Establishment of Amplitude-Phase Model and Control Method for a Voltage-Controlled Inverter

Abstract

The present invention discloses a method for establishing and controlling the amplitude-phase model of a voltage-controlled inverter, belonging to the technical field of distributed power grid-connected inverter control. The method includes establishing a three-phase inverter time-domain state space model in the dq coordinate system; constructing the connection between the traditional model and the amplitude-phase model in the dq two-phase coordinate system, so that the amplitude-phase model can be represented more simply and clearly; decoupling the coupled physical quantities of the three-phase inverter in the dq rotating coordinate system, designing a control circuit according to the three-phase inverter model in this coordinate system, and constructing the amplitude-phase model of the three-phase inverter according to the previously derived connection. The present invention introduces complex variables, uses the amplitude and phase angle to describe the physical quantities of the three-phase inverter after being converted into polar coordinate form. The amplitude-phase model is more concise in derivation and calculation than the traditional model, and is also more intuitive and clear when observing the changes in the amplitude and phase angle of the inverter output.

Description

Technical Field

[0001] The invention belongs to the technical field of distributed power grid-connected inverter control, and particularly relates to a method for establishing an amplitude-phase model and controlling a voltage-controlled inverter. Background Art

[0002] Distributed power inverters can be divided into three categories according to their operating conditions in the power grid, namely grid-forming type, grid-feeding type, and grid-supporting type.

[0003] In an inverter-dominated power grid, since inverters need to share active and reactive power and support the grid voltage and frequency, neither grid-forming inverters nor grid-feeding inverters can meet the requirements. However, through droop control and the performance of non-ideal voltage sources, grid-supporting inverters can achieve the above goals.

[0004] Grid-supporting inverters can be further divided into voltage-controlled type and current-controlled type according to their control methods. Among them, voltage-controlled grid-supporting inverters have received more and more attention due to their good voltage source characteristics. Compared with traditional current-controlled grid-connected inverters, grid-connected interface inverters based on voltage control have obvious grid-friendly advantages. Summary of the Invention

[0005] Object of the Invention: The invention designs a method for establishing an amplitude-phase model and controlling a voltage-controlled inverter. After transforming three-phase data coordinates into two-phase data, a complex variable is introduced, and the three-phase voltage state is described using amplitude and phase angle in polar coordinate form. The amplitude-phase model is more concise in derivation and calculation than the traditional model, and is also more intuitive and clear when observing the changes in the amplitude and phase angle of the inverter output.

[0006] Technical Solution: Compared with the prior art, the invention adopts the following technical solutions:

[0007] A method for establishing an amplitude-phase model and controlling a voltage-controlled inverter includes the following steps:

[0008] (1) For a three-phase inverter circuit with an LC filter configuration, based on the time-domain state space model, a time-domain state space model of the three-phase inverter in the dq rotating coordinate system is established;

[0009] (2) The relationship between the traditional model and the amplitude-phase model in the dq two-phase coordinate system is established, so that the amplitude-phase model can be represented more simply and clearly;

[0010] (3) Decouple the coupled physical quantities of the three-phase inverter in the dq rotating coordinate system, design a control circuit according to the three-phase inverter model in this coordinate system, and construct an amplitude-phase model of the three-phase inverter according to the previously derived relationship.

[0011] Furthermore, the three-phase inverter time-domain state space model in the dq rotating coordinate system in step (1) is as follows:

[0012]

[0013] where a = 1 / L, b = 1 / C, which are the reciprocals of the inductance and capacitance values of each phase in the main circuit, R is the equivalent series resistance of the inductance in each phase of the inverter circuit, i ldq and u Cdq are the inductor current and capacitor voltage respectively, and are also the state variables of the state space model. i ldq is the load current disturbance variable in the inverter circuit, and v cdq is the arm voltage in the inverter circuit, that is, the control input. They are all row vectors composed of physical quantities in the dq two-phase coordinate system;

[0014] Furthermore, in step (2), the connection between the traditional model and the amplitude-phase model in the dq two-phase coordinate system is constructed, so that the amplitude-phase model can be represented more simply and clearly;

[0015] The amplitude-phase representation method of the voltage-controlled inverter is as follows:

[0016] For a three-phase system, the Clark transformation can be used to transform the physical quantities in the three phases into the αβ coordinate system. At the same time, the concept of complex variables is introduced, and any pair of physical quantities is expressed in the form of complex variables, such as x = x α + jx β ;

[0017] And this complex variable can also be expressed in polar coordinate form, that is, x = x α + jx β = xe jθ . In this way, the three-phase physical quantities can be represented by one parameter, and the amplitude, phase angle and other data of the related physical quantities are quite clear;

[0018] The connection between the derived traditional model and the amplitude-phase model is as follows:

[0019] In the αβ stationary coordinate system, the voltage reference value and the output voltage can be expressed as (the following voltage amplitudes are all normalized)

[0020]

[0021] where u is the per-unit value of the output voltage amplitude, θ c , θ r are the angles between the output voltage, the voltage reference value and the stationary coordinate system respectively (this angle changes with time). In the rotating dq two-phase coordinate system, there is an angle θ between the rotating coordinate system and the stationary coordinate system (this angle changes with time). Obviously, θ and θr The change rates are the same. If the initial phase angles of the two are the same, the output voltage has

[0022] u dq = u αβ e -jθ = ue jΔθ = ucosΔθ + jusinΔθ;

[0023] where Δθ is the angle between the output voltage and the voltage reference value (this angle basically does not change with time). Since the output voltage basically follows the voltage reference value, Δθ is very small. Therefore, the above formula can be expressed as

[0024] u dq = u d + ju q = u + juΔθ;

[0025] That is

[0026]

[0027] Therefore, u d can represent the amplitude change in the inverter, and u q / u d can represent the phase angle change in the inverter. The amplitude model of the output voltage can be replaced by the d-axis closed-loop model, and the phase angle model can be obtained by dividing the q-axis closed-loop model by the amplitude.

[0028] Furthermore, step (3) is specifically as follows:

[0029] Perform voltage-current double-loop control on the inverter in the dq two-phase rotating coordinate system, and use the feedforward decoupling control strategy. Use a proportional regulator to control the current inner loop, and the decoupled control equation is as follows

[0030]

[0031]

[0032] where K ip is the proportional coefficient of the current inner loop regulator, v * cd 、v * cq are the reference voltages for the PWM generator, and i refd 、i refq are the reference values of the current inner loop.

[0033] The current reference values i refd 、i refq required by the current inner loop are obtained by regulating the voltage outer loop. If a PI regulator is used to control the voltage outer loop, then the following voltage control equation can be used for decoupling

[0034]

[0035]

[0036] Among them, K up is the proportional coefficient of the voltage outer-loop PI regulator, and K ui is its integral coefficient.

[0037] After satisfying the above conditions of feed-forward decoupling control, ignoring the influence brought by PWM modulation, substituting the control equation into the system state equation after Laplace transform, the closed-loop state space model of the control system is obtained (the influence of the current loop is ignored in the voltage loop relationship in the formula)

[0038]

[0039] Therefore, ignoring the influence brought by PWM modulation, the transfer function G i (s) of the current loop after feed-forward decoupling is

[0040]

[0041] Substituting the transfer function G i (s) of the current closed-loop, calculating the transfer function G u (s) of the voltage closed-loop is

[0042]

[0043] Combined with the derivation of the amplitude-phase model, the transfer functions of the amplitude and phase angle in the model are as follows

[0044]

[0045]

[0046] Among them, u and u ref are the output voltage amplitude and the input voltage amplitude respectively, and θ u , θ uref are the initial phase angles of the output and input voltages respectively.

[0047] Furthermore, a device includes:

[0048] One or more processors;

[0049] A memory for storing one or more programs;

[0050] When one or more of the said programs are executed by one or more of the said processors, the one or more processors implement the amplitude-phase model establishment and control method of a voltage-controlled inverter as described above.

[0051] Further, a storage medium containing computer-executable instructions, which are used to execute the method for establishing and controlling the amplitude-phase model of a voltage-controlled inverter as described above when executed by a computer processor.

[0052] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0053] (1) A complex variable is introduced, and the three-phase inverter system is described using amplitude and phase angle after being transformed into polar coordinate form. This is more concise than the traditional model during derivation and calculation, and is more intuitive and clear than the traditional model in specific application scenarios, such as observing the changes in the amplitude and phase angle of the inverter output.

[0054] (2) The connection between the amplitude-phase model and the traditional dq two-phase model is established, enabling the expression of the amplitude-phase model to be more conveniently presented while using existing mature control methods.

[0055] (3) The three-phase system is regarded as a whole for control, fully considering and utilizing the coupling relationship between the d-axis and the q-axis, and adopting feed-forward decoupling. All control coefficients are in complex form, greatly simplifying the writing and calculation of the control equations.

[0056] The above advantages make the design of control parameters simpler and facilitate the improvement of the system control performance. Description of the Drawings

[0057] Figure 1 Is the circuit topology diagram of a three-phase inverter with LC filtering;

[0058] Figure 2 Is the block diagram of the structure of a three-phase inverter in the dq coordinate system;

[0059] Figure 3 Is the block diagram of the control equation with decoupling function;

[0060] Figure 4 Is the block diagram of the closed-loop model structure of the control system with feed-forward decoupling;

[0061] Figure 5 Is the simplified closed-loop control block diagram of the current after feed-forward decoupling;

[0062] Figure 6 Is the simplified closed-loop control block diagram of the voltage after feed-forward decoupling;

[0063] Figure 7 Is the phase angle control block diagram. Detailed Embodiments

[0064] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0065] The present invention discloses a method for establishing and controlling the amplitude-phase model of a voltage-controlled inverter, including the following steps:

[0066] Step 1: For a three-phase inverter circuit with an LC filter configuration, based on the time-domain state space model, a time-domain state space model of the three-phase inverter in the dq rotating coordinate system is established.

[0067] Since the magnitude and waveform of the load current are strongly related to the load conditions and types, in order to enable the control system of the inverter to adapt to the changes of the load at all times, it is necessary to introduce the load current as an external disturbance input when modeling the inverter. At the same time, taking the other two key physical quantities in the main circuit topology of the three-phase inverter, namely the inductor current and the capacitor voltage, as state variables, the system output value can track the reference value quickly and accurately while well adapting to the changes of the load connected to the system based on such a modeling method design.

[0068] Figure 1 The three-phase inverter topology circuit consists of a three-phase IGBT bridge to form a voltage source inverter, which is connected to the power grid through an LC filter. For Figure 1 the shown three-phase inverter topology circuit, the Kirchhoff voltage and current equations are written as

[0069]

[0070] where a = 1 / L, b = 1 / C, i Labc and u Cabc are the inductor current and the capacitor voltage respectively, v cabc is the control input, i labc is the load current, and they are all row vectors composed of physical quantities in the abc three-phase coordinate system.

[0071] Since the three phases in the three-phase inverter are relatively symmetric, when the three-phase load is symmetric, the sum of the three-phase inductor currents and the sum of the three-phase load currents are both zero, and at the same time the sum of the three-phase capacitor voltages is also zero. Therefore, only 4 of the 6 equations in Equation (1) are actually independent. The mathematical model of the three-phase three-wire inverter in the abc three-phase coordinate system is a multi-input multi-output three-phase coupling model. In order to simplify the system model, reduce the physical quantities of input and output, and reduce the system order. We use the following transformation matrix to transform the physical quantities in the circuit into the dq two-phase coordinate system.

[0072]

[0073] Among them

[0074]

[0075] Substituting the transformation matrix into Equation (1), the time-domain state-space model of the three-phase inverter in the dq rotating coordinate system can be obtained as follows:

[0076]

[0077] Among them, a = 1 / L, b = 1 / C, which are the reciprocals of the inductance and capacitance values of each phase in the main circuit, R is the equivalent series resistance of the inductance in each phase of the inverter circuit, i ldq and u Cdq are the inductance current and capacitance voltage respectively, and are also the state variables of the state-space model. i ldq is the load current disturbance variable in the inverter circuit, and v cdq is the arm voltage in the inverter circuit, that is, the control input. They are all row vectors composed of physical quantities in the dq two-phase coordinate system.

[0078] According to the relationship given by Equation (4), the structural block diagram of the three-phase inverter in the dq rotating coordinate system can be obtained as Figure 2 shown.

[0079] Step 2: Establish the connection between the traditional model and the amplitude-phase model in the dq two-phase coordinate system, so that the amplitude-phase model can be expressed more simply and clearly. The main implementation steps are as follows:

[0080] First, express each physical quantity in the inverter in amplitude-phase form. For a three-phase system, the Clark transformation can be used to transform the physical quantities in the three phases into the αβ coordinate system, and at the same time, the concept of complex variables is introduced to express any pair of physical quantities in the form of complex variables, such as x = x α + jx β . And this complex variable can also be expressed in polar coordinate form, that is, x = x α + jx β = xe jθ . In this way, the three-phase physical quantities can be expressed by a single parameter, and the amplitude, phase angle and other data of the relevant physical quantities are quite clear.

[0081] In the αβ stationary coordinate system, the voltage reference value and output voltage of the three-phase inverter can be expressed as (the following voltage amplitudes are all normalized)

[0082]

[0083] Among them, u is the per-unit value of the output voltage amplitude, θ c 、θr are the included angles between the output voltage, the voltage reference value and the static coordinate system (these angles change with time), and in the rotating dq two-phase coordinate system, there is an included angle θ (this angle changes with time) between the rotating coordinate system and the static coordinate system. Obviously, the change rates of θ and θ r are the same. If the initial phase angles of the two are the same, then the output voltage has

[0084] u dq = u αβ e -jθ = ue jΔθ = ucosΔθ + jusinΔθ (6);

[0085] where Δθ is the included angle between the output voltage and the voltage reference value (this angle hardly changes with time). Since the output voltage basically follows the change of the voltage reference value, Δθ is very small. Therefore, the above formula can be expressed as

[0086] u dq = u d + ju q = u + juΔθ (7);

[0087] That is

[0088]

[0089] Therefore, u d can represent the amplitude change in the inverter, and u q / u d can represent the phase angle change in the inverter. The amplitude model of the output voltage can be replaced by the d-axis closed-loop model, and the phase angle model can be obtained by dividing the q-axis closed-loop model by the amplitude.

[0090] Step 3: Decouple the coupled physical quantities of the three-phase inverter in the dq rotating coordinate system, design the control circuit according to the three-phase inverter model in this coordinate system, and construct the amplitude-phase model relationship of the three-phase inverter based on the relationship deduced above. The main implementation steps are as follows:[[]]

[0091] After coordinate transformation, the periodic sinusoidal AC signal in the three-phase coordinate system becomes a DC quantity. According to the internal model principle, for the DC quantity in the dq coordinate system, since the integrator has an infinite gain for the DC quantity, a proportional-integral controller is generally used to eliminate the steady-state error. At the same time, in order to improve the system response speed and make the output voltage closely follow the change of the load, we add a current loop in the control system, that is, perform voltage-current double-loop control on the inverter in the dq two-phase rotating coordinate system. In this way, disturbances in extreme cases such as step mutations in the output signal can also be well controlled by the control system.

[0092] It is not difficult to see from Equation (4) that due to the mutual coupling of the physical quantities of the three-phase inverter in the d and q axes, the controller design is relatively difficult. Therefore, in the process of designing the control method of the three-phase inverter, it is necessary to decouple the model under the dq two coordinate axes first.

[0093] The present invention uses a feedforward decoupling control strategy. Although a PI controller is always used for the internal current loop, a proportional controller is sufficient to suppress the system in this paper. After using the proportional regulator to control the current inner loop, the following control equations can be used for decoupling:

[0094]

[0095] Among them, K ip is the proportional coefficient of the current inner loop regulator, v * cd 、v * cq are the reference voltages for the PWM generator, and i refd 、i refq are the reference values of the current inner loop.

[0096] The current reference values i refd 、i refq required by the current inner loop are obtained by regulating the voltage outer loop. If a PI regulator is used to control the voltage outer loop, then the following voltage control equations can be used for decoupling

[0097]

[0098] Among them, K up is the proportional coefficient of the voltage outer loop PI regulator, and K ui is its integral coefficient.

[0099] According to the feedforward decoupling conditions in the above four equations, we can draw the control equation block diagram that can be feedforward decoupled as Figure 3 shown.

[0100] After satisfying the above feedforward decoupling control conditions, ignoring the influence brought by PWM modulation, substituting Equations (9) and (10) into Equation (4) after Laplace transform, we get (the influence of the current loop in the voltage loop relationship is ignored)

[0101]

[0102] Draw the overall closed-loop model structure block diagram of the system as Figure 4 shown.

[0103] It can be seen from Equation (11) that under the condition of feed-forward decoupling, the current-voltage state equations of the dq axes of the three-phase inverter are no longer coupled. Moreover, the current-voltage relationships of the dq axes are basically the same, and the only difference lies in the possible different proportional and integral coefficients on the dq axes. Therefore, only the closed-loop control model on the d axis will be discussed below, and the closed-loop model on the q axis can be deduced by analogy.

[0104] First, ignoring the influence brought by PWM modulation, the simplified closed-loop model structure block diagram of the current loop after feed-forward decoupling is as Figure 5 shown. According to the block diagram, calculate the transfer function G i (s) of the current closed-loop as

[0105]

[0106] Therefore, the simplified closed-loop control block diagram of the voltage outer loop is as Figure 6 shown. According to the block diagram, substitute the transfer function G i (s) of the current closed-loop and calculate the transfer function G u (s) of the voltage closed-loop as

[0107]

[0108] Combined with the derivation of the amplitude-phase model above, the transfer function of the amplitude in the model is as follows

[0109]

[0110] where u and u ref are the output voltage amplitude and the input voltage amplitude respectively.

[0111] The control block diagram of the phase angle is as Figure 7 shown. Since the d axis is always selected to coincide with the reference voltage and the reference phase angle is defaulted to be 0 all the time, only the open-loop transfer function of the phase angle is listed here. Because the phase angle of the reference voltage is 0, the arcsin function is transformed into its Taylor expansion at 0, and the first order is retained. The open-loop transfer function of the phase angle of the amplitude-phase model of the three-phase inverter is as follows

[0112]

[0113] where u and u ref are the output voltage amplitude and the input voltage amplitude respectively, and θ u and θ uref are the initial phase angles of the output and input voltages respectively.

[0114] Based on the same inventive concept, the present invention further provides a computer device, which includes: one or more processors, and a memory for storing one or more computer programs; the program includes program instructions, and the processor is configured to execute the program instructions stored in the memory. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is used to implement one or more instructions, specifically for loading and executing one or more instructions in the computer storage medium to implement the above method.

[0115] It should be further noted that, based on the same inventive concept, the present invention further provides a computer storage medium, on which a computer program is stored, and the computer program, when run by a processor, executes the above method. The storage medium may be any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may, for example, but not be limited to, an electrical, magnetic, optical, electrical, magnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a Random Access Memory (RAM), a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM or flash memory), an optical fiber, a portable compact disk read only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, the computer-readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or combined with an instruction execution system, apparatus, or device.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0117] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A method for establishing an amplitude-phase model of a voltage-controlled inverter, characterized in that It includes the following steps: For a three-phase inverter circuit with an LC filter configuration, based on the time-domain state space model, a three-phase synchronous rotating coordinate system, i.e., the time-domain state space model of the three-phase inverter in the dq rotating coordinate system, is established; The connection between the traditional model and the amplitude-phase model in the dq two-phase coordinate system is established; Decouple the coupled physical quantities of the three-phase inverter in the dq rotating coordinate system, design the control circuit according to the three-phase inverter model in this coordinate system, and construct the amplitude-phase model of the three-phase inverter according to the time-domain state space model of the three-phase inverter; The connection between the traditional model and the amplitude-phase model in the dq two-phase coordinate system is established; The amplitude-phase representation method of the voltage-controlled inverter is as follows: For a three-phase system, the Clark transformation is used to transform the physical quantities in the three phases into the αβ coordinate system. At the same time, the concept of complex variables is introduced, and any pair of physical quantities is expressed in the form of complex variables, x = x α + jx β ; where x α and x β are the α-axis component and β-axis component of the three-phase variables respectively, and x is the complex variable form of the three-phase variables; And the complex variable is also expressed in polar coordinate form, i.e., x = x α + jx β = xe jθ , where x and θ are the amplitude and phase angle of the three-phase variable respectively; thus, the three-phase physical quantity is represented by one parameter; The connection derived between the traditional model and the amplitude-phase model is as follows: In the αβ stationary coordinate system, the following voltage amplitudes are all normalized, and the voltage reference value and the output voltage are expressed as: where u is the per-unit value of the output voltage amplitude, and θ c , θ r are the angles between the output voltage, the voltage reference value and the stationary coordinate system respectively. The angle of the stationary coordinate system changes with time. In the rotating dq two-phase coordinate system, there is an angle θ between the rotating coordinate system and the stationary coordinate system, and the angle θ changes with time. Obviously, the change rate of θ is the same as that of θ r . If their initial phase angles are the same, the output voltage is: u dq = u αβ e -jθ = ue jΔθ = u cosΔθ + ju sinΔθ; Where, Δθ is the angle between the output voltage and the voltage reference value. The angle between the output voltage and the voltage reference value hardly changes with time. Since the output voltage basically follows the voltage reference value, Δθ is very small. Therefore, the above formula is expressed as: u dq = u d + ju q = u + juΔθ; That is Therefore, u d represents the amplitude change in the inverter, and u q / u d represents the phase angle change in the inverter. The amplitude model of the output voltage is replaced by the d-axis closed-loop model, and the phase angle model is obtained by dividing the q-axis closed-loop model by the amplitude.

2. The method for establishing the amplitude-phase model of a voltage-controlled inverter according to claim 1, wherein The time-domain state space model of the three-phase inverter in the dq rotating coordinate system is: where a = 1 / L, b = 1 / C, which are the reciprocals of the inductance and capacitance values of each phase in the main circuit, R is the equivalent series resistance of the inductance in each phase of the inverter circuit, i Ldq and u Cdq are the inductor current and capacitor voltage respectively, and are also the state variables of the state-space model. i ldq is the load current disturbance variable in the inverter circuit, v cdq is the arm voltage in the inverter circuit, that is, the control input. They are all row vectors composed of physical quantities in the dq two-phase coordinate system.

3. The method for establishing the amplitude-phase model of a voltage-controlled inverter according to claim 2, wherein, The specific process of decoupling the coupled physical quantities of the three-phase inverter in the dq rotating coordinate system, designing the control circuit according to the three-phase inverter model in this coordinate system, and constructing the amplitude-phase model of the three-phase inverter according to the time-domain state space model of the three-phase inverter is as follows: Perform voltage-current double-loop control on the inverter in the dq two-phase rotating coordinate system, use the feedforward decoupling control strategy, and use a proportional regulator to control the current inner loop. The decoupling control equation is as follows: Among them, K ip is the proportional coefficient of the inner current loop regulator, v * cd , v * cq are the dq-axis components of the reference voltage given to the PWM generator, i refd , i refq are the dq-axis components of the reference value of the inner current loop, u Cd and u Cq are the dq-axis components of the filter capacitor voltage, i Ld and i Lq are the dq-axis components of the filter inductor current; The current reference values i refd 、i refq required by the inner current loop are obtained by regulating the outer voltage loop. If a proportional-integral regulator, i.e., a PI regulator, is used to control the outer voltage loop, then decoupling is performed using the following voltage control equation: where s is the Laplace operator, K up is the proportional coefficient of the outer voltage loop PI regulator, and K ui is its integral coefficient, i ld and i lq are the dq-axis components of the load current; After meeting the conditions of the above feedforward decoupling control, ignoring the influence brought by PWM modulation, substituting the control equation into the system state equation after Laplace transform, and ignoring the influence of the current loop in the voltage loop relationship, the closed-loop state space model of the control system is Therefore, ignoring the influence brought by PWM modulation, the transfer function G i (s) of the closed-loop current loop after feedforward decoupling is where L is the value of the filtering inductor, substitute it into the transfer function G i (s) of the current closed-loop, and calculate the transfer function G u (s) is Combined with the derivation of the amplitude-phase model, the transfer functions of the amplitude and phase angle in the model are as follows Among them, C is the value of the filter capacitor, u and u ref are the amplitudes of the output voltage and the input voltage respectively, and θ u , θ uref are the initial phase angles of the output voltage and the input voltage respectively.

4. A control method for the amplitude-phase model of a voltage-controlled inverter, characterized in that: It includes controlling the voltage-controlled inverter by using the amplitude-phase model of the voltage-controlled inverter established by using the method for establishing the amplitude-phase model of a voltage-controlled inverter described in any one of claims 1-3.

5. The control method of the amplitude-phase model of a voltage-controlled inverter according to claim 4, wherein, It includes the following steps: Perform voltage-current double-loop control on the inverter in the dq two-phase rotating coordinate system; Decouple the model under the dq two coordinate axes.

6. The control method of the amplitude-phase model of a voltage-controlled inverter according to claim 5, characterized in that, The voltage-current double-loop control enables the output voltage to closely follow the change of the load.

7. The control method of the amplitude-phase model of a voltage-controlled inverter according to claim 5, wherein, The decoupling of the model under the dq two coordinate axes adopts the feedforward decoupling control strategy.

8. An apparatus, characterized in that, The device includes: One or more processors; A memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are caused to execute a method for establishing the amplitude-phase model of a voltage-controlled inverter described in any one of claims 4-7.

9. A computer-readable storage medium storing a computer program, characterized in that, When the program is executed by the processor, it implements a method for establishing the amplitude-phase model of a voltage-controlled inverter described in any one of claims 4-7.

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