A method and device for improving transient voltage stability of a grid-forming converter

Abstract

The application belongs to the field of electric power, and discloses a method and device for improving transient voltage stability of a grid-forming converter, comprising: sampling three-phase grid voltage at a grid connection point of the grid-forming converter to obtain a grid voltage amplitude; when a transient drop occurs in the grid voltage, calculating a reactive power absorption limit of the converter in a current state based on the grid voltage amplitude and a preset line reactance parameter, the reactive power absorption limit being directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance; if a preset reference reactive power meets any preset trigger condition, correcting the reference reactive power of the converter to a sum of the reactive power absorption limit and a preset stability margin; wherein the trigger condition includes: the grid voltage amplitude dropping to a preset first voltage threshold, or detecting that the preset reference reactive power is less than or equal to the sum of the reactive power absorption limit and the preset stability margin.

Description

Technical Field

[0001] This invention belongs to the field of power, and particularly relates to a method and apparatus for improving the transient voltage stability of a grid-type converter. Background Technology

[0002] As new power systems develop towards higher proportions of new energy sources and higher proportions of power electronic equipment, the proportion of synchronous generators is decreasing, and power electronic equipment with converters at its core is becoming the mainstay of grid connection. Unlike traditional grid-connected converters, grid-connected converters can simulate the voltage source characteristics of synchronous generators and actively provide inertia, frequency, and voltage support to the power grid, thus becoming key equipment for building new power systems.

[0003] However, grid-connected converters face severe challenges in maintaining transient voltage stability when grid faults cause voltage dips. The fundamental reason is that the power transfer characteristics between the grid-connected converter and the grid change when the system voltage drops. If a preset fixed reference reactive power is used for control, the converter is likely to attempt to absorb more reactive power than its physical transfer limit, entering the negative slope region of the voltage-reactive power characteristic curve. At this point, traditional droop or voltage-reactive power control fails, creating a positive feedback effect where "the more reactive power absorbed, the lower the voltage; the lower the voltage, the more reactive power the control command requires to be absorbed." This ultimately leads to converter output voltage collapse, system instability, and even equipment disconnection from the grid, further deteriorating the grid condition.

[0004] While some studies have explored the use of virtual inertia in voltage-reactive power control to mitigate transient processes, they have failed to address the root cause of the reactive power setpoint potentially exceeding the stability boundary. Therefore, the key to improving the transient voltage stability of grid-connected converters lies in dynamically and adaptively adjusting the reference reactive power setpoint without increasing hardware complexity, ensuring it remains within the stable region allowed by the current system state. Summary of the Invention

[0005] In view of this, the present invention discloses a method and apparatus for improving the transient voltage stability of a grid-type converter, which can solve the shortcomings of related technologies.

[0006] To achieve the above objectives, the present invention discloses the following technical solution: According to a first aspect of the present invention, a method for improving the transient voltage stability of a grid-type converter is proposed, comprising: The three-phase grid voltage at the grid connection point of the grid-connected converter is sampled to obtain the grid voltage amplitude; When the grid voltage experiences a transient drop, the reactive power absorption limit of the converter under the current state is calculated based on the grid voltage amplitude and the preset line reactance parameters. The reactive power absorption limit is directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance. If the originally set reference reactive power meets any preset triggering condition, the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the preset stability margin; wherein, the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or, the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

[0007] According to a second aspect of the present invention, a device for improving the transient voltage stability of a grid-type converter is provided, comprising: Sampling unit: Samples the three-phase grid voltage at the grid connection point of the grid-connected converter to obtain the grid voltage amplitude; Calculation unit: When the grid voltage experiences a transient drop, it calculates the reactive power absorption limit of the converter under the current state based on the grid voltage amplitude and preset line reactance parameters. The reactive power absorption limit is directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance. Correction unit: If the originally set reference reactive power meets any preset triggering condition, the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the preset stability margin; wherein, the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or, the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

[0008] According to a third aspect of the present invention, an electronic device is provided, comprising: processor; Memory used to store processor-executable instructions; The processor implements the steps of the method as described in the first aspect by running the executable instructions.

[0009] According to a fourth aspect of the invention, a computer-readable storage medium is provided having computer instructions stored thereon that, when executed by a processor, implement the steps of the method as described in the first aspect.

[0010] As can be seen from the above technical solutions, the beneficial effects of the method and device for improving transient voltage stability of grid-type converters disclosed in this invention are as follows: On the one hand, by sensing the grid voltage status in real time, the reference reactive power is calculated and adjusted to always follow the system's allowable reactive power absorption limit (with a margin), thereby avoiding the "reactive power over-limit - voltage instability" positive feedback that may occur when voltage drops in traditional fixed-setting strategies, and improving the converter's transient voltage stability in the face of large disturbances. On the other hand, this invention is implemented through the optimization of software logic and control algorithms, without the need for additional hardware devices or sensors, and can be easily integrated into existing grid-type converter control programs, resulting in low implementation cost and strong compatibility. In addition, the direct calculation and judgment logic based on voltage sampling has a small response delay and can quickly adapt to sudden changes in grid status. At the same time, by introducing a stability margin, it can effectively cope with interference such as model parameter errors and measurement noise, and prevent oscillations caused by the setpoint being too close to the boundary. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the grid-connected control structure of a three-phase grid-type energy storage power station provided in an exemplary embodiment; Figure 2 This is a flowchart of an exemplary embodiment of a method for improving the transient voltage stability of a grid-type converter; Figure 3 This is a simplified schematic diagram of a grid-connected energy storage power station provided in an exemplary embodiment; Figure 4 This is a schematic diagram illustrating the relationship between the output voltage and output power of a converter before and after a voltage drop, provided in an exemplary embodiment. Figure 5 This is a schematic diagram illustrating a voltage sag simulation of a grid-type converter without using a method for improving transient voltage stability based on adaptive adjustment of reference reactive power, provided by an exemplary embodiment. Figure 6 This is a schematic structural diagram of a device provided in an exemplary embodiment; Figure 7 This is a block diagram of an exemplary embodiment of a device for improving the transient voltage stability of a grid-type converter. Detailed Implementation

[0012] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of the present invention as detailed in the appended claims.

[0013] It should be noted that in other embodiments, the corresponding methods are not necessarily performed in the order shown and described in this invention. The method comprises steps. In some other embodiments, the method may include more or fewer steps than those described in this invention. Furthermore, a single step described in this invention may be broken down into multiple steps in other embodiments; and multiple steps described in this invention may be combined into a single step in other embodiments.

[0014] As new power systems develop towards higher proportions of new energy sources and higher proportions of power electronic equipment, the proportion of synchronous generators is decreasing, and power electronic equipment with converters at its core is becoming the mainstay of grid connection. Unlike traditional grid-connected converters, grid-connected converters can simulate the voltage source characteristics of synchronous generators and actively provide inertia, frequency, and voltage support to the power grid, thus becoming key equipment for building new power systems.

[0015] However, grid-connected converters face severe challenges in maintaining transient voltage stability when grid faults cause voltage dips. The fundamental reason is that the power transfer characteristics between the grid-connected converter and the grid change when the system voltage drops. If a preset fixed reference reactive power is used for control, the converter is likely to attempt to absorb more reactive power than its physical transfer limit, entering the negative slope region of the voltage-reactive power characteristic curve. At this point, traditional droop or voltage-reactive power control fails, creating a positive feedback effect where "the more reactive power absorbed, the lower the voltage; the lower the voltage, the more reactive power the control command requires to be absorbed." This ultimately leads to converter output voltage collapse, system instability, and even equipment disconnection from the grid, further deteriorating the grid condition.

[0016] While some studies have explored the use of virtual inertia in voltage-reactive power control to mitigate transient processes, they have failed to address the root cause of the reactive power setpoint potentially exceeding the stability boundary. Therefore, the key to improving the transient voltage stability of grid-connected converters lies in dynamically and adaptively adjusting the reference reactive power setpoint without increasing hardware complexity, ensuring it remains within the stable region allowed by the current system state.

[0017] To address the shortcomings in related technologies, this invention proposes a method, apparatus, equipment, and storage medium for improving the transient voltage stability of a grid-type converter.

[0018] Figure 1 This is a schematic diagram of the grid-connected control structure of a three-phase grid-type energy storage power station, provided as an exemplary embodiment. The three-phase grid-type energy storage power station is connected to the power grid (via a voltage source) through an LCL filter. and The circuit is connected in series (simulation), and the control system uses a power control outer loop (active power determines frequency and phase). Reactive power generation voltage reference + Voltage and Current Dual Inner Loop (Adjusting Output Voltage) With current The system employs a hierarchical architecture, ultimately achieving power conversion and stable control through PWM modulation-driven converters. The system's real-time power is determined by the grid-connected current. With capacitor voltage The calculation yielded the result.

[0019] Figure 2 This is a flowchart illustrating an exemplary embodiment of a method for improving the transient voltage stability of a grid-type converter. For example... Figure 2 As shown, the method may include the following steps: Step 201: Sample the three-phase grid voltage at the grid connection point of the grid-connected converter to obtain the grid voltage amplitude.

[0020] This invention can measure the three-phase voltage at the grid connection point (PCC point) using a voltage sensor (e.g., a Hall voltage sensor). Real-time sampling is performed, and the grid voltage amplitude is obtained after coordinate transformation (such as dq transformation). .

[0021] Step 202: When the grid voltage experiences a transient drop, calculate the reactive power absorption limit of the converter under the current state based on the grid voltage amplitude and the preset line reactance parameters. The reactive power absorption limit is directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance.

[0022] like Figure 3 The diagram shown is a simplified schematic of a grid-connected energy storage power station, where the converter output voltage amplitude is... Characterized together with phase angle 0 Figure 1 Grid-type energy storage power stations; grid voltage amplitude With phase angle Common representation Figure 1 The power grid in the system. The transmission line is simulated using a pure inductor with a reactance of... .based on Figure 3 The simplified equivalent model shown indicates that the grid-type converter can be considered as a converter with a voltage amplitude of A voltage source with a phase of 0 is connected to a reactance. With the power grid (voltage amplitude is Phase is (Connected). Based on power transfer theory, the reactive power q absorbed by the converter can be derived. g Expressions, and through the Take the derivative, set it to zero, and find its maximum value, which is the reactive power absorption limit (actually a negative maximum value, i.e., the minimum absorption value): ; ; (Formula explanation: Mathematically, this formula indicates that q) min It is proportional to the square of Vs, and Inversely proportional. The lower the voltage Vs, the smaller this limit (absolute value), meaning the system can stably absorb less reactive power, which is related to... Figure 4 The physical meaning shown is consistent. This formula can be directly used for calculations.

[0023] Step 203: If the originally set reference reactive power meets any preset triggering condition, then the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the preset stability margin; wherein, the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or, the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

[0024] Calculate the real-time q min Then, compare it with the currently set reference reactive power q. ref A comparison and judgment are performed. The condition for triggering the correction is an "OR" logic; execution is initiated if either condition is met. Condition A (Predictive Correction): If the grid voltage amplitude Vs is detected to drop to a preset first voltage threshold (e.g., 0.9 pu), the grid is considered to have entered an abnormal state, and correction is immediately initiated. This threshold is configurable.

[0025] Condition B (Mandatory Correction): Regardless of the voltage drop, as long as q is satisfied... ref ≤q min If the value is +Δq, then a correction is necessary. Here, Δq is a preset stability margin, which provides a safety buffer to prevent the corrected setpoint q from being affected. min +Δq is too close to the theoretical boundary q min And thus lose stability and robustness.

[0026] like Figure 4 The figure shows a schematic diagram of the relationship between the converter output voltage and output power before and after a voltage drop. As can be seen from the figure, the previously balanced q... ref After the voltage drop, the reactive power absorption limit of the converter was exceeded. For example... Figure 5 The figure shows a simulation of voltage sag in a grid-connected converter without using the adaptive adjustment method based on reference reactive power. It can be seen that after the grid voltage drops, the system cannot track the given reactive power, the regulation logic fails, and ultimately the converter output voltage and reactive power enter a negative correlation region, leading to output voltage collapse.

[0027] When any of the triggering conditions is met, a correction operation is performed: qref =q min +Δq, that is, the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the stability margin. When the grid voltage recovers or q ref Until the triggering condition is no longer met, this modified value will be maintained or a new dynamic calculation will be performed.

[0028] In this embodiment, on the one hand, by sensing the grid voltage state in real time, the reference reactive power is calculated and adjusted to always follow the system's allowable reactive power absorption limit (with a margin), thereby avoiding the "reactive power over-limit - voltage instability" positive feedback that may occur when the voltage drops in traditional fixed setting strategies, and improving the transient voltage stability of the converter in the face of large disturbances. On the other hand, this invention is implemented through the optimization of software logic and control algorithms, without the need for additional hardware devices or sensors, and can be easily integrated into existing grid-type converter control programs, with the advantages of low implementation cost, strong compatibility, and easy promotion and application. In addition, the direct calculation and judgment logic based on voltage sampling has a small response delay and can quickly adapt to sudden changes in grid state. At the same time, by introducing a stability margin, it can effectively deal with interference such as model parameter errors and measurement noise, and prevent oscillations caused by the set point being too close to the boundary.

[0029] In one embodiment, the stability margin Δq can be set to a constant value, a positive constant value preset based on engineering experience, which can be called the base value of the stability margin. This embodiment is simple to implement and can effectively cope with most voltage drop scenarios, preventing the system from losing its stable equilibrium point due to an excessively small reactive power setting.

[0030] In one embodiment, the stability margin is a variable related to the depth of the grid voltage sag, and its value increases as the voltage sag deepens, thereby enhancing the correction magnitude for the reference reactive power. This can be referred to as the correction superposition term of the stability margin.

[0031] To further improve stability during deep voltage dips, the stability margin Δq can be designed as a function related to the voltage dip depth. For example, Δq = k1 + k2(1 Vs)2, where k1 and k2 are positive constants. Thus, as the voltage drop deepens (Vs decreases), the margin Δq automatically increases, thereby adjusting the reference reactive power q. ref Setting it higher (smaller absolute value, less absorption) provides a larger stability margin for the system, effectively avoiding the problem of the equilibrium point disappearing under severe failure.

[0032] In one embodiment, the active power p transmitted by the converter g This will change the power angle δ between the reactive power source and the grid, thus affecting the reactive power transmission limit. A more accurate calculation of the reactive power absorption limit should include this coupling effect. At this point, q minThe calculation formula has been updated to: ; (Formula explanation: Mathematically, this formula adds a second term to the first term. The second term is related to p) ref Sum of squares The product of the two is directly proportional to the power output and inversely proportional to the square of Vs. This means that, at the same voltage, the greater the active power transmitted, the higher the upper limit of reactive power that the converter can stably absorb will be. This formula provides a more accurate calculation. Accordingly, to further compensate for the coupling effect, a term related to p can be added to the stability margin Δq. ref Related superposition terms are used to achieve higher control accuracy and reliability, for example: .

[0033] Figure 6 This is a schematic structural diagram of a device provided in an exemplary embodiment. Please refer to... Figure 6 At the hardware level, the device includes a processor 602, an internal bus 604, a network interface 606, memory 608, and non-volatile memory 610, and may also include other hardware required for its functions. One or more embodiments of the present invention can be implemented in software, for example, the processor 602 reads the corresponding computer program from the non-volatile memory 610 into memory 608 and then runs it. Of course, in addition to software implementation, one or more embodiments of the present invention do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0034] Please refer to Figure 7 A transient voltage stability improvement device for grid-type converters can be applied to, for example... Figure 7 The device shown, in order to implement the technical solution of the present invention, includes: The sampling unit 701 is used to sample the three-phase grid voltage at the grid connection point of the grid-connected converter to obtain the grid voltage amplitude; The calculation unit 702 is used to calculate the reactive power absorption limit of the converter under the current state based on the grid voltage amplitude and preset line reactance parameters when the grid voltage experiences a transient drop. The reactive power absorption limit is proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance. The correction unit 703 is used to correct the reference reactive power of the converter to the sum of the reactive power absorption limit and the preset stability margin if the originally set reference reactive power meets any preset triggering condition; wherein the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

[0035] The first voltage threshold is 0.9 per unit.

[0036] Optionally, the stability margin is a fixed value, used to prevent the reactive power setting value from being too small, which would cause the system to lose its stable balance point.

[0037] Optionally, the stability margin is a variable related to the depth of the grid voltage drop, and its value increases as the voltage drop deepens, so as to enhance the correction range of the reference reactive power.

[0038] Furthermore, the stability margin includes a term based on the square of the grid voltage dip deviation.

[0039] Optionally, when calculating the reactive power absorption limit, the influence of the active power output of the converter on the power angle is further considered. In addition to the first term being proportional to the square of the grid voltage and inversely proportional to the line reactance, a second term is added. This second term is proportional to the square of the reference active power, proportional to the line reactance, and inversely proportional to the square of the grid voltage.

[0040] Furthermore, the stability margin includes a coupled superposition term related to the reference active power to compensate for the influence of active power on the reactive power absorption limit.

[0041] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0042] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0043] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0044] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0045] For any computer-readable medium (or computer-readable storage medium) as described above or otherwise, computer instructions may be stored thereon, which, when executed by a processor, implement one or more of the embodiments described above, thereby realizing the technical solution of the present invention.

[0046] The present invention also proposes a computer program that, when executed by a processor, implements one or more of the embodiments described above, thereby realizing the technical solution of the present invention. This computer program may be specifically recorded on the above-described or other computer-readable media, and the present invention does not impose any limitations on this.

[0047] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] The foregoing has described specific embodiments of the invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0049] The terminology used in one or more embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in one or more embodiments of the invention and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0050] It should be understood that although the terms first, second, third, etc., may be used to describe various information in one or more embodiments of the present invention, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of one or more embodiments of the present invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0051] The above description is merely a preferred embodiment of one or more embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of the present invention should be included within the protection scope of one or more embodiments of the present invention.

Claims

1. A method for improving the transient voltage stability of a grid-type converter, characterized in that, include: The three-phase grid voltage at the grid connection point of the grid-connected converter is sampled to obtain the grid voltage amplitude; When the grid voltage experiences a transient drop, the reactive power absorption limit of the converter under the current state is calculated based on the grid voltage amplitude and the preset line reactance parameters. The reactive power absorption limit is directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance. If the originally set reference reactive power meets any preset triggering condition, the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the preset stability margin; wherein, the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or, the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

2. The method according to claim 1, characterized in that, The first voltage threshold is 0.9 per unit.

3. The method according to claim 1, characterized in that, The stability margin base value is a fixed value, used to prevent the reactive power set value from being too small, which would cause the system to lose its stable balance point.

4. The method according to claim 1, characterized in that, The correction superposition term of the stability margin is a variable related to the depth of the grid voltage drop. Its value increases as the voltage drop deepens, so as to enhance the correction range of the reference reactive power.

5. The method according to claim 4, characterized in that, The stability margin includes a term based on the square of the grid voltage dip deviation.

6. The method according to claim 1, characterized in that, When calculating the reactive power absorption limit, the influence of the active power output of the converter on the power angle is further considered. In addition to the first term being proportional to the square of the grid voltage and inversely proportional to the line reactance, a second term is added. This second term is proportional to the square of the reference active power, proportional to the line reactance, and inversely proportional to the square of the grid voltage.

7. The method according to claim 6, characterized in that, The stability margin includes a coupled superposition term related to the reference active power to compensate for the influence of active power on the reactive power absorption limit.

8. A device for improving the transient voltage stability of a grid-type converter, characterized in that, include: Sampling unit: Samples the three-phase grid voltage at the grid connection point of the grid-connected converter to obtain the grid voltage amplitude; Calculation unit: When the grid voltage experiences a transient drop, it calculates the reactive power absorption limit of the converter under the current state based on the grid voltage amplitude and preset line reactance parameters. The reactive power absorption limit is directly proportional to the square of the grid voltage amplitude and inversely proportional to the line reactance. Correction unit: If the originally set reference reactive power meets any preset triggering condition, the reference reactive power of the converter is corrected to the sum of the reactive power absorption limit and the preset stability margin; wherein, the triggering condition includes: the grid voltage amplitude drops to a preset first voltage threshold, or, the originally set reference reactive power is detected to be less than or equal to the sum of the reactive power absorption limit and the stability margin.

9. An electronic device, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor implements the steps of the method as described in any one of claims 1-7 by running the executable instructions.

10. A computer-readable storage medium storing computer instructions thereon, characterized in that, When executed by the processor, this instruction implements the steps of the method as described in any one of claims 1-7.

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