Method and system for dynamically adjusting and optimizing variable-pitch PID (Proportion Integration Differentiation) gain of wind turbine generator

Abstract

The invention discloses a wind turbine generator variable pitch PID gain dynamic adjustment optimization method and system. The method comprises the following steps that S1, a rotating speed-torque curve is determined; s2, variable-pitch PID gain setting is carried out under the limited rotating speed and the variable air density; s3, variable-pitch PID gain scheduling of the limited rotating speed is carried out; s4, variable-pitch PID gain scheduling of the variable air density is carried out; s5, performing variable pitch PID gain scheduling under variable turbulence; compared with an existing variable-pitch PID control method, the variable-pitch PID control method has the advantages that additional control means do not need to be added, the technical maturity is high, the needed hardware cost is low, robustness is good, the real-time performance is excellent, the influence of the limited rotating speed, air density and turbulence on variable-pitch PID gains is comprehensively considered, and the method is suitable for large-scale popularization and application. Therefore, the problems of overspeed rotating speed and power fluctuation of the generator caused by changes of the rotating speed and the air density under the condition of large turbulence are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine pitch gain regulation, and in particular to a method and system for dynamically regulating and optimizing a wind turbine pitch PID gain. Background Art

[0002] As the climate warms, the turbulence of wind resources increases significantly, and the temperature changes become more dramatic throughout the year, which poses new challenges to the design and operation of wind turbines. PID controllers are widely used in the control of wind turbines because of their simple principles and strong applicability. However, with the significant changes in turbulence and temperature, the variable pitch PID parameters adjusted based on standard air density are no longer applicable under limited speed and variable air density conditions.

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

[0004] In addition, wind turbine pitch PID control also attempts to introduce advanced control theories, such as fuzzy PID and BP neural network. For example, Chinese invention patent application CN117028141A proposes a method for adaptively adjusting PI parameters using BP neural network. Although this method can adjust the pitch according to different working conditions, the BP neural network requires a lot of computing resources and is highly dependent on the quality and quantity of training data, and the control interpretability is poor. Chinese invention patent application CN105508135A proposes a pitch control method combining fuzzy feedforward and fuzzy PID control, but the fuzzy PID controller is not conducive to actual industrial applications due to its complexity of design and adjustment, high computing power requirements and poor real-time performance.

[0005] At present, the industry still mainly relies on traditional PID control under limited speed and variable air density conditions. However, the method of adjusting PID parameters for limited speed and variable air density under high turbulence conditions has not yet received sufficient theoretical support. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a method and system for dynamically adjusting and optimizing the variable pitch PID gain of a wind turbine set, which performs variable pitch PID parameter adjustment under limited speed and variable air density and utilizes turbulence to correct the variable pitch PID, and comprehensively considers the influence of limited speed, air density and turbulence on the variable pitch 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 purpose of the present invention is achieved through the following technical solution: A method for dynamically adjusting and optimizing the variable pitch PID gain of a wind turbine generator system, comprising the following steps:

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

[0009] S2. According to the determined speed-torque curve, the basic data is linearized, and the variable pitch PID gain under the speed limit is adjusted based on the linearization model; and considering the actual air density, the basic data is re-linearized to adjust the variable pitch PID gain under the variable air density;

[0010] S3. When the wind turbine is in a normal power generation state, according to the set speed value and the rated speed value of the wind turbine, the variable pitch PID gain under the speed limit set in step S2 is activated, and the variable pitch PID gain is scheduled for the rated speed and rated torque under the standard air density;

[0011] S4. According to the real-time measured air density and the pitch PID gain after the scheduling in step S3, the pitch PID gain under the variable air density set in step S2 is activated to perform pitch PID gain scheduling;

[0012] S5. According to the variable pitch PID gain scheduled in step S4, the ratio of turbulence to the local average turbulence intensity is calculated in real time, the variable pitch PID gain is scheduled, and finally the dynamic adjustment of the variable pitch PID gain is completed.

[0013] Further, the step S1 comprises:

[0014] According to the design parameters and operation requirements of the wind turbine generator, the speed and torque upper limits of the converter are set. The speed and torque upper limits do not limit 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 the target value of the speed-pitch control loop. The speed of the wind turbine is selected from the grid-connected speed V1 to the rated speed V n There are n speed points, and the torque corresponding to each speed point is from T1 to T n , as the basic data for adjusting the pitch PID gain.

[0015] Further, the step S2 comprises:

[0016] According to the speed-torque curve determined in step S1, the basic data is used as the rated speed and torque of the Bladed model and linearized. The linearized model is used to adjust the pitch PID gain of the speed-pitch control loop of the wind turbine, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the limited speed. While determining the pitch PID gain under the limited speed, the actual air density ρ is taken into account, and each basic data is re-linearized to determine the pitch PID gain under the variable air density.

[0017] Further, the step S3 comprises:

[0018] When the wind turbine is in normal power generation state and the speed setting value V set Less than the rated value V of the wind turbine rated When the variable pitch PID gain at the speed limit set in step S2 is activated, the variable pitch PID parameter K p , K i and K d According to the set pitch PID gain, the pitch PID gain is scheduled for the rated speed and rated torque under standard air density.

[0019] Further, the step S4 comprises:

[0020] During the speed-limited pitch PID gain scheduling process of the wind turbine, when the wind turbine is in normal power generation, the pitch PID parameter K is adjusted according to the real-time measured air density. p , K i and K d Adjustments are made to adapt to actual changes in air density and to complete variable pitch PID gain scheduling under variable air density.

[0021] Further, the step S5 comprises:

[0022] According to the variable pitch PID gain after step S4 scheduling, the turbulence value I is calculated in real time. t The local average turbulence intensity I ave The ratio k I , the pitch PID parameters are corrected, that is, the pitch PID parameters are multiplied by the ratio coefficient k I , by correcting the variable pitch PID gain at different turbulence values, the adaptability and control accuracy of the wind turbine under complex airflow conditions are improved, and finally the dynamic adjustment of the variable pitch PID gain is completed.

[0023] A wind turbine pitch PID gain dynamic adjustment optimization system, used to implement the wind turbine pitch PID gain dynamic adjustment optimization method, comprising:

[0024] The unit speed-torque confirmation module determines the speed-torque curve according to 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 variable pitch PID gain adjustment module under limited speed linearizes the basic data according to the determined speed-torque curve, and adjusts the variable pitch PID gain under limited speed based on the linearization model;

[0026] The variable pitch PID gain adjustment module under variable air density considers the actual air density, re-linearizes the basic data, and adjusts the variable pitch PID gain under variable 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 for the rated speed and rated torque under standard air density;

[0028] The variable pitch PID gain scheduling module for variable air density activates the variable pitch PID gain under the variable air density according to 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 to the local average turbulence intensity in real time according to the variable pitch PID gain after variable air density scheduling, and performs variable pitch PID gain scheduling.

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

[0031] A computing device comprises a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the above-mentioned method for dynamically adjusting and optimizing the variable pitch PID gain of a wind turbine is implemented.

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

[0033] 1. The present invention improves upon the existing variable pitch PID control method and does not require significant performance enhancement of the original programmable logic controller (PLC) of the wind turbine, thereby avoiding an increase in hardware development costs.

[0034] 2. The present invention provides a more scientific PID parameter design method. According to the speed and torque curve of the actual wind turbine, the target speed and torque are reset and linearized using the Bladed model, and the PID parameters are re-adjusted using the transfer function of the wind turbine control loop, so that the PID gain scheduling under the speed limit is more reasonable. Similarly, the parameter setting under variable air density is also more reasonable.

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

[0036] 4. The present invention comprehensively considers the influence of speed limit, air density and turbulence value on variable pitch PID gain, and solves the problem of universality. By adjusting the PID parameters of speed limit, variable air density and variable turbulence, the problem of generator speed overspeed and power fluctuation caused by speed and air density changes under high turbulence conditions is effectively reduced.

[0037] Through these innovations, the present invention improves the adaptability and efficiency of the system while ensuring the operational stability of the wind turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a flow chart of the wind turbine pitch PID gain dynamic adjustment optimization method.

[0039] Figure 2 This is the speed timing diagram of the pitch PID gain scheduling under limited speed.

[0040] Figure 3 This is the power timing diagram of the pitch PID gain scheduling under limited speed.

[0041] Figure 4 The speed timing diagram of variable pitch PID gain scheduling under variable air density.

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

[0043] Figure 6 The speed timing diagram of variable pitch PID gain scheduling under variable turbulence.

[0044] Figure 7 This is the power timing diagram of variable pitch PID gain scheduling under variable turbulence. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with specific embodiments.

[0046] Example 1

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

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

[0049] According to the design parameters and operation requirements of the wind turbine generator, the speed and torque upper limits of the converter are set. The speed and torque upper limits do not limit 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 the target value of the speed-pitch control loop. The speed of the wind turbine is selected from the grid-connected speed V1 to the rated speed V n There are n speed points, and the torque corresponding to each speed point is from T1 to T n , as the basic data for adjusting the pitch PID gain.

[0050] S2. According to the determined speed-torque curve, the basic data is linearized, and the variable pitch PID gain under the speed limit is adjusted based on the linearization model; and considering the actual air density, the basic data is re-linearized, and the variable pitch PID gain under the variable air density is adjusted, including:

[0051] According to the speed-torque curve determined in step S1, the speed points V1, V2 and V3 are selected to correspond to torques T1, T2 and T3, where V1 is the grid-connected speed and V3 is the rated speed. The above basic data are used as the rated speed and torque of the Bladed model and linearized. The linearized model is used to adjust the pitch PID gain of the speed-pitch control loop of the wind turbine, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the limited speed. It is particularly noted that the doubly fed unit should avoid the synchronous speed Ω when adjusting. While adjusting the pitch PID gain under limited speed, the actual air density ρ is considered, each basic data is re-linearized, and the pitch PID gain of the wind turbine speed-pitch control loop is adjusted using the linearization model, and its phase margin is controlled between θ1 and θ2. The pitch PID gain under variable air density is determined, such as selecting air densities ρ1, ρ2 and ρ3, where ρ2 is the air density on site, and ρ1<ρ2<ρ3. When adjusting the PID gain, it should be ensured that the linearization model can accurately reflect the impact of actual air density changes on system performance.

[0052] S3. When the wind turbine is in a normal power generation state, according to the set speed value and the rated speed value of the wind turbine, the variable pitch PID gain under the speed limit set in step S2 is activated, and the variable pitch PID gain is scheduled for the rated speed and rated torque under the standard air density, including:

[0053] When the wind turbine is in normal power generation state and the speed setting value V set Less than the rated value V of the wind turbine rated When the variable pitch PID gain at the speed limit set in step S2 is activated, the variable pitch PID parameter K p , K i and K d According to the set pitch PID gain, the pitch PID gain is scheduled for the rated speed and rated torque under standard air density, such as V set Between V1 and V2, according to the speed corresponding to K p , K i and K d Gain linear lookup table performs gain scheduling on PID parameters. Figure 2 and Figure 3 As shown in the figure, after the speed limit gain scheduling is turned on, the standard deviation of speed and power are reduced to a certain extent, and the speed and power control are more stable.

[0054] S4, according to the real-time measured air density and the pitch PID gain after the scheduling in step S3, the pitch PID gain under the variable air density set in step S2 is activated, and the pitch PID gain scheduling is performed, including:

[0055] During the speed-limited pitch PID gain scheduling process of the wind turbine, when the wind turbine is in normal power generation, the pitch PID parameter K is adjusted according to the real-time measured air density. p , K i and K d Adjustments are made to adapt to the actual air density changes and complete the variable pitch PID gain scheduling under variable air density. If the actual measured air density is between ρ1 and ρ2, the PID parameters are adjusted according to the K corresponding to the air density. p , K i and K d Gain linear lookup table scheduling, these gain adjustments are cumulatively multiplied on the results after speed limit adjustment to ensure that the final PID gain can comprehensively consider the influence of speed limit and variable air density. Figure 4 and Figure 5 As shown in the figure, after the variable air density gain scheduling is turned on, the maximum value and standard deviation of the speed and power are reduced to a certain extent.

[0056] S5, according to the variable pitch PID gain after the scheduling in step S4, the ratio of turbulence to the local average turbulence intensity is calculated in real time, the variable pitch PID gain is scheduled, and finally the variable pitch PID gain dynamic adjustment is completed, including:

[0057] According to the variable pitch PID gain after step S4 scheduling, the turbulence value I is calculated in real time. t The local average turbulence intensity Iave The ratio k I , the pitch PID parameters are corrected, that is, the pitch PID parameters are multiplied by the ratio coefficient k I By correcting the pitch PID gain at 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 completed. Figure 6 and Figure 7 As shown in the figure, after turning on the variable turbulence gain scheduling, the speed and power standard deviations are reduced to a certain extent, and the speed and power fluctuations are smaller.

[0058] Example 2

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

[0060] The unit speed-torque confirmation module determines the speed-torque curve according to 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 variable pitch PID gain adjustment module under limited speed linearizes the basic data according to the determined speed-torque curve, and adjusts the variable pitch PID gain under limited speed based on the linearization model;

[0062] The variable pitch PID gain adjustment module under variable air density considers the actual air density, re-linearizes the basic data, and adjusts the variable pitch PID gain under variable 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 for the rated speed and rated torque under standard air density;

[0064] The variable pitch PID gain scheduling module for variable air density activates the variable pitch PID gain under the variable air density according to 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 to the local average turbulence intensity in real time according to the variable pitch PID gain after variable air density scheduling, and performs variable pitch PID gain scheduling.

[0066] Example 3

[0067] This embodiment discloses a non-transitory computer-readable medium storing instructions. When the instructions are executed by a processor, the steps of the wind turbine pitch PID gain dynamic adjustment optimization method described in Example 1 are performed.

[0068] The non-temporary computer-readable medium in this embodiment may be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.

[0069] Example 4

[0070] This embodiment discloses a computing device, including a processor and a memory for storing programs executable by the processor. When the processor executes the program stored in the memory, the method for dynamically adjusting and optimizing the variable pitch PID gain of a wind turbine set described in Example 1 is implemented.

[0071] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0072] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for dynamically adjusting and optimizing the PID gain of a wind turbine generator set, characterized in that: The following steps are involved: S1. Set the speed and torque upper limit of the wind turbine converter, determine the speed-torque curve, and select several speed points and their corresponding torques as basic data; S2. According to the determined speed-torque curve, the basic data is linearized, and the variable pitch PID gain under the speed limit is adjusted based on the linearization model; and considering the actual air density, the basic data is re-linearized to adjust the variable pitch PID gain under the variable air density; S3. When the wind turbine is in a normal power generation state, according to the set speed value and the rated speed value of the wind turbine, the variable pitch PID gain under the speed limit set in step S2 is activated, and the variable pitch PID gain is scheduled for the rated speed and rated torque under the standard air density; S4. According to the real-time measured air density and the pitch PID gain after the scheduling in step S3, the pitch PID gain under the variable air density set in step S2 is activated to perform pitch PID gain scheduling; S5. According to the variable pitch PID gain scheduled in step S4, the ratio of turbulence to the local average turbulence intensity is calculated in real time, the variable pitch PID gain is scheduled, and finally the dynamic adjustment of the variable pitch PID gain is completed.

2. A method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine according to claim 1, characterized in that: The step S1 comprises: According to the design parameters and operation requirements of the wind turbine generator, the speed and torque upper limits of the converter are set. The speed and torque upper limits do not limit 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 the target value of the speed-pitch control loop. The speed of the wind turbine is selected from the grid-connected speed V1 to the rated speed V n There are n speed points, and the torque corresponding to each speed point is from T1 to T n , as the basic data for adjusting the pitch PID gain.

3. A method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine according to claim 1, characterized in that: The step S2 comprises: According to the speed-torque curve determined in step S1, the basic data is used as the rated speed and torque of the Bladed model and linearized. The linearized model is used to adjust the pitch PID gain of the speed-pitch control loop of the wind turbine, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under the limited speed. While determining the pitch PID gain under the limited speed, the actual air density ρ is taken into account, each basic data is re-linearized, and its phase margin is controlled between θ1 and θ2 to determine the pitch PID gain under variable air density.

4. A method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine according to claim 1, characterized in that: The step S3 comprises: When the wind turbine is in normal power generation state and the speed setting value V set Less than the rated value V of the wind turbine rated When the variable pitch PID gain at the speed limit set in step S2 is activated, the variable pitch PID parameter K p , K i and K d According to the set pitch PID gain, the pitch PID gain is scheduled for the rated speed and rated torque under standard air density.

5. The method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine according to claim 1, characterized in that: The step S4 comprises: During the speed-limited pitch PID gain scheduling process of the wind turbine, when the wind turbine is in normal power generation, the pitch PID parameter K is adjusted according to the real-time measured air density. p , K i and K d Adjustments are made to adapt to actual changes in air density and to complete variable pitch PID gain scheduling under variable air density.

6. A method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine according to claim 1, characterized in that: The step S5 comprises: According to the variable pitch PID gain after step S4 scheduling, the turbulence value I is calculated in real time. t The local average turbulence intensity I ave The ratio k I , the pitch PID parameters are corrected, that is, the pitch PID parameters are multiplied by the ratio coefficient k I , by correcting the variable pitch PID gain at different turbulence values, the adaptability and control accuracy of the wind turbine under complex airflow conditions are improved, and finally the dynamic adjustment of the variable pitch PID gain is completed.

7. A wind turbine variable pitch PID gain dynamic adjustment optimization system, characterized in that: The method for dynamically adjusting and optimizing the pitch PID gain of a wind turbine generator set according to any one of claims 1 to 6 comprises: The unit speed-torque confirmation module determines the speed-torque curve according to the speed and torque upper limit of the wind turbine converter, and selects several speed points and their corresponding torques as basic data; The variable pitch PID gain adjustment module under limited speed linearizes the basic data according to the determined speed-torque curve, and adjusts the variable pitch PID gain under limited speed based on the linearization model; The variable pitch PID gain adjustment module under variable air density considers the actual air density, re-linearizes the basic data, and adjusts the variable pitch PID gain under variable 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 for the rated speed and rated torque under standard air density; The variable pitch PID gain scheduling module for variable air density activates the variable pitch PID gain under the variable air density according to 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 to the local average turbulence intensity in real time according to the variable pitch PID gain after variable air density scheduling, and performs variable pitch PID gain scheduling.

8. 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 to 6 are performed.

9. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the wind turbine pitch PID gain dynamic adjustment optimization method described in any one of claims 1 to 6 is implemented.

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