Wind generating set generating capacity improving method based on genetic algorithm optimization

Abstract

The invention relates to the technical field of wind generating sets, in particular to a wind generating set generating capacity improving method based on genetic algorithm optimization, which comprises the following steps: calculating rated wind speed, adding a feed-forward compensator, superposing feedback control output as a pitch angle set value, and adding the pitch angle set value with a power controller output value of a feedback system, so as to improve the generating capacity of a wind generating set. And the pitch angle is used as a pitch angle set value of the variable pitch execution structure. According to the wind generating set generating capacity improving method based on genetic algorithm optimization, a fuzzy controller judgment rule is established on the basis of analyzing a wind generating set variable pitch control principle, a fuzzy PID controller is adopted to control a variable pitch system, the controller can effectively make up for the defects of a traditional PID controller, and the generating capacity of the wind generating set is improved. And the control precision and the response time of the variable-pitch control system above the rated wind speed are improved.

Description

Technical Field

[0001] The invention relates to the technical field of wind turbine generator sets, and in particular to a method for improving the power generation of wind turbine generator sets based on genetic algorithm optimization. Background Art

[0004] Vigorously developing the new energy industry is a strong support for implementing my country's carbon emission reduction goals and building a dual-circulation development pattern. my country's new energy industry has laid a solid foundation and has obvious competitive advantages in terms of industrial scale, manufacturing technology level, and cost competitiveness. At the same time, there are still shortcomings and deficiencies. It is necessary to consolidate the foundation of my country's new energy industry, make up for the shortcomings, strengthen policy coordination and international cooperation, and enhance the global competitiveness of the new energy industry. Under the background of the country's dual-carbon goals, the development speed of new energy has entered an explosive period and has become the absolute main market for the development of global new energy. Among them, the development of China's wind power has far surpassed the international level, and the application of large-scale units has entered the world's unmanned area. Reducing costs in the industrial chain, promoting localization, technological breakthroughs, and reliability verification have become propositions that must be broken through in the dual-carbon process.

[0005] Among the many renewable energy and new energy technology developments currently underway, wind power generation has its own unique advantages. It can not only save conventional energy, but also reduce environmental pollution, and has good economic and social benefits. It has been widely valued by countries around the world. As one of the key components of a wind power generation system, wind turbines directly affect the performance and efficiency of the entire wind power generation system. In order to maximize the wind turbine's wind energy conversion efficiency and ensure the wind turbine's output power is stable, the wind turbine needs to adjust its pitch.

[0006] At present, large megawatt units basically adopt variable speed and variable pitch control. When the wind speed is greater than the rated wind speed, the variable pitch method is used to control the pitch angle, thereby adjusting the aerodynamic power of the impeller, so that the unit is in full power state. When the wind speed is less than the rated wind speed, the variable torque control method is used to adjust the torque of the generator through the inverter, thereby controlling the generator speed to track the change of wind speed and maintain the optimal power coefficient.

[0007] The external environment faced by the unit during operation is constantly changing, so it is necessary to design a method to increase the power generation of wind turbines that adapts to the changes in the external environment, so that the wind turbine is in the best operating state and the power generation of the wind turbine is increased. In addition, most projects in plain areas now have large wind shear, and the measurement height of the wind tower is usually much lower than the hub height of the wind turbine. If only the wind tower is used to calculate the wind speed at a higher height, it will enter a large evaluation error. Summary of the invention

[0008] The purpose of the present invention is to provide a method for improving the power generation of a wind turbine generator set based on genetic algorithm optimization to solve the problems raised in the above background technology.

[0009] To achieve the above object, the present invention provides the following technical solution: a method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization, comprising the following steps:

[0010] S1: Calculate the rated wind speed. After the wind turbine is connected to the grid, when the wind speed is lower than the rated wind speed, the pitch angle can be kept at 0°. When the wind speed reaches the rated wind speed, the wind turbine enters the rated power state.

[0011] S2: Add a feedforward compensator to give a suitable pitch angle feedforward value β2 according to the wind speed. Use a hybrid lidar to sense the incoming flow information in advance and provide it to the wind turbine control unit. The unit responds and actively matches the wind speed change.

[0012] S3: Compare the power feedback signal with the given value. When the power exceeds the rated power, the blade pitch is rotated by an angle in the direction of reducing the windward area, and vice versa. The fuzzy controller is used to control the pitch of the unit. The error between the generator feedback power and the target power and the error change rate are used as the input of the system, and the output is the change value of the pitch angle β1;

[0013] S4: At rated wind speed, the power can be kept near the rated value by feedback control, and the pitch angle is near 0°. When the wind speed exceeds the rated wind speed, the pitch angle must be increased to a certain angle to keep the power at the rated value. Let v be the current wind speed, v0 be the rated wind speed, and the difference between the current wind speed and the rated wind speed is △v=v-v0. The larger △v is, the larger the pitch angle setting value should be.

[0014] S5: Compensate an angle according to △v, and then superimpose the output β1 of the feedback control as the pitch angle setting value, add it to the output value of the power controller of the feedback system, and use it as the pitch angle setting value β0 of the variable pitch execution structure.

[0015] Preferably, when the wind speed in S1 is lower than the rated wind speed, the generator stator current is adjusted by controlling the machine-side converter, thereby controlling the motor speed, and ultimately achieving maximum power capture of the wind turbine set.

[0016] Preferably, the hybrid laser radar includes a vertical laser radar and a cabin laser radar.

[0017] Preferably, the fuzzy controller membership function uses a triangular membership function, and the fuzzy controller determination rules in S3 include:

[0018] S3.1: If the error between the output power and the target power is positive (negative) or positive (negative), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative (positive);

[0019] S3.2: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative small (positive small), increase the blade pitch angle to negative medium (positive medium);

[0020] S3.3: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative medium (positive medium) or negative large (positive large), the blade pitch angle is kept unchanged;

[0021] S3.4: If the error between the output power and the target power is positively small (negatively small), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative center (positive center);

[0022] S3.5: If the error between the output power and the target power is positive or negative, and the error changes to negative or positive, the blade pitch angle is kept unchanged;

[0023] S3.6: If the error between the output power and the target power is positive small (negative small), and the error changes to negative medium (positive medium) or negative large (positive large), increase the blade pitch angle to negative small (positive small).

[0024] Preferably, in S1, when the rotation speed is less than the rated wind speed, the blades rotate to a certain angle in the direction of increasing the frontal area; otherwise, the blades rotate to a certain angle in the opposite direction to the former. When the fan speed approaches the synchronous speed and runs stably near the rated wind speed value for a period of time, the unit can be connected to the grid.

[0025] Preferably, a system database is set up, and the wind speed data of the wind turbine generator set will be stored in the system database. The data exceeding the rated wind speed for a period of time in the past will be processed and screened, and wind speed segments will be set. Classification and statistics will be conducted on whether there is yaw slip and yaw slip angle in each wind speed segment of each wind turbine, and a yaw slip warning will be set based on the data of yaw slip angle and yaw slip duration.

[0026] Preferably, in said S2, after adding a feedforward compensator, four measuring points are arranged on the end face of the elastic shaft bearing of the wind turbine, and copper-constantan thermocouples are used for measurement to test the temperatures of the measuring points respectively, and the specific steps include:

[0027] S2.1: Start loading the fan. When the wind speed reaches the rated wind speed, record the temperature of each measuring point. When the wind speed exceeds the rated wind speed, record the temperature of the test measuring point every 10 minutes.

[0028] S2.2: When the temperature at the test point changes more every 10 minutes, the heat dissipation device of the wind turbine is started to dissipate heat from the wind turbine.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This method for improving the power generation of wind turbines based on genetic algorithm optimization establishes a fuzzy controller judgment rule on the basis of analyzing the variable pitch control principle of wind turbines, and uses a fuzzy PID controller to control the variable pitch system. This controller can effectively make up for the shortcomings of traditional PID controllers and improve the control accuracy and response time of the variable pitch control system above the rated wind speed.

[0031] 2. The method for improving the power generation of wind turbines based on genetic algorithm optimization arranges four measuring points on the end face of the elastic shaft bearing of the wind turbine, uses copper-constantan thermocouples for measurement, and tests the temperature of the measuring points respectively. When the temperature change amplitude of the test points increases every 10 minutes, the heat dissipation device of the wind turbine is started to dissipate the heat of the wind turbine, thereby reducing the influence of temperature changes on the power generation of the wind turbine and not affecting the performance of the fan in the rated operating area.

[0032] 3. This method for improving the power generation of wind turbines based on genetic algorithm optimization uses a hybrid lidar to sense the incoming flow information in advance and provide it to the wind turbine control unit. The unit responds and actively matches the wind speed changes, optimizes the pitch control and realizes pitch change in advance, which can reduce the unit load and greatly improve the safety and stability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0034] Figure 1 The present invention is a flow chart of a method for increasing power generation of a wind turbine generator set. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 , the present invention provides a technical solution:

[0037] A method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization comprises the following steps:

[0038] S1: Calculate the rated wind speed. After the wind turbine is connected to the grid, when the wind speed is lower than the rated wind speed, the pitch angle can be kept at 0°. When the wind speed reaches the rated wind speed, the wind turbine enters the rated power state.

[0039] When the wind speed is lower than the rated wind speed, the generator stator current is adjusted by controlling the machine-side converter, thereby controlling the motor speed and ultimately achieving maximum power capture of the wind turbine.

[0040] In order to ensure the smooth grid connection of wind turbines and minimize the impact on the power grid, the generator speed can be controlled to run near the synchronous speed for a period of time in order to find a suitable time for grid connection. In order to simplify the control system design, the pitch angle of the variable pitch wind turbine is not controlled before the speed reaches the synchronous speed. At this time, the blades only rotate in the direction of the 0° pitch angle at a preset speed until the wind turbine speed reaches near the synchronous speed. The reference value of the speed control is the synchronous speed value. The speed feedback signal is compared with this value. When the speed is less than the rated wind speed, the blades rotate to a certain angle in the direction of increasing the windward area; otherwise, the blades rotate to a certain angle in the opposite direction of the former. When the wind turbine speed tends to the synchronous speed and runs stably near the rated wind speed value for a period of time, the unit can be connected to the grid.

[0041] S2: Add a feedforward compensator to give a suitable pitch angle feedforward value β2 according to the wind speed. Use a hybrid lidar to sense the incoming flow information in advance and provide it to the wind turbine control unit. The unit responds and actively matches the wind speed change.

[0042] S3: Compare the power feedback signal with the given value. When the power exceeds the rated power, the blade pitch is rotated by an angle in the direction of reducing the windward area, and vice versa. The fuzzy controller is used to control the pitch of the unit. The error between the generator feedback power and the target power and the error change rate are used as the input of the system, and the output is the change value of the pitch angle β1;

[0043] After the wind turbine is connected to the grid, the actual wind speed is less than the rated wind speed, and the output power of the unit is less than the rated power. The unit operates in a low-power state. The control of the working state of the unit at this time is called under-power state control. When the variable-pitch wind turbine is operating in an under-power state, the output power of the unit is lower than the rated power. In order to improve the power generation efficiency of the unit and capture wind energy as much as possible, the wind turbine is subjected to maximum power point tracking (MPPT) control in this operating state. When performing MPPT control, the variable-pitch wind turbine is controlled to remain unchanged near the optimized pitch angle of 0°, and then the generator stator current is adjusted by controlling the machine-side converter, thereby controlling the motor speed, and finally achieving the maximum power capture of the wind turbine.

[0044] Using LiDAR to conduct supplementary measurements of key areas can significantly reduce the investment risk of the project, optimize the wind turbine layout plan, and improve the project rate of return. LiDAR can measure more altitude layers and more types of wind parameter data, which is very valuable data for measuring wind turbine power curves. It can draw more accurate power curves to evaluate and optimize wind turbine performance. At the same time, LiDAR's 1Hz second-level data will provide information with higher time resolution of the wind speed field, which is necessary input data for studying wind resource characteristics, wind turbine loads, and wind turbine performance.

[0045] The use of laser radar can measure the wind speed 150 meters in front of the impeller, accurately identify different wind conditions, and perform active wind and safety control 5 to 10 seconds in advance, thereby significantly reducing the wind turbine load and improving the safety of the wind turbine, while also increasing the power generation of the unit.

[0046] Hybrid lidar includes vertical lidar and cabin lidar.

[0047] Vertical LiDAR can measure wind speed and direction within a vertical height of 290 meters. It can accurately obtain wind speed and direction data and measure 12 altitude layers at the same time. More accurate and reliable wind data can ensure successful project financing and reduce investment costs and uncertainties.

[0048] The nacelle-mounted lidar measures the wind speed at least 2.5D in front of the wind turbine, and the effective range is usually more than 400 meters.

[0049] The vertical laser radar has a range of 40-290m, a frequency of 1Hz, a minimum time resolution of 1 second, 12 data layers, and a wind speed accuracy of 0.1m / s.

[0050] The nacelle-mounted lidar has a range of 50-700m, a frequency of 1Hz, a minimum time resolution of 1 second, 10 data layers, and a wind speed accuracy of 0.1m / s.

[0051] In the available wind speed range, when the actual wind speed is greater than the rated wind speed, the wind turbine output power is generally greater than the rated power, and the unit enters the rated power operation state. Considering the mechanical stress of the wind turbine, the capacity of the generator and the limitation of the converter capacity, the unit needs to be pitch controlled.

[0052] A system database is set up, and the wind speed data of the wind turbine generator set will be stored in the system database. The data exceeding the rated wind speed in the past period of time will be processed and screened, and wind speed segments will be set up. Classification and statistics will be made on whether there is a yaw slip angle and yaw slip duration in each wind speed segment for each wind turbine, and a yaw slip warning will be set according to the yaw slip angle and yaw slip duration data.

[0053] The maximum wind speed is divided into three sections: 8≤wind speed<12, 12≤wind speed<16, wind speed≥16, and the threshold is set to 12. If the maximum wind speed exceeds the threshold 12, a yaw slip warning is issued; the slip angle is divided into three sections: 0<slip angle≤3°, 3°<slip angle≤6°, and slip angle>6°. The threshold is set to 4°. If the slip angle is greater than 4°, a yaw slip warning is issued.

[0054] The rated power of the wind turbine is 5MW; the rated wind speed is 11.1m / s; the cut-in wind speed is 2.5m / s; the rotor diameter is 190m; and the rated speed of the generator is 1700rpm.

[0055] The fuzzy controller membership function uses a triangular membership function, and the fuzzy controller judgment rules in S3 include:

[0056] S3.1: If the error between the output power and the target power is positive (negative) or positive (negative), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative (positive);

[0057] S3.2: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative small (positive small), increase the blade pitch angle to negative medium (positive medium);

[0058] S3.3: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative medium (positive medium) or negative large (positive large), the blade pitch angle is kept unchanged;

[0059] S3.4: If the error between the output power and the target power is positively small (negatively small), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative center (positive center);

[0060] S3.5: If the error between the output power and the target power is positive or negative, and the error changes to negative or positive, the blade pitch angle is kept unchanged;

[0061] S3.6: If the error between the output power and the target power is positive small (negative small), and the error changes to negative medium (positive medium) or negative large (positive large), increase the blade pitch angle to negative small (positive small).

[0062] S4: At rated wind speed, the power can be kept near the rated value by feedback control, and the pitch angle is near 0°. When the wind speed exceeds the rated wind speed, the pitch angle must be increased to a certain angle to keep the power at the rated value. Let v be the current wind speed, v0 be the rated wind speed, and the difference between the current wind speed and the rated wind speed is △v=v-v0. The larger △v is, the larger the pitch angle setting value should be.

[0063] For the sake of simplicity, the feedforward compensator adopts proportional control, that is, β2=K△v, K is a positive value. Considering that β2 and △v are not in completely positive proportional relationship, segmented proportional control can be adopted, that is, K takes different values ​​in different wind speed ranges, and the K value is preferably 2.

[0064] S5: Compensate an angle according to △v, and then superimpose the output β1 of the feedback control as the pitch angle setting value, add it to the output value of the power controller of the feedback system, and use it as the pitch angle setting value β0 of the variable pitch execution structure.

[0065] After adding a feedforward compensator, four measuring points are arranged on the end face of the elastic shaft bearing of the wind turbine. Copper-Constantan thermocouples are used for measurement to test the temperature of the measuring points respectively. The specific steps include:

[0066] S2.1: Start loading the fan. When the wind speed reaches the rated wind speed, record the temperature of each measuring point. When the wind speed exceeds the rated wind speed, record the temperature of the test measuring point every 10 minutes.

[0067] S2.2: When the temperature at the test point changes more every 10 minutes, the heat dissipation device of the wind turbine is started to dissipate heat from the wind turbine.

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0069] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization, characterized in that: The following steps are involved: S1: Calculate the rated wind speed. After the wind turbine is connected to the grid, when the wind speed is lower than the rated wind speed, the pitch angle can be kept at 0°. When the wind speed reaches the rated wind speed, the wind turbine enters the rated power state. S2: Add a feedforward compensator to give a suitable pitch angle feedforward value β2 according to the wind speed. Use a hybrid lidar to sense the incoming flow information in advance and provide it to the wind turbine control unit. The unit responds and actively matches the wind speed change. S3: Compare the power feedback signal with the given value. When the power exceeds the rated power, the blade pitch is rotated by an angle in the direction of reducing the windward area, and vice versa. The fuzzy controller is used to control the pitch of the unit. The error between the generator feedback power and the target power and the error change rate are used as the input of the system, and the output is the change value of the pitch angle β1; S4: At rated wind speed, the power can be kept near the rated value by feedback control, and the pitch angle is near 0°. When the wind speed exceeds the rated wind speed, the pitch angle must be increased to a certain angle to keep the power at the rated value. Let v be the current wind speed, v0 be the rated wind speed, and the difference between the current wind speed and the rated wind speed is △v=v-v0. The larger △v is, the larger the pitch angle setting value should be. S5: Compensate an angle according to △v, and then superimpose the output β1 of the feedback control as the pitch angle setting value, add it to the output value of the power controller of the feedback system, and use it as the pitch angle setting value β0 of the variable pitch execution structure.

2. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: When the wind speed in S1 is lower than the rated wind speed, the generator stator current is adjusted by controlling the machine-side converter, thereby controlling the motor speed, and ultimately achieving maximum power capture of the wind turbine set.

3. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: The hybrid laser radar in S2 includes a vertical laser radar and a cabin laser radar.

4. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: The fuzzy controller membership function uses a triangular membership function, and the fuzzy controller determination rules in S3 include: S3.1: If the error between the output power and the target power is positive (negative) or positive (negative), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative (positive); S3.2: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative small (positive small), increase the blade pitch angle to negative medium (positive medium); S3.3: If the error between the output power and the target power is positive large (negative large) or positive medium (negative medium), and the error changes to negative medium (positive medium) or negative large (positive large), the blade pitch angle is kept unchanged; S3.4: If the error between the output power and the target power is positively small (negatively small), and the error changes to positive (negative) or zero, increase the blade pitch angle to negative center (positive center); S3.5: If the error between the output power and the target power is positive or negative, and the error changes to negative or positive, the blade pitch angle is kept unchanged; S3.6: If the error between the output power and the target power is positive small (negative small), and the error changes to negative medium (positive medium) or negative large (positive large), increase the blade pitch angle to negative small (positive small).

5. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: In S1, when the rotation speed is lower than the rated wind speed, the blades rotate to a certain angle in the direction of increasing the frontal area; otherwise, the blades rotate to a certain angle in the opposite direction. When the fan speed approaches the synchronous speed and runs stably near the rated wind speed for a period of time, the unit can be connected to the grid.

6. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: A system database is set up, and the wind speed data of the wind turbine generator set will be stored in the system database. The data exceeding the rated wind speed in the past period of time will be processed and screened, and wind speed segments will be set. Classification and statistics will be conducted on whether there is yaw slip, yaw slip angle, and yaw slip duration in each wind speed segment for each wind turbine, and a yaw slip warning will be set according to the data of yaw slip angle and yaw slip duration.

7. The method for increasing the power generation of a wind turbine generator set based on genetic algorithm optimization according to claim 1, characterized in that: In S2, after adding a feedforward compensator, four measuring points are arranged on the end surface of the elastic shaft bearing of the wind turbine, and copper-constantan thermocouples are used for measurement to test the temperature of the measuring points respectively. The specific steps include: S2.1: Start loading the fan. When the wind speed reaches the rated wind speed, record the temperature of each measuring point. When the wind speed exceeds the rated wind speed, record the temperature of the test measuring point every 10 minutes. S2.2: When the temperature at the test point changes more every 10 minutes, the heat dissipation device of the wind turbine is started to dissipate heat from the wind turbine.

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