CN104343628B - A kind of Wind turbines variable pitch control method containing dead-zone compensator - Google Patents

Abstract

The invention discloses a pitch control method of a wind turbine with a dead zone compensator, which belongs to the field of wind turbine control systems, and includes establishing a mathematical model of the wind turbine and obtaining the expected value of the pitch angle output by the pitch controller and the variable pitch angle. The mathematical expression of the actual value of the pitch angle output by the pitch actuator, the design of the dead zone compensator of the pitch actuator, the mathematical expression of the pitch angle compensation value, the measurement of the wind speed around the wind turbine and the output of the wind turbine The active power of the pitch angle is calculated and sent to the pitch actuator and the dead zone compensator of the pitch actuator respectively, the actual value of the pitch angle and the compensation value of the pitch angle are calculated and sent to the wind turbine The internal phase regulator, the internal phase regulator of the wind turbine, regulates the wind turbine. This method well solves the interference and influence of the dead zone of the variable pitch actuator on the entire system during the operation of the wind turbine, improves the operating state of the wind turbine, and ensures the stability of power output.

Description

A Pitch Control Method for Wind Turbines Containing a Dead Zone Compensator

technical field

The invention belongs to the field of wind turbine control systems, and in particular relates to a pitch control method for wind turbines with a dead zone compensator.

Background technique

Wind energy, as a clean and renewable energy, has been paid more and more attention by countries all over the world, and has developed rapidly. For the utilization of wind energy, it mainly relies on wind turbines for energy conversion. The wind turbine control system is the core of the normal operation of the wind turbine. Its control technology is one of the key technologies of the wind turbine and is closely related to other parts of the wind turbine. Its precise control and perfect functions will directly affect the safety and efficiency of the entire wind turbine.

Pitch control technology has been widely used as a mainstream control technology of wind turbines. However, due to the strong randomness, intermittent and uncontrollable properties of wind energy, and the deadlock of the pitch actuator zone and many other uncertain factors make the pitch control system have the characteristics of parameter nonlinearity, parameter time-varying, hysteresis, etc., especially the influence brought by the dead zone of the pitch actuator, making the control of the pitch system There is a deviation in the adjustment, which causes the output power of the wind turbine to be unstable.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a pitch control method for a wind turbine with a dead zone compensator.

Technical scheme of the present invention:

Step 1: Establish a mathematical model of the wind turbine, and obtain the mathematical expressions of the expected value of the pitch angle β _r output by the pitch controller and the actual value of the pitch angle β output by the pitch actuator:

Where: τ is the time constant; s is the complex frequency, which is the complement of Fourier transform.

At the same time, the mathematical expression of the wind turbine's ability to capture wind power is obtained:

Where: C _p (λ, β) is the utilization coefficient of wind energy.

Step 2: According to the mathematical expression of the pitch angle expected value β _r output by the pitch controller and the actual pitch angle β output by the pitch actuator obtained in step 1, design the dead zone compensation of the pitch actuator device to obtain the mathematical expression of the pitch angle compensation value Δβ _r , proceed as follows:

Step 2.1: Establish a mathematical model of the dead zone of the variable pitch actuator;

The mathematical model of the dead zone of the variable pitch actuator used in the present invention is as follows:

In the formula: D′(u) represents the functional expression about the dead zone of the pitch actuator; b _r is the upper limit of the wind speed leaving the dead zone of the pitch actuator, m/s; b _l is the wind speed entering the pitch actuator The wind speed of the lower limit of the dead zone, m/s; u is the input of the dead zone of the variable pitch actuator; g _r (u) is the dead zone function expression of the variable pitch actuator when u≥b _r ; g _l (u) is the dead zone function expression of the variable pitch actuator when u≤b _l ;

Step 2.2: Estimation of the nonlinear dynamic function f(x);

f(x)＝W ₁ ^*T σ(V ₁ ^T X ₁ )+ε ₁ (4)

In the formula: X ₁ =[x ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₁ is the weight matrix between the input layer and the hidden layer of the first neural network; W ₁ ^* is the weight matrix of the first neural network The ideal weight matrix between the hidden layer and the output layer; ε ₁ is the reconstruction error of the first neural network; σ is the activation function, and the specific form is

Considering the threshold effect, the activation function of the present invention is selected as Among them, the present invention has l is the number of hidden layer nodes, z represents the generalized output of the whole system; and the actual output of the first neural network is

In the formula, W ₁ is the actual weight matrix between the hidden layer and the output layer of the first neural network; then the estimation error of the first neural network can be expressed as

In the formula: Estimated error for neural network weights;

Step 2.3: Design the compensator for the dead zone of the variable pitch actuator, and obtain the mathematical expression of the pitch angle compensation value _Δβr ;

Utilizing the output of the second neural network in compensator design Offset the system adjustment error η(u) caused by the dead zone of the pitch actuator, where the second neural network input is u _c ;

The generalized mathematical expression of the pitch angle compensation value Δβ _r obtained by using the second neural network is

In the formula: W ₂ is the actual weight matrix between the hidden layer and the output layer of the second neural network; X ₂ =[x ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₂ is the second neural network The weight matrix between the input layer and the hidden layer; ε ₂ is the reconstruction error of the second neural network.

Step 3: Use the wind speed sensor to measure the wind speed v around the wind turbine, use the Hall voltage and current sensors to measure the output voltage and current of the wind turbine, and multiply the two to obtain the active power P output by the wind turbine.

Step 4: The pitch controller calculates the pitch angle expected value β _r and sends them to the pitch actuator and the dead zone compensator of the pitch actuator respectively;

Step 5: The pitch actuator calculates the actual value of the pitch angle β and transmits it to the internal phase modulator of the wind turbine. At the same time, the dead zone compensator of the pitch actuator calculates the pitch angle compensation value Δβ _r and transmits it to Internal phase modulators for wind turbines;

Step 6: According to the received pitch angle value, that is, the actual pitch angle value β and the pitch angle compensation value Δβ _r , the internal phase regulator of the wind turbine adjusts the wind turbine.

Beneficial effect:

There is an objective risk that there is a dead zone in the pitch actuator and the wind turbine is greatly affected by it. Therefore, it is urgent and necessary to construct a complete pitch control method with a dead zone compensator for wind turbines. necessity. The pitch control method of the present invention solves the following problems:

(1) Considering that the amount of data in wind turbines has the characteristics of ambiguity, randomness, uncertainty, and redundancy, the pitch control method of the present invention successfully overcomes the current existing technology that can only change pitch The shortcoming that the distance from the dead zone of the actuator is regarded as an ideal state and cannot be practically solved;

(2) The overall performance of the wind turbine and the control accuracy of the pitch control system are improved, and the influence of the dead zone of the pitch actuator on the wind turbine is basically eliminated. The use of the variable pitch control method including the dead zone compensator specially used for wind turbines solves the interference and influence of the dead zone of the variable pitch actuator on the entire system during the operation of the wind turbine, and can be well improved. The running status of wind turbines ensures the stability of power output.

Description of drawings

Fig. 1 is a schematic diagram of a pitch control structure of a wind turbine in an embodiment of the present invention;

Fig. 2 is a schematic diagram of a dead zone area of a pitch actuator according to an embodiment of the present invention;

Fig. 3 is a flow chart of a pitch control method for wind turbines including a dead zone compensator according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of a pitch control structure of a wind turbine with a dead zone compensator according to an embodiment of the present invention;

Fig. 5 is a wind turbine speed simulation diagram of an embodiment of the present invention;

Fig. 6 is a simulation diagram of output power of a wind power generator according to an embodiment of the present invention.

detailed description

In order to describe the technical content, purpose and effect of the present invention in detail, the following will be further described in detail in conjunction with the accompanying drawings and specific implementation methods.

As shown in Figure 1, it is a schematic diagram of the pitch control structure of a wind turbine without a dead zone compensator, including a wind turbine, a transmission system, a wind generator, and a pitch control system, and the pitch control system includes a pitch control system. Controller and pitch actuator. The wind turbine is the original moving part of the wind turbine, which is used to capture wind energy; the transmission system transmits the wind energy captured by the wind turbine to the wind generator; the wind generator outputs active power through electromagnetic conversion, and the pitch system adjusts the wind turbine The pitch angle is used to adjust the wind energy capture, so as to ensure that the wind turbine can output a constant power value, which meets the system requirements. Among them, the pitch controller calculates the expected value of the pitch angle β _r that should be adjusted according to the received active power P output by the wind turbine and the wind speed v around the wind turbine using the mathematical model of the wind turbine, and sends this value to the variable Pitch actuator to perform. However, due to the dead zone of the pitch actuator, as shown in Figure ₂ , when the wind speed v is higher _than the rated wind speed v1 and less than the cut-out wind speed v2, the pitch system starts to work, that is, in Figure 2 area 2. In this area, due to the dead zone of the pitch actuator, the pitch angle value transmitted to the wind turbine when the final pitch actuator is executed is not β _r , but a pitch angle value with a certain deviation The actual value β, that is, the actual output pitch angle value of the variable pitch actuator, produces a deviation of β′=β _r −β. Due to a certain deviation, the internal phase regulator of the wind turbine does not adjust the wind turbine to the position that should be adjusted, thereby affecting the output of the active power P of the wind turbine.

Based on this, in the present invention, a pitch angle compensation value Δβ _r is generated by designing a dead zone compensator of a variable pitch actuator to offset the pitch angle deviation β', so that the final value transmitted to the internal phase modulator of the wind turbine The pitch angle value should reach the expected value β _r of the pitch angle as much as possible.

The wind turbine pitch control method containing the dead zone compensator in this embodiment, as shown in Figure 3, includes the following specific steps:

Step 1: Establish a mathematical model of the wind turbine, obtain the mathematical expression of the pitch angle expected value β _r output by the pitch controller, and the mathematical expression of the actual pitch angle β output by the pitch actuator;

Step 1.1: Establish a mathematical model of the wind turbine;

A wind turbine is a device that converts wind energy into mechanical energy. According to Bates theory, the power and mechanical torque captured by a wind turbine from wind energy are:

In the formula: P _r is the power captured by the wind turbine, w; T _r is the mechanical torque of the wind rotor, N m; λ is the tip speed ratio; ρ is the density of the air, kg/m ³ ; R is the wind rotor The radius of , m; v is the wind speed, m/s; β is the actual value of the pitch angle, rad; C _T (λ, β) is the mechanical torque coefficient; C _p (λ, β) is the wind energy utilization coefficient;

The relationship between C _T (λ, β) and C _p (λ, β) can be expressed by the following expression:

C _p (λ, β) = λC _T (λ, β) (10)

The wind energy utilization coefficient _Cp (λ, β) represents the ability of the wind turbine to capture wind power, and the present invention adopts the following formula to approximate:

Step 1.2: Establish a mathematical model of the wind turbine;

According to the mathematical model of the wind turbine, the amount of wind energy captured by the wind turbine can be obtained. The wind turbine, as the original moving part, transmits the captured wind energy P _r to the transmission system, and the transmission system converts the wind energy into mechanical energy and transmits it to the wind turbine. The final torque transmitted by the transmission system to the wind turbine is T _g . Then, according to the transmitted mechanical energy, it is converted into the required electric energy through electromagnetic conversion. For the convenience of calculation, the mathematical model of the wind power generator established in this embodiment is as follows:

In the formula: J _r is the moment of inertia of the wind rotor, kg m ² ; J _g is the moment of inertia of the wind turbine, kg m ² ; ω _r is the actual speed of the wind turbine, r/min; v _i is the reduction ratio; T _e is the electromagnetic torque of the wind turbine, N m; T _D is the resistance torque of the wind turbine, N m; C ₁ , C ₂ , C ₃ are the damping coefficients;

Step 1.3: establish the mathematical model of the variable pitch controller, and obtain the mathematical expression of the pitch angle expected value β _r output by the variable pitch controller and the actual value β of the pitch angle output by the variable pitch actuator;

Through the established mathematical models of the wind turbine and the wind generator, the wind energy captured by the wind turbine and the electrical energy converted and output by the wind generator in this embodiment can be obtained. In area 2 of Fig. 2, it is necessary to adjust the pitch angle through the pitch control system to ensure the constant output power of the wind turbine. For the variable pitch system, including the two parts of the pitch controller and the pitch actuator, the present invention needs to obtain the pitch angle expected value β _r output by the pitch controller by establishing the mathematical model of the pitch controller and The mathematical expression of the actual value β of the pitch angle output by the pitch actuator.

The mathematical model of the pitch controller established in this embodiment is as follows:

where: τ is the time constant; β _r is the expected value of the pitch angle, rad;

The obtained mathematical expression of the pitch angle expected value β _r output by the pitch controller and the mathematical expression of the actual pitch angle β output by the pitch actuator are a common relational expression, such as formula (1) Shown:

In the formula: s is the complex frequency, which is the complement of Fourier transform.

Step 2: According to the result of step 1, design the dead zone compensator of the variable pitch actuator, and obtain the mathematical expression of the pitch angle compensation value Δβ _r ;

Step 2.1: Establish a mathematical model of the dead zone of the variable pitch actuator;

The mathematical model of the dead zone of the variable pitch actuator used in this embodiment is as follows:

In the formula: D′(u) represents the functional expression about the dead zone of the pitch actuator; b _r is the upper limit of the wind speed leaving the dead zone of the pitch actuator, m/s; b _l is the wind speed entering the pitch actuator The wind speed of the lower limit of the dead zone, m/s; u is the input of the dead zone of the variable pitch actuator; g _r (u) is the dead zone function expression of the variable pitch actuator when u≥b _r ; g _l (u) is the dead zone function expression of the variable pitch actuator when u≤b _l ;

Step 2.2: Estimation of the nonlinear dynamic function f(x);

In order to design the dead zone compensator of the variable pitch actuator, the present invention must dynamically estimate the controlled system, that is, estimate the nonlinear dynamic function f(x) of the controlled system, and then input the obtained estimated value into the dead zone zone compensator as a compensation reference. According to the neural network function approximation theory, in this embodiment, a simple first neural network is used to estimate the nonlinear dynamic function of the controlled system. Assuming that the weights between the hidden layer and the input layer of the first neural network are randomly given and no longer adjusted, then:

f(x)＝W ₁ ^*T σ(V ₁ ^T X ₁ )+ε1 (4)

In the formula: X ₁ =[x ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₁ is the weight matrix between the input layer and the hidden layer of the first neural network; W ₁ ^* is the weight matrix of the first neural network The ideal weight matrix between the hidden layer and the output layer; ε ₁ is the reconstruction error of the first neural network; σ is the activation function, and the specific form is

Considering the threshold effect, the activation function in this embodiment is selected as in, l is the number of hidden layer nodes, z represents the generalized output of the whole system; and the actual output of the first neural network is

In the formula, W ₁ is the actual weight matrix between the hidden layer and the output layer of the first neural network;

Then the estimation error of the first neural network can be expressed as

In the formula: Estimated error for neural network weights;

Step 2.3: Design the compensator for the dead zone of the variable pitch actuator, and obtain the mathematical expression of the pitch angle compensation value _Δβr ;

Utilizing the output of the second neural network in the dead zone compensator design of the pitch actuator Offset the system adjustment error η(u) caused by the pitch adjustment and the dead zone of the mechanism, wherein the input of the second neural network is u _c ;

The generalized mathematical expression of the pitch angle compensation value Δβ _r obtained by using the second neural network is

In the formula: W ₂ is the actual weight matrix between the hidden layer and the output layer of the second neural network; X ₂ =[x ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₂ is the second neural network The weight matrix between the input layer and the hidden layer; ε ₂ is the reconstruction error of the second neural network.

As shown in Figure 4, the present invention adds a dead zone compensator at the pitch actuator to compensate for the system deviation caused by the dead zone of the pitch actuator. As shown in Figure 4, the pitch controller not only transmits the obtained pitch angle expected value β _r to the pitch actuator, but also transmits it to the dead zone compensator of the pitch actuator. At the same time, The pitch actuator should also transmit the actual value of the pitch angle β that it finally outputs to the dead zone compensator of the pitch actuator, and the dead zone compensator uses the above-mentioned internal neural network algorithm and the error and deviation set value, Finally, the corresponding pitch angle compensation value Δβ _r is given, and the pitch angle compensation value is sent to the internal phase modulator of the wind turbine. The pitch angle compensation value Δβ _r and the actual value β of the pitch angle of the pitch actuator. The internal phase modulator of the wind turbine then adjusts the wind turbine according to the received pitch angle value.

Step 3: Measure the wind speed v around the on-site wind turbine and the active power P output by the wind turbine and send it to the pitch controller;

In this embodiment, a wind speed sensor and a power sensor are added to the wind power generating set, as shown in FIG. 4 . Use the wind speed sensor to measure the wind speed v around the wind turbine. The wind speed sensor here adopts the EE65 wind speed transmitter produced by Shanghai Weichuan Precision Instrument Co., Ltd. The measurement range is 0-20m/s, and the output signal is 4-20mA/0- 10V, the accuracy is ±0.2m/s, the working environment is -25-50℃, the output signal amplitude is proportional to the wind speed.

The power signal of the wind turbine is input to the pitch controller through the power sensor, and finally completes the control of the rated power of the wind turbine. The power sensor here uses a Hall current sensor and a Hall voltage sensor to detect current and voltage, and the output active power P of the wind turbine is obtained according to the detected current and voltage. In the present invention, the voltage sensor model is LV 200-AW/2 produced by Swiss Lem Company (LEM), the rated effective current of the primary side is 20mA, and the ±15-24V power supply is used for power supply, and the accuracy is ±0.5%; the current sensor model is The LA28-NP produced by LEM of Switzerland has a rated RMS current of 25mA on the primary side, is powered by a ±15V power supply, and has an accuracy of ±0.5%. The measuring range of the primary side current is 0 to ±36A.

The wind speed v around the wind turbine and the active power P output by the wind generator are measured by the above sensors and sent to the pitch controller. One of the final measured data and the actual wind power system parameters are shown in the following table:

Table 1 The parameters set for testing the wind power generation system

τ=0.2s R=15m η=0.871 v _f =28.32 ρ=1.25kg/m ² J _g ＝32kg·m ² J _r ＝350000kg·m ² v=9m/s C ₁ =1000N·m C ₃ =100s/rad C ₂ =1000rad/s ω ^* _r = 22.3(r·min ^-1 )

Step 4: The pitch controller calculates the pitch angle expected value β _r and sends them to the pitch actuator and the dead zone compensator of the pitch actuator respectively;

In this embodiment, simulation software MATLAB/Simulink is used to simulate the pitch-variable actuator of the wind turbine.

The simulation process of this embodiment is realized on the basis of a variable-pitch wind turbine with a rated power of 600KW. The structures of the first neural network and the second neural network are respectively selected as 2-21-1 (that is, the number of input layers is 2, the number of hidden layers is 21 and the number of output layers is 1) and 3-11-1 (that is, , the number of input layers is 3, the number of hidden layers is 11 and the number of output layers is 1), the initial value W ₁ and the setting value W ₂ of the weight are 0.1 and 0.1 respectively, and the other initial weights of the two networks The value is set to 0.01. The activation function is set to a unipolar sigmoid function

Set the data in Table 1 in step 3 as the parameters of the simulated wind turbine, and directly transmit the data measured by the sensor in step 3 to the pitch controller as the input value, then the pitch controller uses the step The mathematical model established in 1 calculates the expected value of the pitch angle β _r . In the simulation process of this embodiment, the specific value of the expected value of the pitch angle β _r is not displayed, but is transmitted to the pitch actuator respectively and the dead zone compensator of the pitch actuator;

Step 5: The pitch actuator calculates the actual value of the pitch angle β and transmits it to the internal phase modulator of the wind turbine. At the same time, the pitch angle compensation value Δβ _r calculated by the dead zone compensator of the pitch actuator is also transmitted Internal phase modulators for wind turbines;

In the MATLAB/Simulink simulation of this embodiment, the simulation model built substitutes the expected value of pitch angle β _r calculated in step 4 into the expected value of pitch angle β _r output by the pitch controller obtained in step 1 The mathematical expression and the mathematical expression of the actual pitch angle value β output by the variable pitch actuator are obtained, and the actual value β of the pitch angle of the pitch actuator is obtained and sent to the internal phase modulator of the wind turbine. At the same time, the variable The dead zone compensator of the pitch actuator calculates the pitch angle compensation value Δβ _r by using the parameter values in Table 1 in step 3 and the expected pitch angle value β _r obtained in step 4 according to the mathematical expression in step 2 and sends it to Internal phase modulators of wind turbines;

Step 6: According to the received pitch angle value, that is, the actual pitch angle value β and the pitch angle compensation value Δβ _r , the internal phase regulator of the wind turbine adjusts the wind turbine.

Accompanying drawing 5 and accompanying drawing 6 are the simulation diagrams of the rotational speed of the wind turbine and the active power output by the wind generator, respectively. As shown in Figure 5, the speed of the wind turbine is basically maintained near the rated speed, and the change is stable without large fluctuations. It can be seen from Figure 6 that the active power output has been basically constant, basically maintained at 600KW, and the fluctuation is also within a very small range. These two simulation diagrams have well illustrated that the pitch control method of the wind turbine containing the dead zone compensator of the present invention has a good effect, and basically offsets the deviation caused by the dead zone of the pitch variable actuator on the wind power. impact on the unit.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to these embodiments without departing from the principles and principles of the present invention. substance. The scope of the invention is limited only by the appended claims.

Claims (4)

1. A wind turbine variable pitch control method containing a dead zone compensator, is characterized in that: comprise the steps: Step 1: Establish a mathematical model of the wind turbine, obtain the mathematical expression of the pitch angle expected value β _r output by the pitch controller, and the mathematical expression of the actual pitch angle β output by the pitch actuator; Step 2: According to the result of step 1, design the dead zone compensator of the variable pitch actuator, and obtain the mathematical expression of the pitch angle compensation value; Step 3: Measure the wind speed v around the on-site wind turbine and the active power P output by the wind turbine and send it to the pitch controller; Step 4: The pitch controller calculates the pitch angle expected value β _r and sends them to the pitch actuator and the dead zone compensator of the pitch actuator respectively; Step 5: The pitch actuator calculates the actual value of the pitch angle β and transmits it to the internal phase modulator of the wind turbine. At the same time, the pitch angle compensation value Δβ _r calculated by the dead zone compensator of the pitch actuator is also transmitted Internal phase modulators for wind turbines; Step 6: According to the received pitch angle value, that is, the actual pitch angle value β and the pitch angle compensation value Δβ _r , the internal phase regulator of the wind turbine adjusts the wind turbine. 2. the wind turbine pitch control method that contains dead zone compensator according to claim 1, is characterized in that: the mathematics of the pitch angle expected value β _r of the pitch controller output that obtains in described step 1 The expression, the mathematical expression of the actual value β of the pitch angle output by the pitch actuator is a common relational expression, as shown in formula (1): $\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&tau;s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ In the formula: τ is the time constant; s is the complex frequency, which is the supplement of Fourier transform; At the same time, the mathematical expression of the wind turbine's ability to capture wind power is obtained, as shown in formula (2): ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0.44</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0167</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.3</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.00184</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ Where: C _p (λ, β) is the utilization coefficient of wind energy. 3. The wind turbine pitch control method containing a dead zone compensator according to claim 1, characterized in that: the dead zone compensator of the design variable pitch actuator in the step 2 obtains the pitch angle compensation The mathematical expression of the value Δβ _r , the method is carried out as follows: Step 2.1: Establish a mathematical model of the dead zone of the variable pitch actuator; The mathematical model of the pitch actuator dead zone is shown in formula (3): ${\mathrm{<span\; class="notranslate">\; D.</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>& \mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>& {\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}\\ {\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>& \mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ In the formula: D′(u) represents the functional expression about the dead zone of the pitch actuator; b _r is the upper limit of the wind speed leaving the dead zone of the pitch actuator, m/s; b _l is the wind speed entering the pitch actuator The wind speed of the lower limit of the dead zone, m/s; u is the input of the dead zone of the variable pitch actuator; g _r (u) is the dead zone function expression of the variable pitch actuator when u≥b _r ; g _l (u) is the dead zone function expression of the variable pitch actuator when u≤b _l ; Step 2.2: using the first neural network to estimate the nonlinear dynamic function f(x) of the wind turbine; f(x)＝W ₁ ^*T σ(V ₁ ^T X ₁ )+ε ₁ (4) In the formula: X ₁ =[X ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₁ is the weight matrix between the input layer and the hidden layer of the first neural network; W ₁ ^* is the hidden layer of the first neural network The ideal weight matrix between the layer and the output layer; ε ₁ is the reconstruction error of the first neural network; σ is the activation function, considering the threshold effect, the activation function is selected as in, l is the number of nodes in the hidden layer, z represents the generalized output of the entire system; and the actual output of the first neural network, that is, the estimated value of the nonlinear dynamic function f(x) of the wind turbine is $\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ In the formula, W ₁ is the actual weight matrix between the hidden layer and the output layer of the first neural network; then the estimation error of the first neural network is expressed as $\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{{\stackrel{<span\; class="notranslate">\; ~</span>}{\mathrm{<span\; class="notranslate">\; W</span>}}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$ In the formula: Estimated error for neural network weights; Step 2.3: Design the compensator for the dead zone of the variable pitch actuator, and use the estimated value obtained in step 2.2 as the compensation reference value to obtain the mathematical expression of the pitch angle compensation value _Δβr ; Utilizing the output of the second neural network in compensator design Offset the system adjustment error η(u) caused by the dead zone of the pitch actuator, where the second neural network input is u _c ; The generalized mathematical expression of the pitch angle compensation value Δβ _r obtained by using the second neural network is In the formula: W ₂ is the actual weight matrix between the hidden layer and the output layer of the second neural network; X ₂ =[x ₁ x ₂ …x _n 1] ^T ∈ R ⁿ⁺¹ ; V ₂ is the input of the second neural network The weight matrix between the layer and the hidden layer; ε ₂ is the reconstruction error of the second neural network. 4. The pitch control method of wind turbines containing a dead zone compensator according to claim 1, characterized in that: in said step 3, a wind speed sensor is used to measure the wind speed v around the on-site wind turbine, Hall voltage, current The sensors respectively measure the voltage and current output by the wind generator, and multiply the two to obtain the active power P output by the wind generator.