Inertia and damping parameter measuring method and system of network-forming type wind turbine generator

Abstract

The invention discloses a method and system for measuring inertia and damping parameters of a grid-forming type wind turbine generator, and relates to the technical field of grid-connected converter detection, and the method comprises the steps: connecting a test device to a to-be-tested grid-forming type wind turbine generator operating in an off-grid mode, enabling the test device to apply frequency disturbance and small-phase disturbance to the to-be-tested wind turbine generator at an initial moment, acquiring voltage and current of a unit port until the virtual synchronous generator reaches a stable working state, and respectively acquiring a steady-state value of the active power variation of the unit and a transient response curve of the active power variation in the whole response process; on the basis of the steady-state value of the active power variable quantity, the applied frequency disturbance is combined, and a damping coefficient is calculated according to a first relation; and on the basis of the transient response curve, an envelope line of the curve is calculated and obtained, then a product value of the natural oscillation angular frequency and the damping ratio is obtained, the reference angular frequency and the damping coefficient are combined, and the virtual inertia is calculated according to a second relation. According to the invention, accurate and efficient measurement of inertia and damping parameters can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of grid-connected converter detection, and in particular to a method and system for measuring inertia and damping parameters of a grid-connected wind turbine set. Background Art

[0002] With the rapid development of new energy technologies, the penetration rate of new energy power generation represented by wind power and photovoltaic power generation has been continuously increasing. In the face of the problems of weak active support capability and low system inertia caused by the grid-following control of new energy power generation systems, in recent years, a variety of grid-forming (GFM) converter control strategies have been proposed at home and abroad. Among them, the most typical grid-forming converter control strategy is the virtual synchronous generator (VSG) control strategy. The VSG technology enables the grid-connected converter to simulate the operating characteristics of the synchronous generator, embed the rotor motion model of the synchronous generator into the control algorithm of the grid-connected converter, and control the formation of the internal potential with the virtual rotor motion characteristics, so as to autonomously build the voltage and thus have the ability to actively support the power grid. At present, the research on VSG mainly focuses on the application of technology, while ignoring the research on measuring the external characteristics actually exhibited by the converter after adopting the VSG control strategy.

[0003] The main parameters of VSG control include the inertia and damping coefficient of active and reactive control links, among which the inertia and damping parameters in the rotor motion equation reflect the inertia and damping characteristics of the controlled object, which are the external characteristics. At present, the research on virtual inertia and damping coefficient of converters focuses on improving the dynamic and static characteristics of converters, and lacks the method of using voltage and current information to calculate and identify multiple parameters in the off-grid state. Inertia and damping are a pair of important parameters in dynamic performance evaluation and stability analysis of microgrids. Therefore, it is of great practical significance to measure the off-grid parameters of virtual inertia (referred to as inertia) and damping of VSG.

[0004] For new energy power generation systems such as grid-connected wind turbines, the existing methods for testing virtual synchronous generator parameters in off-grid environments mainly have the following difficulties:

[0005] (1) At present, the test method of grid-following type units is mostly used for testing. Wind turbines under grid-following control rely on detecting the grid frequency change rate and frequency change to perform virtual inertia and active power-frequency droop control. During the test, the corresponding performance parameters can be tested by applying an external frequency change signal and observing the active power output response. However, for grid-building type wind turbines, their virtual inertia and droop control response depend on the internal virtual rotor speed. The relationship between the external frequency and active power response cannot accurately reflect their performance parameters. Therefore, the grid-following test method is actually not suitable for the test of grid-building type units, and the test results obtained using the grid-following type unit test method are not accurate.

[0006] (2) The coupling of multiple performance parameters affects the power characteristics. For example, there is a complex interaction relationship between parameters such as frequency, phase, and inertia, which jointly affect the power characteristics. During the test process, it is necessary to consider the influence of multiple parameters at the same time. In addition, in the off-grid test, only the voltage and current at the test equipment port can be obtained, and the signal waveform of important parameters such as frequency and phase angle cannot be obtained, which makes the test complicated and difficult. Summary of the invention

[0007] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides a method and system for measuring the inertia and damping parameters of a grid-type wind turbine. According to the relationship between the active power of the grid-type wind turbine and the two parameters of inertia and damping, the grid-type wind turbine to be tested is connected to a specific test device, so that the test device applies frequency and phase disturbances to the unit to be tested for testing. During the test, the voltage and current output from the unit port are measured to calculate the active power. The inertia parameter J and damping parameter D of the grid-type wind turbine under the off-grid test are calculated based on the observed and collected steady-state value of the unit's active power change and the transient response curve, so as to achieve accurate and efficient measurement of the inertia and damping parameters.

[0008] In a first aspect, the present invention provides a method for measuring inertia and damping parameters of a grid-type wind turbine.

[0009] A method for measuring inertia and damping parameters of a grid-type wind turbine generator set comprises:

[0010] Connect the test equipment to the grid-connected wind turbine to be tested in off-grid mode, and at the initial moment, make the test equipment apply frequency disturbance and small phase disturbance to the tested turbine respectively, collect the voltage and current at the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively;

[0011] Based on the steady-state value of the active power variation and the applied frequency disturbance, a damping parameter is calculated according to a first relationship;

[0012] Based on the transient response curve, the envelope of the curve is calculated to obtain the product value of the natural oscillation angular frequency and the damping ratio, and then the inertia parameter is calculated according to the second relationship by combining the product value, the reference angular frequency and the calculated damping parameter.

[0013] In a second aspect, the present invention provides a system for measuring inertia and damping parameters of a grid-type wind turbine.

[0014] A system for measuring inertia and damping parameters of a grid-type wind turbine generator system, comprising:

[0015] The data acquisition module is used to connect the test equipment to the grid-connected wind turbine to be tested in the off-grid mode, and to make the test equipment apply frequency disturbance and small phase disturbance to the test turbine respectively at the initial moment, collect the voltage and current of the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively;

[0016] A damping parameter determination module, configured to calculate the damping parameter according to a first relationship based on the steady-state value of the active power variation and the applied frequency disturbance;

[0017] The inertia parameter determination module is used to calculate the envelope of the curve based on the transient response curve, and then obtain the product value of the natural oscillation angular frequency and the damping ratio, and then combine the product value, the reference angular frequency and the calculated damping parameter to calculate the inertia parameter according to the second relationship.

[0018] In a third aspect, the present invention further provides an electronic device comprising a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the steps of the method described in the first aspect are completed.

[0019] In a fourth aspect, the present invention further provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, complete the steps of the method described in the first aspect.

[0020] One or more of the above technical solutions have the following beneficial effects:

[0021] 1. The present invention provides a method and system for measuring inertia and damping parameters of a grid-type wind turbine. According to the relationship between the active power and the two parameters of inertia and damping of the grid-type wind turbine, a specific test device is connected to the grid-type wind turbine to be tested, and the test device applies frequency and phase disturbances to the unit to be tested for testing. During the test, the voltage and current output from the unit port are measured to calculate the active power. The inertia parameter J and damping parameter D of the grid-type wind turbine under the off-grid test are calculated based on the observed and collected steady-state value of the unit's active power change and the transient response curve, so as to achieve accurate and efficient measurement of inertia and damping parameters. Compared with the measurement method of the grid-type unit, the measurement method proposed by the present invention only uses the external characteristics of the unit without interacting with the control system. The measurement results fully reflect the actual operation results, and the measurement results are more accurate.

[0022] 2. In the inertia and damping parameter determination method of the grid-type wind turbine proposed in the present invention, the virtual synchronous generator rotor motion equation is used as the mathematical model of the virtual synchronous generator control. The relationship between the active power of the unit and the inertia and damping parameters is obtained through analysis, and the corresponding parameter determination method is generated. This method can be used to calculate the inertia parameter J and the damping parameter D, and the accuracy of the determination result is further verified through simulation tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 It is a flow chart of the method for determining the inertia and damping parameters of a grid-type wind turbine generator set according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the operating characteristics of the virtual synchronous generator rotor;

[0026] Figure 3 is an equivalent circuit diagram of a grid-connected converter system based on voltage source virtual synchronous generator control;

[0027] Figure 4 A schematic diagram of a transient response curve taking a maximum value in an embodiment of the present invention;

[0028] Figure 5 A schematic diagram of frequency disturbance applied during the simulation verification process of an embodiment of the present invention;

[0029] Figure 6 A schematic diagram of a curve showing a change in active power output by a wind turbine during a simulation verification process of an embodiment of the present invention;

[0030] Figure 7A schematic diagram of the result of calculating the damping parameter value during the simulation verification process of the embodiment of the present invention;

[0031] Figure 8 A schematic diagram of a small phase disturbance applied during the simulation verification process of an embodiment of the present invention;

[0032] Fig. 9 A schematic diagram of an active power transient response curve and its envelope output by a wind turbine generator set during a simulation verification process of an embodiment of the present invention;

[0033] Fig.10 It is a schematic diagram of the attenuation curve during the simulation verification process of the embodiment of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are exemplary only, are intended to describe specific embodiments, are intended to provide further explanation of the present invention, and are not intended to limit exemplary embodiments according to the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] Embodiment 1

[0036] This embodiment provides a method for determining the inertia and damping parameters of a grid-type wind turbine generator set. Figure 1 As shown, the following steps are included:

[0037] Connect the test equipment to the grid-connected wind turbine to be tested in off-grid mode, and at the initial moment, make the test equipment apply frequency disturbance and small phase disturbance to the tested turbine respectively, collect the voltage and current at the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively;

[0038] Based on the steady-state value of the active power variation and the applied frequency disturbance, a damping parameter is calculated according to a first relationship;

[0039] Based on the transient response curve, the envelope of the curve is calculated to obtain the product value of the natural oscillation angular frequency and the damping ratio, and then the inertia parameter is calculated according to the second relationship by combining the product value, the reference angular frequency and the calculated damping parameter.

[0040] The following content introduces the inertia and damping parameter determination method of the grid-type wind turbine generator set proposed in this embodiment in more detail.

[0041] (1) Modeling the virtual synchronous generator control data model

[0042] Virtual synchronous generator control realizes the function of grid-connected converter simulating the output characteristics of traditional synchronous generator, thereby improving the stability of the system. Its control block diagram is as follows: Figure 2 The method proposed in this embodiment is based on the virtual synchronous generator rotor motion equation to perform mathematical modeling on VSG control.

[0043] Firstly, the virtual synchronous generator rotor motion equation is used as the mathematical model of virtual synchronous generator control, and the virtual synchronous generator rotor motion equation is normalized.

[0044] Specifically, the mathematical model of virtual synchronous generator control uses the virtual synchronous machine rotor motion equation, which is:

[0045]

[0046] In the above formula, J and D are the virtual inertia time constant (kg·m 2 ), damping coefficient, the virtual inertia time constant is the virtual inertia, and the damping coefficient is the damping coefficient; P ref , P e are the input mechanical power and output active power of the virtual synchronous generator (W), respectively; ω is the rotor angular frequency of the virtual synchronous generator (rad / s); ω0 is the angular frequency of the VSG grid-connected common bus (rad / s), and by default ω0 is equal to the reference angular frequency, which can be used as a constant: ω ref =ω0=2πf0,ω ref represents the reference value of the angular frequency, f0 represents the rated frequency of the power grid, and in this embodiment, f0=50Hz.

[0047] Afterwards, the above rotor operation equation is normalized, including:

[0048] First, divide both sides by the power reference value S b (this value is a constant value), is:

[0049]

[0050] Then, if ω is normalized to unit, the following process is obtained:

[0051]

[0052] The normalized form is as follows:

[0053]

[0054] At the same time, if the base value of J is The reference value of D is Then we have the following normalized equation:

[0055]

[0056] Furthermore, removing the asterisk to represent the per-unit value, the per-unit formula has the following concise form:

[0057]

[0058] Among them, ω b It refers to the reference value of the angular frequency, which is consistent with the parameter ω0 and is equal to 100π.

[0059] In the above formula, in order to simulate the synchronous generator, the parameter P ref On the control side is a power reference value. If there is no special control, the reference value usually will not change suddenly. Within the test time scale, it is treated as a constant.

[0060] Secondly, according to the equivalent circuit diagram of the grid-connected converter system based on voltage source virtual synchronous generator control, the virtual impedance is introduced to determine the expression of the converter active power. Then the expression of the converter active power is substituted into the normalized rotor motion equation and linearized.

[0061] Specifically, the equivalent circuit diagram of the grid-connected converter system based on voltage source virtual synchronous generator (VSG) control is as follows: Figure 3 As shown, Z = R + jωL represents the sum of the line impedance and the converter equivalent impedance. In high-voltage lines, the influence of R can be ignored, and the line impedance is almost inductive; while in medium and low-voltage lines, virtual impedance control technology is often introduced to make the line impedance mainly inductive, reducing the power coupling caused by the line impedance. Based on the above method, the converter active power P can be obtained e The expression of is:

[0062]

[0063] In the above formula, X represents the equivalent impedance of the converter output; θ E ,θ U They represent the converter phase angle and grid phase angle respectively.

[0064] Substituting it into formula (6), we get:

[0065]

[0066] Linearize equation (8) and get:

[0067]

[0068] Since the inertia and damping of the synchronous generator affect the stability of the power system, the virtual inertia time constant J and the damping coefficient D are the two most core parameters in the VSG control algorithm. The damping parameter D and the inertia parameter J are measured in turn by the following method.

[0069] (2) Determine the damping coefficient D and the virtual inertia time constant J (i.e., the damping parameter D and the inertia parameter J)

[0070] (2.1) For the damping coefficient D, the active power is calculated by measuring the voltage and current at the unit port, and the power reference value P is subtracted from the active power. ref The active power variation is obtained, and at the same time, the rotor angular frequency variation of the virtual synchronous generator, i.e., the frequency disturbance Δω, is introduced for solution. The frequency disturbance Δω is:

[0071] ω=ω0+Δω (10)

[0072] Further, based on the normalized rotor motion equation, a first relationship between the damping coefficient and the rotor angular frequency change and the active power change of the virtual synchronous generator is determined. On this basis, according to the determined first relationship, the damping coefficient can be calculated by measuring the active power change of the virtual synchronous generator and the introduced frequency disturbance (i.e., the rotor angular frequency change).

[0073] Specifically, the grid-connected wind turbine to be tested operating in off-grid mode is connected to the test equipment. The test equipment can use a large-capacity, four-quadrant operating, programmable fast-response three-phase AC power supply. At the initial moment, the test equipment is used to apply a frequency disturbance Δω to the unit to be tested. At this time, the active power output of the unit will change accordingly. The current and voltage output of the unit port when the virtual synchronous generator reaches a stable working state are measured and collected, and then the unit active power change ΔP is calculated. e The steady-state value of, that is, the change in active power in the steady state.

[0074] Secondly, based on the steady-state value of the active power change and the applied frequency disturbance, the damping coefficient is calculated according to the first relationship. The expression of the first relationship is:

[0075] P e -P ref =D(ω0-ω) (11)

[0076]

[0077] Substitute the introduced frequency disturbance and the steady-state value of the measured active power variation into the expression of the first relationship to calculate the damping coefficient D, which can be used as a known parameter to determine the parameter J in the next step.

[0078] (2.2) For the virtual inertia time constant J (i.e., inertia parameter J), the product of the natural oscillation angular frequency and the damping ratio is introduced for solution.

[0079] First, according to the above linearized formula (9), the change of the virtual synchronous generator rotor angular frequency Δω and the change of the voltage source phase angle Δθ in the formula are E is the state variable, and the state equation group, namely the transfer function model, is derived. The process is:

[0080]

[0081] The transfer function model is:

[0082]

[0083] In the above formula, the natural oscillation angular frequency ω can be obtained n and damping ratio ξ, respectively:

[0084]

[0085]

[0086] Based on the above transfer function model, the second relationship between the inertia parameter and the damping coefficient, the reference angular frequency, the natural oscillation angular frequency and the damping ratio can be determined as follows:

[0087]

[0088] On this basis, according to the determined second relationship, by measuring the product value of the natural oscillation angular frequency and the damping ratio, combined with the reference angular frequency and the calculated damping coefficient, the inertia parameter J can be calculated and solved.

[0089] Specifically, first, a test device is connected to the grid-connected wind turbine to be tested in the off-grid mode, and a small phase disturbance is applied to the test turbine using the test device at the initial moment. In this embodiment, a disturbance with an angle less than 8° is used as a small phase disturbance. The output power of the turbine port is collected until the virtual synchronous generator reaches a stable working state, and the transient response curve of the active power change in the entire response process is obtained. In this embodiment, a small phase disturbance Δθ is applied to the test device at the initial moment (i.e., moment t0). U Here, the phase disturbance should be small because the voltage regulation does not have a big impact. In this way, it can be considered that the internal potential remains unchanged. The active power change ΔP is obtained by measuring e The transient response curve is a periodic function whose amplitude decays exponentially with time. Furthermore, since the disturbance occurs at time t0, it is also necessary to convert the initially obtained ΔPe The transient response curve is shifted to the left by t0, and a transient response curve that oscillates from 0s is obtained.

[0090] Secondly, based on the transient response curve, the envelope of the curve is obtained. In this embodiment, based on the transient response curve, the envelope of the curve is obtained by taking the maximum value of the curve, such as Figure 4 As shown, the expression of the envelope is:

[0091]

[0092] Then multiple maximum values ​​ΔP em Substituting (i) and its corresponding point t(i) into the envelope expression / equation (17), we get:

[0093]

[0094] By solving the equation group, we can get the product of the natural oscillation angular frequency and the damping ratio, which is:

[0095]

[0096] In the above solution process, n maximum points are taken and substituted into the calculation in pairs, that is, n maximum values ​​and their corresponding points are substituted into the envelope expression to calculate n-1 natural oscillation angular frequencies and damping ratio product values ​​ω n ξ(i); then average the n-1 product values ​​to get the final product value ω of the natural oscillation angular frequency and the damping ratio n ξ.

[0097] Finally, based on the product value of the natural oscillation angular frequency and the damping ratio calculated above, the product value is combined with the reference angular frequency and the calculated damping coefficient to calculate the inertia parameter J according to the second relationship (i.e., formula (16)).

[0098] In addition, the damping coefficient and inertia parameter obtained by calculation are all per unit values, and the per unit values ​​of the damping coefficient and the per unit values ​​of the inertia parameter are respectively Benchmark value The product of is the final nominal value of the damping parameter and the nominal value of the inertia parameter.

[0099] To verify the effectiveness of the determination method proposed in this embodiment, the following simulation example is used to verify and illustrate. Specifically, the test equipment model is built using Power Factory software, and parameter solution calculation is performed in Matlab, where the model parameter settings are shown in Table 1 below.

[0100] Table 1 Model setting parameters

[0101]

[0102] First, determine the damping coefficient D. Figure 5 As shown in the figure, at 1s, the grid frequency suddenly changes from the rated frequency of 50Hz to 49.2Hz. At this time, the unit output power increases, and the active power change curve is as follows: Figure 6 Take the change in the active power of the unit in steady state and solve the damping coefficient D through equation (12). The result is as follows: Figure 7 As shown, the per-unit value of the damping coefficient D calculated after steady state is 12.0367, and the nominal value of the damping coefficient D is 0.115MNms / rad. By comparing the calculated value with the set value, the accuracy of the measurement method proposed in this embodiment is further verified.

[0103] Secondly, the damping coefficient obtained by the above calculation is used as a known parameter to determine the virtual inertia coefficient J. Figure 8 As shown, at 1s, a The phase disturbance, the active power change curve and its envelope after steady state are as follows Fig. 9 The decay curve is shown in Fig.10 As shown. Substituting the method proposed in this embodiment into equations (18), (19) and (16), the virtual inertia coefficient J can be solved. The final solution is J = 1.8703 × 10 2 kg·m 2 , and the model setting value is 1.824×10 2 kg·m 2 Almost identical.

[0104] Embodiment 2

[0105] This embodiment provides a system for measuring inertia and damping parameters of a grid-type wind turbine generator set, including:

[0106] The data acquisition module is used to connect the test equipment to the grid-connected wind turbine to be tested in the off-grid mode, and to make the test equipment apply frequency disturbance and small phase disturbance to the test turbine respectively at the initial moment, collect the voltage and current of the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively;

[0107] A damping parameter determination module, configured to calculate the damping parameter according to a first relationship based on the steady-state value of the active power variation and the applied frequency disturbance;

[0108] The inertia parameter determination module is used to calculate the envelope of the curve based on the transient response curve, and then obtain the product value of the natural oscillation angular frequency and the damping ratio, and then combine the product value, the reference angular frequency and the calculated damping parameter to calculate the inertia parameter according to the second relationship.

[0109] Embodiment 3

[0110] This embodiment provides an electronic device, including a memory and a processor, and computer instructions stored in the memory and running on the processor. When the computer instructions are run by the processor, the steps in the method for determining inertia and damping parameters of a grid-type wind turbine set as described above are completed.

[0111] Embodiment 4

[0112] This embodiment further provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the steps in the method for determining inertia and damping parameters of a grid-type wind turbine generator set as described above are completed.

[0113] The steps involved in the above embodiments 2 to 4 correspond to the method embodiment 1, and the specific implementation methods can refer to the relevant description part of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood to include any medium that can store, encode or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0114] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0115] The above description is only a preferred embodiment of the present invention. Although the specific implementation mode of the present invention is described in conjunction with the accompanying drawings, it is not a limitation of the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the protection scope of the present invention.

Claims

1. A method for measuring inertia and damping parameters of a grid-type wind turbine, characterized in that: include: Connect the test equipment to the grid-connected wind turbine to be tested in off-grid mode, and at the initial moment, make the test equipment apply frequency disturbance and small phase disturbance to the tested turbine respectively, collect the voltage and current at the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively; Based on the steady-state value of the active power variation and the applied frequency disturbance, a damping parameter is calculated according to a first relationship; Based on the transient response curve, the envelope of the curve is calculated to obtain the product value of the natural oscillation angular frequency and the damping ratio, and then the inertia parameter is calculated according to the second relationship by combining the product value, the reference angular frequency and the calculated damping parameter.

2. The method for determining inertia and damping parameters of a grid-type wind turbine according to claim 1, characterized in that: The determination of the first relationship includes: The virtual synchronous generator rotor motion equation is used as the mathematical model of virtual synchronous generator control, and the virtual synchronous generator rotor motion equation is normalized. Based on the normalized rotor motion equation, a first relationship between the damping coefficient and the rotor angular frequency change and active power change of the virtual synchronous generator is determined; wherein the rotor angular frequency change of the virtual synchronous generator is the frequency disturbance.

3. The method for determining inertia and damping parameters of a grid-type wind turbine according to claim 2, characterized in that: The expression of the first relation is: Where D represents the damping coefficient, Δω represents the frequency disturbance, that is, the change in the rotor angular frequency of the virtual synchronous generator, and P ref is the mechanical power of the virtual synchronous generator, which is used as the power reference value, P e is the active power of the virtual synchronous generator.

4. The method for measuring inertia and damping parameters of a grid-type wind turbine according to claim 1, characterized in that: The determination of the second relationship includes: The virtual synchronous generator rotor motion equation is used as the mathematical model of virtual synchronous generator control, and the virtual synchronous generator rotor motion equation is normalized. Substitute the expression of the converter active power into the normalized rotor motion equation, and after linearization, use the change of the virtual synchronous generator rotor angular frequency and the change of the voltage source phase angle in the formula as state variables to derive the state equation group, i.e., the transfer function model. Based on the transfer function model, a second relationship between the virtual inertia and the damping coefficient, the reference angular frequency, the natural oscillation angular frequency, and the damping ratio is determined.

5. The method for determining inertia and damping parameters of a grid-type wind turbine generator set according to claim 4, characterized in that: The expression of the second relation is: Where D represents the damping coefficient, J represents the virtual inertia coefficient, ω n represents the natural oscillation angular frequency, ξ represents the damping ratio, and ω0 represents the angular frequency of the VSG grid-connected common bus.

6. The method for determining inertia and damping parameters of a grid-type wind turbine according to claim 1, characterized in that: The determination of the inertia parameter comprises: Based on the transient response curve, the envelope of the curve is obtained by taking the maximum value; Substitute multiple maximum values ​​and their corresponding points into the expression of the envelope to solve and obtain the product value of the natural oscillation angular frequency and the damping ratio; wherein, substitute n maximum values ​​and their corresponding points into the expression of the envelope to calculate and obtain n-1 product values ​​of the natural oscillation angular frequency and the damping ratio; average the n-1 product values ​​to obtain the final product value of the natural oscillation angular frequency and the damping ratio; Based on the product of the natural oscillation angular frequency and the damping ratio, combined with the reference angular frequency and the calculated damping coefficient, the virtual inertia is calculated.

7. The method for measuring inertia and damping parameters of a grid-type wind turbine generator set according to claim 1, characterized in that: The calculated damping coefficient and virtual inertia are both per-unit values. The products of the per-unit value of the damping coefficient and the per-unit value of the virtual inertia with the corresponding reference values ​​are the final nominal value of the damping coefficient and the nominal value of the virtual inertia.

8. A system for measuring inertia and damping parameters of a grid-type wind turbine, characterized in that: include: The data acquisition module is used to connect the test equipment to the grid-connected wind turbine to be tested in the off-grid mode, and to make the test equipment apply frequency disturbance and small phase disturbance to the test turbine respectively at the initial moment, collect the voltage and current of the turbine port until the virtual synchronous generator reaches a stable working state, and obtain the steady-state value of the active power change of the turbine and the transient response curve of the active power change in the whole response process respectively; A damping parameter determination module, configured to calculate the damping parameter according to a first relationship based on the steady-state value of the active power variation and the applied frequency disturbance; The inertia parameter determination module is used to calculate the envelope of the curve based on the transient response curve, and then obtain the product value of the natural oscillation angular frequency and the damping ratio, and then combine the product value, the reference angular frequency and the calculated damping parameter to calculate the inertia parameter according to the second relationship.

9. An electronic device, characterized in that: The invention comprises a memory and a processor and computer instructions stored in the memory and executed on the processor. When the computer instructions are executed by the processor, the steps of the method for determining the inertia and damping parameters of a grid-type wind turbine set as described in any one of claims 1 to 7 are completed.

10. A computer-readable storage medium, characterized in that: Used to store computer instructions, which, when executed by a processor, complete the steps of a method for determining inertia and damping parameters of a grid-type wind turbine set according to any one of claims 1-7.

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