Photovoltaic inverter impedance modeling method with inertia simulation function

Abstract

The invention relates to an impedance modeling method for a photovoltaic inverter configured with an inertia simulation function. The method comprises the following steps: S1, constructing a main circuit mathematical model of the photovoltaic inverter configured with the inertia simulation function; s2, performing linearization processing on the main circuit mathematical model in the S1 to obtain a small-signal mathematical model of the main circuit so as to establish a main circuit transfer function relationship for establishing an impedance model in the S5; s3, constructing a controller mathematical model of the photovoltaic inverter configured with the inertia simulation function; s4, performing linearization processing on the controller mathematical model in the S3 to obtain a small-signal mathematical model of the controller so as to establish a controller transfer function relationship for establishing an impedance model in the S5; and S5, determining and constructing an impedance model Zertia of the photovoltaic inverter configured with the inertia simulation function. According to the photovoltaic inverter impedance modeling method configured with the inertia simulation function, the established model is accurate in modeling, and a model basis is provided for small signal stability analysis of the inverter connected to an alternating current power grid.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic inverter impedance modeling, and relates to a photovoltaic inverter impedance modeling method configured with an inertia simulation function. Background Art

[0002] PV inverters equipped with inertia simulation function can provide frequency support for AC power grids, which is conducive to improving the inertia level of power grids with a high proportion of PV. However, the impact of the addition of inertia simulation function on the small disturbance stability of the "source-grid" interactive system composed of PV inverters and AC power grids is not yet clear. Therefore, it is urgent to carry out research on small signal impedance modeling of PV inverters equipped with inertia simulation function to lay the foundation for analyzing the small disturbance stability of its interaction with AC power grid. Summary of the invention

[0003] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a photovoltaic inverter impedance modeling method with an inertia simulation function.

[0004] The present invention solves the technical problem by the following technical solutions:

[0005] A photovoltaic inverter impedance modeling method with an inertia simulation function is characterized in that a main circuit and a controller mathematical model of the photovoltaic inverter with an inertia simulation function are established in a dq coordinate system, and a dq impedance model thereof is established on this basis. The method comprises the following steps:

[0006] S1: Construct the main circuit mathematical model of the photovoltaic inverter with inertia simulation function;

[0007] S2: Linearize the main circuit mathematical model described in S1 to obtain a small signal mathematical model of the main circuit, in order to construct an impedance model for S5 to establish a transfer function relationship of the main circuit;

[0008] S3: Construct a mathematical model of the controller of a photovoltaic inverter with inertia simulation function, including a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller, and a current inner loop controller;

[0009] S4: Linearize the mathematical model of the controller described in S3 to obtain a small signal mathematical model of the controller, in order to establish a transfer function relationship of the controller for constructing an impedance model in S5;

[0010] S5: Constructing the impedance model Z of the photovoltaic inverter with inertia simulation function inertia , respectively using the small signal mathematical model of the main circuit and the small signal mathematical model of the controller as the constructed impedance model to establish the main circuit transfer function relationship and the controller transfer function relationship.

[0011] Among them, S1 and S2 are in a progressive relationship, S3 and S4 are in a progressive relationship, S1, S2 and S3, S4 are in a parallel relationship, and the impedance model of the photovoltaic inverter configured with inertia simulation function described in S5 can be finally obtained based on the derivation of S1-S4.

[0012] The main circuit mathematical model of the photovoltaic inverter configured with the inertia simulation function in step S1 is:

[0013]

[0014]

[0015] In the formula, the superscript s indicates that the variable is in the grid coordinate system; s = d / dt indicates the differential operator; Z dc Indicates the DC side impedance; C dc Indicates the DC side capacitance value of the photovoltaic inverter; P pv Indicates the photovoltaic input power of the front stage on the DC side; u dc and U dc They represent the actual value and stable value of the DC bus voltage of the photovoltaic inverter respectively; u dq and u odq They represent the d-axis component and q-axis component of the voltage at the output side of the photovoltaic inverter and the grid connection point respectively; d dq Represents the d-axis component and q-axis component of the duty cycle; L f and R f They represent the filter inductance and parasitic resistance respectively; ω represents the angular velocity of the power grid.

[0016] Furthermore, the step S2 linearizes the main circuit model in step S1 to obtain a main circuit small signal model of the photovoltaic inverter configured with an inertia simulation function:

[0017]

[0018]

[0019] Where Δ represents the small signal disturbance of the electrical quantity; Z f Represents the transfer function matrix of the PV inverter output filter;

[0020] By combining equations (3) and (4) and eliminating the duty cycle variable, we can obtain the transfer matrix between the small disturbance of DC voltage and the small disturbance of AC voltage and current:

[0021]

[0022] In the formula, G 1 represents the current disturbance matrix; G 2 represents the voltage disturbance matrix; D dqThe d-axis component and q-axis component represent the steady-state quantity of the duty cycle; U dq Represents the d-axis component and q-axis component of the steady-state voltage at the grid connection point; I dq Represents the d-axis component and q-axis component of the steady-state current at the grid connection point;

[0023] Further, the step S3 configures a mathematical model of a controller of a photovoltaic inverter with an inertia simulation function, wherein the mathematical model of a controller of a photovoltaic inverter with an inertia simulation function is constructed, including a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller and a current inner loop controller.

[0024] The phase-locked loop mathematical model is:

[0025]

[0026] In the formula, the superscript c indicates that the variable is in the controller coordinate system; θ indicates the phase angle of the phase-locked loop output; k pp and k ip Respectively represent the proportional and differential coefficients of the phase-locked loop controller; Δθ represents the angle difference between the grid dq coordinate system and the controller dq coordinate system. In steady state, the phase-locked loop can track the grid phase well, that is, Δθ=0;

[0027] The mathematical model of the inertia simulation controller is:

[0028]

[0029] In the formula, u dcref Indicates the DC voltage reference value of the photovoltaic inverter; H v Represents the simulated inertia time constant; S n Indicates the rated capacity of the photovoltaic inverter; G filter represents the transfer function of the first-order low-pass filter; T represents the filtering time constant of the first-order low-pass filter; f pll represents the phase-locked loop output frequency, expressed as:

[0030]

[0031] The mathematical model of the DC voltage outer loop controller is:

[0032]

[0033] In the formula, i dref Indicates the current reference value of the inner current loop d axis; k pdc and k idc They represent the proportional and differential coefficients of the DC voltage outer loop controller respectively;

[0034] The mathematical model of the current inner loop controller is:

[0035]

[0036] In the formula, i qref Indicates the current reference value of the inner loop q axis current. In the unity power factor mode, i qref =0.

[0037] Further, the step S4 linearizes the controller mathematical model in step S3 to obtain a controller small signal model of a photovoltaic inverter equipped with an inertia simulation function, which is characterized by including a phase-locked loop small signal model, an inertia simulation controller small signal model, a DC voltage outer loop controller small signal model, and a current inner loop controller small signal model.

[0038] The small signal model of the phase-locked loop is:

[0039]

[0040] In the formula, G PLL Represents the transfer function from the q-axis voltage to the angle difference at the PCC point;

[0041] The voltage transfer function matrix G caused by the phase-locked loop disturbance can be obtained vPLL , G ePLL and the current transfer function matrix G iPLL for:

[0042]

[0043] The small signal model of the inertia simulation controller is:

[0044]

[0045] In the formula, G inertia represents the transfer function matrix of the inertia simulation controller;

[0046] The small signal model of the DC voltage outer loop controller is:

[0047]

[0048] In the formula, G dc represents the transfer function matrix of the DC voltage outer loop controller;

[0049] The small signal model of the current inner loop controller is:

[0050]

[0051] In the formula, G i represents the transfer function matrix of the current inner loop controller; G dec The transfer function matrix representing the decoupling term of the current inner loop controller;

[0052] The delayed small signal model introduced by the controller and modulation is:

[0053]

[0054] In the formula, G del The transfer function matrix representing the delay introduced by the controller and modulation; T del Indicates the delay time;

[0055] The impedance model Z of the photovoltaic inverter configured with the inertia simulation function in step S5 is obtained according to the disturbance transfer relation of each state quantity. inertia :

[0056]

[0057] Where I represents the second-order identity matrix.

[0058] The advantages and beneficial effects of the present invention are:

[0059] The impedance modeling method of the photovoltaic inverter with inertia simulation function is accurate in modeling the dq impedance model of the photovoltaic inverter with inertia simulation function, which provides a model basis for the small signal stability analysis of such inverters connected to the AC power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A main circuit topology and control structure diagram of a photovoltaic inverter configured with an inertia simulation function according to an embodiment of the present invention;

[0061] Figure 2 A schematic diagram of a dq impedance model of a photovoltaic inverter configured with an inertia simulation function according to an embodiment of the present invention;

[0062] Figure 3 The dq impedance characteristics and simulation measurement results of a photovoltaic inverter configured with an inertia simulation function according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0064] Figure 1 It is the main circuit topology and control structure of the photovoltaic inverter with inertia simulation function. a,b,c and i a,b,c represents the voltage and current of point PCC in the abc coordinate system; L g and R g Represents the equivalent inductance and resistance of the power grid; u dcIndicates the voltage value of the DC side of the photovoltaic inverter. The previous photovoltaic power generation can be equivalent to a current source with constant power characteristics, P pv Indicates the photovoltaic power generation power of the previous stage.

[0065] The present invention provides an impedance modeling method for a photovoltaic inverter configured with an inertia simulation function, characterized in that the method specifically comprises the following steps:

[0066] S1: Construct the main circuit mathematical model of the photovoltaic inverter with inertia simulation function;

[0067] S2: Linearize the main circuit mathematical model described in S1 to obtain a small signal mathematical model of the main circuit, in order to construct an impedance model for S5 to establish a transfer function relationship of the main circuit;

[0068] S3: Construct a mathematical model of the controller of a photovoltaic inverter with inertia simulation function, including a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller, and a current inner loop controller;

[0069] S4: Linearize the mathematical model of the controller described in S3 to obtain a small signal mathematical model of the controller, in order to establish a transfer function relationship of the controller for constructing an impedance model in S5;

[0070] S5: Determine the impedance model Z of the PV inverter that builds the configuration inertia simulation function inertia .

[0071] Among them, S1 and S2 are in a progressive relationship, S3 and S4 are in a progressive relationship, S1, S2 and S3, S4 are in a parallel relationship, and the impedance model of the photovoltaic inverter configured with inertia simulation function described in S5 can be finally obtained based on the derivation of S1-S4.

[0072] The main circuit mathematical model of the photovoltaic inverter configured with the inertia simulation function in step S1 is:

[0073]

[0074]

[0075] In the formula, the superscript s indicates that the variable is in the grid coordinate system; s = d / dt indicates the differential operator; Z dc Indicates the DC side impedance; C dc Indicates the DC side capacitance value of the photovoltaic inverter; P pv Indicates the photovoltaic input power of the front stage on the DC side; u dc and U dc They represent the actual value and stable value of the DC bus voltage of the photovoltaic inverter respectively; u dq and u odqThey represent the d-axis component and q-axis component of the voltage at the output side of the photovoltaic inverter and the grid connection point respectively; d dq Represents the d-axis component and q-axis component of the duty cycle; L f and R f They represent the filter inductance and parasitic resistance respectively; ω represents the angular velocity of the power grid.

[0076] Furthermore, the step S2 linearizes the main circuit model in step S1 to obtain a main circuit small signal model of the photovoltaic inverter configured with an inertia simulation function:

[0077]

[0078]

[0079] Where Δ represents the small signal disturbance of the electrical quantity; Z f Represents the transfer function matrix of the PV inverter output filter;

[0080] By combining equations (3) and (4) and eliminating the duty cycle variable, we can obtain the transfer matrix between the small disturbance of DC voltage and the small disturbance of AC voltage and current:

[0081]

[0082] In the formula, G 1 represents the current disturbance matrix; G 2 represents the voltage disturbance matrix; D dq The d-axis component and q-axis component represent the steady-state quantity of the duty cycle; U dq Represents the d-axis component and q-axis component of the steady-state voltage at the grid connection point; I dq Represents the d-axis component and q-axis component of the steady-state current at the grid connection point;

[0083] Further, the step S3 configures a mathematical model of a controller of a photovoltaic inverter with an inertia simulation function, wherein the mathematical model of a controller of a photovoltaic inverter with an inertia simulation function is constructed, including a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller and a current inner loop controller.

[0084] The phase-locked loop mathematical model is:

[0085]

[0086] In the formula, the superscript c indicates that the variable is in the controller coordinate system; θ indicates the phase angle of the phase-locked loop output; k pp and k ip Respectively represent the proportional and differential coefficients of the phase-locked loop controller; Δθ represents the angle difference between the grid dq coordinate system and the controller dq coordinate system. In steady state, the phase-locked loop can track the grid phase well, that is, Δθ=0;

[0087] The mathematical model of the inertia simulation controller is:

[0088]

[0089] In the formula, u dcref Indicates the DC voltage reference value of the photovoltaic inverter; H v Represents the simulated inertia time constant; S n Indicates the rated capacity of the photovoltaic inverter; G filter represents the transfer function of the first-order low-pass filter; T represents the filtering time constant of the first-order low-pass filter; f pll represents the phase-locked loop output frequency, expressed as:

[0090]

[0091] The mathematical model of the DC voltage outer loop controller is:

[0092]

[0093] In the formula, i dref Indicates the current reference value of the inner current loop d axis; k pdc and k idc They represent the proportional and differential coefficients of the DC voltage outer loop controller respectively;

[0094] The mathematical model of the current inner loop controller is:

[0095]

[0096] In the formula, i qref Indicates the current reference value of the inner loop q axis current. In the unity power factor mode, i qref =0.

[0097] Further, the step S4 linearizes the controller mathematical model in step S3 to obtain a controller small signal model of a photovoltaic inverter equipped with an inertia simulation function, which is characterized by including a phase-locked loop small signal model, an inertia simulation controller small signal model, a DC voltage outer loop controller small signal model, and a current inner loop controller small signal model.

[0098] The small signal model of the phase-locked loop is:

[0099]

[0100] In the formula, G PLL Represents the transfer function from the q-axis voltage to the angle difference at the PCC point;

[0101] The voltage transfer function matrix G caused by the phase-locked loop disturbance can be obtained vPLL , GePLL and the current transfer function matrix G iPLL for:

[0102]

[0103] The small signal model of the inertia simulation controller is:

[0104]

[0105] In the formula, G inertia represents the transfer function matrix of the inertia simulation controller;

[0106] The small signal model of the DC voltage outer loop controller is:

[0107]

[0108] In the formula, G dc represents the transfer function matrix of the DC voltage outer loop controller;

[0109] The small signal model of the current inner loop controller is:

[0110]

[0111] In the formula, G i represents the transfer function matrix of the current inner loop controller; G dec The transfer function matrix representing the decoupling term of the current inner loop controller;

[0112] The delayed small signal model introduced by the controller and modulation is:

[0113]

[0114] In the formula, G del The transfer function matrix representing the delay introduced by the controller and modulation; T del Indicates the delay time;

[0115] The impedance model Z of the photovoltaic inverter configured with the inertia simulation function in step S5 is obtained according to the disturbance transfer relation of each state quantity. inertia :

[0116]

[0117] Where I represents the second-order identity matrix.

[0118] In order to verify the accuracy of the impedance modeling of the photovoltaic inverter with inertia simulation function of the present invention, a photovoltaic inverter grid-connected model with inertia simulation function is built in the simulation platform. The system parameters are shown in Table 1. Figure 3The figure shows the dq impedance characteristics and simulation measurement results of the photovoltaic inverter equipped with inertia simulation function. It can be seen from the figure that the impedance model (solid line) can be well matched with the impedance measurement results (hollow dots), which proves the accuracy of the impedance modeling of the photovoltaic inverter equipped with inertia simulation function.

[0119] Table 1

[0120] parameter symbol Numeric Grid-side line voltage <![CDATA[U g ]]> 380V Filter Inductor <![CDATA[L f ]]> 0.69mH Parasitic resistance <![CDATA[R f ]]> 0.0022Ω DC bus capacitor <![CDATA[C dc ]]> 62.5mF DC voltage <![CDATA[U dc ]]> 800V Voltage outer loop controller proportional coefficient <![CDATA[k pdc ]]> 5 Voltage outer loop controller integral coefficient <![CDATA[k idc ]]> 30 Current inner loop controller proportional coefficient <![CDATA[k pi ]]> 0.6 Current inner loop controller integral coefficient <![CDATA[k ii ]]> 36 Phase-locked loop ratio <![CDATA[k pp ]]> 60 Phase-locked loop integral coefficient <![CDATA[k ip ]]> 1400 Rated capacity of photovoltaic inverter <![CDATA[S n ]]> 100kW Front stage photovoltaic power <![CDATA[P pv ]]> 0.7pu Simulated inertia time constant <![CDATA[H v ]]> 1s Low pass filter time constant T 0.1s Grid angular frequency ω 2π·50rad / s Control delay <![CDATA[T del ]]> 1.5 / 10000s

[0121] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0122] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0123] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0124] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic inverter impedance modeling method configured with inertia simulation function, characterized in that: The method specifically comprises the following steps: S1: Construct the main circuit mathematical model of the photovoltaic inverter with inertia simulation function; S2: Linearize the main circuit mathematical model described in S1 to obtain a small signal mathematical model of the main circuit, in order to construct an impedance model for S5 to establish a transfer function relationship of the main circuit; S3: Construct a mathematical model of the controller of a photovoltaic inverter with inertia simulation function, including a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller, and a current inner loop controller; S4: Linearize the mathematical model of the controller described in S3 to obtain a small signal mathematical model of the controller, in order to establish a transfer function relationship of the controller for constructing an impedance model in S5; S5: Constructing the impedance model Z of the photovoltaic inverter with inertia simulation function inertia , respectively using the small signal mathematical model of the main circuit and the small signal mathematical model of the controller as the constructed impedance model to establish the main circuit transfer function relationship and the controller transfer function relationship.

2. The photovoltaic inverter impedance modeling method with inertia simulation function according to claim 1 is characterized in that: The main circuit mathematical model of the photovoltaic inverter configured with inertia simulation function is: In the formula, the superscript s indicates that the variable is in the grid coordinate system; s = d / dt indicates the differential operator; Z dc Indicates the DC side impedance; C dc Indicates the DC side capacitance value of the photovoltaic inverter; P pv Indicates the photovoltaic input power of the front stage on the DC side; u dc and U dc They represent the actual value and stable value of the DC bus voltage of the photovoltaic inverter respectively; u dq and u odq They represent the d-axis component and q-axis component of the voltage at the output side of the photovoltaic inverter and the grid connection point respectively; d dq Represents the d-axis component and q-axis component of the duty cycle; L f and R f They represent the filter inductance and parasitic resistance respectively; ω represents the angular velocity of the power grid.

3. The photovoltaic inverter impedance modeling method with inertia simulation function according to claim 1 is characterized in that: The main circuit mathematical model in S1 is linearized to obtain the small signal mathematical model of the main circuit: Where Δ represents the small signal disturbance of the electrical quantity; Z f Represents the transfer function matrix of the PV inverter output filter; By combining equations (3) and (4) and eliminating the duty cycle variable, we can obtain the transfer matrix between the small disturbance of DC voltage and the small disturbance of AC voltage and current: Where G1 represents the current disturbance matrix; G2 represents the voltage disturbance matrix; D dq The d-axis component and q-axis component represent the steady-state quantity of the duty cycle; U dq Represents the d-axis component and q-axis component of the steady-state voltage at the grid connection point; I dq Represents the d-axis component and q-axis component of the steady-state current at the grid connection point.

4. The photovoltaic inverter impedance modeling method with inertia simulation function according to claim 1 is characterized in that: The controller mathematical model of the photovoltaic inverter configured with inertia simulation function comprises a phase-locked loop, an inertia simulation controller, a DC voltage outer loop controller and a current inner loop controller. The phase-locked loop mathematical model is: In the formula, the superscript c indicates that the variable is in the controller coordinate system; θ indicates the phase angle of the phase-locked loop output; k pp and k ip Respectively represent the proportional and differential coefficients of the phase-locked loop controller; Δθ represents the angle difference between the grid dq coordinate system and the controller dq coordinate system. In steady state, the phase-locked loop can track the grid phase well, that is, Δθ=0; The mathematical model of the inertia simulation controller is: In the formula, u dcref Indicates the DC voltage reference value of the photovoltaic inverter; H v Represents the simulated inertia time constant; S n Indicates the rated capacity of the photovoltaic inverter; G filter represents the transfer function of the first-order low-pass filter; T represents the filtering time constant of the first-order low-pass filter; f pll represents the phase-locked loop output frequency, expressed as: The mathematical model of the DC voltage outer loop controller is: In the formula, i dref Indicates the current reference value of the inner current loop d axis; k pdc and k idc They represent the proportional and differential coefficients of the DC voltage outer loop controller respectively; The mathematical model of the current inner loop controller is: In the formula, i qref Indicates the current reference value of the inner loop q axis current. In the unity power factor mode, i qref =0.

5. The photovoltaic inverter impedance modeling method with inertia simulation function according to claim 1 is characterized in that: The controller mathematical model described in S3 is linearized to obtain a small signal mathematical model of the controller, which includes a phase-locked loop small signal model, an inertia analog controller small signal model, a DC voltage outer loop controller small signal model, and a current inner loop controller small signal model. The small signal model of the phase-locked loop is: In the formula, G PLL Represents the transfer function from the q-axis voltage to the angle difference at the PCC point; The voltage transfer function matrix G caused by the phase-locked loop disturbance can be obtained vPLL , G ePLL and the current transfer function matrix G iPLL for: The small signal model of the inertia simulation controller is: In the formula, G inertia represents the transfer function matrix of the inertia simulation controller; The small signal model of the DC voltage outer loop controller is: In the formula, G dc represents the transfer function matrix of the DC voltage outer loop controller; The small signal model of the current inner loop controller is: In the formula, G i represents the transfer function matrix of the current inner loop controller; G dec The transfer function matrix representing the decoupling term of the current inner loop controller; The delayed small signal model introduced by the controller and modulation is: In the formula, G del The transfer function matrix representing the delay introduced by the controller and modulation; T del Indicates the delay time.

6. The photovoltaic inverter impedance modeling method configured with inertia simulation function according to claim 1 is characterized in that: The determination is to construct the impedance model Z of the photovoltaic inverter with the configuration inertia simulation function inertia The method is: The impedance model Z is derived based on the disturbance transfer relation of the photovoltaic inverter equipped with inertia simulation function. inertia The expression is: Where I represents the second-order identity matrix.

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