Direct-driven fan impedance model dynamic order reduction method, device and equipment and storage medium

Abstract

The invention discloses a direct-drive fan impedance model dynamic order reduction method, device and equipment and a storage medium, and the method comprises the following steps: obtaining an initial control transfer function, a main circuit expression and a filtering link transfer function according to the parameters of a direct-drive fan and a disturbance signal, and obtaining a direct-drive fan impedance model according to a steady state; constructing a full-order impedance model of the direct-drive fan by adopting a small signal method; based on the signal transmission path, a disturbance control transfer function is obtained, factors are decomposed based on typical links to obtain a Bode diagram and a turning angle frequency, and then a degradation frequency and a degradation control transfer function are obtained; and based on the degradation frequency, according to the initial control transfer function and the degradation control transfer function, carrying out dynamic order reduction on the direct-drive fan full-order impedance model to obtain a wide-frequency-band impedance order reduction model. According to the dynamic order reduction method for the impedance model of the direct-driven fan, the calculation complexity is reduced, the calculation convergence speed is increased, the adaptability is high, and the fitting degree is high.

Description

Technical Field

[0001] The present invention relates to the technical field of direct-drive wind turbines in offshore wind farms, and in particular to a method, device, equipment and storage medium for dynamically reducing the impedance model of a direct-drive wind turbine. Background Art

[0002] As global energy issues become increasingly serious, the development and utilization of renewable energy has received attention from all countries. Under the guidance of the dual carbon goals, accelerating the low-carbon transformation of the power system is the key to achieving low-carbon development. At the same time, the rapid development of large-scale grid-connected technology with a high proportion of new energy and the improvement of onshore power grids have promoted the development of offshore wind farms. The mainstream model currently used in offshore wind farms is permanent magnet direct-drive wind turbines. System modeling and calculation of wind turbines are an indispensable part of building a grid-connected system.

[0003] In actual engineering calculations, a large number of equipment are involved, and the grid-connected new energy adds a large number of power electronic nonlinear devices. The amount of calculation data is extremely large and the solution order is high. How to reduce the complexity of the calculation and speed up the solution calculation speed is of great significance to the safe control of the grid-connected system. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present invention provides a dynamic order reduction method for a direct-drive wind turbine impedance model, which reduces the complexity of calculations, accelerates the calculation convergence speed, has strong adaptability and high fitting degree.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a method for dynamic order reduction of impedance model of direct-drive wind turbine, comprising the following steps:

[0006] Obtain direct drive fan parameters; obtain disturbance signals;

[0007] Obtaining an initial control transfer function, a main circuit expression and a filter link transfer function according to the direct-drive fan parameters and the disturbance signal;

[0008] Based on the steady state, a full-order impedance model of the direct-drive wind turbine is constructed according to the initial control transfer function, the main circuit expression and the filter link transfer function by using a small signal method;

[0009] Based on the signal transfer path, obtaining a disturbance control transfer function according to the disturbance signal and the initial control transfer function;

[0010] Factoring the disturbance control transfer function based on typical links;

[0011] Obtain the Bode diagram and the corner frequency according to the factorized disturbance control transfer function;

[0012] Obtaining a degradation frequency according to the Bode diagram and the turning angle frequency;

[0013] Based on the Bode diagram, a degradation control transfer function is obtained according to the factorized disturbance control transfer function;

[0014] Based on the degradation frequency, the full-order impedance model of the direct-drive wind turbine is dynamically reduced in order according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model.

[0015] Furthermore, the initial control transfer function includes an initial inner loop transfer function, an initial outer loop transfer function and an initial phase-locked loop transfer function, and the initial phase-locked loop transfer function includes a first initial phase-locked loop transfer function and a second initial phase-locked loop transfer function; the filter link transfer function includes a power filter link transfer function and a dq axis voltage filter link transfer function; the full-order impedance model of the direct-drive wind turbine is:

[0016]

[0017] K=0.5K m V dc ,

[0018] K i =ω g l,

[0019] K out =G v G i U m0 ,

[0020] K PLL =G v U m0 ,

[0021]

[0022] In the formula, Z inv is the full-order impedance of the direct-drive wind turbine, s is a complex variable in the frequency domain, K is the first calculated intermediate value, K m is a constant coefficient, V dc is the capacitor voltage, H in is the initial inner loop transfer function, H out is the initial outer loop transfer function, j is the imaginary unit, K i Calculate the intermediate value for the second, ω g is the power frequency angular frequency, l is the fan outlet inductance, G lpf is the transfer function of the power filter link, G i is the normalized transfer function of current, G F is the transfer function of the dq axis voltage filter, K out Calculate the intermediate value for the third, G vis the voltage normalized transfer function, U m0 is the AC voltage during steady-state operation, I m0 is the current in steady state operation, is the phase difference during steady-state operation, H PLL is the first initial phase-locked loop transfer function, s0 is the complex frequency at the power frequency, K PLL Calculate the intermediate value for the fourth, G PLL is the second initial phase-locked loop transfer function.

[0023] Further, the disturbance control transfer function includes an inner loop disturbance transfer function, an outer loop disturbance transfer function and a phase-locked loop disturbance transfer function; the Bode diagram includes an inner loop Bode diagram, an outer loop Bode diagram and a phase-locked loop Bode diagram; the turning angle frequency includes an inner loop turning angle frequency, an outer loop turning angle frequency and a phase-locked loop turning angle frequency;

[0024] The degradation frequency includes the inner loop degradation frequency, the outer loop degradation frequency and the phase-locked loop degradation frequency;

[0025] The degenerate control transfer function includes a degenerate inner loop transfer function, a degenerate outer loop transfer function and a degenerate phase-locked loop transfer function;

[0026] Obtaining an inner loop Bode diagram and an inner loop turning angle frequency according to the factored inner loop disturbance transfer function, and obtaining the inner loop degradation frequency according to the inner loop Bode diagram and the inner loop turning angle frequency; obtaining the degraded inner loop transfer function according to the factored inner loop disturbance transfer function based on the inner loop Bode diagram;

[0027] Obtaining an outer loop Bode diagram and an outer loop turning angle frequency according to the factored outer loop disturbance transfer function, and obtaining the outer loop degenerate frequency according to the outer loop Bode diagram and the outer loop turning angle frequency; obtaining the degenerate outer loop transfer function according to the factored outer loop disturbance transfer function based on the outer loop Bode diagram;

[0028] The phase-locked loop Bode diagram and the phase-locked loop corner frequency are obtained according to the decomposed phase-locked loop disturbance transfer function, and the phase-locked loop degradation frequency is obtained according to the phase-locked loop Bode diagram and the phase-locked loop corner frequency; based on the phase-locked loop Bode diagram, the degraded phase-locked loop transfer function is obtained according to the decomposed phase-locked loop disturbance transfer function.

[0029] Furthermore, the step of obtaining the inner loop degradation frequency is:

[0030] Based on the signal transfer path, obtaining an inner loop disturbance transfer function according to the initial inner loop transfer function;

[0031] Based on the typical links, the inner loop disturbance transfer function is factored; the factored inner loop disturbance transfer function is:

[0032]

[0033] Where G1 is the inner loop disturbance transfer function, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain;

[0034] Obtaining the inner loop Bode diagram and the inner loop turning angle frequency according to the factorized inner loop disturbance transfer function;

[0035] Obtaining an inner loop turning frequency according to the inner loop Bode diagram and the inner loop turning angle frequency;

[0036] The degenerate inner loop transfer function is obtained according to the factorized inner loop disturbance transfer function and the inner loop corner frequency; the degenerate inner loop transfer function is:

[0037] H i ' n =K p_in ;

[0038] In the formula, H i ' n is the degenerate inner loop transfer function;

[0039] Based on the margin and the frequency shift, the inner loop degradation frequency is obtained according to the inner loop corner frequency.

[0040] Furthermore, the step of obtaining the outer loop degradation frequency is:

[0041] Based on the signal transfer path, obtaining an outer loop disturbance transfer function according to the initial inner loop transfer function and the initial outer loop transfer function;

[0042] Based on the typical links, the outer loop disturbance transfer function is factored; the factored outer loop disturbance transfer function is:

[0043]

[0044] Where G2 is the outer loop disturbance transfer function, K p_out is the power outer loop ratio parameter, K i_out is the power outer loop integral parameter, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain;

[0045] Obtaining the outer loop Bode diagram and the outer loop turning angle frequency based on the factorized outer loop disturbance transfer function;

[0046] Obtaining an outer loop turning frequency according to the outer loop Bode diagram and the outer loop turning angle frequency;

[0047] The degenerate outer loop transfer function is obtained according to the factorized outer loop disturbance transfer function and the outer loop corner frequency; the degenerate outer loop transfer function is:

[0048] H' out =K p_out ;

[0049] In the formula, H o ' ut is the degenerate outer loop transfer function;

[0050] Based on the margin and the frequency shift, an outer loop degeneration frequency is obtained according to the outer loop corner frequency.

[0051] Furthermore, the step of obtaining the phase-locked loop degradation frequency is:

[0052] Based on the signal transfer path, obtaining a phase-locked loop disturbance transfer function according to the disturbance signal and the first initial phase-locked loop transfer function;

[0053] Based on the typical links, the phase-locked loop disturbance transfer function is factored; the factored phase-locked loop disturbance transfer function is:

[0054]

[0055] Where G2 is the phase-locked loop disturbance transfer function, K pp is the phase-locked loop ratio parameter, K pi is the phase-locked loop integral parameter, V m is the AC voltage value, s is a complex variable in the frequency domain;

[0056] Obtaining the phase-locked loop Bode diagram and the phase-locked loop corner frequency based on the factorized phase-locked loop disturbance transfer function;

[0057] Obtaining a phase-locked loop corner frequency according to the phase-locked loop Bode diagram and the phase-locked loop corner frequency;

[0058] The degenerate phase-locked loop transfer function is obtained according to the decomposed phase-locked loop disturbance transfer function and the phase-locked loop corner frequency; the degenerate phase-locked loop transfer function is:

[0059]

[0060] In the formula, G' PLL is the degenerate phase-locked loop transfer function;

[0061] Based on the margin and the frequency shift, a phase-locked loop degradation frequency is obtained according to the phase-locked loop corner frequency.

[0062] Furthermore, the steps of dynamically reducing the order of the full-order impedance model of the direct-drive wind turbine are as follows:

[0063] Obtaining a degraded frequency domain according to the degraded frequency; the degraded frequency domain includes a phase-locked loop degraded frequency domain, an inner loop degraded frequency domain and an outer loop degraded frequency domain; the phase-locked loop degraded frequency domain is located after the phase-locked loop degraded frequency, the inner loop degraded frequency domain is located after the inner loop degraded frequency, and the outer loop degraded frequency domain is located after the outer loop degraded frequency;

[0064] The wide-band impedance reduction model includes a phase-locked loop degenerate direct-drive fan reduced-order impedance model, an inner-loop degenerate direct-drive fan reduced-order impedance model, and an outer-loop degenerate direct-drive fan reduced-order impedance model;

[0065] Obtaining a degraded frequency axis according to the degraded frequency and the degraded frequency domain;

[0066] Based on the degraded frequency axis, starting from the phase-locked loop degraded frequency, in the phase-locked loop degraded frequency domain, the second initial phase-locked loop transfer function in the direct-drive wind turbine full-order impedance model is replaced with the degraded phase-locked loop transfer function to obtain the phase-locked loop degraded direct-drive wind turbine reduced-order impedance model;

[0067] Based on the degradation frequency axis, starting from the inner loop degradation frequency, the initial inner loop transfer function in the phase-locked loop degenerate direct-drive wind turbine reduced-order impedance model is replaced with the degenerate inner loop transfer function in the inner loop degradation frequency domain to obtain the inner loop degenerate direct-drive wind turbine reduced-order impedance model;

[0068] Based on the degraded frequency axis, starting from the outer loop degraded frequency and in the outer loop degraded frequency domain, the initial outer loop transfer function in the inner loop degraded direct-drive wind turbine reduced-order impedance model is replaced with the degraded outer loop transfer function to obtain the outer loop degraded direct-drive wind turbine reduced-order impedance model.

[0069] A storage medium includes a stored program, and when the program is run, the device where the storage medium is located is controlled to execute the direct-drive wind turbine impedance model dynamic reduction method.

[0070] A device for implementing the direct-drive wind turbine impedance model dynamic order reduction method, comprising a construction module, a calculation module and a dynamic order reduction module;

[0071] The building blocks:

[0072] Used to input the direct-drive fan parameters and the disturbance signal;

[0073] Used to obtain an initial control transfer function, a main circuit expression and a filter link transfer function according to the direct-drive fan parameters and the disturbance signal;

[0074] Used to construct a full-order impedance model of a direct-drive wind turbine based on a steady state and using a small signal method according to an initial control transfer function, the main circuit expression and the filter link transfer function;

[0075] for obtaining a disturbance control transfer function according to the disturbance signal and the initial control transfer function based on a signal transfer path;

[0076] The computing module:

[0077] for factoring the disturbance control transfer function based on typical links;

[0078] Used to obtain Bode plots and corner frequencies based on factored disturbance control transfer functions;

[0079] Used to obtain the degenerate frequency according to the Bode diagram and the obtained turning angle frequency;

[0080] for obtaining a degradation control transfer function according to the factorized disturbance control transfer function based on the Bode diagram;

[0081] The dynamic order reduction module is used to dynamically reduce the order of the full-order impedance model of the direct-drive wind turbine based on the degradation frequency according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model.

[0082] Further, the calculation module includes a factorization unit and a degradation data acquisition unit;

[0083] The factorization unit:

[0084] for factoring the disturbance control transfer function based on typical links;

[0085] Used to obtain Bode plots and corner frequencies based on factored disturbance control transfer functions;

[0086] The degradation data acquisition unit:

[0087] Used to obtain the degenerate frequency according to the Bode diagram and the obtained turning angle frequency;

[0088] The method is used for obtaining a degraded control transfer function according to the decomposed disturbance control transfer function based on the Bode diagram.

[0089] An electronic device includes a processor and a memory, wherein the memory stores computer-readable instructions, and the processor is used to run the computer-readable instructions. When the computer-readable instructions are run, the dynamic order reduction method of the impedance model of a direct-drive wind turbine is executed.

[0090] The beneficial effects of the present invention are:

[0091] (1) The method provided by the present invention adopts the small signal method to derive the full-order impedance model of the direct-drive wind turbine, thereby ensuring the correctness of the full-order impedance expression of the direct-drive wind turbine. On this basis, it is proposed to flexibly split the transfer functions of the control links based on typical links, and to integrate the Bode diagram, which not only considers the transmission of small signals in the actual control loop, but also considers the margin required for the turning frequency of the typical link in the actual engineering, thereby realizing the dynamic reduction of the full-order impedance model of the direct-drive wind turbine with high fitting degree.

[0092] (2) The method provided by the present invention finally calculates a wide-band reduced-order impedance model of a direct-drive fan, and obtains reduced-order impedance models of direct-drive fans of different orders after link degradation in different frequency bands. In actual engineering applications, corresponding to the calculation of certain frequency bands, the reduction of the order can alleviate the heavy and complex high-order calculations, reduce the complexity of solving the problem, accelerate the convergence speed of the calculation, and obtain the results as soon as possible.

[0093] (3) The method provided by the present invention is general and highly adaptable. For nonlinear devices with similar structures, after completing the linearization derivation, the method can be used to split the links and then dynamically reduce the order to obtain a simplified expression that is acceptable within the allowable error range of a wide frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 It is a schematic flow chart of the direct-drive wind turbine impedance model dynamic order reduction method of the present invention;

[0095] Figure 2 Schematic diagram of the principle of the direct-drive wind turbine impedance model dynamic reduction method of the present invention;

[0096] Figure 3 is a control block diagram of the direct-drive fan in the present invention;

[0097] Figure 4 G is ignored in the present invention. θ_c Comparison of full-order impedance curves of front and rear direct-drive fans;

[0098] Figure 5 A comparison diagram of the full-order impedance model of a direct-drive fan calculated in the time-domain simulation model of the present invention and the actual fan outlet frequency sweep;

[0099] Figure 6 It is a block diagram of the inner loop disturbance transfer function in the present invention;

[0100] Figure 7 It is a block diagram of the outer loop disturbance transfer function in the present invention;

[0101] Figure 8 is a basic control loop diagram of the phase-locked loop in the present invention;

[0102] Fig. 9It is a block diagram of the phase-locked loop disturbance transfer function in the present invention;

[0103] Fig.10 is the inner loop Bode diagram corresponding to the inner loop disturbance transfer function in the present invention;

[0104] Fig.11 is the outer loop Bode diagram corresponding to the outer loop disturbance transfer function in the present invention;

[0105] Fig.12 is a phase-locked loop Bode diagram corresponding to the phase-locked loop disturbance transfer function in the present invention;

[0106] Fig.13 A comparison diagram of impedance results of a direct-drive fan before and after inner ring degradation in the present invention;

[0107] Fig.14 This is a comparison diagram of the impedance results of the direct-drive fan before and after the outer ring is degraded in the present invention;

[0108] Fig.15 A comparison diagram of impedance results of a direct-drive fan before and after degradation of the phase-locked loop in the present invention;

[0109] Fig.16 It is a schematic diagram of the degenerate frequency axis in the present invention;

[0110] Fig.17 Schematic diagram of the dynamic order reduction process in the present invention;

[0111] Fig.18 G in the present invention F Comparison of impedance results of direct-drive wind turbine before and after degradation. DETAILED DESCRIPTION

[0112] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0113] See also Figure 1 , 2 The embodiment of the present invention provides a method for dynamic order reduction of impedance model of a direct-drive wind turbine, comprising the following steps:

[0114] Obtain direct drive fan parameters; obtain disturbance signals;

[0115] According to the direct-drive fan parameters and disturbance signals, the initial control transfer function, the main circuit expression and the filter link transfer function are obtained; the initial control transfer function includes the initial inner loop transfer function H in

[0116] (H in =K p_in +K i_in / s), initial outer loop transfer function H out (H out =Kp_out +K i_out / s) and an initial phase-locked loop transfer function, the initial phase-locked loop transfer function including a first initial phase-locked loop transfer function H PLL and the second initial phase-locked loop transfer function G PLL , the filter link transfer function includes the power filter link transfer function G lpf And the dq axis voltage filter transfer function G F ;

[0117] First initial phase-locked loop transfer function It represents the transfer function composed of the product of the PI link of the phase-locked loop and the inertia link after the PI link of the phase-locked loop;

[0118] The second initial phase-locked loop transfer function The transfer function from the disturbance voltage to the small disturbance of the phase-locked loop;

[0119] Power filter transfer function The characteristic frequency of the transfer function of the power filter link is set to 300 Hz, and the damping ratio is 0.7;

[0120] dq axis voltage filter transfer function G F =1 / (1+sT), the time constant of the transfer function of the dq axis voltage filter link is set to 0.02;

[0121] Based on the steady state, the full-order impedance model of the direct-drive wind turbine is constructed by the small signal method according to the initial control transfer function, the main circuit expression and the filter link transfer function; specifically, see Figure 3 , Figure 3 This is the control block diagram of the grid-side converter of the direct-drive wind turbine. In the figure, P pu is the unit active power value at the fan outlet, Q pu is the reactive power per unit value at the fan outlet, P ref is the active reference value, Q ref is the reactive power reference value, K p_out is the power outer loop ratio parameter, K i_out is the power outer loop integral parameter, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, i dpu is the per unit value of the d-axis current, i qpu is the per unit value of the q-axis current, v dpu is the d-axis voltage per unit value, v qpu is the q-axis voltage per unit value, v dref is the d-axis reference voltage, v qref is the q-axis reference voltage, ω g is the angular frequency of the power frequency, l is the inductance of the fan outlet, and s is a complex variable in the frequency domain.

[0122] Figure 3 The final output v dref 、v qref After the Park inverse transformation, it enters the PWM power electronic switch. In view of the existence of nonlinear links such as power electronic equipment and Park transformation, it is necessary to first establish a frequency domain steady-state model of the nonlinear system. In the steady-state state of the system, a small signal disturbance is superimposed, that is, the small signal method. The nonlinear links are linearly described using methods such as Taylor series expansion and Fourier transform. An input and output linearization model of the direct-drive fan is established, and the response relationship between the voltage and current at the fan outlet under small signal disturbance is obtained. According to the response relationship, the impedance of the system at the small signal disturbance frequency is obtained. By traversing and changing the disturbance frequency, the full-order impedance model of the direct-drive fan can be established.

[0123]

[0124] G v =sl,

[0125] G I =-0.5K m V dc H in G lpf G i -0.5K m V dc H in H out G F G i +jK i G i G lpf ,

[0126]

[0127] G U =G u +G θ G PLL ,

[0128] G u =0.5K m V dc G lpf G v ,

[0129]

[0130] In the formula, Z inv0 is the full-order initial impedance model of the direct-drive wind turbine, G z Calculate the intermediate value for the fifth, G I G represents the transfer function from the disturbance current to the voltage on the fan outlet valve side. Urepresents the transfer function from the disturbance voltage to the fan outlet valve side voltage, s is a complex variable in the frequency domain, l is the fan outlet inductance, K m is a constant coefficient, V dc is the capacitor voltage, H in is the initial inner loop transfer function, H out is the initial outer loop transfer function, j is the imaginary unit, K i Calculate the intermediate value for the second, G lpf is the transfer function of the power filter link, G i is the normalized current transfer function, G F is the transfer function of the dq axis voltage filter, K out Calculate the intermediate value for the third, G v is the voltage normalized transfer function, U m0 is the AC voltage during steady-state operation, I m0 is the current in steady state operation, is the phase difference during steady-state operation, H PLL is the first initial phase-locked loop transfer function, s0 is the complex frequency at the power frequency, K PLL Calculate the intermediate value for the fourth, U dref0 is the d-axis reference voltage during steady-state operation, U qref0 is the q-axis reference voltage during steady-state operation, G u Calculate the intermediate value for the sixth, G θ G represents the transfer function from the small disturbance of the phase-locked loop to the voltage on the fan outlet valve side. PLL is the second initial phase-locked loop transfer function;

[0131] G θ The last three items in the above table represent the dq coupling term G in the phase-locked loop. θ_c , considering that the disturbance from small voltage and current disturbance to the phase-locked loop is very small after ignoring the coupling term, see Figure 4 Ignore G θ_c Comparison of full-order impedance curves of front and rear direct-drive fans, so G is ignored θ In represents the dq coupling term in the phase-locked loop, the full-order impedance model of the direct-drive wind turbine is obtained as follows:

[0132]

[0133] K=0.5K m V dc ,

[0134] K i =ω g l,

[0135] K out =G v G i U m0 ,

[0136] K PLL =G v U m0 ,

[0137]

[0138] In the time domain simulation, the main circuit and control loop simulation model of the direct-drive fan is built to ensure that the control parameters and electrical parameters of the simulation model are the same as those of the direct-drive fan. The full-order impedance model of the direct-drive fan calculated in the time domain simulation model is compared with the actual fan outlet frequency sweep. The results are as follows: Figure 5 As shown in the figure, the full-order impedance model of the direct-drive wind turbine is correct. Except for the large difference value near the steady-state working point of the power frequency and the small deviation of the interpolation near the possible resonance frequency, the fitting degree of the other frequency points is high, and the overall error is not large and acceptable.

[0139] The full-order impedance model of the direct-drive wind turbine includes an initial inner loop transfer function, an initial outer loop transfer function and an initial phase-locked loop transfer function; the initial phase-locked loop transfer function includes a first initial phase-locked loop transfer function H PLL (represents the transfer function composed of the product of the phase-locked loop PI link and the inertia link after the phase-locked loop PI link) and the second initial phase-locked loop transfer function G PLL (represents the transfer function from the disturbance voltage to the small disturbance of the phase-locked loop);

[0140] Based on the signal transfer path, a disturbance control transfer function is obtained according to the disturbance signal and the initial control transfer function; the disturbance control transfer function includes an inner loop disturbance transfer function, an outer loop disturbance transfer function and a phase-locked loop disturbance transfer function;

[0141] See also Figure 6 It can be seen that under small signal disturbance, the inner loop disturbance transfer function is the same as the initial inner loop transfer function, and the inner loop disturbance transfer function is

[0142] See also Figure 7 It can be seen that due to the small signal disturbance, the disturbance variable of the power outer loop has to pass through the current inner loop when acting on the control loop. The outer loop disturbance transfer function is related to the initial inner loop transfer function and the initial outer loop transfer function.

[0143] The basic control loop of the phase-locked loop is shown in Figure 8 The three-phase AC voltage is transformed by Park to obtain the d-axis and q-axis voltage components, where the q-axis voltage component generates a phase-locked angle through the PI link and the integral link. In the figure, V a is the voltage of phase a at the fan outlet, V b is the voltage of phase b at the fan outlet, V c is the fan outlet c-phase voltage, Vq is the q-axis component of the fan outlet voltage after Park transformation, K pp is the phase-locked loop ratio parameter, K pi is the phase-locked loop integral parameter, V m is the AC voltage value, θ PLL is the final output angle of the phase-locked loop. The AC voltage small signal disturbance will introduce a small signal component into the phase-locked angle. Combined with the AC disturbance component U ap , the closed-loop transfer function can be obtained as:

[0144]

[0145] The block diagram of the phase-locked loop disturbance transfer function can be derived from the closed-loop transfer function. Fig. 9 , the perturbation transfer function of the phase-locked loop is obtained as

[0146] The disturbance control transfer function is factored out based on typical links, that is, the inner-loop disturbance transfer function, the outer-loop disturbance transfer function and the phase-locked loop disturbance transfer function are factored out respectively; the signal transmission influencing paths of the various control links of the direct-drive wind turbine, including the inner-loop control link, the outer-loop control link and the phase-locked loop control link, in the full-order impedance model of the direct-drive wind turbine can be split according to typical links to obtain the Bode diagram, and then the action area on the Bode diagram of each link is analyzed to find the turning frequency, and the reorganization is carried out after considering the margin and frequency displacement, so as to reshape the full-order impedance model of the direct-drive wind turbine after impedance reduction in different frequency bands, and obtain a wide-band impedance reduction model.

[0147] Based on the typical links, the inner loop disturbance transfer function is factored, that is, the inner loop disturbance transfer function is factored into an expression with typical links as factors, and the inner loop disturbance transfer function is decomposed into the inner loop integral link With the first-order differential link of the inner loop Two factors; the inner loop disturbance transfer function after factorization is:

[0148]

[0149] Where G1 is the inner loop disturbance transfer function, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain;

[0150] Based on the typical links, the outer loop disturbance transfer function is factored, that is, the outer loop disturbance transfer function is factored into an expression with the typical links as factors, and the outer loop disturbance transfer function is decomposed into an outer loop integral link The first first-order differential link of the outer loop The second first-order differential link of the outer loop and the outer ring inertia link Four factors; the outer loop perturbation transfer function after factorization is:

[0151]

[0152] Where G2 is the outer loop disturbance transfer function, K p_out is the power outer loop ratio parameter, K i_out is the power outer loop integral parameter, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain;

[0153] Based on the typical links, the phase-locked loop disturbance transfer function is factored, that is, the phase-locked loop disturbance transfer function is factored into an expression with typical links as factors, and the phase-locked loop disturbance transfer function is decomposed into the phase-locked loop integral link and the first-order differential link of the phase-locked loop Two factors; the factored phase-locked loop disturbance transfer function is:

[0154]

[0155] A Bode diagram and a turning angle frequency are obtained according to the decomposed disturbance control transfer function; the Bode diagram includes an inner loop Bode diagram, an outer loop Bode diagram and a phase-locked loop Bode diagram; similarly, the turning angle frequency includes an inner loop turning angle frequency, an outer loop turning angle frequency and a phase-locked loop turning angle frequency;

[0156] The degradation frequency is obtained according to the Bode diagram and the turning angle frequency; the degradation frequency includes the inner loop degradation frequency, the outer loop degradation frequency and the phase-locked loop degradation frequency;

[0157] Based on the Bode diagram, the degradation control transfer function is obtained according to the factorized disturbance control transfer function;

[0158] The inner loop Bode diagram is obtained from the factorized inner loop perturbation transfer function. Fig.10 ;

[0159] Based on the inner loop Bode diagram, the inner loop remains stable after 25 rad / s, that is, after the inner loop turning angle frequency, and the inner loop turning frequency can be obtained as 3.98 Hz according to the inner loop turning angle frequency.

[0160] According to the factorized inner loop disturbance transfer function, the inner loop turning angle frequency can be obtained as K i_in / K p_in , and before the inner loop turning angle frequency, the inner loop integral link Play a major role, after the inner loop turning angle frequency, the inner loop integral link With the first-order differential link of the inner loop They work together and cancel each other out, leaving only the current inner loop proportional parameters, which results in the degenerate inner loop transfer function being:

[0161] H i ' n =K p_in ;

[0162] Based on the margin and frequency displacement, the inner loop degradation frequency is obtained according to the inner loop turning frequency. Considering the actual engineering, a ten-fold margin is usually taken. The inner loop turning frequency after the margin is 39.8Hz. According to the frequency displacement, the theoretical value of the inner loop degradation frequency is 89.8Hz. Through time domain simulation, the comparison of the full-order impedance results of the direct-drive wind turbine before and after the inner loop degradation is shown in Fig.11 It can be seen that except for the deviation in the resonant frequency, the fitting is good after 90Hz, so the inner loop degeneration frequency is taken as 90Hz.

[0163] The outer loop Bode diagram is obtained from the factorized outer loop perturbation transfer function. Fig.12 ;

[0164] According to the decomposed outer loop disturbance transfer function, there are three outer loop turning angle frequencies, namely the first outer loop turning angle frequency K i_out / K p_out 、The second outer ring turning angle frequency K i_in / K p_in and the third outer ring turning angle frequency K i_in / (1+K p_in ), by determining the positions of the three outer loop turning angle frequency points on the outer loop Bode diagram and the corresponding curve parts, it can be obtained that the first outer loop turning angle frequency is 250 rad / s, the second outer loop turning angle frequency is 25 rad / s and the third outer loop turning angle frequency is 11.1 rad / s;

[0165] Based on the power outer loop Bode diagram, the outer loop turning frequency is obtained according to the outer loop turning angle frequency; combined with the outer loop Bode diagram, it can be seen that the outer loop remains stable after 250rad / s, that is, after the first outer loop turning angle frequency, and the corresponding outer loop turning frequency is 39.8Hz;

[0166] The degenerate outer loop transfer function is obtained according to the factorized outer loop disturbance transfer function and the first outer loop corner frequency; the degenerate outer loop transfer function is:

[0167] H' out =K p_out ;

[0168] In the formula, H o ' ut is the degenerate outer loop transfer function;

[0169] Based on the margin and frequency displacement, the outer loop degradation frequency is obtained according to the outer loop turning frequency. Considering the actual engineering, a ten-fold margin is usually taken. The outer loop turning frequency after the margin is 398Hz. According to the frequency displacement, the theoretical value of the outer loop degradation frequency is 439.8Hz. Through time domain simulation, the comparison of the full-order impedance results of the direct-drive wind turbine before and after the outer loop degradation is shown in Fig.13 It can be seen that the curve at 440Hz is basically fitted correctly after the outer loop is degraded, so the outer loop degradation frequency is taken as 440Hz.

[0170] The Bode diagram of the phase-locked loop is obtained from the factorized phase-locked loop perturbation transfer function. Fig.14 ;

[0171] According to the decomposed phase-locked loop disturbance transfer function, the phase-locked loop corner frequency can be obtained as K pi / K pp Based on the Bode diagram of the phase-locked loop, the phase-locked loop turning frequency is obtained according to the turning angular frequency of the phase-locked loop. It can be calculated that the phase-locked loop Bode diagram has a turning point at the angular frequency point of 20rad / s, that is, the turning angular frequency of the phase-locked loop is 20rad / s, and the phase-locked loop is degraded after the turning angular frequency of the phase-locked loop. A curved link, namely the second initial phase-locked loop transfer function G in the full-order impedance model of the direct-drive wind turbine PLL It degenerates into the degenerate phase-locked loop transfer function shown below:

[0172]

[0173] Based on the margin and frequency displacement, the PLL degradation frequency is obtained according to the PLL transition frequency. Also considering the actual project, the theoretical value of the PLL degradation frequency is 82Hz, which is usually 10 times the margin and frequency displacement. Through time domain simulation, the full-order impedance results of the direct-drive wind turbine before and after the PLL degradation are compared. Fig.15 , 82Hz can be taken as a reasonable phase-locked loop degradation frequency, so the phase-locked loop degradation frequency is taken as 82Hz.

[0174] Based on the degradation frequency, the full-order impedance model of the direct-drive wind turbine is dynamically reduced according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model. The dynamic reduction process is shown in Fig.17 , Fig.17 The numbers on the right side of the figure indicate the order changes. Specifically:

[0175] A degraded frequency domain is obtained according to the degraded frequency; the degraded frequency domain includes a phase-locked loop degraded frequency domain, an inner loop degraded frequency domain and an outer loop degraded frequency domain; the phase-locked loop degraded frequency domain is located after the phase-locked loop degraded frequency, the inner loop degraded frequency domain is located after the inner loop degraded frequency, and the outer loop degraded frequency domain is located after the outer loop degraded frequency;

[0176] The wide-band impedance reduction model includes the phase-locked loop degenerate direct-drive fan reduced-order impedance model, the inner-loop degenerate direct-drive fan reduced-order impedance model and the outer-loop degenerate direct-drive fan reduced-order impedance model.

[0177] To obtain the degraded frequency axis based on the degraded frequency and the degraded frequency domain, refer to Fig.16 ;

[0178] Based on the degraded frequency axis, starting from the phase-locked loop degraded frequency, in the phase-locked loop degraded frequency domain, the second initial phase-locked loop transfer function in the direct-drive wind turbine full-order impedance model is replaced with the degraded phase-locked loop transfer function to obtain a phase-locked loop degraded direct-drive wind turbine reduced-order impedance model;

[0179] Based on the degradation frequency axis, starting from the inner loop degradation frequency, in the inner loop degradation frequency domain, the initial inner loop transfer function in the phase-locked loop degenerate direct-drive wind turbine reduced-order impedance model is replaced with the degenerate inner loop transfer function to obtain the inner loop degenerate direct-drive wind turbine reduced-order impedance model;

[0180] Based on the degradation frequency axis, starting from the outer loop degradation frequency and in the outer loop degradation frequency domain, the initial outer loop transfer function in the inner loop degraded direct-drive wind turbine reduced-order impedance model is replaced with the degraded outer loop transfer function to obtain the outer loop degraded direct-drive wind turbine reduced-order impedance model.

[0181] From the perspective of the above dynamic order reduction analysis, there are only two filter transfer functions that have not been simplified:

[0182]

[0183] G F After the angular frequency is 500 rad / s, that is, the frequency is about 130 Hz, it degenerates to 50 / s, G F For a comparison of the impedance results of direct-drive fans before and after degradation, see Fig.18 ; G lpf It will degenerate to 300 at a frequency of about 3000 Hz. 2 / s 2 , the degradation of the transfer functions of the two filtering links does not reduce the order of the denominator, but only reduces the complexity, so the formula will not be repeated.

[0184] A storage medium includes a stored program, which controls a device where the storage medium is located to execute a dynamic order reduction method for a direct-drive wind turbine impedance model when the program is running.

[0185] A device for implementing a dynamic order reduction method for a direct-drive wind turbine impedance model, comprising a construction module, a calculation module and a dynamic order reduction module;

[0186] Building blocks:

[0187] Used to input direct-drive fan parameters and disturbance signals;

[0188] Used to obtain the initial control transfer function, main circuit expression and filter link transfer function according to the direct-drive fan parameters and disturbance signals;

[0189] It is used to construct a full-order impedance model of a direct-drive wind turbine based on a steady-state state and using a small signal method according to the initial control transfer function, the main circuit expression and the filter link transfer function;

[0190] for obtaining a disturbance control transfer function according to a disturbance signal and an initial control transfer function based on a signal transfer path;

[0191] Compute module:

[0192] Used to factorize the disturbance control transfer function based on typical links;

[0193] Used to obtain Bode plots and corner frequencies based on factored disturbance control transfer functions;

[0194] Used to obtain the degenerate frequency based on the Bode plot and obtain the turning angle frequency;

[0195] for obtaining a degraded control transfer function from a factorized disturbance control transfer function based on a Bode diagram;

[0196] The dynamic order reduction module is used to dynamically reduce the full-order impedance model of the direct-drive wind turbine based on the degradation frequency according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model.

[0197] Further, the calculation module includes a factorization unit and a degradation data acquisition unit;

[0198] Factoring Units:

[0199] Used to factorize the disturbance control transfer function based on typical links;

[0200] Used to obtain Bode plots and corner frequencies based on factored disturbance control transfer functions;

[0201] Degradation data acquisition unit:

[0202] Used to obtain the degenerate frequency based on the Bode plot and obtain the turning angle frequency;

[0203] Used to obtain the degraded control transfer function from the factored disturbance control transfer function based on the Bode plot.

[0204] An electronic device includes a processor and a memory, wherein the memory stores computer-readable instructions, and the processor is used to run the computer-readable instructions. When the computer-readable instructions are run, a dynamic order reduction method of a direct-drive wind turbine impedance model is executed.

[0205] The system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., 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 scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0206] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0207] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A dynamic order reduction method for impedance model of direct-drive wind turbine, characterized in that: The following steps are involved: Obtain direct drive fan parameters; obtain disturbance signals; Obtaining an initial control transfer function, a main circuit expression and a filter link transfer function according to the direct-drive fan parameters and the disturbance signal; Based on the steady state, a full-order impedance model of the direct-drive wind turbine is constructed according to the initial control transfer function, the main circuit expression and the filter link transfer function by using a small signal method; Based on the signal transfer path, obtaining a disturbance control transfer function according to the disturbance signal and the initial control transfer function; Factoring the disturbance control transfer function based on typical links; Obtain the Bode diagram and the corner frequency according to the factorized disturbance control transfer function; Obtaining a degradation frequency according to the Bode diagram and the turning angle frequency; Based on the Bode diagram, a degradation control transfer function is obtained according to the factorized disturbance control transfer function; Based on the degradation frequency, the full-order impedance model of the direct-drive wind turbine is dynamically reduced in order according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model.

2. The direct-drive wind turbine impedance model dynamic reduction method according to claim 1 is characterized in that: The initial control transfer function includes an initial inner loop transfer function, an initial outer loop transfer function and an initial phase-locked loop transfer function, wherein the initial phase-locked loop transfer function includes a first initial phase-locked loop transfer function and a second initial phase-locked loop transfer function; the filter link transfer function includes a power filter link transfer function and a dq axis voltage filter link transfer function; the full-order impedance model of the direct-drive wind turbine is: K=0.5K m V dc , K i =ω g l, K out =G v G i U m0 , K PLL =G v U m0 , In the formula, Z inv is the full-order impedance of the direct-drive wind turbine, s is a complex variable in the frequency domain, K is the first calculated intermediate value, K m is a constant coefficient, V dc is the capacitor voltage, H in is the initial inner loop transfer function, H out is the initial outer loop transfer function, j is the imaginary unit, K i Calculate the intermediate value for the second, ω g is the power frequency angular frequency, l is the fan outlet inductance, G lpf is the transfer function of the power filter link, G i is the normalized current transfer function, G F is the transfer function of the dq axis voltage filter, K out Calculate the intermediate value for the third, G v is the voltage normalized transfer function, U m0 is the AC voltage during steady-state operation, I m0 is the current in steady state operation, is the phase difference during steady-state operation, H PLL is the first initial phase-locked loop transfer function, s0 is the complex frequency at the power frequency, K PLL Calculate the intermediate value for the fourth, G PLL is the second initial phase-locked loop transfer function.

3. The direct-drive wind turbine impedance model dynamic reduction method according to claim 2 is characterized in that: The disturbance control transfer function includes an inner loop disturbance transfer function, an outer loop disturbance transfer function and a phase-locked loop disturbance transfer function; the Bode diagram includes an inner loop Bode diagram, an outer loop Bode diagram and a phase-locked loop Bode diagram; the turning angle frequency includes an inner loop turning angle frequency, an outer loop turning angle frequency and a phase-locked loop turning angle frequency; The degradation frequency includes the inner loop degradation frequency, the outer loop degradation frequency and the phase-locked loop degradation frequency; The degenerate control transfer function includes a degenerate inner loop transfer function, a degenerate outer loop transfer function and a degenerate phase-locked loop transfer function; Obtaining an inner loop Bode diagram and an inner loop turning angle frequency according to the factored inner loop disturbance transfer function, and obtaining the inner loop degradation frequency according to the inner loop Bode diagram and the inner loop turning angle frequency; obtaining the degraded inner loop transfer function according to the factored inner loop disturbance transfer function based on the inner loop Bode diagram; Obtaining an outer loop Bode diagram and an outer loop turning angle frequency according to the factored outer loop disturbance transfer function, and obtaining the outer loop degenerate frequency according to the outer loop Bode diagram and the outer loop turning angle frequency; obtaining the degenerate outer loop transfer function according to the factored outer loop disturbance transfer function based on the outer loop Bode diagram; The phase-locked loop Bode diagram and the phase-locked loop corner frequency are obtained according to the decomposed phase-locked loop disturbance transfer function, and the phase-locked loop degradation frequency is obtained according to the phase-locked loop Bode diagram and the phase-locked loop corner frequency; based on the phase-locked loop Bode diagram, the degraded phase-locked loop transfer function is obtained according to the decomposed phase-locked loop disturbance transfer function.

4. The direct-drive wind turbine impedance model dynamic reduction method according to claim 3 is characterized in that: The steps of obtaining the inner loop degradation frequency are: Based on the signal transfer path, obtaining an inner loop disturbance transfer function according to the initial inner loop transfer function; Based on the typical links, the inner loop disturbance transfer function is factored; the factored inner loop disturbance transfer function is: Where G1 is the inner loop disturbance transfer function, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain; Obtaining the inner loop Bode diagram and the inner loop turning angle frequency according to the factorized inner loop disturbance transfer function; Obtaining an inner loop turning frequency according to the inner loop Bode diagram and the inner loop turning angle frequency; The degenerate inner loop transfer function is obtained according to the factorized inner loop disturbance transfer function and the inner loop corner frequency; the degenerate inner loop transfer function is: H i ' n =K p_in ; In the formula, H i ' n is the degenerate inner loop transfer function; Based on the margin and the frequency shift, the inner loop degradation frequency is obtained according to the inner loop corner frequency.

5. The direct-drive wind turbine impedance model dynamic reduction method according to claim 3 is characterized in that: The steps of obtaining the outer ring degradation frequency are: Based on the signal transfer path, obtaining an outer loop disturbance transfer function according to the initial inner loop transfer function and the initial outer loop transfer function; Based on the typical links, factoring the outer loop disturbance transfer function; The factorized outer loop perturbation transfer function is: Where G2 is the outer loop disturbance transfer function, K p_out is the power outer loop ratio parameter, K i_out is the power outer loop integral parameter, K p_in is the current inner loop proportional parameter, K i_in is the current inner loop integral parameter, s is the complex variable in the frequency domain; Obtaining the outer loop Bode diagram and the outer loop turning angle frequency based on the factorized outer loop disturbance transfer function; Obtaining an outer loop turning frequency according to the outer loop Bode diagram and the outer loop turning angle frequency; The degenerate outer loop transfer function is obtained according to the factorized outer loop disturbance transfer function and the outer loop corner frequency; the degenerate outer loop transfer function is: H' out =K p_out ; Where H' out is the degenerate outer loop transfer function; Based on the margin and the frequency shift, an outer loop degeneration frequency is obtained according to the outer loop corner frequency.

6. The direct-drive wind turbine impedance model dynamic reduction method according to claim 3 is characterized in that: The steps of obtaining the phase-locked loop degradation frequency are: Based on the signal transfer path, obtaining a phase-locked loop disturbance transfer function according to the disturbance signal and the first initial phase-locked loop transfer function; Based on the typical links, factoring the phase-locked loop disturbance transfer function; The factored phase-locked loop disturbance transfer function is: Where G2 is the phase-locked loop disturbance transfer function, K pp is the phase-locked loop ratio parameter, K pi is the phase-locked loop integral parameter, V m is the AC voltage value, s is a complex variable in the frequency domain; Obtaining the phase-locked loop Bode diagram and the phase-locked loop corner frequency based on the factorized phase-locked loop disturbance transfer function; Obtaining a phase-locked loop corner frequency according to the phase-locked loop Bode diagram and the phase-locked loop corner frequency; The degenerate phase-locked loop transfer function is obtained according to the decomposed phase-locked loop disturbance transfer function and the phase-locked loop corner frequency; the degenerate phase-locked loop transfer function is: In the formula, G' PLL is the degenerate phase-locked loop transfer function; Based on the margin and the frequency shift, a phase-locked loop degradation frequency is obtained according to the phase-locked loop corner frequency.

7. The direct-drive wind turbine impedance model dynamic reduction method according to claim 3 is characterized in that: The steps of dynamically reducing the order of the full-order impedance model of the direct-drive wind turbine are as follows: Obtaining a degraded frequency domain according to the degraded frequency; the degraded frequency domain includes a phase-locked loop degraded frequency domain, an inner loop degraded frequency domain and an outer loop degraded frequency domain; the phase-locked loop degraded frequency domain is located after the phase-locked loop degraded frequency, the inner loop degraded frequency domain is located after the inner loop degraded frequency, and the outer loop degraded frequency domain is located after the outer loop degraded frequency; The wide-band impedance reduction model includes a phase-locked loop degenerate direct-drive fan reduced-order impedance model, an inner-loop degenerate direct-drive fan reduced-order impedance model, and an outer-loop degenerate direct-drive fan reduced-order impedance model; Obtaining a degraded frequency axis according to the degraded frequency and the degraded frequency domain; Based on the degraded frequency axis, starting from the phase-locked loop degraded frequency, in the phase-locked loop degraded frequency domain, the second initial phase-locked loop transfer function in the direct-drive wind turbine full-order impedance model is replaced with the degraded phase-locked loop transfer function to obtain the phase-locked loop degraded direct-drive wind turbine reduced-order impedance model; Based on the degradation frequency axis, starting from the inner loop degradation frequency, the initial inner loop transfer function in the phase-locked loop degenerate direct-drive wind turbine reduced-order impedance model is replaced with the degenerate inner loop transfer function in the inner loop degradation frequency domain to obtain the inner loop degenerate direct-drive wind turbine reduced-order impedance model; Based on the degraded frequency axis, starting from the outer loop degraded frequency and in the outer loop degraded frequency domain, the initial outer loop transfer function in the inner loop degraded direct-drive wind turbine reduced-order impedance model is replaced with the degraded outer loop transfer function to obtain the outer loop degraded direct-drive wind turbine reduced-order impedance model.

8. A storage medium, characterized in that: It includes a stored program, which, when running, controls the device where the storage medium is located to execute the dynamic order reduction method of the impedance model of a direct-drive wind turbine as described in any one of claims 1 to 7.

9. A device for implementing the direct-drive wind turbine impedance model dynamic reduction method according to any one of claims 1 to 7, characterized in that: Includes building blocks, calculation blocks and dynamic order reduction blocks; The building blocks: Used to input the direct-drive fan parameters and the disturbance signal; Used to obtain an initial control transfer function, a main circuit expression and a filter link transfer function according to the direct-drive fan parameters and the disturbance signal; Used to construct a full-order impedance model of a direct-drive wind turbine based on a steady state and using a small signal method according to an initial control transfer function, the main circuit expression and the filter link transfer function; for obtaining a disturbance control transfer function according to the disturbance signal and the initial control transfer function based on a signal transfer path; The computing module: for factoring the disturbance control transfer function based on typical links; Used to obtain Bode plots and corner frequencies based on factored disturbance control transfer functions; Used to obtain the degenerate frequency according to the Bode diagram and the obtained turning angle frequency; for obtaining a degradation control transfer function according to the factorized disturbance control transfer function based on the Bode diagram; The dynamic order reduction module is used to dynamically reduce the order of the full-order impedance model of the direct-drive wind turbine based on the degradation frequency according to the initial control transfer function and the degradation control transfer function to obtain a wide-band impedance reduction model.

10. An electronic device comprising a processor and a memory, characterized in that: The memory stores computer-readable instructions, and the processor is used to execute the computer-readable instructions. When the computer-readable instructions are executed, the dynamic order reduction method of the impedance model of a direct-drive wind turbine according to any one of claims 1 to 7 is executed.

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