A wind turbine variable pitch PID gain dynamic adjustment optimization method and system

Abstract

The application discloses a kind of wind turbine variable pitch PID gain dynamic adjustment optimization method and system, the method includes the following steps: S1, determine the speed-torque curve;S2, limit speed and under variable air density under variable pitch PID gain setting;S3, limit speed variable pitch PID gain scheduling;S4, variable air density variable pitch PID gain scheduling;S5, under variable turbulence variable pitch PID gain scheduling;The application compared with existing variable pitch PID control method, without increasing additional control means, high technical maturity, the hardware cost required is low, robustness is good, real-time performance is excellent, and the influence of limit speed, air density and turbulence on variable pitch PID gain is comprehensively considered, so as to effectively reduce the generator speed overspeed and power fluctuation problem caused by speed and air density change under large turbulence conditions.

Description

Technical Field

[0001] This invention relates to the technical field of wind turbine pitch gain regulation, and in particular to a method and system for dynamic adjustment and optimization of wind turbine pitch PID gain. Background Technology

[0002] With global warming, wind turbulence has increased significantly, and temperature variations throughout the year have become more dramatic, posing new challenges to the design and operation of wind turbines. PID controllers, due to their simple principle and wide applicability, are widely used in wind turbine control. However, with significant changes in turbulence and temperature, pitch PID parameters tuned based on standard air density are no longer suitable under conditions of limited speed and variable air density.

[0003] Current methods for correcting pitch PID parameters generally lack theoretical basis. For example, Chinese invention patent application CN106368898A discloses a regulation and control method for large wind turbine generators, which corrects the gain of the pitch PI controller by the proportion by which the generator speed exceeds a set limit. However, this correction method only utilizes the speed ratio and does not consider the stability of the entire wind turbine generator control model, which can easily lead to inaccurate PID parameters, thereby causing overshoot and oscillation problems.

[0004] Furthermore, advanced control theories, such as fuzzy PID and BP neural networks, have been attempted to be introduced into the pitch PID control of wind turbines. For example, Chinese invention patent application CN117028141A proposes a method for adaptively adjusting PI parameters using a BP neural network. Although this method can adjust pitch for different operating conditions, BP neural networks require significant computational resources and are highly dependent on the quality and quantity of training data, resulting in poor interpretability of the control. Chinese invention patent application CN105508135A proposes a pitch control method combining fuzzy feedforward and fuzzy PID control; however, the fuzzy PID controller is not suitable for practical industrial applications due to its design and adjustment complexity, high computational requirements, and poor real-time performance.

[0005] Currently, under conditions of limited speed and variable air density, industry still mainly relies on traditional PID control. However, methods for adjusting PID parameters under conditions of limited speed and variable air density in highly turbulent conditions have not yet received sufficient theoretical support. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and propose a dynamic adjustment and optimization method and system for the PID gain of wind turbine pitch control. This method performs pitch control PID parameter tuning under limited speed and varying air density, and uses turbulence to correct the pitch control PID. It comprehensively considers the influence of limited speed, air density and turbulence on the pitch control PID gain, thereby effectively reducing the problems of generator speed overspeed and power fluctuation caused by changes in speed and air density under high turbulence conditions.

[0007] The objective of this invention is achieved through the following technical solution: a method for dynamic adjustment and optimization of PID gain in wind turbine pitch control, comprising the following steps:

[0008] S1. Set the upper limit of the speed and torque of the wind turbine converter, determine the speed-torque curve, and select several speed points and their corresponding torques as basic data.

[0009] S2. Based on the determined speed-torque curve, linearize the basic data and tune the pitch PID gain under the limit speed based on the linearization model; and considering the actual air density, linearize the basic data again and tune the pitch PID gain under varying air density.

[0010] S3. When the wind turbine is in normal power generation, according to the set speed value and the rated speed value of the wind turbine, activate the pitch PID gain under the speed limit set in step S2, and perform pitch PID gain scheduling on the rated speed and rated torque under standard air density.

[0011] S4. Based on the real-time measured air density and the pitch PID gain after step S3, activate the pitch PID gain under the variable air density tuned in step S2 and perform pitch PID gain scheduling.

[0012] S5. Based on the pitch PID gain after scheduling in step S4, calculate the ratio of turbulence to local average turbulence intensity in real time, perform pitch PID gain scheduling, and finally complete the dynamic adjustment of pitch PID gain.

[0013] Furthermore, step S1 includes:

[0014] Based on the design parameters and operating requirements of the wind turbine generator, upper limits for the converter's speed and torque are set. These upper limits do not restrict the power output of the wind turbine during normal power generation. The speed-torque curve is determined and output, and several points are selected as target values ​​for the speed-pitch control loop. The target values ​​are selected from the wind turbine's grid-connected speed V1 to its rated speed V1. n There are n rotational speed points, and the torque corresponding to each rotational speed point is from T1 to T2. n This serves as the basis for adjusting the pitch PID gain.

[0015] Furthermore, step S2 includes:

[0016] Based on the speed-torque curve determined in step S1, the basic data are used as the rated speed and torque of the Bladed model and linearized. The linearized model is then used to tune the pitch PID gain of the wind turbine's speed-pitch control loop, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the speed limit. While determining the pitch PID gain under the speed limit, the actual air density ρ is considered, and each basic data is re-linearized to determine the pitch PID gain under varying air density.

[0017] Furthermore, step S3 includes:

[0018] When the wind turbine is in normal power generation mode, and the speed setpoint V set Less than the rated value of the wind turbine V rated At that time, the pitch PID gain under the speed limit tuned in step S2 is activated, so that the pitch PID parameter K p K i and K d The pitch PID gain is adjusted according to the tuned pitch PID gain to control the rated speed and rated torque under standard air density.

[0019] Furthermore, step S4 includes:

[0020] During the speed-limited pitch PID gain scheduling of wind turbines, when the wind turbine is generating electricity normally, the pitch PID parameter K is adjusted based on the real-time measured air density. p K i and K d Adjustments are made to adapt to actual changes in air density, thus completing the variable pitch PID gain scheduling under varying air density conditions.

[0021] Furthermore, step S5 includes:

[0022] Based on the pitch PID gain after step S4, the turbulence value I is calculated in real time. t With local average turbulence intensity I ave The ratio k I The pitch PID parameters are corrected by multiplying each pitch PID parameter by a ratio coefficient k. I By correcting the pitch PID gain under different turbulence values, the adaptability and control accuracy of the wind turbine under complex airflow conditions are improved, and the dynamic adjustment of the pitch PID gain is finally achieved.

[0023] A dynamic adjustment and optimization system for the PID gain of a wind turbine pitch control unit, used to implement the aforementioned dynamic adjustment and optimization method for the PID gain of a wind turbine pitch control unit, comprising:

[0024] The unit speed-torque confirmation module determines the speed-torque curve based on the speed and torque upper limit of the wind turbine converter, and selects several speed points and their corresponding torques as basic data.

[0025] The pitch PID gain tuning module under speed limit linearizes the basic data based on the determined speed-torque curve and tunes the pitch PID gain under speed limit based on the linearization model.

[0026] The pitch PID gain tuning module under varying air density takes into account the actual air density and re-linearizes the basic data to tune the pitch PID gain under varying air density.

[0027] The speed-limited pitch PID gain scheduling module activates the speed-limited pitch PID gain according to the set speed value and the rated speed value of the wind turbine when the wind turbine is in normal power generation state, and performs pitch PID gain scheduling on the rated speed and rated torque under standard air density.

[0028] The variable air density variable pitch PID gain scheduling module activates the variable pitch PID gain under variable air density based on the real-time measured air density and the variable pitch PID gain after scheduling in step S3, and performs variable pitch PID gain scheduling.

[0029] The variable turbulence pitch PID gain scheduling module calculates the ratio of turbulence intensity to local average turbulence intensity in real time based on the pitch PID gain after variable air density scheduling, and performs pitch PID gain scheduling accordingly.

[0030] A non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the wind turbine pitch PID gain dynamic adjustment optimization method described above.

[0031] A computing device includes a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the above-described method for dynamic adjustment and optimization of the PID gain of wind turbine pitch control.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] 1. This invention improves upon the existing pitch PID control method, eliminating the need for significant performance upgrades to the original programmable logic controller (PLC) of the wind turbine, thereby avoiding increased hardware development costs.

[0034] 2. This invention provides a more scientific PID parameter design method. Based on the actual wind turbine speed-torque curve, the target speed and torque are reset and linearized using the Bladed model. The PID parameters are then retuned using the transfer function of the wind turbine control loop, resulting in more reasonable PID gain scheduling under speed-limited conditions. Similarly, parameter tuning under varying air density conditions is also more reasonable.

[0035] 3. This invention takes into account the influence of turbulence on the pitch PID parameters and uses the ratio of real-time turbulence to local average turbulence to correct the pitch PID parameters, thereby improving the adaptability of the control system under complex airflow conditions.

[0036] 4. This invention comprehensively considers the effects of speed limit, air density, and turbulence on the pitch PID gain, thus solving the problem of versatility. By adjusting the PID parameters for speed limit, variable air density, and variable turbulence, it effectively reduces generator speed overspeed and power fluctuations caused by changes in speed and air density under high turbulence conditions.

[0037] Through these innovations, this invention improves the system's adaptability and efficiency while ensuring the operational stability of the wind turbine generator set. Attached Figure Description

[0038] Figure 1 This is a flowchart of an optimization method for dynamic adjustment of PID gain in wind turbine pitch control.

[0039] Figure 2 The speed timing diagram for pitch PID gain scheduling under speed limit conditions.

[0040] Figure 3 Power timing diagram for pitch PID gain scheduling under speed-limited conditions.

[0041] Figure 4 The timing diagram shows the rotational speed of the variable air density PID gain scheduling of the pitch control.

[0042] Figure 5 The power timing diagram is for variable air density PID gain scheduling of pitch control.

[0043] Figure 6 The rotational speed timing diagram is for the PID gain scheduling of pitch control under variable turbulence.

[0044] Figure 7 The power timing diagram is for the PID gain scheduling of pitch control under variable turbulence. Detailed Implementation

[0045] The present invention will be further described below with reference to specific embodiments.

[0046] Example 1

[0047] See Figure 1 As shown in this embodiment, the wind turbine pitch PID gain dynamic adjustment optimization method includes the following steps:

[0048] S1. Set the upper limit of the wind turbine converter speed and torque, determine the speed-torque curve, and select several speed points and their corresponding torques as basic data, including:

[0049] Based on the design parameters and operating requirements of the wind turbine generator, upper limits for the converter's speed and torque are set. These upper limits do not restrict the power output of the wind turbine during normal power generation. The speed-torque curve is determined and output, and several points are selected as target values ​​for the speed-pitch control loop. The target values ​​are selected from the wind turbine's grid-connected speed V1 to its rated speed V1. n There are n rotational speed points, and the torque corresponding to each rotational speed point is from T1 to T2. n This serves as the basis for adjusting the pitch PID gain.

[0050] S2. Based on the determined speed-torque curve, linearize the basic data and tune the pitch PID gain at the limit speed using the linearized model; then, considering the actual air density, re-linearize the basic data and tune the pitch PID gain under varying air densities, including:

[0051] Based on the speed-torque curve determined in step S1, the torques corresponding to speed points V1, V2, and V3 are selected as T1, T2, and T3, respectively, where V1 is the grid-connected speed and V3 is the rated speed. These basic data are used as the rated speed and torque of the Bladed model and linearized. The linearized model is then used to tune the pitch PID gain of the wind turbine's speed-pitch control loop, controlling its phase margin between θ1 and θ2. The pitch PID gain under speed limits is determined. It is particularly important to note that the synchronous speed Ω should be avoided during tuning of the doubly-fed induction generator (DFIG) unit. While considering the actual air density ρ under the limited speed, the pitch PID gain is re-linearized for each basic data point. The linearized model is used to tune the pitch PID gain of the wind turbine speed-pitch control loop, and its phase margin is controlled between θ1 and θ2. The pitch PID gain under varying air density is determined, such as by selecting air densities ρ1, ρ2, and ρ3, where ρ2 is the actual air density on site, and ρ1 < ρ2 < ρ3. When adjusting the PID gain, it should be ensured that the linearized model can accurately reflect the impact of actual air density changes on system performance.

[0052] S3. When the wind turbine is in normal power generation, based on the set speed value and the rated speed value of the wind turbine, activate the pitch PID gain under the speed limit set in step S2, and perform pitch PID gain scheduling on the rated speed and rated torque under standard air density, including:

[0053] When the wind turbine is in normal power generation mode, and the speed setpoint V set Less than the rated value of the wind turbine V rated At that time, the pitch PID gain under the speed limit tuned in step S2 is activated, so that the pitch PID parameter K p K i and K d Based on the tuned pitch PID gain, the rated speed and rated torque under standard air density are adjusted using the pitch PID gain, such as V. set Between V1 and V2, according to the K corresponding to the rotational speed. p K i and K d Gain linear lookup table is used to adjust the gain of the PID parameters. See also Figure 2 and Figure 3 As shown, after enabling speed-limited gain control, the standard deviations of both speed and power are reduced to some extent, and speed and power control are more stable.

[0054] S4. Based on the real-time measured air density and the pitch PID gain scheduled in step S3, activate the pitch PID gain tuned in step S2 under varying air density, and perform pitch PID gain scheduling, including:

[0055] During the speed-limited pitch PID gain scheduling of wind turbines, when the wind turbine is generating electricity normally, the pitch PID parameter K is adjusted based on the real-time measured air density. p K i and K d Adjustments are made to adapt to actual air density changes, enabling variable-density PID gain scheduling of the pitch control under varying air densities. For example, if the measured air density is between ρ1 and ρ2, the PID parameters are adjusted according to the K value corresponding to the air density. p K i and K d Gain is linearly lookup-based for scheduling. These gain adjustments are multiplied cumulatively based on the results after speed limit adjustments to ensure that the final PID gain comprehensively considers the effects of both speed limit and variable air density factors. See also Figure 4 and Figure 5 As shown, after enabling variable air density gain scheduling, the maximum value and standard deviation of speed and power are all reduced to some extent.

[0056] S5. Based on the pitch PID gain after scheduling in step S4, calculate the ratio of turbulence intensity to local average turbulence intensity in real time, perform pitch PID gain scheduling, and finally complete the dynamic adjustment of pitch PID gain, including:

[0057] Based on the pitch PID gain after step S4, the turbulence value I is calculated in real time. t With local average turbulence intensity Iave The ratio k I The pitch PID parameters are corrected by multiplying each pitch PID parameter by a ratio coefficient k. I By adjusting the pitch PID gain under different turbulence values, the adaptability and control accuracy of the wind turbine under complex airflow conditions are improved, ultimately achieving dynamic adjustment of the pitch PID gain. (See also...) Figure 6 and Figure 7 As shown, after enabling variable turbulence gain scheduling, the standard deviations of speed and power are reduced to some extent, and the fluctuations in speed and power are smaller.

[0058] Example 2

[0059] The wind turbine pitch PID gain dynamic adjustment and optimization system disclosed in this embodiment is used to implement the wind turbine pitch PID gain dynamic adjustment and optimization method described in Embodiment 1, including:

[0060] The unit speed-torque confirmation module determines the speed-torque curve based on the speed and torque upper limit of the wind turbine converter, and selects several speed points and their corresponding torques as basic data.

[0061] The pitch PID gain tuning module under speed limit linearizes the basic data based on the determined speed-torque curve and tunes the pitch PID gain under speed limit based on the linearization model.

[0062] The pitch PID gain tuning module under varying air density takes into account the actual air density and re-linearizes the basic data to tune the pitch PID gain under varying air density.

[0063] The speed-limited pitch PID gain scheduling module activates the speed-limited pitch PID gain according to the set speed value and the rated speed value of the wind turbine when the wind turbine is in normal power generation state, and performs pitch PID gain scheduling on the rated speed and rated torque under standard air density.

[0064] The variable air density variable pitch PID gain scheduling module activates the variable pitch PID gain under variable air density based on the real-time measured air density and the variable pitch PID gain after scheduling in step S3, and performs variable pitch PID gain scheduling.

[0065] The variable turbulence pitch PID gain scheduling module calculates the ratio of turbulence intensity to local average turbulence intensity in real time based on the pitch PID gain after variable air density scheduling, and performs pitch PID gain scheduling accordingly.

[0066] Example 3

[0067] This embodiment discloses a non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the wind turbine pitch PID gain dynamic adjustment optimization method according to Embodiment 1.

[0068] In this embodiment, the non-transitory computer-readable medium can be a disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), USB flash drive, portable hard drive, etc.

[0069] Example 4

[0070] 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 wind turbine pitch PID gain dynamic adjustment optimization method described in Embodiment 1.

[0071] 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.

[0072] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes made in accordance with the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for dynamic adjustment and optimization of PID gain in wind turbine pitch control, characterized in that, Includes the following steps: S1. Set the upper limit of the speed and torque of the wind turbine converter, determine the speed-torque curve, and select several speed points and their corresponding torques as basic data. S2. Based on the determined speed-torque curve, linearize the basic data and tune the pitch PID gain at the limit speed using the linearized model; then, considering the actual air density, re-linearize the basic data and tune the pitch PID gain under varying air densities, including: Based on the speed-torque curve determined in step S1, the basic data are used as the rated speed and torque of the Bladed model and linearized. The linearized model is used to tune the pitch PID gain of the wind turbine's speed-pitch control loop, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the speed limit. While determining the pitch PID gain under the speed limit, the actual air density ρ is considered, and each basic data is re-linearized, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the variable air density. S3. When the wind turbine is in normal power generation, according to the set speed value and the rated speed value of the wind turbine, activate the pitch PID gain under the speed limit set in step S2, and perform pitch PID gain scheduling on the rated speed and rated torque under standard air density. S4. Based on the real-time measured air density and the pitch PID gain after step S3, activate the pitch PID gain under the variable air density tuned in step S2 and perform pitch PID gain scheduling. S5. Based on the pitch PID gain after scheduling in step S4, calculate the ratio of turbulence intensity to local average turbulence intensity in real time, perform pitch PID gain scheduling, and finally complete the dynamic adjustment of pitch PID gain, including: Based on the pitch PID gain after step S4, the turbulence value I is calculated in real time. t With local average turbulence intensity I ave The ratio k I The pitch PID parameters are corrected by multiplying each pitch PID parameter by a ratio coefficient k. I By correcting the pitch PID gain under different turbulence values, the adaptability and control accuracy of the wind turbine under complex airflow conditions are improved, and the dynamic adjustment of the pitch PID gain is finally achieved.

2. The method for dynamic adjustment and optimization of PID gain in wind turbine pitch control according to claim 1, characterized in that, Step S1 includes: Based on the design parameters and operating requirements of the wind turbine generator, upper limits for the converter's speed and torque are set. These upper limits do not restrict the power output of the wind turbine during normal power generation. The speed-torque curve is determined and output, and several points are selected as target values ​​for the speed-pitch control loop. The target values ​​are selected from the wind turbine's grid-connected speed V1 to its rated speed V1. n There are n rotational speed points, and the torque corresponding to each rotational speed point is from T1 to T2. n This serves as the basis for adjusting the pitch PID gain.

3. The method for dynamic adjustment and optimization of PID gain in wind turbine pitch control according to claim 1, characterized in that, Step S3 includes: When the wind turbine is in normal power generation mode, and the speed setpoint V set Less than the rated value of the wind turbine V rated At that time, the pitch PID gain under the speed limit tuned in step S2 is activated, so that the pitch PID parameter K p K i and K d The pitch PID gain is adjusted according to the tuned pitch PID gain to control the rated speed and rated torque under standard air density.

4. The method for dynamic adjustment and optimization of PID gain in wind turbine pitch control according to claim 1, characterized in that, Step S4 includes: During the speed-limited pitch PID gain scheduling of wind turbines, when the wind turbine is generating electricity normally, the pitch PID parameter K is adjusted based on the real-time measured air density. p K i and K d Adjustments are made to adapt to actual changes in air density, thus completing the variable pitch PID gain scheduling under varying air density conditions.

5. A dynamic adjustment and optimization system for PID gain of wind turbine pitch control, characterized in that, The method for dynamically adjusting and optimizing the PID gain of a wind turbine pitch control unit as described in any one of claims 1-4 includes: The unit speed-torque confirmation module determines the speed-torque curve based on the speed and torque upper limit of the wind turbine converter, and selects several speed points and their corresponding torques as basic data. The pitch PID gain tuning module under speed limit linearizes the basic data based on the determined speed-torque curve and tunes the pitch PID gain under speed limit based on the linearization model. The pitch PID gain tuning module under varying air density takes into account the actual air density and re-linearizes the basic data to tune the pitch PID gain under varying air density. The speed-limited pitch PID gain scheduling module activates the speed-limited pitch PID gain according to the set speed value and the rated speed value of the wind turbine when the wind turbine is in normal power generation state, and performs pitch PID gain scheduling on the rated speed and rated torque under standard air density. The variable air density variable pitch PID gain scheduling module activates the variable pitch PID gain under variable air density based on the real-time measured air density and the variable pitch PID gain after scheduling in step S3, and performs variable pitch PID gain scheduling. The variable turbulence pitch PID gain scheduling module calculates the ratio of turbulence intensity to local average turbulence intensity in real time based on the pitch PID gain after variable air density scheduling, and performs pitch PID gain scheduling accordingly.

6. A non-transitory computer-readable medium storing instructions, characterized in that, When the instruction is executed by the processor, the steps of the wind turbine pitch PID gain dynamic adjustment optimization method according to any one of claims 1-4 are performed.

7. A computing device, comprising a processor and a memory for storing a processor-executable program, characterized in that, When the processor executes the program stored in the memory, it implements the wind turbine pitch PID gain dynamic adjustment optimization method according to any one of claims 1-4.

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