Method, system and equipment for improving transient stability of network construction converter based on active damping and storage medium

Abstract

The invention discloses a method, a system and equipment for improving transient stability of a network construction converter based on active damping, and a storage medium, and relates to the technical field of power system network construction control, and the method comprises the steps: carrying out the processing of a DC voltage controller based on a DC voltage given value, a DC side actual voltage and a power grid angular frequency ideal value, generating control generation angular frequency and phase; d-axis and q-axis voltage actual reference values are generated through processing of the reactive power controller; the d-axis voltage actual reference value and the q-axis voltage actual reference value serve as input of a voltage loop, and modulation voltage is generated through a current inner loop and an amplitude limiting link; performing coordinate transformation and further modulation on the modulation voltage to form closed-loop control; according to the method, oscillation instability possibly occurring in the transient process of the GFM converter is effectively suppressed, the transient stability of a new energy grid-connected system is improved, and safe and stable operation of a power system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power system grid control, and in particular to a method, system, device and storage medium for improving transient stability of a grid converter based on active damping. Background Art

[0002] With the rapid development of renewable energy generation technology, grid-forming (GFM) converters, as key devices connecting renewable energy generation systems to the power grid, are becoming increasingly important in new power systems. Unlike traditional grid-following (GFL) converters, GFM converters can autonomously construct grid voltage and frequency, providing inertia and damping support for the system, demonstrating significant advantages in weak grid or islanded operation conditions. However, GFM converters are susceptible to transient disturbances and suffer from stability issues, which restrict their large-scale application. The transient stability issues of GFM converters primarily stem from the lack of physical inertia and the strong coupling of control loops. They rely on control algorithms to simulate the inertial response of synchronous generators, but their virtual inertia time constant is typically small, resulting in insufficient damping when subjected to large disturbances. Furthermore, the GFM converter's power, voltage, and current loops are strongly coupled, making it prone to oscillations during transients, impacting system stability.

[0003] To address these issues, existing technologies primarily focus on simulating the synchronous generator's rotor motion equations and excitation control, improving the GFM converter's inertial response and damping characteristics. However, existing technologies still have some shortcomings. Virtual synchronous machine technology struggles to balance system inertia and dynamic response speed; the introduced additional damping control design relies on a precise system model, making it difficult to ensure robustness in practical applications and challenging to dynamically adjust. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: for the stability problem of the grid-connected converter, the existing technology has the disadvantages of being difficult to balance the system inertia and dynamic response speed, the additional damping control design relies on the precise system model, it is difficult to ensure robustness and difficult to dynamically adjust.

[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 improving transient stability of a grid-connected converter based on active damping, comprising:

[0008] Based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency, the DC voltage controller is used to generate the angular frequency and phase;

[0009] Based on the control-generated angular frequency, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, the actual reference values of the d-axis and q-axis voltages are generated after being processed by the reactive power controller;

[0010] The actual reference values of the d-axis voltage and the q-axis voltage are used as inputs of the voltage loop, and the modulation voltage is generated through the current inner loop and the limiter link;

[0011] Combined with the phase, the modulated voltage is coordinate transformed and further modulated to form a closed-loop control.

[0012] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0013] The generating of the angular frequency and phase based on the given DC voltage value, the actual DC side voltage and the ideal grid angular frequency through processing by the DC voltage controller includes:

[0014] Calculate the DC voltage square error based on the DC voltage given value and the actual DC side voltage;

[0015] The DC voltage square error is input into the DC voltage controller to obtain the DC voltage control quantity.

[0016] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0017] The generating of the angular frequency and phase based on the given DC voltage value, the actual DC side voltage and the ideal grid angular frequency through processing by the DC voltage controller also includes:

[0018] Based on the DC voltage control quantity and the ideal value of the grid angular frequency, the control generated angular frequency is obtained;

[0019] The phase is obtained by integrating the angular frequency generated by the control and used for subsequent coordinate transformation.

[0020] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0021] The control-based generation of the angular frequency, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, is processed by the reactive power controller to generate the actual reference values of the d-axis and q-axis voltages, including:

[0022] Calculate reactive power error based on reactive power setpoint and actual reactive power at the grid connection point;

[0023] Inputting the reactive power error into the reactive power controller to obtain the reactive power control quantity;

[0024] Calculating the actual reference value of the d-axis voltage based on the reactive power control amount and the virtual voltage d-axis component;

[0025] Based on the ideal q-axis voltage value and the virtual voltage q-axis component, the actual reference value of the q-axis voltage is calculated.

[0026] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0027] The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the amplitude limiting link includes:

[0028] Voltage inner loop control: Taking the actual reference values of the d-axis and q-axis voltages as input, the voltage inner loop control is performed to output the d-axis current and q-axis current respectively.

[0029] The beneficial effect of this preferred technical solution is that through voltage inner-loop control, the actual reference values of the d-axis and q-axis voltages are used as input and output currents, enabling preliminary control and regulation of current. This voltage inner-loop control can quickly respond to voltage changes, improve the dynamic performance of the system, and provide a stable current foundation for subsequent generation of the modulation voltage.

[0030] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0031] The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the limiting link further includes:

[0032] Limiting processing: The d-axis current and q-axis current output by the voltage inner loop control are passed through the limiting link, and the current values are adjusted to obtain the limited d-axis current and q-axis current.

[0033] The beneficial effect of this preferred technical solution is that the amplitude limiting process can effectively prevent excessive current from causing damage to the system, ensuring system safety. By adjusting the current value, the current operates within a safe range, avoiding equipment failure and system instability caused by overcurrent, and improving the reliability and service life of the grid-connected converter.

[0034] As a preferred solution for the method of improving transient stability of grid-connected converters based on active damping, the following is proposed:

[0035] The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the limiting link further includes:

[0036] Current loop control and modulation voltage calculation: The d-axis current and q-axis current after limiting are subtracted from the corresponding actual current values. The differences are processed by the PI controller to obtain the control values. The d-axis component and q-axis component of the modulation voltage are calculated based on the control values.

[0037] The beneficial effect of this preferred technical solution is that through current loop control and modulation voltage calculation, the PI controller processes the current difference and accurately calculates the d-axis and q-axis components of the modulation voltage. The PI controller has good regulation performance and can quickly eliminate errors, allowing the modulation voltage to more accurately track the reference value, thereby improving the control accuracy and transient stability of the grid-connected converter.

[0038] In a second aspect, an embodiment of the present invention provides a system for improving transient stability of a grid-connected converter based on active damping, comprising:

[0039] The phase generation module is used to generate the angular frequency and phase based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency after processing by the DC voltage controller;

[0040] The voltage actual reference value generation module is used to generate the angular frequency based on the control, combine the reactive power set value, the actual reactive power of the grid connection point and the virtual voltage component, and generate the d-axis and q-axis voltage actual reference values after processing by the reactive power controller;

[0041] A modulation voltage preliminary generation module is used to take the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop, and generate the modulation voltage through the current inner loop and the limiter link;

[0042] The control module is used to combine the phase, coordinate transform and further modulate the modulated voltage to form a closed-loop control.

[0043] In a third aspect, an embodiment of the present invention provides an electronic device, including:

[0044] memory and processor;

[0045] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the one or more programs are executed by the one or more processors, the one or more processors implement the method for improving the transient stability of a grid-connected converter based on active damping as described in any embodiment of the present invention.

[0046] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the method for improving transient stability of a grid-connected converter based on active damping.

[0047] Beneficial effects of the present invention: By introducing an active damping control link, the present invention can monitor the angular frequency generated by the grid control in real time, dynamically adjust the virtual damping coefficient, effectively suppress the oscillation instability phenomenon of the GFM converter when subjected to transient disturbances, and improve the dynamic performance of the system, significantly improving the transient stability of the new energy grid-connected system using the grid converter, helping to improve the system stability margin and thus ensure the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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 paying any creative labor.

[0049] Figure 1 This is an overall flow chart of the method for improving transient stability of a grid-connected converter based on active damping provided by the present invention;

[0050] Figure 2 This is a system structure diagram and main control block diagram of the method for improving transient stability of a grid-connected converter based on active damping provided by the present invention;

[0051] Figure 3 This is a block diagram of the voltage loop and current loop control of the method for improving transient stability of a grid-connected converter based on active damping provided by the present invention;

[0052] Figure 4 This is a comparison curve diagram of the grid-connected current waveform and active power waveform of the system before and after the introduction of the active damping-based grid converter transient stability improvement method provided by the present invention in a simulation experiment. DETAILED DESCRIPTION

[0053] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0054] Example 1, with reference to Figure 1 , which is the first embodiment of the present invention, provides a method for improving transient stability of a grid-connected converter based on active damping, comprising:

[0055] S1: Based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency, the DC voltage controller generates the angular frequency and phase.

[0056] S2: Based on the control-generated angular frequency, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, the reactive power controller processes it to generate the actual reference values of the d-axis and q-axis voltages;

[0057] S3: Use the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop, and generate a modulation voltage through the current inner loop and the limiter link;

[0058] S4: Combined with the phase, the modulated voltage is coordinate transformed and further modulated to form a closed-loop control.

[0059] It should be noted that through steps S1-S4, precise control of the output voltage and current of the grid-connected converter is achieved, which effectively improves the transient stability of the new energy grid-connected system, suppresses oscillation instability, ensures that the system can operate stably and reliably under complex working conditions, and ensures that new energy is efficiently and safely integrated into the grid.

[0060] Example 2, reference Figure 1-Figure 3 , which is an embodiment of the present invention, provides a method for improving transient stability of a grid-connected converter based on active damping based on the previous embodiment, comprising:

[0061] In this embodiment, in step S1, based on the given DC voltage value, the actual DC side voltage, and the ideal grid angular frequency, the DC voltage controller generates and controls the generated angular frequency and phase, including:

[0062] Calculate the DC voltage square error based on the DC voltage given value and the actual DC side voltage;

[0063] Input the DC voltage square error into the DC voltage controller to obtain the DC voltage control quantity;

[0064] Based on the DC voltage control quantity and the ideal value of the grid angular frequency, the control generated angular frequency is obtained;

[0065] Integrate the control-generated angular frequency to obtain the phase for subsequent coordinate transformation;

[0066] Specifically, obtain the DC voltage given value u of the grid converter dcref and the actual DC side voltage u dc , calculate the DC voltage square error (u 2 dcref -u 2 dc ), the error is input into the DC voltage controller G dc(s), output control quantity G dc (s)·(u 2 dcref -u 2 dc ), combined with the ideal value of the grid angular frequency ω0, the control generated angular frequency ω g , expressed as:

[0067] ω g =G dc (s)·(u 2 dcref -u 2 dc )+ω0

[0068] ω g Integrate to get the phase θ g .

[0069] In this embodiment, in step S2, the angular frequency is generated based on the control, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, and processed by the reactive power controller to generate the actual reference values of the d-axis and q-axis voltages, including:

[0070] Calculate reactive power error based on reactive power setpoint and actual reactive power at the grid connection point;

[0071] Inputting the reactive power error into the reactive power controller to obtain the reactive power control quantity;

[0072] Calculating the actual reference value of the d-axis voltage based on the reactive power control amount and the virtual voltage d-axis component;

[0073] Calculating an actual reference value of the q-axis voltage based on the ideal value of the q-axis voltage and the q-axis component of the virtual voltage;

[0074] Specifically, based on the grid-connected point reactive power given value Q ref And the actual reactive power Q of the grid connection point, the reactive power error e is obtained, which is expressed as:

[0075] e=Q ref -Q

[0076] Input the reactive power error into the reactive power controller G q (s), and the reactive power control quantity G is obtained q (s)·e, combined with the virtual voltage d-axis component u df Get the actual reference value u of the d-axis voltage dref , expressed as:

[0077] u dref =G q (s) eu df

[0078] Based on the ideal value of q-axis voltage and the virtual voltage q-axis component u qf , calculate the actual reference value u of the q-axis voltage qref , expressed as:

[0079] u qref =0-u qf

[0080] The ideal value of the q-axis voltage is 0.

[0081] Virtual voltage d-axis component u df The expression is:

[0082] u df =(i df -i dr )·k

[0083] Among them, i df is the d-axis current output after voltage inner loop control, i dr is the d-axis current after adjustment by the limiting link, and k is the virtual damping coefficient.

[0084] Virtual voltage q-axis component u qf The expression is:

[0085] u qf =(i qf -i qr )·k

[0086] Among them, i qf is the q-axis current output after voltage inner loop control, i qr is the q-axis current after adjustment by the limiting link, k is the virtual damping coefficient;

[0087] The expression of the virtual damping coefficient k is:

[0088]

[0089] Among them, ω g To control the generated angular frequency, is the damping factor.

[0090] In this embodiment, in the above step S3, the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage are used as inputs of the voltage loop, and the modulation voltage is generated through the current inner loop and the limiter link, including:

[0091] Perform voltage inner loop control: Calculate the d-axis current i output after voltage inner loop control df , expressed as:

[0092] i df =(u dref -ud )·PI-u q ·ω0C f

[0093] Where PI represents the PI controller, ω0 is the ideal value of the grid angular frequency, and C f is the AC side filter capacitor. Calculate the q-axis current i output after voltage inner loop control qf , expressed as:

[0094] i qf =(u qref -u q )·PI-u d ·ω0C f

[0095] The d-axis current i output after the voltage inner loop control df And the q-axis current i output after voltage inner loop control qf Through the limiting link, the d-axis current i adjusted by the limiting link is obtained. dr and the q-axis current i after adjustment by the limiting link qr ;

[0096] The d-axis current i after adjustment by the limiting link dr The actual value of the d-axis current i d The value obtained by subtraction is multiplied by the PI controller to obtain the control value of the d-axis current and calculate the d-axis component u of the modulation voltage odref , expressed as:

[0097] u odref =(i dr -i d )·PI+u d -i q ·ω0L f

[0098] Where ω0 is the ideal value of the grid angular frequency, L f is the AC side filter inductor;

[0099] The q-axis current i after adjustment by the limiting link qr The actual value of the q-axis current i q The value obtained by subtraction is multiplied by the PI controller to obtain the control value of the q-axis current and calculate the q-axis component u of the modulation voltage oqref , expressed as:

[0100] u oqref =(i qr -i q )·PI+u q +i d ·ω0L f

[0101] The actual reference value of the d-axis voltage u dref and the actual reference value u of the q-axis voltage qref After being applied to the voltage loop control, the amplitude limiting link and the current loop control, the modulated voltage d-axis component u is obtained. odref and the modulation voltage q-axis component u oqref .

[0102] In another possible implementation, feedforward control can be incorporated into the voltage inner-loop control loop, using grid voltage changes as a feedforward signal to preemptively compensate for voltage fluctuations and reduce system response time. For example, when grid voltage increases, feedforward control can rapidly adjust the output current to maintain voltage stability.

[0103] A deadbeat control algorithm can be used to track the output current to the reference current within a sampling period based on the system's mathematical model, achieving fast and accurate current control. Deadbeat control can effectively improve the system's dynamic performance.

[0104] Dynamic limiting can be implemented in the limiting process: the limit value can be dynamically adjusted based on the system's operating status. For example, during system startup or fault recovery, the limit value can be appropriately increased to enable the system to reach a stable state more quickly; during normal operation, the limit value can be reduced to ensure system security and stability.

[0105] Multi-variable limiting is also possible: in addition to limiting the d-axis and q-axis currents, other variables such as power and voltage can also be limited. By comprehensively considering the limiting conditions of multiple variables, the system can avoid abnormal conditions such as overcurrent and overvoltage.

[0106] In this embodiment, in step S4, the modulation voltage is coordinate-transformed and further modulated in combination with the phase to form a closed-loop control, which includes:

[0107] The d-axis component u of the modulation voltage is obtained odref and the modulation voltage q-axis component u oqref After that, it needs to be converted from the dq rotating coordinate system to the α-β stationary coordinate system, because the subsequent space vector pulse width modulation (SVPWM) is usually performed in the stationary coordinate system.

[0108] According to the modulation voltage d-axis component u odref and the modulation voltage q-axis component u oqref Modulation control is performed to generate SVPWM waves to drive the grid-side grid converter of the new energy grid-connected system, so that the converter outputs appropriate voltage and current, improves the transient stability of the new energy grid-connected system, and suppresses oscillation instability.

[0109] In another possible implementation, the dq-axis voltages are converted to stationary coordinate system (αβ-axis) voltages through an inverse Park transform. Three-phase voltage commands are generated through an inverse Clarke transform. The three-phase voltages are normalized in SVPWM modulation, the reference vector sector is determined, the switching times are calculated, and a PWM wave is generated to drive the switching devices of the grid-connected converter, forming a closed-loop control system.

[0110] Example 3. The above is a schematic scheme of the method for improving transient stability of a grid-connected converter based on active damping according to this embodiment. It should be noted that the technical scheme of the system for improving transient stability of a grid-connected converter based on active damping and the technical scheme of the method for improving transient stability of a grid-connected converter based on active damping are based on the same concept. For details not described in detail in the technical scheme of the system for improving transient stability of a grid-connected converter based on active damping in this embodiment, please refer to the description of the technical scheme of the method for improving transient stability of a grid-connected converter based on active damping.

[0111] This embodiment further provides a system for improving transient stability of a grid-connected converter based on active damping, including:

[0112] The phase generation module is used to generate the angular frequency and phase based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency after processing by the DC voltage controller;

[0113] The voltage actual reference value generation module is used to generate the angular frequency based on the control, combine the reactive power set value, the actual reactive power of the grid connection point and the virtual voltage component, and generate the d-axis and q-axis voltage actual reference values after processing by the reactive power controller;

[0114] A modulation voltage preliminary generation module is used to take the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop, and generate the modulation voltage through the current inner loop and the limiter link;

[0115] The control module is used to combine the phase, coordinate transform and further modulate the modulated voltage to form a closed-loop control.

[0116] This embodiment further provides an electronic device applicable to a method for improving transient stability of a grid-connected converter based on active damping, including:

[0117] Memory and processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the method for improving the transient stability of the grid-connected converter based on active damping as proposed in the above embodiment.

[0118] This embodiment further provides a storage medium having a computer program stored thereon. When the program is executed by a processor, the method for improving transient stability of a grid-connected converter based on active damping as proposed in the above embodiment is implemented.

[0119] The storage medium proposed in this embodiment and the method for improving transient stability of a grid-connected converter based on active damping proposed in the above embodiment belong to the same inventive concept. For technical details not fully described in this embodiment, please refer to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0120] Example 4, with reference to Figure 4 , which is an embodiment of the present invention, provides a method for improving the transient stability of a grid-connected converter based on active damping. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through simulation experiments.

[0121] like Figure 4 The following curves compare the grid-connected current and active power waveforms of the system before and after the introduction of this method. Without this method, when the system is subjected to transient disturbances, the grid-connected current transition time is long, and the system active power drops from nearly 1 pu to near -1 pu, resulting in power reverse flow and serious impact on system stability. With this method, when subjected to transient disturbances, the grid-connected current transition time is shorter, and the system active power does not experience significant changes compared to before the improvement. The system's dynamic performance and stability are significantly improved compared to before the improvement. This shows that the proposed control strategy can effectively suppress transient disturbances while ensuring the dynamic performance of the converter, enhance the damping of the grid-connected converter, and improve the stability of the renewable energy grid-connected system.

[0122] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. 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 improving transient stability of a grid-connected converter based on active damping, characterized in that: include: Based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency, the DC voltage controller is used to generate the angular frequency and phase; Based on the control-generated angular frequency, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, the actual reference values of the d-axis and q-axis voltages are generated after being processed by the reactive power controller; The actual reference values of the d-axis voltage and the q-axis voltage are used as inputs of the voltage loop, and the modulation voltage is generated through the current inner loop and the limiter link; Combined with the phase, the modulated voltage is coordinate transformed and further modulated to form a closed-loop control.

2. The method for improving transient stability of a grid-connected converter based on active damping according to claim 1, characterized in that: The generating of the angular frequency and phase based on the given DC voltage value, the actual DC side voltage and the ideal grid angular frequency through processing by the DC voltage controller includes: Calculate the DC voltage square error based on the DC voltage given value and the actual DC side voltage; The DC voltage square error is input into the DC voltage controller to obtain the DC voltage control quantity.

3. The method for improving transient stability of a grid-connected converter based on active damping according to claim 2, characterized in that: The generating of the angular frequency and phase based on the given DC voltage value, the actual DC side voltage and the ideal grid angular frequency through processing by the DC voltage controller also includes: Based on the DC voltage control quantity and the ideal value of the grid angular frequency, the control generated angular frequency is obtained; The phase is obtained by integrating the angular frequency generated by the control and used for subsequent coordinate transformation.

4. The method for improving transient stability of a grid-connected converter based on active damping according to claim 3, characterized in that: The control-based generation of the angular frequency, combined with the reactive power set value, the actual reactive power at the grid connection point, and the virtual voltage component, is processed by the reactive power controller to generate the actual reference values of the d-axis and q-axis voltages, including: Calculate reactive power error based on reactive power setpoint and actual reactive power at the grid connection point; Inputting the reactive power error into the reactive power controller to obtain the reactive power control quantity; Calculating the actual reference value of the d-axis voltage based on the reactive power control amount and the virtual voltage d-axis component; Based on the ideal q-axis voltage value and the virtual voltage q-axis component, the actual reference value of the q-axis voltage is calculated.

5. The method for improving transient stability of a grid-connected converter based on active damping according to claim 4, characterized in that: The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the amplitude limiting link includes: Voltage inner loop control: Taking the actual reference values of the d-axis and q-axis voltages as input, the voltage inner loop control is performed to output the d-axis current and q-axis current respectively.

6. The method for improving transient stability of a grid-connected converter based on active damping according to claim 5, characterized in that: The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the limiting link further includes: Limiting processing: The d-axis current and q-axis current output by the voltage inner loop control are passed through the limiting link, and the current values are adjusted to obtain the limited d-axis current and q-axis current.

7. The method for improving transient stability of a grid-connected converter based on active damping according to claim 6, characterized in that: The method of using the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop and generating the modulation voltage through the current inner loop and the limiting link further includes: Current loop control and modulation voltage calculation: The d-axis current and q-axis current after limiting are subtracted from the corresponding actual current values. The differences are processed by the PI controller to obtain the control values. The d-axis component and q-axis component of the modulation voltage are calculated based on the control values.

8. A system for improving transient stability of a grid-connected converter based on active damping, applying the method according to any one of claims 1 to 7, characterized in that: include: The phase generation module is used to generate the angular frequency and phase based on the DC voltage set value, the actual DC side voltage and the ideal grid angular frequency after processing by the DC voltage controller; The voltage actual reference value generation module is used to generate the angular frequency based on the control, combine the reactive power set value, the actual reactive power of the grid connection point and the virtual voltage component, and generate the d-axis and q-axis voltage actual reference values after processing by the reactive power controller; A modulation voltage preliminary generation module is used to take the actual reference value of the d-axis voltage and the actual reference value of the q-axis voltage as inputs of the voltage loop, and generate the modulation voltage through the current inner loop and the limiter link; The control module is used to combine the phase, coordinate transform and further modulate the modulated voltage to form a closed-loop control.

9. An electronic device comprising: memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are capable of implementing the steps of the method according to any one of claims 1 to 7 when executed by a processor.

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