Fault cooperative reactive power control method and device for wind and light station

Abstract

The invention discloses a fault cooperative reactive power control method and device for a wind and light station, and relates to the technical field of automatic control of a power system. According to the method, the optimal support for the grid-connected point voltage of each station can be realized when the fault occurs, and meanwhile, the wind and light station can output certain active power when the fault occurs, so that the system frequency is supported, and the fault control flexibility of the wind and light station is remarkably improved.

Description

Technical Field

[0001] The present invention discloses a fault collaborative reactive power control method and device for a wind-solar power station, which relates to the technical field of automatic control of power systems. Background Art

[0002] With the proposal of the "dual carbon" goal, China has been paying more and more attention to the development of new energy. The penetration rate of new energy in the power grid has been continuously increasing. Due to the characteristics of new energy units such as strong randomness, scattered distribution, low inertia, and poor anti-disturbance ability, after large-scale access to the power grid, the flexibility of reactive power control in the power system is insufficient, resulting in significant changes in the voltage dynamic characteristics of the power system and prone to voltage sags. And with the continuous increase of the installed capacity of new energy, the weak over-current characteristics of power electronic devices themselves have gradually reduced the grid strength. In China, scenarios of large-scale new energy access to weak grids have gradually emerged. For example, the "Demonstration Operation Base for New Energy Access to Extremely Weak Grids" in the southern Xinjiang power grid of China has met the definition of extremely weak grids (SCR < 2) in the IEC standard. It can be foreseen that the scenarios of new energy access to weak grids will continue to increase. The lack of flexibility in reactive power control of new energy during faults will cause more serious problems, and the voltage sags caused during faults will be more serious.

[0003] With the continuous weakening of the new energy grid connection strength, there have been accidents such as sub-synchronous oscillations occurring multiple times in wind farms under weak grids, large power outages caused by insufficient voltage support capacity in high-proportion new energy access areas, and large power outages caused by insufficient frequency regulation capacity of offshore wind power. The above accidents have exposed serious problems in the current wind-solar power generation system, such as a narrow frequency band regulation range, insufficient frequency and voltage support amplitude and regulation speed. When a fault occurs in a weak grid scenario, it is required that new energy units give full play to their reactive power support capabilities as much as possible to ensure that the system can achieve safe fault ride-through. When a serious fault occurs in a weak grid, due to the insufficient voltage support capacity of new energy power stations, it may cause a large voltage drop at the grid connection point, and even trigger serious fault conditions such as cascading disconnection from the grid. Summary of the Invention

[0004] In view of the problems of the prior art, the present invention provides a fault collaborative reactive power control method and device for a wind-solar power station. The technical solutions adopted are as follows:

[0005] In a first aspect, a fault collaborative reactive power control method for a wind-solar power station includes:

[0006] Detecting a fault signal according to a station controller, and collecting the three-phase voltage and current of the PCC and obtaining their corresponding components;

[0007] Obtaining a positive-sequence reactive current command value by measuring the effective values of the voltages at the fault point and the PCC point;

[0008] According to the positive-sequence reactive current command value, the proportionality coefficient k of the positive-sequence active and reactive currents output by each substation is obtained by Lagrange multiplication and division, and the reactive current output by the substation is restricted in value;

[0009] According to the coordinated control of the reactive currents output by each substation, the sum of the positive-sequence and negative-sequence reactive currents is obtained by equivalent calculation of the substations;

[0010] According to the sum of the positive-sequence and negative-sequence currents of each electric field, the reactive current between substations is allocated;

[0011] According to the sum of the positive-sequence and negative-sequence currents of each electric field, the active current between substations is allocated by the proportionality coefficient k;

[0012] According to the current control command value, power decoupling transformation is performed by the substation coordinated controller and input into the current control loop of each substation unit.

[0013] In some implementation manners, the substation controller detects a fault signal, and collects the three-phase voltage and current of the PCC and obtains their corresponding components, including:

[0014] According to the fault signal detected by the substation controller, the wind-solar substation is switched to fault control measurement and drives an online impedance estimator to perform voltage detection on the power grid on the opposite side of the PCC;

[0015] According to the coordinated controller, the three-phase voltage and current of the PCC are collected, and voltage components and current components are obtained through component analysis by a Clarke transformation module;

[0016] According to the voltage components and current components, DC voltage components and DC current components are obtained through component analysis by a Park transformation.

[0017] In some implementation manners, through the coordinated control of the reactive currents output by each substation, the sum of the positive-sequence and negative-sequence reactive currents is obtained by equivalent calculation of the substations, including:

[0018] According to the value limit of the reactive current, the sum of the positive-sequence and negative-sequence reactive currents is obtained through the voltages at the common connection points of each substation and the grid side and the equivalent reactance from the common collection point to the grid.

[0019] In some implementation manners, when allocating the active current between substations by the proportionality coefficient k according to the sum of the positive-sequence and negative-sequence currents of each electric field, the negative-sequence active current is set to 0.

[0020] In a second aspect, an embodiment of the present invention provides a fault coordinated reactive power control device for a wind-solar substation, including:

[0021] A component acquisition module, configured to detect a fault signal according to a substation controller, collect the three-phase voltage and current of the PCC, and obtain their corresponding components;

[0022] An instruction acquisition module, configured to obtain a positive-sequence reactive current instruction value by measuring the effective values of the voltages at the fault point and the PCC point;

[0023] A value limitation module, configured to analytically obtain the proportionality coefficient k of the positive-sequence active and reactive currents output by each substation through Lagrange multiplication and division according to the positive-sequence reactive current instruction value, and limit the value of the reactive current output by the substation;

[0024] A current limiting processing module, configured to obtain the sum of the positive-sequence and negative-sequence reactive currents by performing equivalent calculation on the substations according to the coordinated control of the reactive currents output by each substation;

[0025] A reactive current distribution module, configured to distribute the reactive current among the substations according to the sum of the positive-sequence and negative-sequence currents of each electric field;

[0026] An active current distribution module, configured to distribute the active current among the substations according to the sum of the positive-sequence and negative-sequence currents of each electric field through the proportionality coefficient k;

[0027] An instruction processing module, configured to perform power decoupling transformation through a substation coordinated controller according to a current control instruction value and input it into the current control loop of each substation unit.

[0028] In some implementation manners, the component acquisition module includes:

[0029] A voltage unit, configured to detect a fault signal according to a substation controller, switch the wind-solar substation to fault control measurement, drive an online impedance estimator, and perform voltage detection on the power grid on the opposite side of the PCC;

[0030] A transformation unit, configured to collect the three-phase voltage and current of the PCC according to a coordinated controller, and perform component analysis through a Clarke transformation module to obtain voltage components and current components;

[0031] A component unit, configured to perform component analysis through Park transformation according to the voltage components and current components to obtain a DC voltage component and a DC current component.

[0032] In some implementation manners, the current limiting processing module obtains the sum of the positive-sequence and negative-sequence reactive currents through the value limitation of the reactive current, the voltages at the common connection points of each substation and the grid side, and the equivalent reactance from the common collection point to the grid.

[0033] In some implementation manners, in the active current distribution module, the negative-sequence active current is set to 0.

[0034] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor. The memory is used to store one or more computer instructions. When the one or more computer instructions are executed by the processor, the method described in the first aspect above is implemented.

[0035] In a fourth aspect, an embodiment of the present invention provides a computer storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, the method described in the first aspect is implemented.

[0036] One or more embodiments of the present invention can at least bring the following beneficial effects:

[0037] The present invention discloses a fault collaborative reactive power control method for a wind-solar power station. First, the positive-sequence active and reactive current proportional coefficients for achieving optimal voltage support are obtained through the Lagrange multiplier method. Secondly, the reactive current command value collaboration calculation and reactive current command value allocation are carried out according to the characteristics of large-scale power stations connected to the grid. Then, the active current command value to be output is determined according to the output reactive current command value of each power station. In this process, the output current limit of the converters of each power station is considered to ensure that there is no overcurrent during fault output. Finally, the calculated current command value is input into the current control loop of each power station unit, and the control strategy is completed. This method can achieve optimal support for the voltage at the grid connection point of each power station during a fault, and at the same time ensure that a certain amount of active power is output by the wind-solar power station during a fault, thereby supporting the system frequency and significantly improving the fault control flexibility of the wind-solar power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 is a flowchart of a fault collaborative reactive power control method for a wind-solar power station provided by an embodiment of the present invention;

[0040] Figure 2 is an execution diagram of a fault collaborative reactive power control method for a wind-solar power station provided by an embodiment of the present invention.

[0041] Figure 3 is a structure topology diagram of a wind-solar power station provided by an embodiment of the present invention;

[0042] Figure 4It is a comparison chart of the fault collaborative reactive power control method for wind-solar power stations provided by the embodiments of the present invention and the current national standard voltage support performance;

[0043] Among them, a is the schematic diagram of the phase A voltage of each power station under the current national standard output; b is the schematic diagram of the phase A voltage of each power station under the embodiments of the present invention; c is the schematic diagram of the phase B voltage of each power station under the current national standard output; d is the schematic diagram of the phase B voltage of each power station under the embodiments of the present invention; e is the schematic diagram of the phase C voltage of each power station under the current national standard output; f is the schematic diagram of the phase C voltage of each power station under the embodiments of the present invention. Detailed implementation mode

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention usually described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0045] Embodiment 1:

[0046] Figure 1 It shows a flowchart of a fault collaborative reactive power control method for wind-solar power stations. As Figure 1 shown, the fault collaborative reactive power control method for wind-solar power stations provided in this embodiment includes:

[0047] S1. Detect the fault signal according to the station controller, and collect the three-phase voltage and current of the PCC and obtain their corresponding components;

[0048] S2. Obtain the positive-sequence reactive current command value by measuring the effective values of the voltage at the fault point and the PCC point;

[0049] S3. According to the positive-sequence reactive current command value, analyze and obtain the proportional coefficient k of the positive-sequence active and reactive currents output by each power station through the Lagrange multiplier method, and limit the value of the reactive current output by the power station;

[0050] S4. According to the coordinated control of the reactive current output by each power station, obtain the sum of the positive-sequence and negative-sequence reactive currents by performing equivalent calculations on the power stations;

[0051] S5. Distribute the reactive current among the power stations according to the sum of the positive-sequence and negative-sequence currents of each power plant;

[0052] S6, distributing the active current among the stations according to the sum of the positive-sequence current and the negative-sequence current of each electric field using the proportional coefficient k;

[0053] S7, based on the current control command value, performs power decoupling transformation through the station collaborative controller and inputs it into the current control loop of each station unit.

[0054] Specifically, the S1 detects the fault signal according to the station controller, collects the three-phase voltage and current of the PCC and obtains the corresponding components, including:

[0055] S11: Based on the fault signal detected by the station controller, the wind and solar station is switched to fault control measurement and the online impedance estimator is driven to perform voltage detection on the opposite side of the PCC grid.

[0056] S12, collecting the three-phase voltage and current of the PCC according to the collaborative controller, and performing component analysis through a Clarke transform module to obtain voltage components and current components;

[0057] S13, performing component analysis based on the voltage component and the current component through Park transformation to obtain a DC voltage component and a DC current component.

[0058] like Figure 2 As shown in the execution diagram, first, according to S11, the station controller of the wind and solar station immediately switches to the fault control strategy after detecting the fault. At this time, the online impedance estimator is started, which can calculate the equivalent positive and negative sequence voltages V of the PCC opposite side grid within 20ms. g + 、V g - , and the equivalent impedance R g +jX g , the equivalent impedance R from the exit of station i to the public collection point i +jX i .

[0059] Next, according to S12, the station's cooperative controller collects the three-phase voltage and current at the PCC point. The three-phase data is input into the Clarke transform module and decomposed into the αβ coordinate system to obtain the αβ voltage component v at the PCC point during the fault period. α 、v β And the current component i α 、i β .

[0060] Next, according to S13, v α 、v β 、i α 、i β Input to Park transformation, further transform the AC component v in dq coordinate system α, v β , i α , i β is transformed into the DC component U d + , U q + , U d - , U q - , I d + , I q + , I d - , I q - .

[0061] Then, according to S2, with the goal of optimal voltage support, the derivative of the positive-sequence voltage with respect to the positive-sequence reactive current is solved according to formula (1), and the positive-sequence reactive current command value under the condition of optimal positive-sequence voltage support is obtained as shown in formula (2):

[0062]

[0063] In the formula, is the positive-sequence reactive current command value output by the i-th substation, and R i , X i are respectively the equivalent resistance and reactance values from the outlet of the i-th substation to the convergence point. k is the ratio of to to meet the optimal positive-sequence voltage support.

[0064] Then, according to S3, through the Lagrange multiplier method, the ratio k of the positive-sequence active and reactive currents output by each substation with the goal of optimal positive-sequence voltage support can be solved, and the objective function and the final result are shown in the following formulas (3) and (4):

[0065]

[0066] In the formula, are respectively the positive- and negative-sequence active and reactive current command value components output by the i-th substation. I i,max is the maximum amplitude of the current output by the i-th substation, and its value can be limited according to the current output capacity of the substation, usually in the range of 1.0 - 1.3 p.u. are respectively the limit values of the positive-sequence and negative-sequence currents output by substation i, usually taken as 1.0 p.u. and 0.1 p.u.

[0067] Then, according to S4, in the scenario of large-scale new energy grid connection, there are usually more than two grid-connected stations. At this time, in order to make flexible and full use of the reactive power controllable resources of each station, it is necessary to consider the coordinated control of the reactive current output by multiple stations during a fault. Since the control characteristics of each new energy station are basically the same, they can be equivalent to one station for calculation, and the calculation formula is:

[0068]

[0069] In the formula, and are the sum of the positive-sequence and negative-sequence reactive currents output by n stations respectively. and are the reference voltage values of the common connection points of each station, usually set to 0.9 p.u. and 0.05 p.u. respectively. and are the positive-sequence and negative-sequence voltage values on the grid side respectively. X sum is the equivalent reactance from the common collection point to the grid.

[0070] Then, according to S5, the calculated reactive current is distributed among the stations, and the distribution method is as follows:

[0071]

[0072] Then, according to S6, for the active current, the positive-sequence active current is given according to the ratio k obtained in step 5), and the negative-sequence active current is usually set to 0. Finally, the calculation methods of the positive-sequence active, reactive, negative-sequence active, and reactive current command values of each station are as follows:

[0073]

[0074] Finally, according to S7, the calculated current control command value is substituted into the power decoupling transformation to obtain I d +* 、I q +* 、I d -* 、I q -* It should be noted that in the present invention, the above calculation process is all carried out in the station coordinated controller. After the calculation is completed, the above current control command value is input into the current control loop of each station unit, and this control strategy ends.

[0075] To further illustrate the performance of the present invention, a detailed description is given in combination with an embodiment. Referring to the Guangran-Yandun wind-solar power generation system in Xinjiang, a three-station grid connection research example is built as Figure 1 shown. The specific system parameters are shown in Table 1, the parameters of the new energy conversion equipment and filters, and Table 2, the impedance of the line and transformer and other parameters.

[0076] Table 1

[0077]

[0078] Table 2

[0079]

[0080] The fault occurred on the grid side within 1 second and lasted for 200ms. This paper compares the latest 2021 national standard for low voltage ride-through control for wind and solar power stations to illustrate the advancement of the control strategy provided.

[0081] The comparison results between the proposed control strategy and the current national standard are as follows: Figure 4 As shown. Figure 4 As can be seen, the voltages on phases 1, 2, and 3A at the stations increased from approximately 0.5 pu to approximately 0.7 pu, the voltage on phase B increased from approximately 0.3 pu to over 0.4 pu, and the voltage on phase C increased from approximately 0.6 pu to over 0.8 pu, significantly improving the voltage support capabilities of each station. In contrast, the proposed control strategy significantly enhances the control flexibility of wind and solar stations during faults.

[0082] Example 2:

[0083] In a second aspect, an embodiment of the present invention provides a fault-coordinated reactive power control device for a wind-solar station, comprising:

[0084] The component acquisition module is used to detect fault signals from the station controller, collect the three-phase voltage and current of the PCC and obtain their corresponding components;

[0085] The instruction acquisition module is used to obtain the positive sequence reactive current instruction value by measuring the effective value of the voltage at the fault point and the PCC point;

[0086] A value limiting module is used to obtain the proportional coefficient k of the positive-sequence active and reactive currents output by each station through Lagrange multiplication and division according to the positive-sequence reactive current command value, and to limit the value of the reactive current output by the station;

[0087] The current limiting processing module is used to obtain the sum of positive-sequence and negative-sequence reactive currents by performing equivalent calculations on the stations based on the coordinated control of the reactive current output by each station;

[0088] A reactive current distribution module is used to distribute the reactive current between the stations according to the sum of the positive sequence current and the negative sequence current of each electric field;

[0089] An active current distribution module, configured to distribute the active current between the stations according to the sum of the positive-sequence and negative-sequence currents of each electric field using the proportional coefficient k;

[0090] The instruction processing module is used to perform power decoupling conversion through the station collaborative controller according to the current control instruction value and input it into the current control loop of each station unit.

[0091] Furthermore, the component acquisition module includes:

[0092] The voltage unit is used to detect fault signals from the station controller, switch the wind and solar stations to fault control measurement, and drive the online impedance estimator to perform voltage detection for the PCC's opposite-side grid.

[0093] a conversion unit, configured to collect the three-phase voltage and current of the PCC according to the collaborative controller, and perform component analysis through a Clarke transformation module to obtain voltage components and current components;

[0094] The component unit is used to perform component analysis based on the voltage component and the current component through Park transformation to obtain a DC voltage component and a DC current component.

[0095] Furthermore, the current limiting processing module obtains the sum of positive-sequence and negative-sequence reactive currents by limiting the value of the reactive current, through the voltage of the public grid connection point of each station and the grid side and the equivalent reactance from the public collection point to the grid.

[0096] Furthermore, in the active current distribution module, the negative sequence active current is set to 0.

[0097] Example 3:

[0098] This embodiment further provides an electronic device, including a memory and a processor, wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions, when executed by the processor, implement the method of embodiment 1;

[0099] In practical applications, the processor can be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller unit (MCU), a microprocessor or other electronic components to execute the methods in the above embodiments.

[0100] The method implemented in this embodiment is described as recorded in Embodiment 1.

[0101] Embodiment 4:

[0102] This embodiment also provides a computer storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is executed by one or more processors, the method of Embodiment 1 is implemented;

[0103] Among them, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, abbreviated as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, abbreviated as EEPROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, abbreviated as EPROM), programmable read-only memory (Programmable Read-Only Memory, abbreviated as PROM), read-only memory (Read-Only Memory, abbreviated as ROM), magnetic memory, flash memory, a magnetic disk or an optical disc.

[0104] The method implemented in this embodiment is described as recorded in Embodiment 1.

[0105] In several embodiments provided by the embodiments of the present invention, it should be understood that the disclosed systems and methods can also be implemented in other ways. The system and method embodiments described above are only illustrative.

[0106] It should be noted that in this article, the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. The term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0107] Although the embodiments disclosed in the present invention are as described above, the content described is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A fault collaborative reactive power control method for a wind-solar power station, characterized in that Including: Detecting a fault signal according to a substation controller, collecting the three-phase voltage and current of the PCC, and obtaining corresponding components thereof; Obtaining a positive-sequence reactive current command value by measuring the effective values of the voltages at the fault point and the PCC point; According to the positive-sequence reactive current command value, resolving through Lagrange multiplication and division to obtain a proportionality coefficient k for the positive-sequence active and reactive currents output by each substation, and restricting the value of the reactive current output by the substation; According to the coordinated control of the reactive currents output by each substation, obtaining the sum of the positive-sequence and negative-sequence reactive currents through equivalent calculation of the substation; Distributing the reactive currents among the substations according to the sum of the positive-sequence and negative-sequence currents of each electric field; Distributing the active currents among the substations through the proportionality coefficient k according to the sum of the positive-sequence and negative-sequence currents of each electric field; According to the current control command value, performing power decoupling transformation through a substation coordinated controller and inputting it into the current control loop of each substation unit.

2. The method according to claim 1, wherein The step of detecting a fault signal according to a substation controller, collecting the three-phase voltage and current of the PCC, and obtaining corresponding components thereof includes: Detecting a fault signal according to a substation controller, switching the wind-solar substation to fault control measurement and driving an online impedance estimator to perform voltage detection on the power grid on the opposite side of the PCC; Collecting the three-phase voltage and current of the PCC according to a coordinated controller, and performing component analysis through a Clarke transformation module to obtain voltage components and current components; According to the voltage components and current components, performing component analysis through Park transformation to obtain DC voltage components and DC current components.

3. The method according to claim 2, characterized in that The step of obtaining the sum of the positive-sequence and negative-sequence reactive currents through equivalent calculation of the substation according to the coordinated control of the reactive currents output by each substation includes: According to the value restriction of the reactive current, obtaining the sum of the positive-sequence and negative-sequence reactive currents through the voltages at the common connection points of each substation and the power grid side and the equivalent reactance from the common collection point to the power grid.

4. The method according to claim 1, wherein When distributing the active currents among the substations through the proportionality coefficient k according to the sum of the positive-sequence and negative-sequence currents of each electric field, setting the negative-sequence active current to 0.

5. A fault collaborative reactive power control device for a wind-solar power station, characterized in that, Including: A component acquisition module for detecting a fault signal according to a substation controller, collecting the three-phase voltage and current of the PCC, and obtaining corresponding components thereof; A command acquisition module for obtaining a positive-sequence reactive current command value by measuring the effective values of the voltages at the fault point and the PCC point; A value restriction module for resolving through Lagrange multiplication and division according to the positive-sequence reactive current command value to obtain a proportionality coefficient k for the positive-sequence active and reactive currents output by each substation, and restricting the value of the reactive current output by the substation; A current limiting processing module for obtaining the sum of the positive-sequence and negative-sequence reactive currents through equivalent calculation of the substation according to the coordinated control of the reactive currents output by each substation; A reactive current distribution module for distributing the reactive currents among the substations according to the sum of the positive-sequence and negative-sequence currents of each electric field; An active current distribution module for distributing the active currents among the substations through the proportionality coefficient k according to the sum of the positive-sequence and negative-sequence currents of each electric field; An instruction processing module, configured to perform power decoupling transformation through a substation collaborative controller according to a current control instruction value and input it into the current control loop of each substation unit.

6. The device according to claim 5, wherein The component acquisition module includes: A voltage unit, configured to switch the wind-solar substation to fault control measurement according to a fault signal detected by the substation controller, drive an online impedance estimator, and perform voltage detection on the power grid on the opposite side of the PCC; A transformation unit, configured to collect the three-phase voltage and current of the PCC according to the collaborative controller, and perform component analysis through a Clarke transformation module to obtain voltage components and current components; A component unit, configured to perform component analysis through Park transformation according to the voltage components and current components to obtain a DC voltage component and a DC current component.

7. The device according to claim 6, wherein The current limiting processing module obtains the sum of the positive-sequence and negative-sequence reactive currents according to the value limit of the reactive current, through the voltage at the common connection point of each substation and the grid side and the equivalent reactance from the common collection point to the grid.

8. The device according to claim 5, characterized in that In the active current distribution module, the negative-sequence active current is set to 0.

9. An electronic device, characterized in that, It includes a memory and a processor, and the memory is used to store one or more computer instructions. Among them, when the one or more computer instructions are executed by the processor, the method described in any one of the above claims 1-4 is implemented.

10. A computer-readable storage medium, characterized in that, A computer program is stored in the computer-readable storage medium, and when the computer program is executed by the processor, the method described in any one of the above claims 1-4 is implemented.

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