Modeling method and device for electromechanical coupling characteristics of network-forming doubly-fed wind turbine generator

Abstract

The invention discloses an electromechanical coupling characteristic modeling method for a grid-forming type double-fed wind turbine generator, which comprises the following steps of: establishing a small signal transmission model of each control link of a grid-forming type double-fed wind turbine generator on the basis of considering a current loop according to a grid-forming type double-fed wind turbine generator control topology; according to the small signal model, establishing a transfer function of an electromagnetic torque-rotating speed difference of the electromechanical coupling characteristic of the meter machine, and drawing a Bode diagram of the transfer function; based on the natural oscillation frequency of the shaft system of the doubly-fed fan, an electric damping analysis method is adopted, the amplitude and the phase corresponding to the oscillation frequency are intercepted, and the equivalent damping coefficient provided by the electromagnetic torque for the transmission system is analyzed.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation control, and in particular to a method and device for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set. Background Art

[0002] Under the guidance of the "dual carbon" goal, wind power will gradually become the main power source in the future. Doubly fed induction generator (DFIG) has the advantages of variable speed constant frequency operation, no demagnetization risk, and low cost, so it has been widely studied and applied.

[0003] DFIG is a mechanical-electrical strong coupling structure. Its stable operation requires not only the coordinated grid-connected control of the electrical system, but also the reasonable adjustment of the mechanical structure. When subject to external interference such as sudden changes in wind speed and grid failure, the inherent low-frequency oscillation mode of the DFIG unit's mechanical structure will be excited, generating shaft system oscillations, causing fatigue damage to the parts on the transmission chain, which not only increases maintenance costs, but also affects the safe and stable operation of the wind turbine.

[0004] At present, the following studies have been conducted on the shaft oscillation problem of doubly fed wind turbines at home and abroad: (1) The effects of power control and speed control on DFIG shaft damping were compared; (2) The influence of system operating conditions, generator parameters and control parameters on shaft oscillation was revealed; (3) A multi-mode adaptive damping control strategy with active-reactive mixed modulation was used to suppress the shaft oscillation of DFIG. The proposed method can identify the oscillation frequency online and adaptively adjust the wind power; (4) Grid control will reduce the active loop bandwidth, thereby affecting the size of shaft damping.

[0005] In summary, the above studies all believe that the current loop bandwidth is large enough, and rarely consider the impact of the current loop on the shaft system oscillation. However, the current loop affects the electromagnetic torque by adjusting the rotor current, which will change the damping characteristics of the shaft system. Summary of the invention

[0006] In view of this, the present invention provides a method for modeling the electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set to analyze the effect of the current loop on the shaft system damping.

[0007] According to a first aspect of an embodiment of the present application, a method for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator system is provided, comprising:

[0008] According to the control topology of the grid-type doubly-fed wind turbine, the first small signal transmission model considering the mechanical transmission system and speed control link is established;

[0009] According to the control topology of the grid-type doubly-fed wind turbine, the second minimum signal transmission model considering the doubly-fed wind turbine model, the voltage outer loop control link, and the current inner loop control link is established;

[0010] According to the control topology of the grid-type doubly-fed wind turbine, a third small signal transmission model is established, which takes into account the coordinate transformation link, power calculation link, power control link, and power torque link.

[0011] According to the first small signal transfer model, the second small signal transfer model and the third small signal transfer model, a mathematical model of electromagnetic torque-speed difference of a grid-type doubly-fed wind turbine characterizing the electromechanical coupling characteristics is established.

[0012] According to a second aspect of an embodiment of the present application, a device for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator system is provided, comprising:

[0013] The first model building module is used to build a first small signal transmission model that considers the mechanical transmission system and the speed control link according to the control topology of the grid-type doubly-fed wind turbine generator set;

[0014] The second model building module is used to build a second small signal transmission model that considers the double-fed wind turbine model, the voltage outer loop control link, and the current inner loop control link according to the control topology of the grid-type double-fed wind turbine group;

[0015] The third model building module is used to build a third small signal transmission model that considers the coordinate transformation link, power calculation link, power control link, and power torque link according to the control topology of the grid-type doubly-fed wind turbine group;

[0016] The fourth model building module is used to establish a mathematical model of electromagnetic torque-speed difference of a grid-type doubly fed wind turbine that characterizes the electromechanical coupling characteristics based on the first small signal transfer model, the second small signal transfer model and the third small signal transfer model.

[0017] According to a third aspect of an embodiment of the present application, there is provided an electronic device, including:

[0018] one or more processors;

[0019] A memory for storing one or more programs;

[0020] When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in the first aspect.

[0021] According to a fourth aspect of an embodiment of the present application, a computer-readable storage medium is provided, on which computer instructions are stored, and when the instructions are executed by a processor, the steps of the method described in the first aspect are implemented.

[0022] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0023] The present invention takes the current loop characteristics into consideration during the modeling process and finds that it can affect the electromagnetic torque by adjusting the rotor current, thereby changing the damping characteristics of the shaft system. This method overcomes the problem of the difficulty in accurately modeling the traditional electromagnetic torque and shaft system damping, establishes an electromagnetic torque-speed difference small signal model considering the current loop, and combines it with electrical damping analysis to accurately reveal the influence of electromagnetic torque on the damping of the transmission system.

[0024] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0026] Figure 1 It is a flow chart of a method for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set provided in an embodiment of the present invention.

[0027] Figure 2 It is a schematic diagram of the grid-connected operation of a grid-connected doubly-fed wind turbine provided in an embodiment of the present invention.

[0028] Figure 3 It is a block diagram of a small signal model of a grid-type doubly-fed wind turbine provided in an embodiment of the present invention.

[0029] Figure 4 It is a small signal structure diagram of the speed difference and electromagnetic torque of a grid-type doubly-fed wind turbine provided in an embodiment of the present invention.

[0030] Figure 5 The embodiment of the present invention provides a Bode diagram that considers whether the electromagnetic rotation of the current loop and the speed difference are considered.

[0031] Figure 6 It is a diagram of equivalent damping coefficients corresponding to different active inertias provided in an embodiment of the present invention.

[0032] Figure 7 It is a graph of equivalent damping coefficients corresponding to different active damping coefficients provided in an embodiment of the present invention.

[0033] Figure 8 It is a graph of equivalent damping coefficients corresponding to different short-circuit ratios provided in an embodiment of the present invention.

[0034] Fig. 9 It is a flow chart of a device for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0036] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0037] Figure 1 is a flow chart of a method for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator system according to an exemplary embodiment. Figure 1 As shown, the method is applied in a terminal and may include the following steps:

[0038] S1: According to the control topology of the grid-type doubly-fed wind turbine generator system, the first small signal transmission model is established;

[0039] Specifically, considering the characteristics of the wind turbine before the doubly fed wind turbine, the first small signal transmission model of the mechanical transmission system and the speed control link are established as follows:

[0040] Mechanical transmission system: ;

[0041] Speed ​​control link: ;

[0042] Among them, Δ represents the small signal amount of the variable; H t , H g are the equivalent wind wheel inertia and the equivalent motor inertia respectively; T m 、T 12 、T e are the wind wheel input mechanical torque, transmission shaft torque and motor input electromagnetic torque respectively; ω t and ω r are the wind wheel speed and generator speed respectively; θ Δ and ω Δ are the angular displacement and speed difference of the wind turbine relative to the doubly fed wind turbine rotor; K m and D m is the mechanical stiffness coefficient and mechanical damping coefficient; P refrepresents the active power command given value, G7 is the speed-power command change matrix; k opt represents the constant related to the wind turbine, ω t0 is the rotor speed of the wind turbine during steady-state operation; H ω Indicates speed controller.

[0043] S2: According to the control topology of the grid-type doubly-fed wind turbine generator system, the second small signal transmission model is established;

[0044] Specifically, Figure 2 is a control block diagram of a grid-type doubly-fed wind turbine generator set according to an exemplary embodiment. Figure 2 , considering the electrical control characteristics of the doubly fed wind turbine, the second smallest signal transmission model of the doubly fed wind turbine model, the voltage outer loop control link, and the current control inner loop link are established as follows:

[0045] Doubly fed wind turbine model: ;

[0046] Voltage outer loop control link: ;

[0047] Current inner loop control link: ;

[0048] Among them, Δ represents the small signal amount of the variable; U sdq ,I sdq , U rdq ,I rdq are the dq axis components of the stator voltage and current and the rotor voltage and current of the doubly fed wind turbine respectively; s is the Laplace operator; ω1 is the power frequency angular frequency; R s , R r , L s , L r , L m They are stator and rotor resistance, stator and rotor inductance and mutual inductance; ω s is the slip angular frequency; ψ rd0 , rd0 are the steady-state values ​​of the rotor flux d-axis and q-axis respectively; G 0_1 and G 0_2 They are the stator current-stator voltage change matrix and the rotor current-stator voltage change matrix respectively; G 0_3 , G 0_4 and G 0_5 They are stator current-rotor voltage change matrix, rotor current-rotor voltage change matrix and speed-rotor voltage change matrix respectively; G 2_0 and G 2_1 are the coefficient change matrices caused by control, G 2_3 and G 2_4are the voltage loop and current loop controllers; the superscript “ref” indicates the command value of the corresponding variable; θ and E are the power synchronization angle and the voltage loop amplitude given value respectively; the superscript “s” indicates the variable in the actual coordinate system; the superscript “c” indicates the variable in the control coordinate system.

[0049] S3: According to the control topology of the grid-type doubly-fed wind turbine generator system, the third small signal transmission model is established;

[0050] Specifically, Figure 2 is a control block diagram of a grid-type doubly-fed wind turbine generator set according to an exemplary embodiment. Figure 2 , after linearizing some control links, it is necessary to supplement the mathematical model to make the control equation valid. Therefore, the third small signal transmission model of the coordinate transformation link, power calculation link, power control link, and power torque link is established as follows:

[0051] Coordinate transformation link: ;

[0052] Power calculation link: ;

[0053] Power control link: ;

[0054] Power torque model: ;

[0055] Among them, Δ represents the small signal quantity of the variable; the superscript "s" represents the variable in the actual coordinate system; the superscript "c" represents the variable in the control coordinate system; X represents the stator voltage and rotor voltage and current of the doubly fed wind turbine; θ and E are the power synchronization angle and the voltage loop amplitude given value respectively; G3 is the transformation matrix between the system rotating coordinate system and the control rotating coordinate system; P e and Q e are stator active power and reactive power respectively; U sdq ,I sdq , are the dq axis components of the stator voltage and current of the doubly fed wind turbine respectively; I sd0 ,I sq0 are the steady-state values ​​of the stator current d-axis and q-axis respectively; U sd0 , U sq0 are the steady-state values ​​of the stator voltage d-axis and q-axis respectively; G4 and G5 are the stator voltage-power change matrix and the stator current-power change matrix; Q ref represents the reactive power command given value; J and D represent the active inertia and active damping coefficient of the network control respectively; s is the Laplace operator; ω1 is the power frequency angular frequency; H Q is the reactive power controller; T e is the electromagnetic torque of the motor.

[0056] S4: According to the first small signal transmission model, the second small signal transmission model and the third small signal transmission model, a corresponding transmission model is established to analyze the shaft damping of the grid-connected double-fed wind turbine.

[0057] Specifically, the above three small signal models are combined, and the mathematical model of electromagnetic torque-speed difference of the grid-type doubly fed wind turbine with characteristic electromechanical coupling characteristics is obtained through elimination. According to the mathematical model, the small signal model block diagram and the Bode diagram of electromagnetic torque-speed difference are drawn, the shaft system natural oscillation frequency of the doubly fed wind turbine is intercepted, and the shaft system damping is analyzed in combination with the Bode diagram.

[0058] The mathematical model is as follows:

[0059]

[0060] Where, ΔT e and Δω Δ are the small signal components of electromagnetic torque and speed difference, ω1 is the power frequency angular frequency; k is the ratio of equivalent motor inertia to equivalent wind wheel inertia; G7 is the speed-power command change matrix; G 0_1 and G 0_2 They are the stator current-stator voltage change matrix and the rotor current-stator voltage change matrix respectively; G 0_3 , G 0_4 and G 0_5 They are stator current-rotor voltage change matrix, rotor current-rotor voltage change matrix and speed-rotor voltage change matrix respectively; G1 is the main circuit change matrix; G 2_0 and G 2_1 are the coefficient change matrices caused by control, G 2_3 and G 2_4 G is the voltage loop and current loop controller; 3_1 , G 3_2 , G 3_3 They are the transformation matrices between the stator voltage, rotor current, and rotor voltage coordinate systems respectively; G4 and G5 are the stator voltage-power change matrix and the stator current-power change matrix.

[0061] Figure 3 This is the small signal model block diagram of the grid-type doubly fed wind turbine, such as Figure 3 As shown in the figure, due to the existence of multiple variables, the shaft damping of the grid-connected double-fed wind turbine cannot be analyzed. In order to analyze its shaft damping characteristics, it is necessary to Figure 3 The small signal block diagram is simplified. Figure 3 After simplification, we can get Figure 4 , Figure 4 is the small signal model structure diagram of electromagnetic torque and speed difference, Figure 4 It can be seen that the current loop provides a coupling path for the speed and active power, thereby changing the magnitude of the shaft system damping.

[0062] according to Figure 4 The small signal transmission model is used to draw the small signal Bode diagram of the grid-connected double-fed wind turbine for analysis. Figure 5 The Bode diagram of electromagnetic torque and speed difference of grid-type doubly fed wind turbine considering the current loop characteristics. Figure 5 It can be seen that the current loop will cause differences in the amplitude and phase of the Bode diagram within the shaft oscillation frequency range (1~3Hz). This error will have an important impact on the analysis results of the shaft damping of the grid-type doubly fed wind turbine.

[0063] The natural oscillation frequency of the shaft system is calculated using the following formula:

[0064]

[0065] Among them, f osc is the natural oscillation frequency of the shaft system; π is the circumference of a circle; K m is the mechanical stiffness coefficient; H t , H g are the equivalent wind wheel inertia and the equivalent motor inertia respectively; ω1 is the power frequency angular frequency.

[0066] According to the above steps, the shaft system natural oscillation frequency corresponding to the doubly fed wind turbine can be calculated, and then Figure 5 The equivalent damping coefficient is calculated from the Bode diagram. The equivalent damping coefficient provided by the electromagnetic torque under different operating areas, grid strengths, and control parameters can be analyzed, and the influence of each parameter on the shaft oscillation of the doubly fed wind turbine can be summarized.

[0067] Figure 6 is the equivalent damping coefficient diagram for different active inertias, Figure 7 is the equivalent damping coefficient diagram for different active damping coefficients. Figure 6 and Figure 7 As shown in the figure, increasing the active inertia and active damping coefficient has opposite effects on the equivalent damping coefficient in the MPPT area and the constant speed area. In the MPPT area, with the increase of active inertia, the equivalent damping coefficient increases, which is beneficial to the stability of the DFIG shaft system; in the constant speed area, with the increase of active inertia, ΔT e Providing negative damping for the transmission system is not conducive to the stability of the shaft system. At the same time, increasing the active damping coefficient will weaken the shaft system damping in the MPPT area, but it can increase the equivalent damping coefficient in the constant speed area.

[0068] Figure 8 The MPPT control mode and constant speed mode ΔT under different short circuit ratios e / Δω Δ The equivalent damping coefficient diagram of Figure 8As shown in the figure, when other parameters remain unchanged, as the short-circuit ratio increases, whether the DFIG operates in the MPPT area or the constant speed area, the equivalent damping coefficient The larger it is, the more conducive it is to the shaft stability of the DFIG wind power system. Therefore, the grid-type double-fed wind turbine has the risk of low-frequency oscillation of the shaft under weak power grid.

[0069] It can be seen from the above embodiments that, on the basis of considering the current loop, the present application establishes an electromagnetic torque-speed difference small signal model that characterizes the electromechanical coupling characteristics of the doubly fed wind turbine. Based on the drawn Bode diagram of the electromagnetic torque-speed difference and according to the inherent oscillation frequency of the shaft system of the doubly fed wind turbine, the equivalent damping coefficient is studied by using the method of electrical damping analysis, thereby analyzing the influence of different parameters on the shaft system oscillation of the doubly fed wind turbine. In the modeling process, the current loop is established in the overall model, and then the mathematical model of the electromechanical coupling characteristics of the grid-connected doubly fed wind turbine set is accurately established.

[0070] Corresponding to the above-mentioned embodiment of the method for modeling the electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set, the present application also provides an embodiment of a device for modeling the electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator set.

[0071] Fig. 9 1 is a block diagram of a device for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator system according to an exemplary embodiment. Fig. 9 , the device comprises:

[0072] The first model building module 1 is used to build a first small signal transmission model considering the mechanical transmission system and the speed control link according to the control topology of the grid-type doubly-fed wind turbine generator set;

[0073] The second model building module 2 is used to build a second small signal transmission model that considers the double-fed wind turbine model, the voltage outer loop control link, and the current inner loop control link according to the control topology of the grid-type double-fed wind turbine group;

[0074] The third model building module 3 is used to establish a third small signal transmission model considering the coordinate transformation link, power calculation link, power control link, and power torque link according to the control topology of the grid-type double-fed wind turbine group;

[0075] The fourth model building module 4 is used to build a mathematical model of electromagnetic torque-speed difference of a grid-type doubly-fed wind turbine that characterizes electromechanical coupling characteristics based on the first small signal transfer model, the second small signal transfer model and the third small signal transfer model.

[0076] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0077] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0078] Correspondingly, the present application also provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the electromechanical coupling characteristics modeling method of the grid-type doubly-fed wind turbine set as described above.

[0079] Correspondingly, the present application also provides a computer-readable storage medium on which computer instructions are stored, and when the instructions are executed by a processor, the electromechanical coupling characteristic modeling method of the grid-type doubly-fed wind turbine generator set as described above is implemented.

[0080] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0081] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator system, characterized in that: include: According to the control topology of the grid-type doubly-fed wind turbine, the first small signal transmission model considering the mechanical transmission system and speed control link is established; According to the control topology of the grid-type doubly-fed wind turbine, the second minimum signal transmission model considering the doubly-fed wind turbine model, the voltage outer loop control link, and the current inner loop control link is established; According to the control topology of the grid-type doubly-fed wind turbine, a third small signal transmission model is established, which takes into account the coordinate transformation link, power calculation link, power control link, and power torque link. According to the first small signal transfer model, the second small signal transfer model and the third small signal transfer model, a mathematical model of electromagnetic torque-speed difference of a grid-type doubly-fed wind turbine characterizing the electromechanical coupling characteristics is established.

2. The method according to claim 1, characterized in that The first small signal transfer model is as follows: Mechanical transmission system: ; Speed ​​control link: ; Among them, Δ represents the small signal amount of the variable; H t , H g are the equivalent wind wheel inertia and the equivalent motor inertia respectively; T m , T 12 , T e are the wind wheel input mechanical torque, transmission shaft torque and motor input electromagnetic torque respectively; ω t and ω r are the wind wheel speed and generator speed respectively; θ Δ and ω Δ are the angular displacement and speed difference of the wind turbine relative to the doubly fed wind turbine rotor; K m and D m is the mechanical stiffness coefficient and mechanical damping coefficient; P ref represents the active power command given value, G7 is the speed-power command change matrix; k opt represents the constant related to the wind turbine, ω t0 is the rotor speed of the wind turbine during steady-state operation; H ω Indicates speed controller.

3. The method according to claim 1, characterized in that The second small signal transfer model is as follows: Doubly fed wind turbine model: ; Voltage outer loop control link: ; Current inner loop control link: ; Among them, Δ represents the small signal amount of the variable; U sdq ,I sdq , U rdq ,I rdq are the dq axis components of the stator voltage and current and the rotor voltage and current of the doubly fed wind turbine respectively; s is the Laplace operator; ω1 is the power frequency angular frequency; R s , R r , L s , L r , L m They are stator and rotor resistance, stator and rotor inductance and mutual inductance; ω s is the slip angular frequency; ψ rd0 , rd0 are the steady-state values ​​of the rotor flux d-axis and q-axis respectively; G 0_1 and G 0_2 They are the stator current-stator voltage change matrix and the rotor current-stator voltage change matrix respectively; G 0_3 , G 0_4 and G 0_5 They are stator current-rotor voltage change matrix, rotor current-rotor voltage change matrix and speed-rotor voltage change matrix respectively; G 2_0 and G 2_1 are the coefficient change matrices caused by control, G 2_3 and G 2_4 are the voltage loop and current loop controllers; the superscript "ref" represents the command value of the corresponding variable; θ and E are the power synchronization angle and the voltage loop amplitude given value respectively; the superscript "s" represents the variable in the actual coordinate system; the superscript "c" represents the variable in the control coordinate system.

4. The method according to claim 1, characterized in that: The third small signal transmission model is as follows: Coordinate transformation link: ; Power calculation link: ; Power control link: ; Power torque model: ; Wherein, Δ represents the small signal quantity of the variable; the superscript "s" represents the variable in the actual coordinate system; the superscript "c" represents the variable in the control coordinate system; X represents the stator voltage and rotor voltage and current of the doubly fed wind turbine; θ and E are the power synchronization angle and the voltage loop amplitude given value respectively; G3 is the transformation matrix between the system rotating coordinate system and the control rotating coordinate system; P e and Q e are stator active power and reactive power respectively; U sdq ,I sdq , are the dq axis components of the stator voltage and current of the doubly fed wind turbine respectively; I sd0 ,I sq0 are the steady-state values ​​of the stator current d-axis and q-axis respectively; U sd0 , U sq0 are the steady-state values ​​of the stator voltage d-axis and q-axis respectively; G4 and G5 are the stator voltage-power change matrix and the stator current-power change matrix; Q ref represents the reactive power command given value; J and D represent the active inertia and active damping coefficient of the network control respectively; s is the Laplace operator; ω1 is the power frequency angular frequency; H Q is the reactive power controller; T e is the electromagnetic torque of the motor.

5. The method according to claim 1, characterized in that The mathematical model is as follows:

6. Among them, ΔT e and Δω Δ are the small signal components of electromagnetic torque and speed difference, ω1 is the power frequency angular frequency; k is the ratio of equivalent motor inertia to equivalent wind wheel inertia; G7 is the speed-power command change matrix; G 0_1 and G 0_2 They are the stator current-stator voltage change matrix and the rotor current-stator voltage change matrix respectively; G 0_3 , G 0_4 and G 0_5 They are stator current-rotor voltage change matrix, rotor current-rotor voltage change matrix and speed-rotor voltage change matrix respectively; G1 is the main circuit change matrix; G 2_0 and G 2_1 are the coefficient change matrices caused by control, G 2_3 and G 2_4 G is the voltage loop and current loop controller; 3_1 , G 3_2 , G 3_3 They are the transformation matrices between the stator voltage, rotor current, and rotor voltage coordinate systems respectively; G4 and G5 are the stator voltage-power change matrix and the stator current-power change matrix.

7. A device for modeling electromechanical coupling characteristics of a grid-type doubly-fed wind turbine generator, characterized in that: include: The first model building module is used to build a first small signal transmission model that considers the mechanical transmission system and the speed control link according to the control topology of the grid-type doubly-fed wind turbine generator set; The second model building module is used to build a second small signal transmission model that considers the double-fed wind turbine model, the voltage outer loop control link, and the current inner loop control link according to the control topology of the grid-type double-fed wind turbine group; The third model building module is used to build a third small signal transmission model that considers the coordinate transformation link, power calculation link, power control link, and power torque link according to the control topology of the grid-type doubly-fed wind turbine group; The fourth model building module is used to establish a mathematical model of electromagnetic torque-speed difference of a grid-type doubly fed wind turbine that characterizes the electromechanical coupling characteristics based on the first small signal transfer model, the second small signal transfer model and the third small signal transfer model.

8. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 5.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instruction is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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