Method and system for expanding network construction control to DC bus voltage control

Abstract

The invention discloses a method and system for expanding network construction control to DC bus voltage control, and relates to the technical field of intelligent power grid control, and the method comprises the steps: generating a grid-connected phase angle needed by park conversion through a DC capacitor voltage self-synchronization controller; generating a reference voltage amplitude by using a reactive droop controller; converting the acquired three-phase voltage and current signals into two-phase dq-axis voltage and current signals; a current instruction value required by the current inner loop control module is obtained through the voltage outer loop control module, and a modulation voltage signal is obtained through the current inner loop control module. GFM control is expanded to direct-current bus voltage control, dynamic balance of voltage and power is achieved by controlling the power angle of the converter, potential conflicts between traditional GFM control and direct-current voltage control are avoided, the robustness of the system is improved, the system can adapt to wider power grid conditions including a strong power grid and a weak power grid, and the system can be widely applied to power grid control. And normal operation can still be maintained when an alternating-current power grid is lost.

Description

Technical Field

[0001] The present invention relates to the field of smart grid control technology, and in particular to a method and system for extending network control to DC bus voltage control. Background Art

[0002] As the global climate change problem becomes increasingly serious, more and more countries and regions are beginning to promote the widespread use of renewable energy. In order to effectively integrate these intermittent and unpredictable energy resources, such as wind and solar energy, high-voltage direct current (HVDC) transmission systems have gradually become a key technology. HVDC systems can not only achieve long-distance high-power transmission, but also achieve flexible power dispatching and interconnection between different AC power grids.

[0003] In HVDC systems, voltage source converters (VSCs) have been widely used, usually through the "grid-following" (GFL) control strategy to achieve synchronization with the AC grid. However, with the increase in the penetration of renewable energy, the dynamic characteristics of the power grid have become more complex and fragile, especially in weak grid or island operation, the traditional GFL control strategy has great challenges in maintaining system stability. In recent years, "grid-forming" (GFM) control, as an emerging technology, has shown great potential to enhance system stability, especially in power grids with a high proportion of power electronic interfaces. However, how to effectively combine GFM control and DC bus voltage control is still a technical problem that needs to be solved urgently.

[0004] The traditional solution adopts the master-slave control mode, that is, one converter is responsible for DC voltage control, and the other converter is responsible for power control. However, when GFM control is adopted, the voltage control of the two converters may conflict, resulting in poor dynamic response of the system. Therefore, designing a control strategy that can ensure the stability of DC bus voltage and realize the grid-forming function is the focus of current research. Summary of the invention

[0005] In view of the existing problems in the system of extending the existing network control to the DC bus voltage control, the present invention is proposed.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for extending network construction control to DC bus voltage control, which comprises the following steps:

[0008] Get the three-phase output voltage signal v of the grid-connected inverter abc , three-phase output current signal i abc , filter inductor current iLabc And the DC capacitor voltage signal v dc ;

[0009] The three-phase output voltage signal v of the grid-connected inverter at the grid-connected point abc And the three-phase output current signal i abc Perform park coordinate transformation to obtain the dq axis voltage signal v of the grid connection point dq , grid-connected point dq axis current signal i dq and the filter inductor dq axis current signal i Ldq ;

[0010] The dq axis voltage signal v obtained by the grid connection point dq and the grid-connected point dq axis current signal i dq , perform power calculation and obtain the output active power P out And reactive power Q out ;

[0011] The DC capacitor voltage self-synchronous controller generates the grid-connected phase angle required for the inverter park conversion, and the reactive power droop controller generates the reference voltage amplitude E ref ;

[0012] The grid-connected phase angle θ and the reference voltage amplitude E generated by the control module ref , get the grid-connected point dq axis voltage command value v required by the voltage outer loop control module dref and v qref ;

[0013] The voltage outer loop control module generates the current command value i required by the current inner loop control module dref and i qref ;

[0014] The current inner loop control module generates the grid-connected point dq axis modulation voltage signal v through the grid-connected point dq axis decoupling transformation dm and v qm ;

[0015] The obtained grid-connected point dq axis modulation voltage signal v dm and v qm The PWM pulse modulation voltage signal v is obtained by inverse park transformation mabc , to realize the synchronous grid-connected control of grid-connected inverters.

[0016] As a preferred solution of the method of extending the grid control to the DC bus voltage control of the present invention, the park transformation is to transform the collected grid connection point three-phase output voltage signal v abc And the three-phase output current signal i abc Transformed into the two-phase rotating coordinate system dq axis voltage signal vdq and dq axis current signal i dq ;

[0017] The power calculation is performed by using the dq axis voltage signal v of the two-phase rotating coordinate system dq and the grid-connected point dq axis current signal i dq The active power P is calculated by the following formula: out And reactive power Q out :

[0018]

[0019] As a preferred solution of the method of extending the network control to the DC bus voltage control according to the present invention, the voltage outer loop control module is:

[0020]

[0021] in, and They are the current command values ​​transmitted to the current inner loop controller, K p1 and K i1 are the proportional parameter and integral parameter of the voltage outer loop controller, C f It is a filter capacitor.

[0022] As a preferred solution of the method of extending the network control to the DC bus voltage control according to the present invention, the current inner loop control module is:

[0023]

[0024] Among them, v dm and v qm is the modulation voltage signal of the dq axis, K p2 and K i2 They are the proportional parameter and integral parameter of the current inner loop controller, L f It is the filter inductor.

[0025] As a preferred solution of the method of extending the grid control to the DC bus voltage control of the present invention, the grid-side mathematical model of the inverter is expressed as:

[0026]

[0027] Where, v is the effective value of the inverter port voltage, v e is the ideal grid voltage effective value, X c is the filter impedance, X g is the grid equivalent impedance, θ is the inverter port phase angle, θ e is the ideal grid phase angle.

[0028] As a preferred solution of the method of extending the grid control to the DC bus voltage control of the present invention, the DC side mathematical model of the inverter is expressed as:

[0029]

[0030] Among them, p dc1 is the DC input power, p dc2 is the DC side output power, v dc is the DC side capacitor voltage, and the DC capacitor equivalent inertia time constant can be expressed as:

[0031]

[0032] Among them, C dc is the DC capacitance, v dcref is the DC voltage reference value, P N is the rated voltage.

[0033] As a preferred solution of the method of extending the network control to the DC bus voltage control according to the present invention, wherein: the DC capacitor voltage self-synchronous controller, the angle reference θ * Generated by the controller according to the DC voltage deviation, the controller is in the DC voltage v dc The relationship between and converter power angle in the frequency domain can be expressed as:

[0034]

[0035] Therefore the angle reference θ* and The direct relationship between them is as follows:

[0036]

[0037] and The transfer function between can be expressed as:

[0038]

[0039] Among them, K p and K d are the proportional gain and derivative gain of the controller, Δv dc is the difference between the actual DC voltage and the DC voltage reference value, ω n is the rated electrical angular velocity, ω b is the reference electrical angular velocity.

[0040] In a second aspect, an embodiment of the present invention provides a system for extending grid control to DC bus voltage control, which includes a grid-connected phase angle generation module, a reference voltage amplitude generation module, a coordinate transformation module, a voltage outer loop control module, and a current inner loop control module;

[0041] The grid-connected phase angle generation module generates the grid-connected phase angle required for park conversion by using a DC capacitor voltage self-synchronous controller;

[0042] The reference voltage amplitude generation module generates a reference voltage amplitude using a reactive power droop controller;

[0043] The coordinate transformation module converts the collected three-phase voltage and current signals into two-phase dq axis voltage and current signals;

[0044] The voltage outer loop control module obtains a current command value by using a voltage command value generated by the generated reference voltage amplitude and the grid-connected phase angle through PI decoupling control;

[0045] The current inner loop control module obtains a modulated voltage signal through PI decoupling control based on the current command value generated by the voltage outer loop control module.

[0046] In a third aspect, an embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, it implements any step of the above-mentioned method of extending the grid control to DC bus voltage control.

[0047] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned method of extending the grid control to DC bus voltage control is implemented.

[0048] The beneficial effects of the present invention are as follows: by extending the GFM control to the DC bus voltage control, the dynamic balance of voltage and power is achieved by controlling the power angle of the converter, thereby avoiding the potential conflict between the traditional GFM control and the DC voltage control, improving the robustness of the system, and enabling the system to adapt to a wider range of grid conditions, including strong grids and weak grids, and maintaining normal operation when the AC grid is lost. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0050] Figure 1 The present invention is a flow chart of a method for extending grid control to DC bus voltage control.

[0051] Figure 2 A block diagram of a grid-connected phase angle generation module for a method that extends grid control to DC bus voltage control.

[0052] Figure 3 A block diagram of a reference voltage amplitude generation module for a method that extends grid control to DC bus voltage control.

[0053] Figure 4 A block diagram of the coordinate transformation module for the method of extending the grid control to DC bus voltage control.

[0054] Figure 5 Block diagram of the voltage outer loop control module for the method of extending the grid control to DC bus voltage control.

[0055] Figure 6 A block diagram of the current inner loop control module for a method of extending grid control to DC bus voltage control.

[0056] Figure 7 Phase angle tracking comparison diagram for extending grid control to DC bus voltage control.

[0057] Figure 8 The output power stability comparison chart of the method of extending the grid control to DC bus voltage control. DETAILED DESCRIPTION

[0058] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0059] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0060] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0061] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0062] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] Example 1

[0065] Reference Figure 1 to Figure 6 , which is the first embodiment of the present invention, provides a method for extending network control to DC bus voltage control, comprising the following steps:

[0066] S1. Obtain the three-phase output voltage signal v of the grid-connected point of the grid-connected inverter abc , three-phase output current signal i abc , filter inductor current i Labc And the DC capacitor voltage signal v dc .

[0067] S2, such as Figure 4 As shown, the three-phase output voltage signal v of the grid-connected inverter is abc And the three-phase output current signal i abc Perform park coordinate transformation to obtain the dq axis voltage signal v of the grid connection point dq , grid-connected point dq axis current signal i dq and the filter inductor dq axis current signal i Ldq .

[0068] Among them, park transformation is a method of rotating the coordinate system.

[0069] S3, through the obtained grid-connected point dq axis voltage signal v dq and the grid-connected point dq axis current signal i dq , perform power calculation and obtain the output active power P out And reactive power Q out .

[0070] The collected three-phase output voltage signal v abc And the three-phase output current signal i abc Transformed into the two-phase rotating coordinate system dq axis voltage signal v dq and dq axis current signal i dq ;

[0071] The power calculation is performed by using the dq axis voltage signal v of the two-phase rotating coordinate system dq and the grid-connected point dq axis current signal i dq The active power P is calculated by the following formula: out And reactive power Q out :

[0072]

[0073] S4, generate the grid-connected phase angle required for inverter park conversion through the DC capacitor voltage self-synchronous controller, and generate the reference voltage amplitude E through the reactive power droop controller ref .

[0074] like Figure 2 As shown, the DC capacitor voltage self-synchronous controller is used to generate the grid-connected phase angle required for park conversion. The DC capacitor voltage self-synchronous controller has an angle reference θ * Generated by the controller according to the DC voltage deviation, the controller is in the DC voltage v dc The relationship between and converter power angle in the frequency domain can be expressed as:

[0075]

[0076] Therefore the angle reference θ* and The direct relationship between them is as follows:

[0077]

[0078] and The transfer function between can be expressed as:

[0079]

[0080] Among them, K p and K d are the proportional gain and derivative gain of the controller, Δv dcis the difference between the actual DC voltage and the DC voltage reference value, ω n is the rated electrical angular velocity, ω b is the reference electrical angular velocity;

[0081] like Figure 3 As shown, the input is the reactive voltage reference value and the calculated reactive voltage value of the grid-connected point. Through the reactive droop controller, the inverter reference amplitude E is obtained. ref .

[0082] The DC side mathematical model of the inverter is expressed as:

[0083]

[0084] Among them, p dc1 is the DC input power, p dc2 is the DC side output power, v dc is the DC side capacitor voltage, and the DC capacitor equivalent inertia time constant can be expressed as:

[0085]

[0086] Among them, C dc is the DC capacitance, v dcref is the DC voltage reference value, P N is the rated voltage.

[0087] The grid-side mathematical model of the inverter is expressed as:

[0088]

[0089] Where, v is the effective value of the inverter port voltage, v e is the ideal grid voltage effective value, X c is the filter impedance, X g is the grid equivalent impedance, θ is the inverter port phase angle, θ e is the ideal grid phase angle.

[0090] S5: The grid-connected phase angle θ and the reference voltage amplitude E generated by the control module ref , get the grid-connected point dq axis voltage command value v required by the voltage outer loop control module dref and v qref .

[0091] S6, the voltage outer loop control module generates the current command value i required by the current inner loop control module dref and i qref .

[0092] like Figure 5 As shown, the voltage outer loop control module is:

[0093]

[0094] in, and They are the current command values ​​transmitted to the current inner loop controller, K p1 and K i1 are the proportional parameter and integral parameter of the voltage outer loop controller, C f It is a filter capacitor.

[0095] S7, the current inner loop control module generates a grid-connected point dq axis modulation voltage signal v through the grid-connected point dq axis decoupling transformation dm and v qm .

[0096] like Figure 6 As shown, the current inner loop control module is:

[0097]

[0098] Among them, v dm and v qm is the modulation voltage signal of the dq axis, K p2 and K i2 They are the proportional parameter and integral parameter of the current inner loop controller, L f It is the filter inductor.

[0099] S8, the obtained grid-connected point dq axis modulation voltage signal v dm and v qm The PWM pulse modulation voltage signal v is obtained by inverse park transformation mabc , to realize the synchronous grid-connected control of grid-connected inverters.

[0100] In summary, by extending GFM control to DC bus voltage control, the dynamic balance of voltage and power is achieved by controlling the power angle of the converter, avoiding the potential conflict between traditional GFM control and DC voltage control, improving the robustness of the system, and enabling the system to adapt to a wider range of grid conditions, including strong and weak grids, and maintain normal operation when the AC grid is lost.

[0101] Example 2

[0102] On the basis of the first embodiment, this embodiment further provides a system for extending the grid control to the DC bus voltage control, including a grid-connected phase angle generation module, a reference voltage amplitude generation module, a coordinate transformation module, a voltage outer loop control module, and a current inner loop control module;

[0103] The grid-connected phase angle generation module generates the grid-connected phase angle required for park conversion by using a DC capacitor voltage self-synchronous controller;

[0104] The reference voltage amplitude generation module generates a reference voltage amplitude using a reactive power droop controller;

[0105] The coordinate transformation module converts the collected three-phase voltage and current signals into two-phase dq axis voltage and current signals;

[0106] The voltage outer loop control module obtains a current command value by using a voltage command value generated by the generated reference voltage amplitude and the grid-connected phase angle through PI decoupling control;

[0107] The current inner loop control module obtains a modulated voltage signal through PI decoupling control based on the current command value generated by the voltage outer loop control module.

[0108] This embodiment also provides a computer device, which is suitable for the method of extending network control to DC bus voltage control, including a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method of extending network control to DC bus voltage control as proposed in the above embodiment.

[0109] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0110] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for extending the grid control to the DC bus voltage control proposed in the above embodiment is implemented.

[0111] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0112] Example 3

[0113] Reference Figure 7 and Figure 8 Based on the previous two embodiments, this embodiment provides a method for extending the network control to the DC bus voltage control. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0114] Two grid-connected inverter models are established: one using the method of Embodiment 1, and the other using the traditional PLL method.

[0115] Simulate grid disturbances such as voltage sags or phase jumps.

[0116] The performance of the two methods is compared in terms of phase angle tracking speed and accuracy, and output power stability.

[0117] As can be seen from the figure, compared with the traditional method, Example 1 has a faster response in phase angle tracking, a shorter time to reach a stable state, smaller fluctuations in output power, and better stability.

[0118] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for extending network construction control to DC bus voltage control, characterized in that: The following steps are included: Get the three-phase output voltage signal v of the grid-connected inverter abc , three-phase output current signal i abc , filter inductor current i Labc And the DC capacitor voltage signal v dc ; The three-phase output voltage signal v of the grid-connected inverter at the grid-connected point abc And the three-phase output current signal i abc Perform park coordinate transformation to obtain the dq axis voltage signal v of the grid connection point dq , grid-connected point dq axis current signal i dq and the filter inductor dq axis current signal i Ldq ; The dq axis voltage signal v obtained by the grid connection point dq and the grid-connected point dq axis current signal i dq , perform power calculation and obtain the output active power P out And reactive power Q out ; The DC capacitor voltage self-synchronous controller generates the grid-connected phase angle required for the inverter park conversion, and the reactive power droop controller generates the reference voltage amplitude E ref ; The grid-connected phase angle θ and the reference voltage amplitude E generated by the control module ref , get the grid-connected point dq axis voltage command value v required by the voltage outer loop control module dref and v qref ; The voltage outer loop control module generates the current command value i required by the current inner loop control module dref and i qref ; The current inner loop control module generates the grid-connected point dq axis modulation voltage signal v through the grid-connected point dq axis decoupling transformation dm and v qm ; The obtained grid-connected point dq axis modulation voltage signal v dm and v qm The PWM pulse modulation voltage signal v is obtained by inverse park transformation mabc , to realize the synchronous grid-connected control of grid-connected inverters.

2. The method for extending network construction control to DC bus voltage control according to claim 1, characterized in that: The park transformation is to transform the collected three-phase output voltage signal v of the grid connection point by rotating the coordinate system. abc And the three-phase output current signal i abc Transformed into the two-phase rotating coordinate system dq axis voltage signal v dq and dq axis current signal i dq ; The power calculation is performed by using the dq axis voltage signal v of the two-phase rotating coordinate system dq and the grid-connected point dq axis current signal i dq The active power P is calculated by the following formula: out And reactive power Q out :

3. The method for extending the network construction control to the DC bus voltage control according to claim 2, characterized in that: The voltage outer loop control module is: in, and They are the current command values ​​transmitted to the current inner loop controller, K p1 and K i1 are the proportional parameter and integral parameter of the voltage outer loop controller, C f It is a filter capacitor.

4. The method for extending the network construction control to the DC bus voltage control according to claim 3, characterized in that: The current inner loop control module is: Among them, v dm and v qm is the modulation voltage signal of the dq axis, K p2 and K i2 They are the proportional parameter and integral parameter of the current inner loop controller, L f It is the filter inductor.

5. The method for extending the network construction control to the DC bus voltage control according to claim 4, characterized in that: The grid-side mathematical model of the inverter is expressed as: Where, v is the effective value of the inverter port voltage, v e is the ideal grid voltage effective value, X c is the filter impedance, X g is the grid equivalent impedance, θ is the inverter port phase angle, θ e is the ideal grid phase angle.

6. The method for extending the network construction control to the DC bus voltage control according to claim 5, characterized in that: The DC side mathematical model of the inverter is expressed as: Among them, p dc1 is the DC input power, p dc2 is the DC side output power, v dc is the DC side capacitor voltage, and the DC capacitor equivalent inertia time constant can be expressed as: Among them, C dc is the DC capacitance, v dcref is the DC voltage reference value, P N is the rated voltage.

7. The method for extending the network construction control to the DC bus voltage control according to claim 6, characterized in that: The DC capacitor voltage self-synchronous controller, the angle reference θ * Generated by the controller according to the DC voltage deviation, the controller is in the DC voltage v dc The relationship between and converter power angle in the frequency domain can be expressed as: Therefore the angle reference θ* and The direct relationship between them is as follows: and The transfer function between can be expressed as: Among them, K p and K d are the proportional gain and derivative gain of the controller, Δv dc is the difference between the actual DC voltage and the DC voltage reference value, ω n is the rated electrical angular velocity, ω b is the reference electrical angular velocity.

8. A system for extending network construction control to DC bus voltage control, based on the method for extending network construction control to DC bus voltage control according to any one of claims 1 to 7, characterized in that: It includes a grid-connected phase angle generation module, a reference voltage amplitude generation module, a coordinate transformation module, a voltage outer loop control module, and a current inner loop control module; The grid-connected phase angle generation module generates the grid-connected phase angle required for park conversion by using a DC capacitor voltage self-synchronous controller; The reference voltage amplitude generation module generates a reference voltage amplitude using a reactive power droop controller; The coordinate transformation module converts the collected three-phase voltage and current signals into two-phase dq axis voltage and current signals; The voltage outer loop control module obtains a current command value by using a voltage command value generated by the generated reference voltage amplitude and the grid-connected phase angle through PI decoupling control; The current inner loop control module obtains a modulated voltage signal through PI decoupling control based on the current command value generated by the voltage outer loop control module.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for extending the grid control to the DC bus voltage control as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for extending grid control to DC bus voltage control as described in any one of claims 1 to 7 are implemented.

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