Double-fed wind turbine generator equivalent inertia evaluation method considering reactive power control influence and storage medium thereof

Abstract

The invention discloses a doubly-fed wind turbine generator equivalent inertia evaluation method considering reactive power control influence and a storage medium thereof. The method comprises the following steps: acquiring a stator voltage signal, a rotor current signal and a rotor rotating speed signal of a doubly-fed wind turbine generator in real time; obtaining a motor parameter, a reactive power controller and a phase-locked loop control parameter of the doubly-fed fan; park transformation is carried out on the electric quantity collected under the static coordinate system through a phase-locked angle provided by a phase-locked loop to obtain direct current electric quantity under a rotating coordinate system; calculating a correlation coefficient according to the direct current electric quantity and the motor parameters under the rotating coordinate system; substituting the parameters into a fan inertia transfer function, and drawing a Baut diagram; and judging the equivalent inertia of the fan according to the amplitude-frequency characteristic and the phase-frequency characteristic of the Baud diagram. The evaluation method not only maintains the advantage that the existing inertia transfer function can analyze the influence of controller parameters on the equivalent inertia, but also has the advantages of small detection amount, small calculation amount and more accurate equivalent inertia evaluation, and is more suitable for engineering application.

Description

Technical Field

[0001] The present invention belongs to the technical field of inertia response of a doubly-fed wind turbine generator set, and more specifically, relates to an equivalent inertia evaluation method for a doubly-fed wind turbine generator set considering the influence of reactive power control and a storage medium thereof. Background Art

[0002] With the access of large-scale renewable energy power generation equipment to the power system, the inertia level of the power system has rapidly decreased, and the frequency offset and frequency change rate of the system during conventional load disturbances have increased significantly. When there is a large impact load on the power system, the frequency fluctuation of the system is particularly severe, and when the frequency offset reaches a certain level, it may even cause the power system to be decoupled. In order to cope with the frequency stability problem caused by the rapid increase in the penetration rate of renewable energy in the current new power system, the grid guidelines clearly state that renewable energy power generation systems must have rapid inertia response capabilities.

[0003] As a mainstream new energy power generation equipment, doubly-fed wind turbines are generally considered to have no spontaneous inertial response capability. For this reason, most inertia control methods introduce additional control loops to enable doubly-fed wind turbines to have inertial response capabilities. Most of the inertia control loops introduced are added to the power loop, speed loop, pitch angle adjustment link or DC bus control link. In addition to the above-mentioned more traditional inertia control methods, some scholars in recent years have also enabled doubly-fed wind turbines to have active inertial response by modifying the controller parameters of the doubly-fed wind turbines themselves. However, there are large differences in the inertia response effects of doubly-fed wind turbines under different inertia control methods, so it is urgent to evaluate the equivalent inertia of doubly-fed wind turbines.

[0004] The existing equivalent inertia evaluation method of doubly-fed wind turbines was initially characterized based on the inertia constant. Its essence is to calculate the kinetic energy released by the wind turbine during the inertia response. However, the above evaluation method is an average value evaluation method and requires real-time data of rotor speed changes during the disturbance, which is a post-disturbance evaluation method. In addition, this evaluation method completely ignores the role of the wind turbine's own control loop. Then, some scholars considered the active control loop, and introduced the dynamic performance of the wind turbine during the inertia response under the additional inertia control loop by referring to the mathematical model of the traditional synchronous unit. However, this method cannot be used to analyze the strategy of modifying the phase-locked loop control parameters to achieve inertia response. Further, the inertia evaluation method gradually considers the coupling of the active control loop and the phase-locked loop, and preliminarily establishes the dynamic inertia transfer function expression of the doubly-fed wind turbine. However, the above inertia evaluation method believes that the equivalent inertia of the wind turbine is only related to the active control and the phase-locked loop, and the reactive control can be completely ignored.

[0005] The applicant of the present invention patent found through research that in the evaluation of equivalent inertia of doubly-fed wind turbines, reactive power control plays a huge role, which will profoundly affect the increase in active power during the inertia response, while the active power control loop will reduce the equivalent inertia of the wind turbine. Therefore, the existing equivalent inertia evaluation method lacks consideration of reactive power control, which leads to the need for further improvement of the equivalent inertia evaluation method. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to provide a method for evaluating the equivalent inertia of a doubly-fed wind turbine generator set taking into account the influence of reactive power control, aiming to more accurately characterize the technical problems such as the equivalent inertia of the doubly-fed wind turbine generator set and the variation characteristics of the inertia with control parameters.

[0007] The present invention provides, on one hand, a method for evaluating equivalent inertia of a doubly-fed wind turbine generator system taking into account the influence of reactive control, comprising:

[0008] S110. Real-time acquisition of stator voltage signal, rotor current signal, and rotor phase angle signal of the doubly-fed wind turbine;

[0009] S120. Obtaining motor parameters, reactive power controller and phase-locked controller parameters of the doubly-fed wind turbine generator set;

[0010] S130. The AC electrical quantity collected is transformed by Park through the phase-locked angle provided by the phase-locked loop to obtain the DC electrical quantity in the rotating coordinate system;

[0011] S140. According to the DC electrical quantity and motor parameters, calculate the dq excitation voltage, excitation voltage, rotor internal potential power angle, internal potential d-axis excitation voltage coefficient, calculate the internal potential d-axis active coefficient, synchronous power angle active coefficient, synchronous power angle reactive coefficient;

[0012] S150. Substitute the above parameters into the inertia transfer function of the doubly-fed wind turbine generator set and draw a Bode diagram;

[0013] S160. Determine the magnitude of the fan's inertia based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode plot.

[0014] Preferably, the step S110 specifically includes:

[0015] Collect the stator voltage signal V of the double-fed wind turbine sabc ;

[0016] Collect the rotor current signal I of the double-fed wind turbine rabc ;

[0017] Collect the rotor phase angle signal θ of the doubly fed wind turbine r .

[0018] Preferably, the step S120 specifically includes:

[0019] Get the stator inductance parameter X of the doubly-fed wind turbine s , mutual inductance parameter X m ;

[0020] Get the reactive power controller proportional parameter k pQ , integration parameter k iQ ;

[0021] Get the phase-locked loop controller proportional parameter k ppll , integration parameter k ipll .

[0022] Preferably, the step S130 specifically includes:

[0023] Stator three-phase voltage V sabc The phase-locked angle θ is obtained after phase-locked loop processing pll ;

[0024] According to the phase-locking angle θ pll The stator voltage signal V sabc The stator voltage amplitude signal V is obtained through Park transformation s0 ;

[0025] According to the phase-locking angle θ pll and rotor phase angle θ r The rotor current signal I rabc After Park transformation, it becomes a DC signal I rd0 ,I rq0 .

[0026] Preferably, the step S140 specifically includes:

[0027] Calculate the rotor dq axis excitation voltage, where,

[0028] d-axis excitation voltage E md0 For: E md0 =-X m i rq0 , q-axis excitation voltage E mq0 For: E mq0 =X m i rd0 ;

[0029] Excitation voltage E m0 for:

[0030] Calculate the internal potential control angle coefficient, where:

[0031] Calculate the initial rotor internal potential power angle δ E0 :δ E0 =arctan(E mq0 / Emd0 );

[0032] Calculate the internal potential d-axis control angle coefficient k cmd :

[0033] Calculate the internal potential d-axis excitation voltage coefficient k Emd :

[0034] Calculate the internal potential d-axis active coefficient k PEd :

[0035] Calculate the synchronous power angle factor, where,

[0036] Synchronous power angle active coefficient k δ :

[0037] Synchronous power angle reactive coefficient k q :

[0038] Preferably, the step S150 specifically includes:

[0039] Substitute the parameters calculated in step S140 into the inertia evaluation transfer function of the fan, and the inertia transfer function of the fan is:

[0040]

[0041] in:

[0042]

[0043]

[0044] According to the inertia transfer function J RPC (s) Draw the amplitude-frequency and phase characteristics of the Bode plot.

[0045] Preferably, the step S160 specifically includes:

[0046] The equivalent inertia of the doubly-fed wind turbine generator set can be determined based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode plot. If the amplitude-frequency characteristics of the Bode plot are quite different, and the starting value and the cutoff value of the phase-frequency characteristics are consistent, then it is only necessary to determine the equivalent inertia of the doubly-fed wind turbine generator set based on the angular frequency 10 in the amplitude-frequency characteristics. -2 Up to 10 0 The amplitude between rad / s determines the equivalent inertia. The larger the amplitude, the greater the equivalent inertia.

[0047] If the amplitude-frequency characteristics in the Bode plot are almost consistent, and the starting value and the cutoff value of the phase-frequency characteristic are quite different, the equivalent inertia is determined based on the phase value of the phase-frequency characteristic. The smaller the phase, the larger the equivalent inertia.

[0048] Preferably, the present invention also discloses a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to execute the above-mentioned equivalent inertia evaluation method for a doubly-fed wind turbine generator system considering the influence of reactive control.

[0049] Compared with the prior art, the above technical solutions conceived by the present invention can achieve the following

[0050] Beneficial effects:

[0051] (1) The evaluation method provided by the present invention is a pre-disturbance analysis method, that is, the equivalent inertia of the doubly-fed wind turbine generator set can be analyzed before the frequency disturbance occurs. In addition, it is also used to evaluate the inertia level of the doubly-fed wind turbine generator set in real time;

[0052] (2) Compared with the existing dynamic inertia evaluation method, the evaluation method provided by the present invention has the advantages of less detection and less calculation;

[0053] (3) The evaluation method provided by the present invention takes into account the influence of the reactive power control link and can more accurately characterize the equivalent inertia level of the doubly-fed wind turbine generator set;

[0054] (4) The evaluation method provided by the present invention can be used to analyze the influence of internal controller parameters on equivalent inertia. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A flowchart of a method for evaluating equivalent inertia of a doubly-fed wind turbine generator system taking into account the influence of reactive power control provided by an embodiment of the present invention;

[0056] Figure 2 A main circuit topology structure of a doubly-fed wind turbine provided in an embodiment of the present invention;

[0057] Figure 3 A rotor-side converter control structure provided by an embodiment of the present invention;

[0058] Figure 4 A schematic diagram of a phase-locked loop provided in an embodiment of the present invention;

[0059] Figure 5 A Bode diagram of the amplitude-frequency characteristics of the inertia transfer function of the doubly-fed wind turbine provided in an embodiment of the present invention;

[0060] Figure 6 A Bode diagram of the phase-frequency characteristics of the inertia transfer function of the doubly-fed wind turbine provided in an embodiment of the present invention;

[0061] Figure 7 A response diagram of active power and system frequency change rate of a doubly-fed wind turbine considering the influence of reactive power control provided in an embodiment of the present invention;

[0062] Figure 8 The embodiment of the present invention provides a response diagram of active power and system frequency change rate of a doubly-fed wind turbine without considering the influence of reactive power control. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0064] Embodiment 1:

[0065] like Figure 1 As shown, the present invention provides a method for evaluating the equivalent inertia of a doubly-fed wind turbine generator set considering the influence of reactive power control, which is used to more accurately and quickly evaluate the dynamic inertia of the doubly-fed wind turbine generator set, including:

[0066] S110. Real-time acquisition of stator voltage signal, rotor current signal, and rotor phase angle signal of the doubly-fed wind turbine;

[0067] S120. Obtaining motor parameters, reactive power control and phase-locked controller parameters of the doubly-fed wind turbine generator set;

[0068] S130. The AC electrical quantity collected is transformed by Park through the phase-locked angle provided by the phase-locked loop to obtain the DC electrical quantity in the rotating coordinate system;

[0069] S140. According to the DC electrical quantity and motor parameters, calculate the dq excitation voltage, excitation voltage, rotor internal potential power angle, internal potential d-axis control angle coefficient, internal potential d-axis excitation voltage coefficient, calculate the internal potential d-axis active coefficient, synchronous power angle active coefficient, synchronous power angle reactive coefficient;

[0070] S150. Substitute the above parameters into the inertia transfer function of the doubly-fed wind turbine generator set and draw a Bode diagram;

[0071] S160. Determine the magnitude of the fan's inertia based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode plot.

[0072] Collect the real-time three-phase AC electrical quantities of the doubly fed wind turbine; obtain the parameters of the doubly fed wind turbine itself; use Park transformation to convert the three-phase AC electrical quantities into dq DC quantities according to the phase-locked angle output by the phase-locked loop; calculate the corresponding coefficients according to the dq DC quantities and the parameters of the doubly fed unit itself; substitute the corresponding coefficients into the inertia transfer function, and then draw the Bode diagram; judge the size of the inertia of the doubly fed wind turbine according to the amplitude-frequency characteristics and phase-frequency characteristics of the Bode diagram. This evaluation method takes into account the influence of reactive power control. Compared with the evaluation method of inertia constant, it can be a pre-disturbance evaluation method, and can also evaluate the equivalent inertia of the doubly fed wind turbine in real time, and can be used to evaluate the process of inertia change of the doubly fed wind turbine during frequency disturbance. Compared with the existing dynamic inertia evaluation method, this method has a small amount of calculation, requires less detection, and the evaluation result is more accurate. Therefore, this evaluation method has significant advantages.

[0073] The present invention also provides an application scenario of an equivalent inertia evaluation method for a doubly-fed wind turbine generator set considering the influence of reactive control, comprising: a sampling processing unit 1, a coordinate transformation unit 2, a rotor-side converter control unit 3, and a phase-locked loop 4.

[0074] The sampling processing unit 1 is used to collect the stator AC voltage signal V of the double-fed wind turbine. sabc , rotor AC current signal I rabc , rotor phase angle signal θ r ;

[0075] The coordinate transformation unit 2 is used to transform the three-phase AC electrical quantity into a DC electrical quantity;

[0076] The rotor-side converter control unit 3 is used to realize the control of active and reactive power and obtain the modulation signal of the rotor-side converter;

[0077] Phase-locked loop 4 is used to obtain the grid-connected point voltage V sabc The phase signal θ pll .

[0078] like Figure 2 The figure shows the main circuit topology of the doubly fed wind turbine. Figure 2 In the figure, DFIG stands for doubly-fed wind turbine, RSC stands for rotor-side converter, V sabc Indicates the voltage at the grid-connected point port; I rabc Indicates the three-phase power output on the rotor side; θ r Rotor rotation angle, step 110 is mainly used to collect the above electrical quantities.

[0079] Step 120 is used to obtain the motor parameters, reactive loop and phase-locked loop controller parameters of the doubly-fed wind turbine, specifically, the stator inductance parameter X of the doubly-fed wind turbine. s , mutual inductance parameter X m ;like Figure 3The controller proportional parameter k of the reactive power control part in the rotor-side converter control structure is shown as pQ , integration parameter k iQ ;like Figure 4 The proportional parameter k of the phase-locked loop controller is shown ppll , integration parameter k ipll .

[0080] like Figure 4 The phase-locked loop shown in the figure has the following working process: collecting the port voltage signal V of the double-fed wind turbine connected to the power grid sabc ; Through coordinate transformation, the port voltage signal V in the three-phase stationary coordinate system is converted sabc Transformed into the port voltage V in the two-phase stationary coordinate system sαβ ; Through coordinate transformation, the port voltage signal V in the two-phase stationary coordinate system is converted sαβ Transformed into the port voltage V in the two-phase rotating coordinate system sd and V sq , where the coordinate transformation angle signal θ pll Provided by the phase-locked loop output phase signal; the q-axis voltage signal V sq The input phase-locked loop PI controller, the output result and the rated angular frequency signal ω0 are added to obtain the real-time angular frequency signal ω; the real-time angular frequency signal ω is integrated to obtain the phase angle reference signal θ of the whole system. pll Step 130 is mainly based on the phase angle reference signal θ provided by the phase-locked loop. pll and the rotor rotation angle signal θ in step 110 r By coordinate transformation, the stator voltage signal V sabc The stator voltage amplitude signal V is obtained through Park transformation s0 ; The rotor current signal I rabc After Park transformation, it becomes a DC signal I rd0 ,I rq0 ;

[0081] Specifically, the use of Park transformation to convert three-phase AC electrical quantity into dq DC quantity according to the phase-locked angle output by the phase-locked loop mainly includes: pll The stator voltage signal V sabc The stator voltage amplitude signal V is obtained through Park transformation s0 ; According to the phase-locking angle θ pll and rotor phase angle θ r The rotor current signal I rabc After Park transformation, it becomes a DC signal I rd0 ,I rq0 .

[0082] Step 140 calculates the corresponding coefficients according to the quantities obtained in step 120 and step 130. Specifically, the corresponding coefficients are calculated according to the dq DC quantity and the parameters of the doubly fed unit itself and the parameters of the unit connected to the power grid. The relevant coefficients mainly include: stator inductance weight coefficient, line inductance weight coefficient, dq excitation voltage, dq control angle coefficient, initial rotor internal angle, excitation voltage coefficient, port voltage coefficient, synchronous power angle coefficient, dq port voltage angle coefficient, dq excitation voltage angle coefficient, grid voltage offset coefficient, equivalent port voltage coefficient, equivalent dq excitation voltage coefficient. The specific relevant calculation method is as follows:

[0083] d-axis excitation voltage E md0 For: E md0 =-X m i rq0 , q-axis excitation voltage E mq0 For: E mq0 =X m i rd0 ;

[0084] Excitation voltage E m0 for:

[0085] Initial rotor internal potential angle δ E0 :δ E0 =arctan(E mq0 / E md0 );

[0086] Internal potential d-axis control angle coefficient k cmd :

[0087] Internal potential d-axis excitation voltage coefficient k Emd :

[0088] Internal potential d-axis active coefficient k PEd :

[0089] Synchronous power angle active coefficient k δ :

[0090] Synchronous power angle reactive coefficient k q :

[0091] Step 150 substitutes the correlation coefficient in step 140 into the inertia evaluation transfer function, and draws a Bode diagram according to the inertia transfer function. Specifically, the inertia evaluation function is:

[0092]

[0093] in:

[0094]

[0095]

[0096] Step 160: Determine the inertia of the doubly-fed wind turbine generator system based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode diagram. Specifically, if the amplitude-frequency characteristics of the Bode diagram are quite different, and the starting value and the ending value of the phase-frequency characteristics are consistent, then it is only necessary to determine the inertia of the doubly-fed wind turbine generator system based on the angular frequency 10 in the amplitude-frequency characteristics. -2 Up to 10 0 If the amplitude-frequency characteristics of the Bode plot are almost the same, and the starting value and the end value of the phase-frequency characteristic are quite different, the equivalent inertia is determined based on the phase value of the phase-frequency characteristic.

[0097] Specifically: if the amplitude-frequency characteristics of the Bode plot are quite different, and the starting value and the cutoff value of the phase-frequency characteristic are consistent, then only the angular frequency 10 in the amplitude-frequency characteristic needs to be calculated. -2 Up to 10 0 rad / s to determine the equivalent inertia. The larger the amplitude, the larger the equivalent inertia. If the amplitude-frequency characteristics of the Bode plot are almost the same, and the starting value and the cutoff value of the phase-frequency characteristic are quite different, the equivalent inertia is determined based on the phase value of the phase-frequency characteristic. The smaller the phase, the larger the equivalent inertia.

[0098] It should be noted that, in step 110 and step 130 of a method for evaluating the equivalent inertia of a doubly-fed wind turbine generator taking into account the influence of reactive control, the method includes: a sampling processing unit 1, a coordinate transformation unit 2, a rotor-side converter control unit 3 and a phase-locked loop 4, wherein the input end of the sampling processing unit 1 is connected to the stator side and the rotor side of the doubly-fed generator for collecting stator voltage signals, rotor-side current signals and rotor angular velocity signals.

[0099] In the embodiment of the present invention, the sampling processing unit 1 includes: a sampling unit for collecting the stator AC voltage signal V of the double-fed motor sabc , rotor AC current signal I rabc ; Encoder unit, used to obtain the rotor angle θ of the doubly fed motor r ; The stator voltage and rotor current measurements at its output are connected to the input of the coordinate transformation 2; The stator voltage measurement at its output is connected to the input of the phase-locked loop 4.

[0100] The coordinate transformation unit 2 comprises: a Park coordinate transformation unit, which is used to transform the voltage and current signals in the three-phase coordinate system into the voltage and current signals in the two-phase rotating dq coordinate system through coordinate transformation.

[0101] The rotor-side converter control 3 includes: an active control unit for generating a rotor d-axis current reference signal; a reactive control unit for generating a rotor q-axis current reference signal; a current control unit for calculating a modulation voltage in a two-phase rotating dq coordinate system; a space vector modulation SVPWM unit for converting the modulation voltage into a PWM wave for specifically controlling the rotor-side inverter; and a subtractor unit for comparing the reference signal with the feedback signal.

[0102] The phase-locked loop 4 includes: a Park coordinate transformation unit, which is used to transform the stator voltage signal V sabc Transformed into the stator d-axis voltage V in the two-phase rotating coordinate system sd , q-axis voltage V sq ; A controller unit is used to calculate the system angular frequency deviation signal according to the q-axis voltage; an adder unit is used to superimpose the system rated angular frequency signal to obtain the system real-time angular frequency signal; an integrator unit is used to obtain the phase angle θ of the grid connection point voltage according to the integration of the system real-time angular frequency signal pll .

[0103] The method of this embodiment considers the inertia transfer function affected by reactive control to evaluate the dynamic characteristics of the equivalent inertia of the doubly fed wind turbine. This method is a pre-evaluation method or a real-time evaluation method. Compared with the existing evaluation methods, it has the advantages of less detection and less calculation, and the evaluation results are more accurate while taking into account the advantages of the existing dynamic inertia evaluation methods.

[0104] In order to better illustrate the effect of this embodiment, a typical 1.5MW double-fed wind turbine is taken as an example for analysis and experimental research. The stator rated voltage of the double-fed wind turbine is 690V, the stator inductance is 3.08pu, and the mutual inductance is 2.9pu. In this example, the Bode diagram obtained by using the evaluation method proposed in this embodiment when the initial operating point of the wind turbine is 0.7pu is as follows: Figure 5-6 As shown, Figure 5-6 The Bode diagram of the inertia transfer function of the doubly fed wind turbine with and without reactive power control is shown in Figure 2. Figure 7-8 As shown, a frequency disturbance occurs at 6s. Figure 7 Output diagram of active power and system frequency change rate of doubly-fed wind turbine considering the influence of reactive power control; Figure 8 Output diagram of active power and system frequency change rate of doubly-fed wind turbine without considering the impact of reactive control.

[0105] Embodiment 2:

[0106] The present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to execute the above-mentioned method for evaluating the equivalent inertia of a doubly-fed wind turbine generator set considering the influence of reactive control.

[0107] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control, characterized in that: include: S110. Real-time acquisition of stator voltage signal, rotor current signal, and rotor phase angle signal of the doubly-fed wind turbine; S120. Obtaining motor parameters, reactive power controller and phase-locked controller parameters of the doubly-fed wind turbine generator set; S130. The AC electrical quantity collected is transformed by Park through the phase-locked angle provided by the phase-locked loop to obtain the DC electrical quantity in the rotating coordinate system; S140. According to the DC electrical quantity and motor parameters, calculate the dq excitation voltage, excitation voltage, rotor internal potential power angle, internal potential d-axis excitation voltage coefficient, calculate the internal potential d-axis active coefficient, synchronous power angle active coefficient, synchronous power angle reactive coefficient; S150. Substitute the above parameters into the inertia transfer function of the doubly-fed wind turbine generator set and draw a Bode diagram; S160. Determine the magnitude of the fan's inertia based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode diagram.

2. The method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 1, characterized in that: The step S110 specifically includes: Collect the stator voltage signal V of the double-fed wind turbine sabc ; Collect the rotor current signal I of the double-fed wind turbine rabc ; Collect the rotor phase angle signal θ of the doubly fed wind turbine r .

3. The method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 1, characterized in that: The step S120 specifically includes: Get the stator inductance parameter X of the doubly-fed wind turbine s , mutual inductance parameter X m ; Get the reactive power controller proportional parameter k pQ , integration parameter k iQ ; Get the phase-locked loop controller proportional parameter k ppll , integration parameter k ipll .

4. The equivalent inertia evaluation method of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 1 is characterized in that: The step S130 specifically includes: Stator three-phase voltage V sabc The phase-locked angle θ is obtained after phase-locked loop processing pll ; According to the phase-locking angle θ pll The stator voltage signal V sabc The stator voltage amplitude signal V is obtained through Park transformation s0 ; According to the phase-locking angle θ pll and rotor phase angle θ r The rotor current signal I rabc After Park transformation, it becomes a DC signal I rd0 ,I rq0 .

5. The method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 1, characterized in that: The step S140 specifically includes: Calculate the rotor dq axis excitation voltage, where, d-axis excitation voltage E md0 For: E md0 =-X m i rq0 , q-axis excitation voltage E mq0 For: E mq0 =X m i rd0 ; Excitation voltage E m0 for: Calculate the internal potential control angle coefficient, where: Calculate the initial rotor internal potential angle δ E0 :δ E0 =arctan(E mq0 / E md0 ); Calculate the internal potential d-axis control angle coefficient k cmd : Calculate the internal potential d-axis excitation voltage coefficient k Emd : Calculate the internal potential d-axis active coefficient k PEd : Calculate the synchronous power angle factor, where, Synchronous power angle active coefficient k δ : Synchronous power angle reactive coefficient k q :

6. The method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 5, characterized in that: The step S150 specifically includes: Substitute the parameters calculated in step S140 into the inertia evaluation transfer function of the fan, and the inertia transfer function of the fan is: in: According to the inertia transfer function J RPC (s) Draw the amplitude-frequency and phase characteristics of the Bode plot.

7. The method for evaluating equivalent inertia of a doubly-fed wind turbine generator system considering the influence of reactive control according to claim 1, characterized in that: The step S160 specifically includes: The equivalent inertia of the doubly-fed wind turbine generator set can be determined based on the amplitude-frequency characteristics and phase-frequency characteristics of the Bode plot. If the amplitude-frequency characteristics of the Bode plot are quite different, and the starting value and the cutoff value of the phase-frequency characteristics are consistent, then it is only necessary to determine the equivalent inertia of the doubly-fed wind turbine generator set based on the angular frequency 10 in the amplitude-frequency characteristics. -2 Up to 10 0 The amplitude between rad / s determines the equivalent inertia. The larger the amplitude, the greater the equivalent inertia. If the amplitude-frequency characteristics in the Bode plot are almost consistent, and the starting value and the cutoff value of the phase-frequency characteristic are quite different, the equivalent inertia is determined based on the phase value of the phase-frequency characteristic. The smaller the phase, the larger the equivalent inertia.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to execute the equivalent inertia evaluation method for a doubly-fed wind turbine generator system considering the influence of reactive control as described in any one of claims 1 to 6.

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