A method for operating a double-wind-wheel wind turbine

Abstract

The application discloses a kind of dual wind wheel wind turbine operation control methods, comprising: obtaining the speed and pitch angle of the front and rear wind wheels of dual wind wheel wind turbine under current wind speed;With the maximum overall output power of dual wind wheel wind turbine as the target, the target speed and pitch angle of the front and rear wind wheels of dual wind wheel wind turbine under current wind speed are determined;Linearization model based on state space of the transmission chain of the front and rear wind wheels is established respectively;Based on the linearization model, a state observer, a disturbance adjustment controller and a quadratic regulator are introduced, and the torque controller and the pitch controller of the front and rear wind wheels are designed to control the front and rear wind wheels.The method can take the maximum power output of the whole machine as the target, realize a control strategy based on linear quadratic regulation and disturbance adjustment technology, to solve the mutual influence problem of the front and rear wind wheels of dual wind wheel wind turbine during operation, improve the robustness of the system, improve the overall wind energy absorption rate of dual wind wheel, and fully exert the high-efficiency wind energy conversion capacity of dual wind wheel wind turbine.

Description

Technical Field

[0001] This invention relates to the field of wind power generation control technology, and more specifically to a method for controlling the operation of a dual-rotor wind turbine. Background Technology

[0002] Currently, most mainstream wind turbines adopt a single rotor with a horizontal shaft, resulting in low wind energy utilization. As wind turbines develop towards larger sizes, the key technologies of their core components are subject to many limitations, creating an urgent need for more efficient new wind turbines.

[0003] Tandem dual-rotor wind turbines convert wind energy simultaneously through two rotors, improving wind energy utilization and wind farm space utilization while reducing power generation costs, demonstrating significant potential for increased equipment efficiency. However, the front and rear rotors interfere with each other's original flow field distribution during operation, leading to reduced operating efficiency. Quantitative analysis of the interaction between the front and rear rotors using computational fluid dynamics methods suffers from drawbacks such as being untimely, uneconomical, and computationally intensive.

[0004] Therefore, addressing the mutual interference between the front and rear rotors during the operation of dual-rotor wind turbines has become an urgent problem for industry professionals. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method for controlling the operation of a dual-rotor wind turbine, so as to solve the problem of low operating efficiency caused by the mutual influence between the front and rear rotors during the operation of the dual-rotor wind turbine, improve the robustness of the system, and give full play to the high-efficiency wind energy conversion capability of the dual-rotor wind turbine.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for controlling the operation of a dual-rotor wind turbine, wherein the dual-rotor wind turbine is a tandem dual-rotor wind turbine, comprising front and rear rotors. The method includes the following steps:

[0008] Acquire aerodynamic data of the front and rear rotors of a dual-rotor wind turbine at the current wind speed; the aerodynamic data includes: rotational speed and blade pitch angle;

[0009] Based on the aerodynamic data at the current wind speed, with the goal of maximizing the overall output power of the dual-rotor wind turbine, the target rotational speed and pitch angle of the front and rear rotors of the dual-rotor wind turbine are determined at the current wind speed.

[0010] Establish a state-space-based linearized model of the front and rear wind turbine transmission chains;

[0011] Based on the linearized model, a state observer, a disturbance regulation controller, and a quadratic regulator are introduced to design torque controllers and pitch controllers for the front and rear wind turbines, thereby achieving control of the front and rear wind turbines.

[0012] Furthermore, the rotational speed of the front rotor in the dual-rotor wind turbine is obtained from the feedback signal of the front rotor generator-side speed sensor, and the rotational speed of the rear rotor is obtained from the feedback signal of the rear rotor generator-side speed sensor.

[0013] Furthermore, the pitch angle of the front wind turbine in the dual-rotor wind turbine is obtained from the feedback signal of the front wind turbine pitch system sensor, and the pitch angle of the rear wind turbine is obtained from the feedback signal of the rear wind turbine pitch system sensor.

[0014] Furthermore, based on the aerodynamic data at the current wind speed, and with the goal of maximizing the overall output power of the dual-rotor wind turbine unit, the target rotational speeds and pitch angles of the front and rear rotors of the dual-rotor wind turbine unit at the current wind speed are determined; including:

[0015] Based on the aerodynamic data of the front and rear wind turbines at the current wind speed, design their respective optimal tip speed ratios, determine their respective cut-in, cut-out and rated wind speeds, and design their respective single-unit-level control strategies for the front and rear wind turbines.

[0016] Based on the individual unit-level control strategies of the front and rear wind turbines, and combined with their respective speed-torque curves, the optimal target speeds and pitch angles of the front and rear wind turbines at different wind speeds are determined with the goal of maximizing the overall output power of the dual-wind turbine generator set.

[0017] Furthermore, a state-space-based linearized model of the front and rear wind turbine transmission chains is established, including:

[0018] A state-space-based linearized model of the front and rear wind turbine transmission chains is established, represented in the following form:

[0019]

[0020] (1) In the formula, A, B, C, and D are the parameters in the standard state-space representation, and Γ is the disturbance parameter. Let x be the first derivative of x with respect to t; x(t) is the state variable, u(t) is the input control variable, and y(t) is the output variable. d (t) represents the disturbance quantity, u d The change in (t) reflects the influence of the front and rear wind turbines on each other.

[0021] Furthermore, the introduction of state observers includes:

[0022] The mathematical model for constructing the state observer is as follows:

[0023]

[0024] (2) In the formula, for The first derivative with respect to t, Let x(t) be the state estimate. K is the state estimate of y(t). x This is the gain of the state observer.

[0025] Furthermore, the introduction of an interference conditioning controller includes:

[0026] The reconstructed disturbance state is incorporated into the feedback gain to reduce or suppress the mutual influence between the front and rear wind turbines during operation, thus introducing a disturbance model:

[0027]

[0028] (3) In the formula, For x d The first derivative of x with respect to t d (t) is the state variable of the disturbance, A d and C d This is the parameter matrix determined based on the mutual disturbance characteristics of the front and rear wind turbines;

[0029] The mathematical model for the disturbance state observer is constructed as follows:

[0030]

[0031] (4) In the formula, for The first derivative with respect to t, K d For the gain of the disturbance state observer;

[0032] The state equation for estimating the error is constructed as follows:

[0033]

[0034] in, Let be the first derivative of e(t) with respect to t.

[0035] Furthermore, the introduction of a quadratic regulator includes:

[0036] Constructing feedback rules:

[0037] u(t)=Gx(t)+G d x d (t) (6)

[0038] (6) In the formula, G is the feedback gain matrix designed using a linear quadratic regulator controller, G dThis is the feedback gain for interference correction.

[0039] Furthermore, torque controllers and pitch controllers for the front and rear wind turbines are designed to achieve control of the front and rear wind turbines; including:

[0040] Combining formulas (1)-(6), the state-space equations for the torque controller and pitch controller of the front and rear wind turbines are constructed and expressed as follows:

[0041]

[0042] Adjusting the interference correction feedback gain G d , reduce‖BG d +ΓC d This reduces or suppresses the impact of disturbance inputs caused by the mutual influence between the front and rear wind turbines on the current system state, thereby enabling control of the front and rear wind turbines.

[0043] As can be seen from the above technical solution, compared with the prior art, this invention discloses a method for operating control of a dual-rotor wind turbine. Starting from the perspective of disturbance control, it designs a suitable dual-rotor operation control method to reduce or suppress the mutual influence between the front and rear rotors during operation, which is relatively easy to implement in engineering. This method aims at the maximum power output of the entire unit and solves the problem of mutual influence between the front and rear rotors during the operation of the dual-rotor wind turbine by implementing a control strategy based on linear quadratic regulation and disturbance regulation technology. This improves system robustness, increases the overall wind energy absorption rate of the dual rotors, and fully utilizes the high-efficiency wind energy conversion capability of the dual-rotor wind turbine. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0045] Figure 1 A flowchart of the dual-rotor wind turbine operation control method provided by the present invention;

[0046] Figure 2a A schematic diagram of the front wind turbine feedback closed-loop control principle provided by the present invention, which incorporates a state observer, a disturbance regulation controller, and a secondary regulator.

[0047] Figure 2b The schematic diagram of the rear wind turbine feedback closed-loop control principle provided by the present invention includes a state observer, a disturbance regulation controller, and a secondary regulator. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] This invention discloses an operation control method for a dual-rotor wind turbine. Specifically, the dual-rotor wind turbine in this invention is a tandem dual-rotor wind turbine, including a front rotor and a rear rotor. The torque controller and pitch controller for the front and rear rotors are designed by introducing a state observer, a disturbance-accommodation control (DAC), and a linear quadratic regulator (LQR) to control the front and rear rotors.

[0050] Figure 1 A flowchart of a control method for operating a dual-rotor wind turbine provided by the present invention is provided. The method specifically includes the following steps:

[0051] S10. Obtain the aerodynamic data of the front and rear rotors of the dual-rotor wind turbine at the current wind speed; the aerodynamic data includes: rotational speed and blade pitch angle;

[0052] S20. Based on the aerodynamic data at the current wind speed, with the goal of maximizing the overall output power of the dual-rotor wind turbine, determine the target rotational speed and pitch angle of the front and rear rotors of the dual-rotor wind turbine at the current wind speed.

[0053] S30. Establish state-space-based linearized models of the front and rear wind turbine transmission chains respectively.

[0054] S40. Based on the linearized model, a state observer, a disturbance regulation controller, and a quadratic regulator are introduced to design torque controllers and pitch controllers for the front and rear wind turbines, thereby realizing the control of the front and rear wind turbines.

[0055] This method aims to maximize the power output of the entire unit by implementing a control strategy based on linear quadratic regulation and disturbance regulation technology. This addresses the mutual interference between the front and rear rotors during the operation of a dual-rotor wind turbine, improves system robustness, enhances the overall wind energy absorption rate of the dual rotors, and fully leverages the high-efficiency wind energy conversion capability of the dual-rotor wind turbine.

[0056] The following is a detailed explanation of each of the above steps:

[0057] In step S10, at the current wind speed, the rotational speed of the front wind turbine is obtained from the feedback signal of the rotational speed sensor on the front wind turbine generator side, and the rotational speed of the rear wind turbine is obtained from the feedback signal of the rotational speed sensor on the rear wind turbine generator side.

[0058] Wind turbine speed = Generator side speed / Transmission ratio

[0059] At the current wind speed, the pitch angle of the front wind turbine is obtained from the feedback signal of the front wind turbine pitch control system sensor, and the pitch angle of the rear wind turbine is obtained from the feedback signal of the rear wind turbine pitch control system sensor.

[0060] In step S20, based on the aerodynamic data of the front wind turbine, the optimal tip speed ratio is designed, the cut-in, cut-out and rated wind speeds are determined, and a single-unit control strategy for the front wind turbine is designed; based on the aerodynamic data of the rear wind turbine, the optimal tip speed ratio is designed, the cut-in, cut-out and rated wind speeds are determined, and a single-unit control strategy for the rear wind turbine is designed.

[0061] The single-unit control strategies for the front and rear wind turbines include: speed increase control and grid connection control when the wind speed reaches the cut-in wind speed; tracking the optimal tip speed ratio control when the wind speed is lower than the rated wind speed; and pitch control when the wind speed is higher than the rated wind speed.

[0062] By combining the single-unit control strategies of the front and rear wind turbines in step S10 with the speed-torque curves of the front and rear wind turbines, the optimal torque and pitch angle of the front and rear wind turbines at different wind speeds are determined with the goal of maximizing the overall output power of the dual wind turbines.

[0063] In step S30, linearized state-space models of the front and rear wind turbine drive chains are established respectively. The state-space representation of these models is as follows:

[0064]

[0065] (1) In the formula, A, B, C, and D are the parameters in the standard state-space representation, and Γ is the disturbance parameter. Let x be the first derivative of x with respect to t; x(t) is the state variable, u(t) is the input control variable, and y(t) is the output variable. d (t) represents the disturbance quantity, u d The change in (t) reflects the influence of the front and rear wind turbines on each other.

[0066] The input control quantity u(t) selected in this invention is the difference between the torque and pitch angle corresponding to the current wind speed and the optimal torque and pitch angle, that is, the torque error and the pitch angle error.

[0067] Torque error = Current torque - Target optimal torque;

[0068] Pitch angle error = Current pitch angle - Target optimal pitch angle.

[0069] In step S40, to reduce or suppress the mutual influence between the front and rear rotors of the dual-rotor wind turbine unit before and after operation, this influence is considered as an external disturbance to the system. Full-state feedback, disturbance regulation control, and the LQR method are introduced to achieve optimal system control. For example... Figure 2a , 2b The figures shown are block diagrams of the disturbance suppression controllers for the front and rear wind turbines, respectively.

[0070] In engineering, measuring all state variables of a system is impractical. Therefore, a state observer is introduced to estimate the required state variables of the system. The mathematical model of the state observer is as follows:

[0071]

[0072] (2) In the formula, for The first derivative with respect to t, Let x(t) be the state estimate. K is the state estimate of y(t). x This is the gain of the state observer.

[0073] An interference regulation controller (DAC) is introduced, which is a method to reduce or cancel persistent interference. Its core principle is to incorporate the reconstructed interference state into the feedback gain to reduce or suppress the mutual influence between the front and rear wind turbines during operation. An interference model is introduced as follows:

[0074]

[0075] (3) In the formula, For x d The first derivative of x with respect to t d (t) is the state variable of the disturbance, A d and C d This is the parameter matrix determined based on the mutual disturbance characteristics of the front and rear wind turbines;

[0076] The mathematical model for the disturbance state observer is constructed as follows:

[0077]

[0078] (4) In the formula, for The first derivative with respect to t, K d For the gain of the disturbance state observer;

[0079] The state equation for estimating the error is constructed as follows:

[0080]

[0081] in, Let be the first derivative of e(t) with respect to t.

[0082] The parameter K can be adjusted. x and K d This rapidly reduces the estimation error to zero, enabling the state estimate to track the system state well.

[0083] At this point, the LQR method can be used to construct feedback rules:

[0084] u(t)=Gx(t)+G d x d (t) (6)

[0085] (6) In the formula, G is the feedback gain matrix designed using a linear quadratic regulator controller, G d This is the feedback gain for interference correction.

[0086] The state feedback gain G can be calculated using the LQR method to achieve pole placement; the objective function J in the LQR method is defined as follows:

[0087]

[0088] Where Q(t) is the state weight matrix; R(t) is the input weight matrix; δ represents the small increment; J is the performance index function, which is a commonly used objective function in LQR control; and the feedback gain G is expressed as:

[0089] G = -R -1 B T P

[0090] Where P is the symmetric positive definite solution of the Riccati equation; R is the input weight matrix.

[0091] At this point, combining formulas (1)-(6), the state-space equations for the torque controller and pitch controller of the front and rear wind turbines are constructed respectively, and are expressed as follows:

[0092]

[0093] Interference correction feedback gain G d The selection can be made through experimental simulation, and G can be adjusted. d , reduce ||BG d +ΓC d This reduces or suppresses the impact of disturbance inputs caused by the interaction between the front and rear wind turbines during operation on the current state of the system, thereby improving the system's robustness.

[0094] The dual-rotor wind turbine operation control method provided by this invention aims to maximize the overall output power of the dual-rotor wind turbine by establishing separate control systems for the front and rear rotors. The core idea of ​​this invention is to treat the mutual influence between the front and rear rotors during operation as an external disturbance applied to the control system. By introducing a state observer, a disturbance regulation controller, and feedback control designed using the LQR method, the mutual influence between the two rotors during operation is largely eliminated, improving the robustness of the system and enhancing the overall wind energy absorption efficiency of the dual-rotor wind turbine.

[0095] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0096] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the operation of a dual-rotor wind turbine generator set, characterized in that, The dual-rotor wind turbine is a tandem dual-rotor wind turbine, comprising two rotors, front and rear. The method includes the following steps: Acquire aerodynamic data of the front and rear rotors of a dual-rotor wind turbine at the current wind speed; the aerodynamic data includes: rotational speed and blade pitch angle; Based on the aerodynamic data at the current wind speed, with the goal of maximizing the overall output power of the dual-rotor wind turbine, the target rotational speed and pitch angle of the front and rear rotors of the dual-rotor wind turbine are determined at the current wind speed. Linearized state-space models of the front and rear wind turbine transmission chains are established respectively. Based on the linearized model, a state observer, a disturbance regulation controller, and a quadratic regulator are introduced to design torque controllers and pitch controllers for the front and rear wind turbines, thereby achieving control of the front and rear wind turbines. Among them, linearized state-space models of the front and rear wind turbine drive chains are established respectively; including: State-space linearized models of the front and rear wind turbine drive chains are established respectively, and their representations are as follows: （1） (1) In the formula, A, B, C, and D are the parameters in the standard state-space representation, For the disturbance parameters, The first derivative of x with respect to t; For state variables, For input control quantity, For output variables, For the disturbance quantity, The changes reflect the mutual influence between the front and rear wind turbines; The introduction of state observers includes: The mathematical model for constructing the state observer is as follows: （2） (2) In the formula, for The first derivative with respect to t, for State estimates, for State estimates, For state observer gain; The introduced interference conditioning controller includes: The reconstructed disturbance state is incorporated into the feedback gain to reduce or suppress the mutual influence between the front and rear wind turbines during operation, thus introducing a disturbance model: （3） (3) In the formula, for The first derivative with respect to t, For the state variables of the disturbance, and This is the parameter matrix determined based on the mutual disturbance characteristics of the front and rear wind turbines; The mathematical model for the disturbance state observer is constructed as follows: （4） (4) In the formula, for The first derivative with respect to t, For the interference state observer gain; The state equation for estimating the error is constructed as follows: （5） in, ; ; ; ; for The first derivative with respect to t.

2. The method for controlling the operation of a dual-rotor wind turbine generator set according to claim 1, characterized in that, The rotational speed of the front rotor in a dual-rotor wind turbine is obtained from the feedback signal of the front rotor generator-side speed sensor, and the rotational speed of the rear rotor is obtained from the feedback signal of the rear rotor generator-side speed sensor.

3. The method for controlling the operation of a dual-rotor wind turbine generator set according to claim 1, characterized in that, The pitch angle of the front wind turbine in a dual-rotor wind turbine is obtained from the feedback signal of the front wind turbine pitch control system sensor, and the pitch angle of the rear wind turbine is obtained from the feedback signal of the rear wind turbine pitch control system sensor.

4. The method for controlling the operation of a dual-rotor wind turbine generator set according to claim 1, characterized in that, Based on the aerodynamic data at the current wind speed, with the goal of maximizing the overall output power of the dual-rotor wind turbine unit, the target rotational speeds and pitch angles of the front and rear rotors of the dual-rotor wind turbine unit at the current wind speed are determined; including: Based on the aerodynamic data of the front and rear wind turbines under the current wind speed, design their respective optimal tip speed ratios, determine their respective cut-in, cut-out and rated wind speeds, and design their respective single-unit-level control strategies for the front and rear wind turbines. Based on the individual unit-level control strategies of the front and rear wind turbines, and combined with their respective speed-torque curves, the optimal target speeds and pitch angles of the front and rear wind turbines at different wind speeds are determined with the goal of maximizing the overall output power of the dual-wind turbine generator set.

5. The method for controlling the operation of a dual-rotor wind turbine generator set according to claim 1, characterized in that, The introduction of a quadratic regulator includes: Constructing feedback rules: （6） (6) In the formula, G is the feedback gain matrix designed using a linear quadratic regulator. This is the feedback gain for interference correction.

6. The method for controlling the operation of a dual-rotor wind turbine generator set according to claim 5, characterized in that, Design torque controllers and pitch controllers for the front and rear wind turbines to achieve control of the front and rear wind turbines; including: Combining formulas (1)-(6), the state-space equations for the torque controller and pitch controller of the front and rear wind turbines are constructed respectively, and are expressed as follows: （7） Adjusting the interference correction feedback gain , reduce This reduces or suppresses the impact of disturbance inputs caused by the mutual influence between the front and rear wind turbines on the current system state, thereby enabling control of the front and rear wind turbines.

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