimum pitch angle for wind deviation acquisition element obtains the wind deviation pitch angle value of the minimum pitch angle. Both the power pitch angle value and the wind deviation pitch angle value of the minimum pitch angle mentioned here are pre-acquired data, which are input as known data into the pitch position limiting system to facilitate the acquisition of pitch position limiting data based on the first temporary calculation value.

[0141] The implementation principle of a wind turbine pitch control method disclosed in this application is as follows: First, the pitch angles of the first, second, and third blades of the wind turbine are periodically acquired using a pitch angle measuring instrument. Then, the average value of the concentrated pitch angle measurements of the first, second, and third blades is acquired using an amplification element. Based on the average value of the concentrated pitch angle measurements, a concentrated pitch angle filter value is obtained using a pitch angle filter. Next, by using a pre-set adjustment interpolation table, the proportional, integral, and derivative parameters corresponding to the concentrated pitch angle filter value can be selected, thereby obtaining the corresponding pitch PID pitch angle requirement value through PID pitch control. Then, a first temporary calculation value is obtained based on the sum of the pitch PID pitch angle requirement value and the estimated pitch requirement value using a fourth comparison element. Pitch position restriction data is obtained based on the first temporary calculation value, and the pitch control requirement value is obtained by restricting the position, speed, and acceleration of the wind turbine. Finally, the terminal server generates a pitch control signal based on the obtained pitch control requirement value to control the wind turbine to achieve pitch control and to control the wind turbine to operate normally.

[0142] This application also discloses a wind turbine pitch control system, which includes a wind speed acquisition module, a wind speed processing module, a data acquisition module, a first processing module, a second processing module, and an execution module.

[0143] In normal operating mode:

[0144] The wind speed acquisition module acquires wind speed signals and compares them with preset wind speed signals to obtain corresponding pitch control operation information. The wind speed processing module initiates pitch control operation mode whenever pitch control operation information is acquired.

[0145] In pitch control mode:

[0146] The data acquisition module periodically acquires the concentrated pitch angle filter value and the generator speed deviation value. The first processing module acquires the pitch angle requirement value for the pitch control (PID) based on the concentrated pitch angle filter value and the generator speed deviation value. The second processing module acquires the pitch control requirement value based on the pitch angle requirement value for the PID and the preset pitch requirement value. The execution module generates and sends the corresponding pitch control signal and enters the normal operation mode whenever the pitch control requirement value is acquired.

[0147] This application also discloses a storage medium that stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the wind turbine pitch control method.

[0148] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method of wind turbine variable pitch control, the method comprising: The method comprises the following steps: In the normal operation mode: Obtaining a wind speed signal, and comparing the wind speed signal with a preset wind speed signal to obtain corresponding variable pitch operation information; Entering the variable pitch operation mode whenever the variable pitch operation information is obtained; In the variable pitch operation mode: Periodically obtaining a centralized pitch angle filtered value and a generator speed deviation value; Obtaining a variable pitch PID pitch angle demand value according to the centralized pitch angle filtered value and the generator speed deviation value; Obtaining a variable pitch control demand value according to the variable pitch PID pitch angle demand value and a preset variable pitch demand value; Generating and sending a corresponding variable pitch control signal and entering the normal operation mode whenever the variable pitch control demand value is obtained, The periodically obtaining the centralized pitch angle filtered value comprises the following steps: Periodically obtaining blade pitch angle measurement values, the blade pitch angle measurement values comprising a first blade measurement value, a second blade measurement value and a third blade measurement value; Obtaining a centralized pitch angle measurement average value according to the first blade measurement value, the second blade measurement value and the third blade measurement value; Obtaining the centralized pitch angle filtered value based on a pitch angle filter according to the centralized pitch angle measurement average value, The periodically obtaining the generator speed deviation value comprises the following steps: Obtaining a generator speed filtered value; Obtaining a first temporary speed value according to a product of the generator speed filtered value and a preset speed target value; Taking a difference between the first temporary speed value and a preset speed bias value as the generator speed deviation value, The obtaining the variable pitch PID pitch angle demand value according to the centralized pitch angle filtered value and the generator speed deviation value comprises the following steps: Obtaining a control adjustment parameter according to the centralized pitch angle filtered value, the control adjustment parameter comprising a proportional parameter, an integral parameter and a differential parameter; Obtaining proportional data according to a product of the proportional parameter and a preset gain parameter; Obtaining the variable pitch PID pitch angle demand value based on a variable pitch PID controller according to the proportional data, the integral parameter and the differential parameter, The obtaining the variable pitch control demand value according to the variable pitch PID pitch angle demand value and the preset variable pitch demand value comprises the following steps: Obtaining a first temporary calculation value based on a sum of the variable pitch PID pitch angle demand value and the preset variable pitch demand value; Obtaining variable pitch position limit data according to the first temporary calculation value; Obtaining the variable pitch control demand value based on the variable pitch position limit data, a preset variable pitch rate limit and a variable pitch acceleration limit.

2. The wind turbine variable pitch control method of claim 1, wherein, The obtaining the generator speed filtered value comprises the following steps: Periodically obtaining a generator speed measurement value; Obtaining a first filtered speed according to the generator speed measurement value, and obtaining a current generator power according to the first filtered speed; Comparing the current generator power with a preset optimal power in size; If the current generator power is greater than the preset optimal power, generating and sending a control signal for entering the normal operation mode, and generating the generator speed filtered value based on a notch filter.

3. The fan pitch control method of claim 1, wherein, The obtaining the control adjustment parameter according to the centralized pitch angle filtered value comprises the following steps: The control adjustment interpolation table is acquired, and a control adjustment parameter corresponding to the collective pitch angle filtered value is acquired in the control adjustment interpolation table according to the collective pitch angle filtered value.

4. The wind turbine variable pitch control method of claim 1, wherein, The step of acquiring the pitch position limit data according to the first temporary calculation value comprises the following steps: The limit pitch angle data is acquired, and the limit pitch angle data comprises a power pitch angle value representing a minimum pitch angle value under rated power and a wind deviation pitch angle value representing a minimum pitch angle under the same wind deviation; The pitch position limit data is acquired according to the first temporary calculation value, the power pitch angle value and the wind deviation pitch angle value.

5. A wind turbine variable pitch control system, characterized by, The control system for executing the wind turbine pitch control method according to any one of claims 1-4 comprises a wind speed acquisition module, a wind speed processing module, a data acquisition module, a first processing module, a second processing module and an execution module; wherein, In the normal operation mode: The wind speed acquisition module is configured to acquire a wind speed signal and compare the wind speed signal with a preset wind speed signal to acquire corresponding pitch operation information; The wind speed processing module is configured to enter the pitch operation mode whenever the pitch operation information is acquired; In the pitch operation mode: The data acquisition module is configured to periodically acquire a collective pitch angle filtered value and a generator speed deviation value; The first processing module is configured to acquire a pitch angle demand value of the pitch control according to the collective pitch angle filtered value and the generator speed deviation value; The second processing module is configured to acquire a pitch control demand value according to the pitch angle demand value of the pitch control and a preset pitch control demand value; The execution module is configured to generate and send a corresponding pitch control signal whenever the pitch control demand value is acquired and enter the normal operation mode.

6. A storage medium, characterized by The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to realize the wind turbine pitch control method according to any one of claims 1-4.

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