CN117332602B

CN117332602B - Primary frequency modulation simulation method and device for wind driven generator

Info

Publication number: CN117332602B
Application number: CN202311353815.3A
Authority: CN
Inventors: 牛高远; 胡阳; 宋子秋; 房方; 刘吉臻
Original assignee: North China Electric Power University
Current assignee: North China Electric Power University
Priority date: 2023-10-18
Filing date: 2023-10-18
Publication date: 2024-04-19
Anticipated expiration: 2043-10-18
Also published as: CN117332602A

Abstract

The application provides a primary frequency modulation simulation method and device for a wind driven generator, wherein the method comprises the following steps: acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation; according to a relational expression of electromagnetic torque and electromagnetic torque variable of the wind driven generator corresponding to a preset wind speed interval, a double-mass model and a variable pitch model of the wind driven generator are combined to construct a preset state space expression corresponding to the preset wind speed interval, wherein the preset state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variable quantity in the preset wind speed interval; determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator.

Description

Primary frequency modulation simulation method and device for wind driven generator

Technical Field

The application relates to the technical field of wind power generation, in particular to a primary frequency modulation simulation method and device for a wind power generator.

Background

For a variable-speed wind turbine, the current modeling method for primary frequency modulation response of a fan comprises two types: a "black box model" based on input-output data driving and a "white box modeling" based on mechanism analysis. The black box model depends on the appointed input and output characteristics, a large amount of input and output data are needed, and high-precision representation of the dynamic characteristics of the unit structure can be realized through a machine learning algorithm. However, the method has poor interpretation of the physical meaning of the parameters and has strong dependence on the accuracy and the quantity of input data. The representative simulation software of the fans such as GH Bladed and FAST in the white box model contains a high-fidelity model of high-order nonlinear dynamics, but the model is too complex and is not suitable for the design of a controller, and most white box mechanism models of primary frequency modulation response of the fans based on small signal derivation have strict requirements on input signals of frequency modulation instructions and are not suitable for the condition that the machine parameters change under actual complex working conditions.

Disclosure of Invention

Therefore, an object of the present application is to provide a method and an apparatus for simulating primary frequency modulation of a wind driven generator, by converting a power variation of the wind driven generator during primary frequency modulation into state space expressions corresponding to preset state parameters respectively in different wind speed intervals, so as to convert the power variation into linear expressions corresponding to the preset state parameters, when a reference output power variation of an output power of the wind driven generator is received, a preset state parameter is calculated according to the state space expression corresponding to the wind speed interval to which the current wind speed belongs, so that the wind driven generator operates according to the calculated preset state parameter to simulate primary frequency modulation of the wind driven generator, thereby solving the technical problems that a large amount of data is required to perform primary frequency modulation simulation and a constructed model is too complex in the prior art, and achieving the technical effect of improving primary frequency modulation simulation efficiency of the wind driven generator.

The application mainly comprises the following aspects:

In a first aspect, an embodiment of the present application provides a primary frequency modulation simulation method for a wind turbine, where the method includes: acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation; according to a relational expression of electromagnetic torque and electromagnetic torque variable of the wind driven generator corresponding to a preset wind speed interval, a double-mass model and a variable pitch model of the wind driven generator are combined to construct a preset state space expression corresponding to the preset wind speed interval, wherein the preset state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variable quantity in the preset wind speed interval; determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator.

Optionally, the preset wind speed interval includes a first preset interval and a second preset interval, an upper limit value of the first preset interval is equal to a lower limit value of the second preset interval, the preset state space expression includes a first state space expression corresponding to the first preset interval and a second state space expression corresponding to the second preset interval, the target wind speed interval is one of the first preset interval and the second preset interval, the target state space expression is one of a first state space expression and a second state space expression, and when the preset wind speed interval is the first preset interval, the first state space expression is used for representing a relationship between a preset state variable of the wind power generator and the reference output power variation when only changing electromagnetic torque of the wind power generator; and when the preset wind speed interval is the second preset interval, the second state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variation when only the pitch angle of the wind driven generator is changed.

Optionally, the preset state space expression corresponding to the preset wind speed interval is constructed in the following manner: according to a fan blade aerodynamic torque formula, constructing a linear formula of aerodynamic torque and a plurality of preset parameters, wherein each preset parameter is a parameter in the fan blade aerodynamic torque formula and generates a variable parameter in the power generation process; according to a relational expression between the electromagnetic torque of the wind driven generator and the reference electromagnetic torque, combining the linear formula, a double-mass model and a variable pitch model of the wind driven generator, and constructing a standard state space expression of the wind driven generator, wherein the standard state space expression is used for representing a relational expression between preset state parameters of the wind driven generator and variation corresponding to the preset parameters and a relational expression between output power and initial output power of the wind driven generator, and the preset state parameters are parameters which generate variation in the power generation process; when only the electromagnetic torque of the wind driven generator is changed, the first state space expression is constructed through a relational expression of the electromagnetic torque and the reference output power variation, the standard state space expression and a pitch angle first-order inertia link expression in the pitch model when a pitch angle reference value is zero; when only the pitch angle of the wind driven generator is changed, the second state space expression is constructed by a relation of a pitch angle derivative and the reference output power variation, the standard state space expression, a relation of output power and initial output power and a relation expression between the electromagnetic torque and the reference electromagnetic torque when the electromagnetic torque variable is zero.

Optionally, a linear equation of aerodynamic torque with respect to a plurality of preset parameters is constructed by:

T_r＝a×ω_r+b×β+c×V+d

Wherein P _r is the fan pneumatic power of the wind driven generator, ρ is the air density, R is the fan rotor radius of the wind driven generator, V is the wind speed, C _P (λ, β) is the wind energy utilization coefficient, λ is the tip speed ratio of the fan rotor, β is the pitch angle, ω _r is the fan rotor speed, T _r is the pneumatic torque of the wind driven generator, ω _r, β and V are preset parameters, a is the coefficient corresponding to ω _r, b is the coefficient corresponding to β, C is the coefficient corresponding to V, and d is the constant term of the linear formula.

Optionally, a relation between the electromagnetic torque of the wind driven generator and the reference electromagnetic torque is:

Wherein T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _ref is the reference electromagnetic torque of the wind driven generator;

the dual mass model is represented by the following formula:

Wherein J _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; t _sh_aft is the equivalent intermediate shaft torque between the fan rotor and the generator rotor; t _r is the aerodynamic torque of the wind driven generator; t _g is the electromagnetic torque of the generator rotor; θ _r is the angular displacement of the fan rotor; θ _g is the angular displacement of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; b is the damping coefficient of the equivalent intermediate shaft;

the pitch model is represented by the following formula:

ω_ref＝K_w×(P_g,0+ΔP_ref)

wherein, The first-order pitch angle derivative of a variable pitch model is the first-order inertia link with amplitude limiting and speed limiting; τ _β is the time constant of the first-order inertial link; beta _ref is a pitch angle reference value; beta is the pitch angle; k _P is the proportionality coefficient of the first-order inertial link; omega _r is the angular velocity of the fan rotor; omega _ref is the reference angular velocity of the fan rotor; k _I is an integral coefficient of the first-order inertial link; /(I)The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; k _W is a proportionality coefficient between the angular speed and the output power of the fan rotor; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor;

The standard state space expression of the wind driven generator is as follows:

ΔP_g＝P_g-P_g.0

Wherein a is a coefficient corresponding to the angular speed of the fan rotor, b is a coefficient corresponding to the pitch angle, c is a coefficient corresponding to the wind speed, and d is a constant term of the linear formula; p _g is the output power of the generator rotor of the wind driven generator; Δp _g is the output power variation of the generator rotor of the wind generator; Omega _r、ω_g, θ, φ, β and T _g are preset state parameters that are derivatives of the angular displacement difference between the fan rotor and the generator rotor.

Optionally, the relation of the electromagnetic torque and the reference output power variation is:

Wherein T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _ref is the reference electromagnetic torque of the wind driven generator; k is a proportionality coefficient between electromagnetic torque and output power; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor;

the relation between the output power of the wind driven generator and the electromagnetic matrix variable is as follows:

P_g＝η×T_g×ω_g＝P_g.0+η×T_g.0×Δω_g+η×ΔT_g×ω_g.0

Δω_g＝ω_g-ω_g.0

ΔT_g＝T_g-T_g.0

Wherein η is generator efficiency; omega _g is the angular speed of the generator rotor; t _g.0 is the initial electromagnetic torque of the generator rotor; Δω _g is the angular velocity variation of the generator rotor; ΔT _g is the electromagnetic torque variation of the generator rotor; omega _g.0 is the initial angular velocity of the generator rotor;

the first-order inertia link expression of the pitch angle in the variable pitch model when the pitch angle variable is zero is as follows:

Wherein, beta _ref is a pitch angle reference value, and the value is zero; The first-order pitch angle derivative of a variable pitch model is the first-order inertia link with amplitude limiting and speed limiting; τ _β is the time constant of the first-order inertial link; beta is the pitch angle;

The first state space expression is:

Wherein a is a coefficient corresponding to the angular speed of the fan rotor, b is a coefficient corresponding to the pitch angle, c is a coefficient corresponding to the wind speed, and d is a constant term of the linear formula; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; /(I)Is the derivative of the angular displacement difference between the fan rotor and the generator rotor; /(I)The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; v ₀ is the initial wind speed; j _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; and B is the damping coefficient of the equivalent intermediate shaft.

Optionally, the relation of the pitch angle derivative and the reference output power variation is:

wherein, The first-order pitch angle derivative of a variable pitch model is the first-order inertia link with amplitude limiting and speed limiting; τ _β is the time constant of the first-order inertial link; beta is the pitch angle; k _P is the proportionality coefficient of the first-order inertial link; omega _r is the angular velocity of the fan rotor; k _I is an integral coefficient of the first-order inertial link; /(I)The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; k _W is a proportionality coefficient between the angular speed and the output power of the fan rotor; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor;

The relation between the output power and the initial output power is as follows:

Wherein P _g is the output power of the generator rotor of the wind driven generator; η is generator efficiency; omega _g is the angular speed of the generator rotor; p _g.0 is the initial output power of the generator rotor of the wind generator; omega _g.0 is the initial angular velocity of the generator rotor;

the relational expression between the electromagnetic torque and the reference electromagnetic torque when the electromagnetic torque variable is zero is:

Wherein T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _g.0 is the initial electromagnetic torque of the generator rotor; omega _g.0 is the initial angular velocity of the generator rotor;

The second state space expression is:

In a second aspect, an embodiment of the present application further provides a primary frequency modulation simulation device for a wind turbine, where the device includes: the acquisition module is used for acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation; the construction module is used for constructing a preset state space expression corresponding to a preset wind speed interval according to a relational expression corresponding to the electromagnetic torque and the electromagnetic torque variable of the wind driven generator in the preset wind speed interval and combining a double-mass model and a variable pitch model of the wind driven generator, wherein the preset state space expression is used for representing the relation between the preset state variable and the reference output power variable of the wind driven generator in the preset wind speed interval; the determining module is used for determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; and the calculation module is used for substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator.

In a third aspect, an embodiment of the present application further provides an electronic device, including: the wind turbine primary frequency modulation simulation method comprises a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, the processor and the memory are communicated through the bus when the electronic device is running, and the machine-readable instructions are executed by the processor to perform the steps of the wind turbine primary frequency modulation simulation method in the first aspect or any possible implementation manner of the first aspect.

In a fourth aspect, the embodiment of the present application further provides a computer readable storage medium, where a computer program is stored, where the computer program is executed by a processor to perform the steps of the wind turbine primary frequency modulation simulation method described in the first aspect or any possible implementation manner of the first aspect.

The embodiment of the application provides a primary frequency modulation simulation method and device for a wind driven generator, wherein the method comprises the following steps: acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation; according to a relational expression of electromagnetic torque and electromagnetic torque variable of the wind driven generator corresponding to a preset wind speed interval, a double-mass model and a variable pitch model of the wind driven generator are combined to construct a preset state space expression corresponding to the preset wind speed interval, wherein the preset state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variable quantity in the preset wind speed interval; determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation to control the wind driven generator to carry out primary frequency modulation. The power variation during primary frequency modulation of the wind driven generator is converted into state space expressions corresponding to preset state parameters respectively in different wind speed intervals, so that the power variation is converted into linear expressions corresponding to the preset state parameters, when the reference output power variation of the output power of the wind driven generator is received, the preset state parameters are calculated according to the state space expressions corresponding to the wind speed intervals to which the current wind speed belongs, the wind driven generator is operated in a simulated mode according to the calculated preset state parameters, the primary frequency modulation of the wind driven generator is simulated, the technical problem that a large amount of data are needed to perform primary frequency modulation simulation in the prior art, and the built model is too complex is solved, and the technical effect of improving the primary frequency modulation simulation efficiency of the wind driven generator is achieved.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows a flowchart of a primary frequency modulation simulation method for a wind driven generator according to an embodiment of the present application.

Fig. 2 shows a functional block diagram of a primary frequency modulation simulation device of a wind driven generator according to an embodiment of the present application.

Fig. 3 shows a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application, and it should be understood that the drawings in the present application are for the purpose of illustration and description only and are not intended to limit the scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. A flowchart, as used in this disclosure, illustrates operations implemented according to some embodiments of the present application. It should be appreciated that the operations of the flow diagrams may be implemented out of order and that steps without logical context may be performed in reverse order or concurrently. Moreover, one or more other operations may be added to or removed from the flow diagrams by those skilled in the art under the direction of the present disclosure.

In addition, the described embodiments are only some, but not all, embodiments of the application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by a person skilled in the art based on embodiments of the application without making any inventive effort, fall within the scope of the application.

In the prior art, how various data of a generator should be changed when the output power is changed is predicted by a black box model driven based on input-output data, and a large amount of data is required by a prediction mode; or the model of the prediction mode is complex, and the application difficulty is high, so that how to change various data of the generator when the output power changes is predicted through 'white box modeling' based on mechanism analysis.

Based on this, the embodiment of the application provides a wind driven generator primary frequency modulation simulation method and device, by converting the power variation of a wind driven generator during primary frequency modulation into state space expressions corresponding to preset state parameters respectively under different wind speed intervals, the power variation is converted into linear expressions corresponding to the preset state parameters, when the reference output power variation of the output power of the generator is received, a preset state parameter is calculated according to the state space expression corresponding to the wind speed interval to which the current wind speed belongs, so that the wind driven generator operates according to the calculated preset state parameter in a simulation manner to simulate the primary frequency modulation of the wind driven generator, the technical problems that a large amount of data are needed to perform primary frequency modulation simulation and a constructed model is too complex in the prior art are solved, and the technical effect of improving the primary frequency modulation simulation efficiency of the wind driven generator is achieved, and the method comprises the following steps of:

Referring to fig. 1, fig. 1 is a flowchart of a primary frequency modulation simulation method for a wind driven generator according to an embodiment of the application. As shown in fig. 1, the primary frequency modulation simulation method for the wind driven generator provided by the embodiment of the application comprises the following steps:

s101: and acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation.

The reference output power variation Δp _ref is a variation based on the initial output power P _g.0 of the wind turbine, and the output power P _g＝P_g.0±ΔP_ref after the variation. The reference output power variation refers to a theoretical conversion amount of the wind power generator, and the actual output power variation is equal to the reference output power variation.

Before the reference output power variation quantity for controlling the wind driven generator to perform primary frequency modulation is obtained, the wind driven generator is in a steady state, at the moment, the initial fan rotor rotating speed of the wind driven generator is omega _r.0, the initial electromagnetic torque of the wind driven generator is T _g.0, the output initial electromagnetic power P _g,0 is equal to the initial electromagnetic power reference value P _ref,0, and at the moment, the wind speed is the initial wind speed V ₀.

When the frequency of the power grid changes or the voltage output by the power grid is unstable, the output power of the wind driven generator needs to be regulated, at the moment, the reference output power variation delta P _ref for executing primary frequency modulation is sent to the wind driven generator, and delta P _ref is increased or delta P _ref is decreased, so that the wind driven generator is regulated based on delta P _ref, and the wind driven generator enters a steady state again.

S102: and according to a relational expression of electromagnetic torque and electromagnetic torque variable of the wind driven generator corresponding to a preset wind speed interval, combining a double-mass model and a variable pitch model of the wind driven generator, and constructing a preset state space expression corresponding to the preset wind speed interval.

The preset state space expression is used for representing the relation between a preset state variable of the wind driven generator and the reference output power variation in a preset wind speed interval.

The preset wind speed interval comprises a first preset interval and a second preset interval, the upper limit value of the first preset interval is equal to the lower limit value of the second preset interval, and the preset state space expression comprises a first state space expression corresponding to the first preset interval and a second state space expression corresponding to the second preset interval.

When the preset wind speed interval is the first preset interval, the first state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variation when only the electromagnetic torque of the wind driven generator is changed. And when the preset wind speed interval is the second preset interval, the second state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variation when only the pitch angle of the wind driven generator is changed.

The upper limit value of the first preset interval and the lower limit value of the second preset interval are rated wind speeds, and when the current wind speed of the wind driven generator is the rated wind speed V _rated, the output power of the wind driven generator can be changed by changing the electromagnetic torque or the pitch angle of the wind driven generator, so that the rated wind speed can be classified into the first preset interval or the second preset interval.

The first preset interval is an open interval from a minimum operation wind speed V _min to a rated wind speed V _rated, the second preset interval is a left-closed right-open interval from a rated wind speed V _max to a maximum operation wind speed V _max, i.e., the first preset interval is (V _min,V_rated) and the second preset interval is [ V _rated,V_max); or the first preset interval is a left-right opening and closing interval from the lowest running wind speed V _min to less than or equal to the rated wind speed V _rated, the second preset interval is an opening interval from the rated wind speed to less than the highest running wind speed V _max, namely the first preset interval is (V _min,V_rated) and the second preset interval is (V _rated,V_max).

When the current wind speed is less than or equal to the minimum operating wind speed V _min or when the current wind speed is greater than or equal to the maximum operating wind speed V _max, the wind driven generator stops working.

That is, when the current wind speed belongs to the first preset interval, the output power of the wind power generator is changed by the reference output power variation amount by changing the electromagnetic torque of the wind power generator; when the current wind speed belongs to a second preset interval, the output power of the wind driven generator is changed by the reference output power change amount by changing the pitch angle of the wind driven generator.

The preset state space expression corresponding to the preset wind speed interval is constructed by the following steps:

According to a fan blade aerodynamic torque formula, constructing a linear formula of aerodynamic torque and a plurality of preset parameters, wherein each preset parameter is a parameter in the fan blade aerodynamic torque formula and generates a variable parameter in the power generation process;

a linear equation for pneumatic torque in relation to a plurality of preset parameters is constructed by:

T_r＝a×ω_r+b×β+c×V+d(4)

In the formulas (1) to (4), P _r is the fan pneumatic power of the wind driven generator, ρ is the air density, R is the fan rotor radius of the wind driven generator, V is the wind speed, C _P (λ, β) is the wind energy utilization coefficient, λ is the tip speed ratio of the fan rotor, β is the pitch angle, ω _r is the fan rotor speed, T _r is the pneumatic torque of the wind driven generator, ω _r, β and V are preset parameters, a is the coefficient corresponding to ω _r, b is the coefficient corresponding to β, C is the coefficient corresponding to V, and d is the constant term of the linear formula.

Wherein C _P (λ, β) is a high-order nonlinear function between tip speed ratio and pitch angle. That is, as can be seen in conjunction with equation (3), T _r in pneumatic systems is a highly nonlinear function with respect to ω _r, β, and V, which is difficult to describe with a simple mathematical model. Further, simplification can be achieved by linearization. The PWA model (PIECE WISE AFFINE ) is selected, and the nonlinear characteristic of the pneumatic power is approximately represented by utilizing the linear model through dividing different operation conditions, so that the formula (4) is obtained.

The different running conditions divided by the application are divided into a first preset interval or a second preset interval, and when the current wind speed belongs to the first preset interval, all preset state parameters when the output power changes the reference output power variation are predicted through a first state space expression corresponding to the first preset interval; when the current wind speed belongs to a second preset interval, predicting each preset state parameter when the output power changes by the reference output power variation through a second state space expression corresponding to the second preset interval.

And according to a relational expression between the electromagnetic torque of the wind driven generator and the reference electromagnetic torque, combining the linear formula, a double-mass model and a variable pitch model of the wind driven generator to construct a standard state space expression of the wind driven generator.

The standard state space expression is used for representing a relational expression between preset state parameters of the wind driven generator and variation amounts respectively corresponding to the preset parameters and a relational expression between output power and initial output power of the wind driven generator, and the preset state parameters are parameters which change in the power generation process.

Because the electromagnetic transient process of the generator is usually only millisecond, the variable frequency driving model formed by the generator and the frequency converter in the generator system can be accurately replaced by a first-order linear link to be approximate.

Further, a relational expression between the electromagnetic torque of the wind turbine and the reference electromagnetic torque is:

In the formula (5), T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _ref is the reference electromagnetic torque of the wind driven generator, namely the electromagnetic torque of the wind driven generator in theory. And the electromagnetic torque of the wind power generator after the actual transformation is equal to the reference battery torque.

Due to the proportional relationship between electromagnetic torque and output power, and the reference output power P _ref＝ΔP_ref+P_g.0, where Δp _ref is the reference output power variation, and P _g.0 is the initial output power.

Further, the expression between the reference electromagnetic torque and the reference output power variation is:

T_ref＝K×P_ref＝K×ΔP_ref+K×P_g.0(6)

In the formula (6), T _ref is the reference electromagnetic torque of the generator rotor; k is a proportionality coefficient between electromagnetic torque and output power; p _ref is the reference output power; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor.

Substituting formula (6) into formula (5) to obtain a relational expression of the electromagnetic torque and the reference output power variation, wherein the relational expression is as follows:

In the formula (7), T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _ref is the reference electromagnetic torque of the wind driven generator; k is a proportionality coefficient between electromagnetic torque and output power; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor.

The dual mass model is represented by the following formula:

In the formula (8), J _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; t _shaft is the equivalent intermediate shaft torque between the fan rotor and the generator rotor; t _r is the aerodynamic torque of the wind driven generator; t _g is the electromagnetic torque of the generator rotor; θ _r is the angular displacement of the fan rotor; θ _g is the angular displacement of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; and B is the damping coefficient of the equivalent intermediate shaft.

Further, derivative of θ can be obtained:

The double-mass model is characterized in that mechanical energy generated by a fan rotor of a wind driven generator is firstly transmitted to a low-speed shaft of a gear box, and then transmitted to a generator rotor part by a high-speed shaft after the speed change function of the gear box, so that the fan rotor is rotated to drive the generator rotor to move, and wind energy is converted into electric energy.

The pitch model is represented by the following formula:

Equation (10), The first-order pitch angle derivative of a variable pitch model is the first-order inertia link with amplitude limiting and speed limiting; τ _β is the time constant of the first-order inertial link; beta _ref is a pitch angle reference value; beta is the pitch angle.

The expression between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor is:

β_ref＝K_P×(ω_r-ω_ref)+K_I×∫(ω_r-ω_ref)＝K_P×(ω_r-ω_ref)+K_I×φ (11)

In the formula (11), K _P is a proportionality coefficient of the first-order inertial link; omega _r is the angular velocity of the fan rotor; omega _ref is the reference angular velocity of the fan rotor; k _I is an integral coefficient of the first-order inertial link; the derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; k _W is a proportionality coefficient between the angular speed of the fan rotor and the output power.

That is, in order to write into a linear expression, Φ= ≡ (ω _r-ω_ref) is set, and then, the following is obtained:

the expression between the reference angular velocity and the reference output power variation is:

ω_ref＝K_W×(P_g,0+ΔP_ref) (13)

In formula (13), ω _ref is the reference angular velocity of the fan rotor; k _W is a proportionality coefficient between the angular speed and the output power of the fan rotor; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor.

Substituting equations (11) and (13) into the expression between the first order pitch angle derivative of the variable pitch model and the reference output power variation in equation (10):

In the formula (14), K _P is a proportionality coefficient of the first-order inertial link; omega _r is the angular velocity of the fan rotor; omega _ref is the reference angular velocity of the fan rotor; k _I is an integral coefficient of the first-order inertial link; The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; k _W is a proportionality coefficient between the angular speed and the output power of the fan rotor; p _g,0 is the initial output power of the generator rotor of the wind generator; Δp _ref is the reference output power variation of the generator rotor.

And combining the formula (5), the formula (8), the formula (9), the formula (10) and the formula (12) to obtain the standard state space expression of the wind driven generator.

The standard state space expression of the wind driven generator is as follows:

In the formula (15), a is a coefficient corresponding to the angular speed of the fan rotor, b is a coefficient corresponding to the pitch angle, c is a coefficient corresponding to the wind speed, and d is a constant term of the linear formula; p _g is the output power of the generator rotor of the wind driven generator; Δp _g is the output power variation of the generator rotor of the wind generator; Is the derivative of the angular displacement difference between the fan rotor and the generator rotor; omega _r、ω_g, θ, φ, β and T _g are preset state parameters. /(I)

That is, the derivative corresponding to each preset state parameter is written in the form of a state space expression so that the derivative corresponding to each preset state parameter is related to the preset parameter (the preset parameter at this time is ω _ref、β_ref、T_ref).

When only the electromagnetic torque of the wind driven generator is changed, the first state space expression is constructed through a relational expression of the electromagnetic torque and the reference output power variation, the standard state space expression and a pitch angle first-order inertia link expression in the pitch model when a pitch angle reference value is zero.

That is, when the current wind speed belongs to the first preset interval, only the electromagnetic torque of the wind driven generator is changed without changing the pitch angle, and then the value of β _ref is 0, and is irrelevant to the reference angular speed ω _ref of the wind driven generator rotor.

At this time, the relation between the output power of the wind power generator and the electromagnetic matrix variable is as follows:

P_g＝η×T_g×ω_g＝P_g.0+η×T_g.0×Δω_g+η×ΔT_g×ω_g.0(16)

Δω_g＝ω_g-ω_g.0 (17)

ΔT_g＝T_g-T_g.0 (18)

in formulas (16) to (18), η is generator efficiency; omega _g is the angular speed of the generator rotor; t _g.0 is the initial electromagnetic torque of the generator rotor; Δω _g is the angular velocity variation of the generator rotor, and; ΔT _g is the electromagnetic torque variation of the generator rotor; omega _g.0 is the initial angular velocity of the generator rotor.

P_g.0＝η×T_g.0×ω_g.0 (19)

Substituting equations (17) and (18) into equation (16) yields:

P_g＝P_g.0+η×T_g.0×ω_g+η×T_g×ω_g.0-2×η×T_g.0×ω_g.0

＝-P_g.0+η×T_g.0×ω_g+η×T_g×ω_g.0 (20)

further, Δp _g＝P_g-P_g.0＝-2×P_g.0+η×T_g.0×ω_g+η×T_g×ω_g.0.

In the formula (21), beta _ref is a pitch angle reference value, and the value is zero; The first-order pitch angle derivative of a variable pitch model is the first-order inertia link with amplitude limiting and speed limiting; τ _β is the time constant of the first-order inertial link; beta is the pitch angle.

Further, the first state space expression may be obtained by combining equation (7), equation (15), equation (20), and equation (21):

In the formula (22), a is a coefficient corresponding to the angular speed of the fan rotor, b is a coefficient corresponding to the pitch angle, c is a coefficient corresponding to the wind speed, and d is a constant term of the linear formula; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; /(I)Is the derivative of the angular displacement difference between the fan rotor and the generator rotor; /(I)The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; v ₀ is the initial wind speed; j _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; and B is the damping coefficient of the equivalent intermediate shaft.

The initial wind speed may be understood as the wind speed at which the wind turbine is in a steady state condition before the reference output power variation for controlling the wind turbine to perform primary frequency modulation is obtained. When only the pitch angle of the wind driven generator is changed, the second state space expression is constructed by a relation of a pitch angle derivative and the reference output power variation, the standard state space expression, a relation of output power and initial electromagnetic torque, and a relation expression between the electromagnetic torque and the reference electromagnetic torque when the electromagnetic torque variable is zero.

That is, when the current wind speed belongs to the second preset interval, the change of the output power is achieved only by changing the pitch angle.

When the current wind speed belongs to the second preset interval, the wind driven generator is in a power limiting state, the electromagnetic torque keeps unchanged at the initial value, and further,

In the formula (23), P _g is the output power of the generator rotor of the wind driven generator; η is generator efficiency; omega _g is the angular speed of the generator rotor; p _g.0 is the initial output power of the generator rotor of the wind generator; omega _g.0 is the initial angular velocity of the generator rotor.

in the formula (24), T _g is the electromagnetic torque of the generator rotor; A derivative of the electromagnetic torque of the generator rotor; τ _g is the generator constant; t _g.0 is the initial electromagnetic torque of the generator rotor; omega _g.0 is the initial angular velocity of the generator rotor.

Combining equation (12), equation (13), equation (14), equation (23), and equation (24) to obtain the second state space expression:

In the formula (25), a is a coefficient corresponding to the angular speed of the fan rotor, b is a coefficient corresponding to the pitch angle, c is a coefficient corresponding to the wind speed, and d is a constant term of the linear formula; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; /(I)Is the derivative of the angular displacement difference between the fan rotor and the generator rotor; /(I)The derivative of phi is the difference between the angular velocity of the fan rotor and the reference angular velocity of the fan rotor; v ₀ is the initial wind speed; j _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; and B is the damping coefficient of the equivalent intermediate shaft.

S103: and determining a target state space expression corresponding to the target wind speed interval according to the target wind speed interval to which the current wind speed belongs.

The target wind speed interval is one of the first preset interval and the second preset interval, and the target state space expression is one of a first state space expression and a second state space expression.

The current wind speed may be understood as the wind speed when the reference output power variation amount for controlling the wind power generator to perform primary frequency modulation is acquired.

And when the current wind speed belongs to the first preset interval, the target wind speed interval is the first preset interval, and then the target state space expression is determined to be the first state space expression, namely, when only the electromagnetic torque of the wind driven generator is changed, the state space expression between the reference output power variation and each preset state variable is determined.

When the current wind speed belongs to a second preset interval, the target wind speed interval is the second preset interval, and then the target state space expression is determined to be the second state space expression, namely, when the pitch angle of the wind driven generator is only changed, the state space expression between the reference output power variation and each preset state variable is determined.

S104: substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator.

After the target state space expression is determined, the reference output power variation is substituted into the target state space expression, so that the value of each preset state variable is determined, and the wind driven generator is controlled to simulate according to the calculated preset state variable to simulate the primary frequency modulation of the wind driven generator.

By way of example, the first state space expression may also be reduced to:

wherein, x＝[ω_r ω_g θ φ β T_g]^T，u＝ΔP_ref，v＝[V₀P_g.0]^T，y＝ΔP_g，F₁＝-2×P_g.0。

By way of example, the second state space expression may also be reduced to:

wherein, x＝[ω_rω_gθφβT_g]^T，u＝Δp_ref，v＝[V₀p_g.0]^T，y＝ΔP_g，F₂＝-P_g.0。

Furthermore, the fact that the approximation degree of the low-order mechanism model to the complex nonlinearity is limited is considered at the same time, so that a neural network algorithm can be introduced to compensate the mechanism model deviation, the neural network model is used for predicting the first compensation and the second compensation, and a state space expression based on the neural network model is as follows:

In equation (27), a _i、B_i、C_i、D_i、E_i、F_i corresponds to either the first state space expression or the second state space expression, f is the first compensation, and g is the second compensation.

That is, a "black box model" based on input-output data driving or a "white box modeling" based on mechanism analysis is predictedPredicted/>, with the first state space expression or the second state space expressionPerforming difference to obtain a first difference value; the predicted y of the black box model based on the input-output data driving or the white box modeling based on the mechanism analysis is differenced with the predicted y in the first state space expression or the second state space expression to obtain a second difference value, and each time the predicted/>, in the first state space expression or the second state space expression is passedAnd y is taken as sample data, and the corresponding first difference value and second difference value are taken as labels to train the neural network model, so that the neural network model can predict the first difference value and the second difference value, namely, the first compensation and the second compensation, and more accurate/>, can be obtained without using a black box model or white box modelingAnd y, thereby obtaining more accurate x= [ omega _rω_gθφβT_g]^T.

Because the system state quantity in the continuous state space equation can be observed, the joint identification of the wind turbine mechanism parameter and the data parameter in the PWA model in the state space equation can be completed based on the operation data in the actual working field of the wind turbine, that is, the coefficient such as the rigidity coefficient A of the equivalent intermediate shaft, the damping coefficient B of the equivalent intermediate shaft and the like can be inaccurate in value due to the service life and the like, so that the more accurate A, B can be conveniently obtained through joint identification, the calculated preset state variable is more accurate, and the sub-region transient characteristics of a plurality of sub-models approach the nonlinear transient characteristics of the system overall.

Based on the same application conception, the embodiment of the application also provides a wind driven generator primary frequency modulation simulation device corresponding to the wind driven generator primary frequency modulation simulation method provided by the embodiment, and because the principle of solving the problem by the device in the embodiment of the application is similar to that of the wind driven generator primary frequency modulation simulation method provided by the embodiment of the application, the implementation of the device can refer to the implementation of the method, and the repetition is omitted.

As shown in fig. 2, fig. 2 is a functional block diagram of a primary frequency modulation simulation device of a wind driven generator according to an embodiment of the present application. The wind power generator primary frequency modulation simulation device 10 includes: an acquisition module 101, a construction module 102, a determination module 103 and a calculation module 104.

An acquisition module 101, configured to acquire a reference output power variation amount for controlling the wind turbine to perform primary frequency modulation; the construction module 102 is configured to construct a preset state space expression corresponding to a preset wind speed interval according to a relational expression corresponding to an electromagnetic torque and an electromagnetic torque variable of the wind turbine in the preset wind speed interval, and by combining a dual-mass model and a variable pitch model of the wind turbine, where the preset state space expression is used for representing a relation between a preset state variable of the wind turbine and the reference output power variable in the preset wind speed interval; a determining module 103, configured to determine a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; and the calculating module 104 is configured to substitute the reference output power variation into the target state space expression, calculate a preset state variable of primary frequency modulation, and perform primary frequency modulation simulation on the wind driven generator.

Based on the same application concept, referring to fig. 3, a schematic structural diagram of an electronic device according to an embodiment of the present application is shown, where the electronic device 20 includes: the wind turbine generator system comprises a processor 201, a memory 202 and a bus 203, wherein the memory 202 stores machine-readable instructions executable by the processor 201, and when the electronic device 20 is running, the processor 201 and the memory 202 communicate through the bus 203, and the machine-readable instructions are executed by the processor 201 to perform the steps of the wind turbine generator system primary frequency modulation simulation method according to any one of the above embodiments.

In particular, the machine readable instructions, when executed by the processor 201, may perform the following: acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation; according to a relational expression of electromagnetic torque and electromagnetic torque variable of the wind driven generator corresponding to a preset wind speed interval, a double-mass model and a variable pitch model of the wind driven generator are combined to construct a preset state space expression corresponding to the preset wind speed interval, wherein the preset state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variable quantity in the preset wind speed interval; determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs; substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator.

Based on the same application conception, the embodiment of the application also provides a computer readable storage medium, wherein the computer readable storage medium is stored with a computer program, and the computer program executes the steps of the wind driven generator primary frequency modulation simulation method provided by the embodiment when being run by a processor.

Specifically, the storage medium can be a general storage medium, such as a mobile magnetic disk, a hard disk, and the like, when a computer program on the storage medium is run, the above-mentioned wind turbine primary frequency modulation simulation method can be executed, by converting the power variation of the wind turbine primary frequency modulation into state space expressions corresponding to preset state parameters respectively under different wind speed intervals, so as to convert the power variation into linear expressions corresponding to the preset state parameters, when the reference output power variation of the output power of the wind turbine is received, the preset state parameters are calculated according to the state space expressions corresponding to the wind speed intervals to which the current wind speed belongs, so that the wind turbine is simulated to operate according to the calculated preset state parameters, and the technical problems that in the prior art, a large amount of data are required to perform primary frequency modulation simulation and a built model is too complex are solved, the technical effects of improving the primary frequency modulation simulation efficiency of the wind turbine and simplifying the model are achieved.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described system and apparatus may refer to corresponding procedures in the foregoing method embodiments, which are not described herein again. In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random AccessMemory, RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily appreciate variations or alternatives within the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A wind power generator primary frequency modulation simulation method, which is characterized by comprising the following steps:

Acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation;

According to a relational expression of the electromagnetic torque of the wind driven generator and the reference electromagnetic torque corresponding to a preset wind speed interval, a double-mass model and a variable pitch model of the wind driven generator are combined to construct a preset state space expression corresponding to the preset wind speed interval, wherein the preset state space expression is used for representing the relation between a preset state variable of the wind driven generator and the reference output power variation in the preset wind speed interval;

determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs;

Substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator;

Wherein the preset wind speed interval comprises a first preset interval and a second preset interval, the upper limit value of the first preset interval is equal to the lower limit value of the second preset interval, the preset state space expression comprises a first state space expression corresponding to the first preset interval and a second state space expression corresponding to the second preset interval, the target wind speed interval is one of the first preset interval and the second preset interval, the target state space expression is one of the first state space expression and the second state space expression,

When the preset wind speed interval is the first preset interval, the first state space expression is used for representing the relation between a preset state variable of the wind driven generator and the reference output power variation when only the electromagnetic torque of the wind driven generator is changed;

And when the preset wind speed interval is the second preset interval, the second state space expression is used for representing the relation between the preset state variable of the wind driven generator and the reference output power variation when only the pitch angle of the wind driven generator is changed.

2. The method according to claim 1, wherein the preset state space expression corresponding to the preset wind speed interval is constructed by:

According to a relational expression between the electromagnetic torque of the wind driven generator and the reference electromagnetic torque, combining the linear formula, a double-mass model and a variable pitch model of the wind driven generator, and constructing a standard state space expression of the wind driven generator, wherein the standard state space expression is used for representing a relational expression between preset state parameters of the wind driven generator and variation corresponding to the preset parameters and a relational expression between output power and initial output power of the wind driven generator, and the preset state parameters are parameters which generate variation in the power generation process;

When only the electromagnetic torque of the wind driven generator is changed, the first state space expression is constructed through a relational expression of the electromagnetic torque and the reference output power variation, the standard state space expression and a pitch angle first-order inertia link expression in the pitch model when a pitch angle reference value is zero;

When only the pitch angle of the wind driven generator is changed, the second state space expression is constructed by a relation of a pitch angle derivative and the reference output power variation, the standard state space expression, a relation of output power and initial output power and a relation expression between the electromagnetic torque and the reference electromagnetic torque when the electromagnetic torque variation is zero.

3. The method according to claim 2, characterized in that the linear formula of the aerodynamic torque in relation to a plurality of preset parameters is constructed by:

T_r＝a×ω_r+b×β+c×V+d

4. The method according to claim 2, wherein the relation between the electromagnetic torque of the wind power generator and the reference electromagnetic torque is:

the dual mass model is represented by the following formula:

Wherein J _r is the rotational inertia of the fan rotor of the wind driven generator; j _g is the moment of inertia of the generator rotor of the wind generator; t _shaft is the equivalent intermediate shaft torque between the fan rotor and the generator rotor; t _r is the aerodynamic torque of the wind driven generator; t _g is the electromagnetic torque of the generator rotor; θ _r is the angular displacement of the fan rotor; θ _g is the angular displacement of the generator rotor; θ is the angular displacement difference between the fan rotor and the generator rotor; omega _r is the angular velocity of the fan rotor; Is the derivative of the angular velocity of the fan rotor; omega _g is the angular speed of the generator rotor; /(I) Is the derivative of the angular speed of the generator rotor; n _g is the gear ratio of the gearbox; a is the rigidity coefficient of the equivalent intermediate shaft; b is the damping coefficient of the equivalent intermediate shaft;

the pitch model is represented by the following formula:

β_ref＝K_P×(ω_r-ω_ref)+K_I×∫(ω_r-ω_ref)

＝K_P×(ω_r-ω_ref)+K_I×φ

ω_ref＝K_W×(P_g,0+ΔP_ref)

The standard state space expression of the wind driven generator is as follows:

ΔP_g＝P_g-P_g.0

5. The method of claim 2, wherein the electromagnetic torque is related to the reference output power variation by the relation:

P_g＝η×T_g×ω_g＝P_g.0+η×T_g.0×Δω_g+η×ΔT_g×ω_g.0

Δω_g＝ω_g-ω_g.0

ΔT_g＝T_g-T_g.0

wherein P _g is the output power of the generator rotor of the wind driven generator; η is generator efficiency; omega _g is the angular speed of the generator rotor; t _g.0 is the initial electromagnetic torque of the generator rotor; Δω _g is the angular velocity variation of the generator rotor; ΔT _g is the electromagnetic torque variation of the generator rotor; omega _g.0 is the initial angular velocity of the generator rotor;

The first state space expression is:

6. A method according to claim 2, wherein the pitch angle derivative is related to the reference output power variation by:

The relational expression between the electromagnetic torque and the reference electromagnetic torque at the time when the electromagnetic torque variation amount is zero is:

The second state space expression is:

7. A wind turbine primary frequency modulation simulation device, the device comprising:

the acquisition module is used for acquiring a reference output power variation quantity for controlling the wind driven generator to execute primary frequency modulation;

The construction module is used for constructing a preset state space expression corresponding to the preset wind speed interval according to a relational expression corresponding to the electromagnetic torque of the wind driven generator and the reference electromagnetic torque in the preset wind speed interval by combining a double-mass model and a variable pitch model of the wind driven generator, wherein the preset state space expression is used for representing the relation between a preset state variable of the wind driven generator and the reference output power variation under the preset wind speed interval;

The determining module is used for determining a target state space expression corresponding to a target wind speed interval according to the target wind speed interval to which the current wind speed belongs;

The calculation module is used for substituting the reference output power variation into the target state space expression, and calculating a preset state variable of primary frequency modulation so as to perform primary frequency modulation simulation on the wind driven generator;

8. An electronic device, comprising: a processor, a memory and a bus, said memory storing machine readable instructions executable by said processor, said processor and said memory communicating via said bus when the electronic device is operating, said machine readable instructions when executed by said processor performing the steps of the wind turbine primary frequency modulation simulation method according to any one of claims 1 to 6.

9. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, performs the steps of the wind turbine primary frequency modulation simulation method according to any of claims 1 to 6.