A network-configuration type SVG control method and system considering DC capacitor energy compensation

Abstract

This invention discloses a grid-type SVG control method and system considering DC capacitor energy compensation, belonging to the field of smart grid operation control technology. Based on a dual-closed-loop control architecture using a PD controller in the active power loop and virtual inertia and damping in the reactive power loop, this invention constructs a DC energy feedforward compensation branch independent of the frequency integral stage. Specifically, it calculates the transient surplus energy of the DC capacitor deviating from steady state in real time, linearly converts it into a transient energy compensation phase angle, and directly superimposes it into the phase of the output modulation wave. This invention overcomes the inherent physical lag of the frequency integral stage in traditional control, achieving zero-delay rapid compensation for transient active power impacts, effectively suppressing transient fluctuations in the SVG DC bus voltage, and improving the operational reliability of the grid-type SVG under transient fault conditions in the power grid.

Description

Technical Field

[0001] This invention belongs to the field of smart grid operation and control technology, specifically relating to a grid-type SVG control method and system that considers DC capacitor energy compensation. Background Technology

[0002] With the continuous development of new power systems based on new energy sources, the large-scale integration of renewable energy sources such as wind power and photovoltaics has brought significant volatility and uncertainty to the power grid. Most existing new energy generating units adopt grid-following (GFL) control, which is characterized by "low inertia and weak damping," easily leading to insufficient voltage support capacity of the sending-end power grid, and consequently causing problems such as continuous equipment disconnection from the grid.

[0003] Static var generators (SVGs), with their advantages of fast response and flexible control, have become key equipment for mitigating transient overvoltages and supporting remote weak power grids. However, traditional SVGs mostly employ grid-following control, which limits their performance when dealing with weak power grid conditions. In contrast, equipment using grid-forming (GFM) control possesses voltage source characteristics and can achieve synchronization by adjusting power without a phase-locked loop, thus better responding to grid disturbances and providing voltage support. However, in actual operation, there is a significant dynamic coupling effect between the active and reactive power control loops in grid-forming control. During the transient process of reactive power regulation, it is easy to induce drastic fluctuations in the DC bus voltage, which seriously affects the system's synchronization stability and equipment operation safety.

[0004] Existing research on the stability of grid-connected equipment suffers from the following shortcomings: At the control algorithm level, existing virtual synchronous compensators mostly employ proportional-derivative (PD) correction. Due to their inherently "deviation-then-adjustment" feedback characteristic, they are limited by frequency-phase integral delays, resulting in significant response lag and an inability to effectively suppress voltage spikes in the initial stages of faults. At the impedance characteristic level, existing technologies primarily focus on external characteristics of the grid connection point (such as sequence impedance modeling or virtual impedance control), neglecting the transient impact of strong active-reactive coupling on the DC-side voltage of the SVG. Furthermore, some zero-sequence voltage injection strategies for unbalanced operating conditions can only achieve energy redistribution within the system. When a symmetrical dip fault occurs in the grid, causing overall active power backflow, there is a lack of an active mechanism to release energy to the grid, easily leading to bus overvoltage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a grid-type SVG control method and system that considers DC capacitor energy compensation. This method can achieve rapid and proactive compensation for transient impact energy without sacrificing the dynamic response speed of the grid-type equipment or relying on hardware energy-consuming circuits, thereby improving the transient stability and operational reliability of the grid-type SVG system under harsh operating conditions.

[0006] This invention provides the following technical solution:

[0007] Firstly, a grid-based SVG control method considering DC capacitor energy compensation is provided, comprising the following steps: The system acquires real-time status data of the target grid-type SVG system and electrical quantities at the grid connection point, performs signal preprocessing and coordinate transformation, and obtains the actual output voltage component and actual output current component in the rotating coordinate system. The actual reactive power is calculated based on the actual output voltage component and the actual output current component. A reactive power-voltage control loop is constructed by combining virtual inertia and damping characteristics, and the output voltage reference amplitude of the grid-type SVG is obtained. The actual DC capacitor voltage is collected, and the deviation between the actual DC capacitor voltage and the preset reference value is processed through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system. Based on the deviation between the actual DC capacitor voltage and the preset reference value, the transient surplus energy of the DC side of the converter deviating from steady state is calculated in real time, and it is converted into transient energy compensation phase angle using the preset energy compensation coefficient. The basic following phase is obtained by performing time integration on the angular frequency reference value, and then fed forward and superimposed with the transient energy compensation phase angle to obtain the modulated wave phase signal; The output voltage reference amplitude of the grid-type SVG and the modulation wave phase signal are subjected to inverse coordinate transformation to synthesize a three-phase modulation wave signal and output a drive pulse to achieve closed-loop control of the grid-type SVG.

[0008] Optionally, the target grid-type SVG system adopts a three-phase two-level topology connected to the grid via a step-up transformer; the output terminal of the grid-type SVG of the target grid-type SVG system is connected to the low-voltage side of the step-up transformer through an LC filter to filter out switching harmonics and provide reactive power support to the grid.

[0009] Optionally, the step of calculating the transient surplus energy of the converter's DC side deviating from steady state in real time based on the deviation between the actual DC capacitor voltage and a preset reference value, and converting it into a transient energy compensation phase angle using a preset energy compensation coefficient, specifically: By collecting the actual DC capacitor voltage and combining it with the preset reference values ​​of the DC-side capacitor and DC capacitor voltage, the transient surplus energy of the converter's DC side deviating from steady state is calculated. ; Using a preset energy compensation coefficient, the transient surplus energy is directly converted into a transient energy compensation phase angle to form a DC energy feedforward compensation branch independent of the frequency integration stage. The transient energy compensation phase angle... The formula is: ; in, The preset energy compensation coefficient, For DC side capacitors, This is the preset reference value for the DC capacitor voltage. This is the actual DC capacitor voltage.

[0010] Optionally, the step of calculating the actual reactive power based on the actual output voltage component and the actual output current component, and constructing a reactive power-voltage control loop by combining virtual inertia and damping characteristics, to obtain the output voltage reference amplitude of the grid-type SVG, specifically involves: Obtain the rated reactive power and rated output voltage amplitude of the grid-type SVG; The actual reactive power is calculated based on the actual output voltage component and the actual output current component. The deviation between the rated reactive power and the actual reactive power is calculated and input into a transfer function composed of virtual inertia and damping coefficient to obtain the transient voltage amplitude adjustment. ; The transient voltage amplitude adjustment amount The rated output voltage amplitude is linearly superimposed to generate and output the reference amplitude of the grid-type SVG output voltage. : ; in, The rated output voltage amplitude, For virtual inertia, For the Laplace operator, The damping coefficient is... Rated reactive power, This represents the actual reactive power.

[0011] Optionally, the step of processing the deviation between the actual DC capacitor voltage and the preset reference value through the active-frequency control loop including a proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system specifically involves: The deviation between the actual DC capacitor voltage and the preset reference value is calculated, and this deviation is input to the proportional-derivative controller for dynamic processing to calculate the angular frequency adjustment. ; Adjust the angular frequency The angular frequency reference value of the target mesh-type SVG system is extracted and output by superimposing it with the rated angular frequency of the target mesh-type SVG system: ; in, The angular frequency reference value for the target mesh-type SVG system. The rated angular frequency for the target mesh-type SVG system to operate at. The proportional coefficient of the proportional-derivative controller. These are the derivative coefficients of the proportional-derivative controller. For the Laplace operator, This is the preset reference value for the DC capacitor voltage. This is the actual DC capacitor voltage.

[0012] Optionally, the transient energy compensation phase angle satisfies the following constraints: ; in, To compensate for the phase angle of transient energy, The preset energy compensation coefficient, This refers to the transient surplus energy on the DC side of the converter that deviates from steady state. The maximum phase jump threshold allowed to ensure transient power angle stability.

[0013] Secondly, a network-type SVG control system considering DC capacitor energy compensation is provided, including: The state acquisition and transformation module is used to acquire the real-time state data of the target grid-type SVG system and the electrical quantities at the grid connection point, and to perform signal preprocessing and coordinate transformation to obtain the actual output voltage component and the actual output current component in the rotating coordinate system. The reactive-voltage control module is used to calculate the actual reactive power based on the actual output voltage component and the actual output current component, and to construct a reactive-voltage control loop by combining virtual inertia and damping characteristics, and to process and obtain the output voltage reference amplitude of the grid-type SVG. The active-frequency control module is used to acquire the actual DC capacitor voltage and process the deviation between the actual DC capacitor voltage and the preset reference value through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system. The DC energy feedforward compensation module is used to calculate the transient surplus energy of the DC side of the converter deviating from steady state in real time based on the deviation between the actual DC capacitor voltage and the preset reference value, and to convert it into transient energy compensation phase angle using the preset energy compensation coefficient. The phase fusion module is used to perform time integration on the angular frequency reference value to obtain the basic following phase, and to perform feedforward superposition with the transient energy compensation phase angle to obtain the modulated wave phase signal; The drive pulse generation module is used to perform inverse coordinate transformation on the output voltage reference amplitude of the grid-type SVG and the modulation wave phase signal, synthesize a three-phase modulation wave signal and output a drive pulse to realize closed-loop control of the grid-type SVG.

[0014] Thirdly, a computer device is provided, including a processor and a memory; wherein, when the processor executes a computer program stored in the memory, it implements the steps of the grid-type SVG control method considering DC capacitor energy compensation as described in any one of the first aspects.

[0015] Fourthly, a computer-readable storage medium is provided for storing a computer program; when the computer program is executed by a processor, it implements the steps of the grid-type SVG control method considering DC capacitor energy compensation as described in any one of the first aspects.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention calculates the transient surplus energy on the DC side of the converter deviating from steady state in real time and converts it into transient energy compensation phase angle, forming a DC energy feedforward compensation branch that directly acts on the output phase. This effectively bypasses the inherent response lag problem of the frequency integral stage in traditional droop control and significantly suppresses transient DC voltage fluctuations. When facing disturbances such as reactive power step jumps, this invention can reduce the DC voltage fluctuation range of the grid-type SVG by approximately 68.1%, greatly limiting the peak value of transient DC overvoltage and reducing the risk of equipment disconnection due to DC bus voltage exceeding limits. Simultaneously, without affecting the reactive power voltage support capability of the grid-type equipment, this invention greatly enhances the transient damping characteristics of the target grid-type SVG system under severe operating conditions such as symmetrical and asymmetrical voltage dips, effectively suppressing active power backflow and voltage oscillations during fault clearing, and improving the operational reliability of the grid-type converter in weak grid conditions. Furthermore, this method, based purely on optimization at the control algorithm level, achieves active absorption of transient impact energy, effectively avoiding dependence on additional hardware such as DC-side energy dissipation circuits, and improving the transient stability of the network-type SVG system without increasing hardware costs. Attached Figure Description

[0017] Figure 1 This is a flowchart of the network-type SVG control method considering DC capacitor energy compensation according to the present invention; Figure 2 This is a schematic diagram of the three-phase two-level topology of the target network SVG system of the present invention; Figure 3 This is a block diagram of the strategy structure of the network-type SVG control method considering DC capacitor energy compensation of the present invention; Figure 4 This is a comparison diagram of the DC voltage response under reactive step conditions, provided in Embodiment 2 of the present invention, after adopting the control strategy of the present invention and the traditional control strategy of the prior art; Figure 5 This is a comparison diagram of the DC voltage response under the symmetrical voltage drop condition of the power grid, provided by Embodiment 2 of the present invention, after adopting the control strategy of the present invention and the traditional control strategy of the prior art. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be used to limit the scope of protection of the present invention. It should be noted that the term "comprising" and any variations thereof in the specification, claims and the above-mentioned drawings of the present invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or devices.

[0019] Example 1: like Figure 1 As shown, a grid-based SVG control method considering DC capacitor energy compensation includes the following steps: Step S1: Obtain the real-time status data of the target grid-type SVG system and the electrical quantities at the grid connection point, and perform signal preprocessing and coordinate transformation to obtain the actual output voltage component and the actual output current component in the rotating coordinate system.

[0020] like Figure 2 As shown, the target grid-type SVG system in this embodiment adopts a three-phase two-level topology connected to the grid via a step-up transformer. The output terminal of the grid-type SVG on the bridge arm side of the target grid-type SVG system is connected to the low-voltage side of the step-up transformer via an LC filter to filter out switching harmonics and provide reactive power support to the grid.

[0021] Real-time acquisition and filtering of three-phase voltage and current at the grid connection point of the target grid-type SVG system, followed by execution of the filtered three-phase electrical quantities using the phase angle generated internally by the grid-type SVG control. abc / dq Coordinate transformation, thereby obtaining dqActual output voltage components in rotating coordinate system and actual output current component .

[0022] Step S2: Calculate the actual reactive power based on the actual output voltage component and the actual output current component, and construct a reactive power-voltage control loop by combining virtual inertia and damping characteristics to obtain the output voltage reference amplitude of the grid-type SVG.

[0023] like Figure 3 As shown, to simulate the excitation characteristics of a synchronous generator, a virtual inertia is introduced into the reactive power loop. and damping coefficient The actual reactive power is calculated based on the actual output voltage and actual output current components. Then, calculate its relationship with the rated reactive power. The deviation is input into a transfer function composed of virtual inertia and damping coefficient for calculation, resulting in the transient voltage amplitude adjustment. Adjust the transient voltage amplitude. With the rated output voltage amplitude Linear superposition generates the output voltage reference amplitude of the mesh-type SVG. Its governing equation is: ; in, For the Laplace operator.

[0024] Step S3: Acquire the actual DC capacitor voltage, and process the deviation between the actual DC capacitor voltage and the preset reference value through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system.

[0025] like Figure 3 As shown, step S3 specifically includes the following sub-steps: S31: Extract the preset DC capacitor voltage reference value The actual DC capacitor voltage aligned with the time. Obtaining DC voltage deviation by subtraction : .

[0026] S32: DC voltage deviation Input to the proportional coefficient and differential coefficients PD controller Dynamic processing is performed to obtain the angular frequency adjustment amount. and the rated angular frequency of the mesh-type SVG. The angular frequency reference values ​​of the target mesh-type SVG system are superimposed and output. Its governing equations are: ; in, The angular frequency reference value for the target mesh-type SVG system. The rated angular frequency for operation of a mesh-type SVG system. For the Laplace operator, This is the preset reference value for the DC capacitor voltage, i.e., the steady-state operating point voltage; This is the actual DC capacitor voltage.

[0027] Step S4: Based on the deviation between the actual DC capacitor voltage and the preset reference value, calculate the transient surplus energy of the DC side of the converter that deviates from the steady state in real time, and use the preset energy compensation coefficient to convert it into a transient energy compensation phase angle.

[0028] To smooth transient fluctuations without sacrificing response speed, this embodiment introduces a DC energy feedforward branch (such as...) into the active power loop of traditional grid control. Figure 3 (As shown). That is, by calculating the transient surplus energy of the DC side of the converter deviating from the steady state in real time, and using a preset energy compensation coefficient, it is converted into a transient energy compensation phase angle, which directly acts on the output phase in physical terms, bypassing the frequency integration link in traditional control, and realizing the time-delay correction of transient energy impact.

[0029] Step S4 specifically includes the following steps: S41: Collect the actual DC capacitor voltage, and calculate the transient surplus energy of the converter's DC side deviating from steady state by combining the preset reference values ​​of the DC side capacitor and DC capacitor voltage. ; S42: Using a preset energy compensation coefficient, the transient surplus energy is directly converted into the transient energy compensation phase angle to form a DC energy feedforward compensation branch independent of the frequency integration stage.

[0030] ; in, To compensate for the phase angle of transient energy, The preset energy compensation coefficient, For DC side capacitors, This is the preset reference value for the DC capacitor voltage. This is the actual DC capacitor voltage.

[0031] The preset energy compensation coefficient is constrained by the transient physical characteristics of the converter. To prevent phase abrupt changes under large disturbances from causing the target grid-type SVG system to lose synchronization, the transient energy compensation phase angle is constrained, i.e. ;in, The maximum allowable phase jump threshold to ensure transient power angle stability, i.e., if calculated as follows: Greater than Then, the transient energy compensation phase angle actually output in step S4 is the maximum phase jump threshold allowed for transient power angle stability. If calculated... Less than or equal to Then, the transient energy compensation phase angle actually output in step S4 is the calculated value. .

[0032] Step S5: Perform time integration on the angular frequency reference value to obtain the basic following phase, and perform feedforward superposition with the transient energy compensation phase angle to obtain the modulated wave phase signal.

[0033] The angular frequency reference value generated in step S3 The basic following phase is obtained by performing time integration, and then compared with the feedforward transient energy compensation phase angle generated in step S4. By performing feedforward superposition, the modulated wave phase signal acting on the converter is finally obtained. .

[0034] Step S6: Perform inverse coordinate transformation on the output voltage reference amplitude and modulation wave phase signal of the grid-type SVG to synthesize a three-phase modulation wave signal and output a drive pulse to realize closed-loop control of the grid-type SVG.

[0035] The output voltage reference amplitude obtained in step S2 and the modulated wave phase signal obtained in step S5 conduct dq / abc The inverse coordinate transformation synthesizes a three-phase modulated wave signal, which is then used by the PWM module to generate drive pulses to control the on and off of the IGBT switching transistors, thereby achieving closed-loop control of the mesh-type SVG.

[0036] Example 2: A comparative example of applying the control method of this invention and existing traditional strategies for regulation is given. This example is based on a system simulation model built on the Matlab / Simulink platform, and the system and control parameters shown in Table 1 below are used for simulation: Table 1 Simulation Parameters

[0037] Based on the above parameter settings, the strategy of this invention is compared and tested with the traditional frequency compensation strategy: (1) Verification of reactive step operation: such as Figure 4As shown, the reactive power reference command is changed at 2.0s (switching from 10kVar to -10kVar). With the traditional strategy, the DC voltage fluctuation range is 748~896V; however, after introducing the DC energy compensation branch of this invention, the DC voltage fluctuation range is significantly narrowed to 784~830V, a reduction of approximately 68.1%, and the transient overvoltage decreases from 1.12pu to 1.04pu. Simultaneously, the reactive power waveform shows that the strategy of this invention has almost no impact on the reactive power regulation speed and steady-state accuracy of the SVG.

[0038] (2) Verification of grid voltage dip conditions: such as Figure 5 As shown, the simulation depicts a severe power grid condition involving a 50% symmetrical voltage drop and subsequent recovery. Traditional grid control, at the moment of fault clearing (2.0s), causes a significant backflow of active power, resulting in a DC voltage spike to 1200V (1.5pu), posing a substantial risk of equipment disconnection, and the recovery process is accompanied by noticeable oscillations. Using the strategy of this invention, the system's damping characteristics are significantly enhanced. The transient overvoltage at the moment of fault clearing is firmly limited to within 920V (1.15pu), the voltage waveform is smooth without underdamped oscillations, and it quickly returns to the steady-state value of 800V.

[0039] Example 3: A grid-type SVG control system considering DC capacitor energy compensation includes: The state acquisition and transformation module is used to acquire the real-time state data of the target grid-type SVG system and the electrical quantities at the grid connection point, and to perform signal preprocessing and coordinate transformation to obtain the actual output voltage component and the actual output current component in the rotating coordinate system. The reactive-voltage control module is used to calculate the actual reactive power based on the actual output voltage component and the actual output current component, and to construct a reactive-voltage control loop by combining virtual inertia and damping characteristics, and to process and obtain the output voltage reference amplitude of the grid-type SVG. The active-frequency control module is used to acquire the actual DC capacitor voltage and process the deviation between the actual DC capacitor voltage and the preset reference value through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system. The DC energy feedforward compensation module is used to calculate the transient surplus energy of the DC side of the converter deviating from steady state in real time based on the deviation between the actual DC capacitor voltage and the preset reference value, and to convert it into transient energy compensation phase angle using the preset energy compensation coefficient. The phase fusion module is used to perform time integration on the angular frequency reference value to obtain the basic following phase, and to perform feedforward superposition with the transient energy compensation phase angle to obtain the modulated wave phase signal; The drive pulse generation module is used to perform inverse coordinate transformation on the output voltage reference amplitude of the grid-type SVG and the modulation wave phase signal, synthesize a three-phase modulation wave signal and output a drive pulse to realize closed-loop control of the grid-type SVG.

[0040] For more detailed information on the above modules, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0041] Example 4: This invention provides a computer device, including a processor and a memory; wherein, when the processor executes a computer program stored in the memory, it implements the steps of the above-described grid-type SVG control method considering DC capacitor energy compensation. For more detailed information on the above methods, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0042] Example 5: The present invention provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, it implements the steps of the above-described grid-type SVG control method that considers DC capacitor energy compensation.

[0043] For more detailed information on the above methods, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The systems, devices, and storage media disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments; relevant details can be found in the method section.

[0045] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions in the embodiments of the present invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or certain parts of the embodiments of the present invention.

[0046] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A network-based SVG control method considering DC capacitor energy compensation, characterized in that, Includes the following steps: The system acquires real-time status data of the target grid-type SVG system and electrical quantities at the grid connection point, performs signal preprocessing and coordinate transformation, and obtains the actual output voltage component and actual output current component in the rotating coordinate system. The actual reactive power is calculated based on the actual output voltage component and the actual output current component. A reactive power-voltage control loop is constructed by combining virtual inertia and damping characteristics, and the output voltage reference amplitude of the grid-type SVG is obtained. The actual DC capacitor voltage is collected, and the deviation between the actual DC capacitor voltage and the preset reference value is processed through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system. Based on the deviation between the actual DC capacitor voltage and the preset reference value, the transient surplus energy of the DC side of the converter deviating from steady state is calculated in real time, and it is converted into transient energy compensation phase angle using the preset energy compensation coefficient. The basic following phase is obtained by performing time integration on the angular frequency reference value, and then fed forward and superimposed with the transient energy compensation phase angle to obtain the modulated wave phase signal; The output voltage reference amplitude of the grid-type SVG and the modulation wave phase signal are subjected to inverse coordinate transformation to synthesize a three-phase modulation wave signal and output a drive pulse to achieve closed-loop control of the grid-type SVG.

2. The grid-type SVG control method considering DC capacitor energy compensation according to claim 1, characterized in that, The target grid-type SVG system adopts a three-phase two-level topology connected to the grid via a step-up transformer; the output terminal of the grid-type SVG of the target grid-type SVG system is connected to the low-voltage side of the step-up transformer through an LC filter to filter out switching harmonics and provide reactive power support to the grid.

3. The grid-type SVG control method considering DC capacitor energy compensation according to claim 1, characterized in that, The method involves calculating the transient surplus energy of the converter's DC side deviating from steady state in real time based on the deviation between the actual DC capacitor voltage and a preset reference value, and converting it into a transient energy compensation phase angle using a preset energy compensation coefficient. Specifically: By collecting the actual DC capacitor voltage and combining it with the preset reference values ​​of the DC-side capacitor and DC capacitor voltage, the transient surplus energy of the converter's DC side deviating from steady state is calculated. ; Using a preset energy compensation coefficient, the transient surplus energy is directly converted into a transient energy compensation phase angle to form a DC energy feedforward compensation branch independent of the frequency integration stage. The transient energy compensation phase angle... The formula is: ； in, The preset energy compensation coefficient, For DC side capacitors, This is the preset reference value for the DC capacitor voltage. This is the actual DC capacitor voltage.

4. The grid-type SVG control method considering DC capacitor energy compensation according to claim 1, characterized in that, The actual reactive power is calculated based on the actual output voltage and current components, and a reactive power-voltage control loop is constructed by combining virtual inertia and damping characteristics. This process yields the reference amplitude of the output voltage for the grid-type SVG. Specifically: Obtain the rated reactive power and rated output voltage amplitude of the grid-type SVG; The actual reactive power is calculated based on the actual output voltage component and the actual output current component. The deviation between the rated reactive power and the actual reactive power is calculated and input into a transfer function composed of virtual inertia and damping coefficient to obtain the transient voltage amplitude adjustment. ; The transient voltage amplitude adjustment amount The rated output voltage amplitude is linearly superimposed to generate and output the reference amplitude of the grid-type SVG output voltage. : ； in, The rated output voltage amplitude, For virtual inertia, For the Laplace operator, The damping coefficient is... Rated reactive power, This represents the actual reactive power.

5. The grid-type SVG control method considering DC capacitor energy compensation according to claim 1, characterized in that, The deviation between the actual DC capacitor voltage and the preset reference value is processed by the active-frequency control loop containing a proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system, specifically as follows: The deviation between the actual DC capacitor voltage and the preset reference value is calculated, and this deviation is input to the proportional-derivative controller for dynamic processing to calculate the angular frequency adjustment. ; Adjust the angular frequency The angular frequency reference value of the target mesh-type SVG system is extracted and output by superimposing it with the rated angular frequency of the target mesh-type SVG system: ； in, The angular frequency reference value for the target mesh-type SVG system. The rated angular frequency for the target mesh-type SVG system to operate at. The proportional coefficient of the proportional-derivative controller. These are the derivative coefficients of the proportional-derivative controller. For the Laplace operator, This is the preset reference value for the DC capacitor voltage. This is the actual DC capacitor voltage.

6. The grid-type SVG control method considering DC capacitor energy compensation according to claim 1, characterized in that, The transient energy compensation phase angle satisfies the following constraint: ； in, To compensate for the phase angle of transient energy, The preset energy compensation coefficient, This refers to the transient surplus energy on the DC side of the converter that deviates from steady state. The maximum phase jump threshold allowed to ensure transient power angle stability.

7. A network-based SVG control system considering DC capacitor energy compensation, characterized in that, include: The state acquisition and transformation module is used to acquire the real-time state data of the target grid-type SVG system and the electrical quantities at the grid connection point, and to perform signal preprocessing and coordinate transformation to obtain the actual output voltage component and the actual output current component in the rotating coordinate system. The reactive-voltage control module is used to calculate the actual reactive power based on the actual output voltage component and the actual output current component, and to construct a reactive-voltage control loop by combining virtual inertia and damping characteristics, and to process and obtain the output voltage reference amplitude of the grid-type SVG. The active-frequency control module is used to acquire the actual DC capacitor voltage and process the deviation between the actual DC capacitor voltage and the preset reference value through the active-frequency control loop containing the proportional-derivative controller to obtain the angular frequency reference value of the target grid-type SVG system. The DC energy feedforward compensation module is used to calculate the transient surplus energy of the DC side of the converter deviating from steady state in real time based on the deviation between the actual DC capacitor voltage and the preset reference value, and to convert it into transient energy compensation phase angle using the preset energy compensation coefficient. The phase fusion module is used to perform time integration on the angular frequency reference value to obtain the basic following phase, and to perform feedforward superposition with the transient energy compensation phase angle to obtain the modulated wave phase signal; The drive pulse generation module is used to perform inverse coordinate transformation on the output voltage reference amplitude of the grid-type SVG and the modulation wave phase signal, synthesize a three-phase modulation wave signal and output a drive pulse to realize closed-loop control of the grid-type SVG.

8. A computer device, characterized in that, It includes a processor and a memory; wherein, when the processor executes the computer program stored in the memory, it implements the steps of the grid-type SVG control method considering DC capacitor energy compensation as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, Used to store computer programs; when the computer programs are executed by a processor, they implement the steps of the grid-type SVG control method considering DC capacitor energy compensation as described in any one of claims 1-6.

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