Low-voltage current limiting control parameter optimization method, device and computer equipment

Abstract

The present invention relates to a method, device and computer equipment for optimizing low-voltage current-limiting control parameters. By obtaining electrical coupling information between a conventional DC converter station and a flexible DC converter station, and obtaining power information of the flexible DC converter station, a correction value of the low-voltage current-limiting control parameter is obtained based on the electrical coupling information and power information. This method achieves rapid recovery of DC active power after a commutation failure in the DC converter station, provides sufficient reactive power, effectively suppresses subsequent commutation failures in the DC system, and thereby ensures stable operation of the DC power supply and distribution system.

Description

Technical Field

[0001] The present invention relates to the field of direct current transmission control, and in particular to a method and device for optimizing low-voltage current limiting control parameters, and a computer device. Background Art

[0002] As electricity demand continues to grow, DC power supply and distribution systems are becoming increasingly common, owing to their ease of access to distributed energy resources, relatively longer power supply radius, and the proliferation of DC loads such as charging stations. These systems have become a key development direction for distribution networks. As a key component of DC power supply and distribution systems, the stable operation of DC converters is crucial to ensuring their normal operation.

[0003] However, during actual power transmission operations, commutation failure of the DC converter will directly lead to a sudden drop in DC transmission power. During the DC power recovery process after the fault, the converter absorbs a large amount of reactive power from the AC system. If the AC system cannot provide sufficient reactive power, it may cause continuous commutation failure of the DC converter. Summary of the Invention

[0004] Based on this, it is necessary to provide a low-voltage current limiting control parameter optimization method, device and computer equipment to address the above technical problems.

[0005] A method for optimizing low-voltage current limiting control parameters is applied to a multi-terminal direct current (DC) system, wherein the multi-terminal DC system includes a receiving-end converter station, and the receiving-end converter station includes a conventional DC converter station and a flexible DC converter station. The method comprises:

[0006] Acquiring electrical coupling information between the conventional DC converter station and the flexible DC converter station;

[0007] Obtaining power information of the flexible DC converter station;

[0008] A correction value of the low-voltage current limiting control parameter is obtained according to the electrical coupling information and the power information.

[0009] In one embodiment, before obtaining the electrical coupling information between the conventional DC converter station and the flexible DC converter station, the method includes:

[0010] The flexible DC converter station is set as a power transfer station of the conventional DC converter station, and the working mode of the flexible DC converter station is adjusted.

[0011] In one embodiment, obtaining the low-voltage current limiting control parameter correction value according to the electrical coupling information and the power information includes:

[0012] Obtaining a reference value of the low-voltage current limiting control parameter, where the reference value is the low-voltage current limiting control parameter when the receiving-end converter station includes only a single conventional DC converter station in operation;

[0013] The low-voltage current limiting control parameter correction value is obtained according to the reference value, the electrical coupling information, and the power information.

[0014] In one embodiment, the electrical coupling information includes:

[0015] Multi-input interaction factor index between the conventional DC converter station and the flexible DC converter station.

[0016] In one embodiment, the acquiring the power information of the flexible DC converter station includes:

[0017] Obtaining active power support information of the flexible DC converter station;

[0018] Obtain reactive power support information of the flexible DC converter station.

[0019] In one embodiment, the obtaining of active power support information of the flexible DC converter station includes:

[0020] Obtaining the maximum active power and actual active power of the flexible DC converter station;

[0021] Active power support information of the flexible DC converter station is obtained according to the maximum active power and the actual active power.

[0022] In one embodiment, the acquiring of reactive power support information of the HVDC flexible converter station includes:

[0023] Obtaining the maximum reactive power of the flexible DC converter station;

[0024] Reactive power support information of the flexible DC converter station is obtained according to the maximum reactive power.

[0025] A low-voltage current limiting control parameter optimization device is applied to a multi-terminal DC system, wherein the multi-terminal DC system includes a receiving-end converter station, and the receiving-end converter station includes a conventional DC converter station and a flexible DC converter station. The device includes:

[0026] An electrical coupling information module, configured to obtain electrical coupling information between the conventional DC converter station and the flexible DC converter station;

[0027] A power information module, configured to obtain power information of the flexible DC converter station;

[0028] A parameter correction module is used to obtain a correction value of the low-voltage current limiting control parameter according to the electrical coupling information and the power information.

[0029] A computer device includes a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0030] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0031] The above-mentioned low-voltage current limiting control parameter optimization method, device and computer equipment obtain the electrical coupling information between the conventional DC converter station and the flexible DC converter station, obtain the power information of the flexible DC converter station, and obtain the correction value of the low-voltage current limiting control parameter based on the electrical coupling information and power information. This achieves rapid recovery of DC active power after commutation failure of the DC converter station, provides sufficient reactive power, and effectively suppresses the occurrence of subsequent commutation failures in the DC system, thereby ensuring the stable operation of the DC power supply and distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 is a structural block diagram of a multi-terminal DC system in one embodiment;

[0034] Figure 2 Flowchart of a method for optimizing low-voltage current limiting control parameters in one embodiment;

[0035] Figure 3 106 in one embodiment;

[0036] Figure 4 104 is a flowchart of the specific steps of step 104 in one embodiment;

[0037] Figure 5 104 is a flowchart of the specific steps of step 104 in one embodiment;

[0038] Figure 6 Schematic diagram of calculating a correction value of a low-voltage current limiting control parameter through the steps in the above embodiment in one embodiment;

[0039] Figure 71. A comparison diagram of characteristic curves of original low-voltage current limiting control parameters and optimized low-voltage current limiting control parameters in one embodiment;

[0040] Figure 8 FIG. 1 is a structural block diagram of a low-voltage current limiting control parameter optimization device in an embodiment. DETAILED DESCRIPTION

[0041] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0043] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0044] In this embodiment, the low-voltage current limiting control parameter optimization method is applied to a multi-terminal DC system, and the multi-terminal DC system includes a receiving-end converter station; wherein the receiving-end converter station includes a receiving-end conventional DC converter station and a receiving-end flexible DC converter station, respectively referred to as a conventional DC converter station (LCC, line commutated converter) and a flexible DC converter station (MMC, modular multilevel converter).

[0045] Figure 1 FIG. 1 is a schematic diagram of an application environment of a method for optimizing low-voltage current limiting control parameters in an embodiment. Figure 1As shown, the low-voltage current limiting control parameter optimization method is applied to a multi-terminal DC system. The multi-terminal DC system includes a sending-end AC / DC system 100, a receiving-end AC system 200, and a receiving-end converter station 300. The receiving-end converter station 300 includes a receiving-end conventional DC converter station 310 and a receiving-end flexible DC converter station 320. The receiving-end conventional DC converter station 310 is connected to the sending-end AC / DC system 100, the receiving-end AC system 200, and the receiving-end flexible DC converter station 320, respectively. The receiving-end flexible DC converter station 320 is connected to the receiving-end AC system 200. It should be noted that the arrows indicate other possible receiving-end converter stations in the multi-terminal DC system, not limited to the two receiving-end converter stations shown in the figure: the receiving-end conventional DC converter station 310 and the receiving-end flexible DC converter station 320.

[0046] Figure 2 FIG. 1 is a flow chart of a method for optimizing low-voltage current limiting control parameters in one embodiment. Figure 2 As shown, the low-voltage current limiting control parameter optimization method includes steps 102 to 106.

[0047] Step 102: Acquire electrical coupling information between the conventional DC converter station and the flexible DC converter station.

[0048] Optionally, the electrical coupling information between the conventional DC converter station and the flexible DC converter station refers to the multi-infeed interaction factor (MIIF) index between the receiving-end converter stations. The MIIF index is an important indicator reflecting the degree of electrical coupling between the conventional DC converter station and the flexible DC converter station. Generally, the larger the MIIF index, the higher the degree of electrical coupling between the conventional DC converter station and the flexible DC converter station, and the better the active power and reactive power support effect provided to the AC system. Therefore, the electrical coupling information between the conventional DC converter station and the flexible DC converter station is also one of the influencing factors of the low-voltage current limiting control parameter correction value.

[0049] Optionally, the method for obtaining the electrical coupling information between the conventional DC converter station and the flexible DC converter station is the method for obtaining the MIIF index. According to the definition of the MIIF index, the calculation formula of the MIFF index of the two receiving-end converter stations is as follows:

[0050] MIIF j,i =ΔUj / ΔUi

[0051] Wherein, ΔUi is the voltage change of the commutation busbar of a certain DC system transmission inverter station when a voltage step change is applied (expressed in percentage), and optionally, the change is 1%; ΔUj is the response value of the voltage change of the commutation busbar of another DC system transmission inverter station (expressed in percentage).

[0052] Step 104: Obtain power information of the flexible DC converter station.

[0053] Optionally, the power information of the flexible DC converter station includes active power support information of the flexible DC converter station and reactive power support information of the flexible DC converter station.

[0054] Obtaining power information from a flexible DC converter station includes obtaining the station's active power support information and reactive power support information. Active power support information can refer to the ability of a conventional DC converter station to transfer active power after a commutation fault occurs at the conventional DC converter station; reactive power support information can refer to the ability of a conventional DC converter station to provide reactive power to the AC system after a commutation fault occurs. Therefore, both the active power support information and reactive power support information of the flexible DC converter station are factors influencing the correction value of the low-voltage current limiting control parameter.

[0055] Step 106 : Obtain a correction value of the low-voltage current limiting control parameter according to the electrical coupling information and the power information.

[0056] Optionally, the method for obtaining the corrected value of the low-voltage current limiting control parameter based on electrical coupling information and power information refers to obtaining the corrected value of the low-voltage current limiting control parameter based on the multi-input interaction factor index, the active power support information of the flexible DC converter station, the reactive power support information of the flexible DC converter station, and the fixed parameters in the multi-terminal DC system.

[0057] The low-voltage current limiting control parameter optimization method provided in this embodiment obtains electrical coupling information between a conventional DC converter station and a flexible DC converter station, obtains power information of the flexible DC converter station, and obtains a correction value of the low-voltage current limiting control parameter based on the electrical coupling information and power information. This achieves rapid recovery of DC active power after a commutation failure in the DC converter station, provides sufficient reactive power, and effectively suppresses subsequent commutation failures in the DC system, thereby ensuring stable operation of the DC power supply and distribution system.

[0058] In one embodiment, the process before step 102 includes setting the flexible DC converter station as a power transfer station of a conventional DC converter station and adjusting the operating mode of the flexible DC converter station.

[0059] Optionally, in a multi-terminal DC system, a flexible DC converter station is selected as the DC active power transfer station for a conventional DC converter station after a commutation failure, and the active power control mode of the flexible DC converter station is set to a DC voltage control mode. Specifically, in a multi-terminal DC system, if a commutation failure occurs in a conventional DC converter station, after the failure, the DC active power can be partially transferred to the flexible DC converter station. The flexible DC converter station can provide active power support to the AC system during the fault period and during the fault recovery process, reducing the active power shortage caused by the conventional DC converter station failure and the risk of power angle instability in the AC system. At the same time, the flexible DC converter station can provide reactive power to the system during the power recovery period after the fault, providing reactive power support to the conventional DC converter station.

[0060] See Figure 3 , is a flowchart of the specific steps of step 106 in one embodiment. Figure 3 As shown, step 106 includes step 302 and step 304 .

[0061] Step 302: Acquire a reference value of a low-voltage current limiting control parameter, where the reference value is a low-voltage current limiting control parameter when the receiving-end converter station includes only a single conventional DC converter station in operation.

[0062] Alternatively, in a multi-terminal DC system, if only a single conventional DC converter station operates at the receiving-end converter station, DC power cannot be transferred if a commutation failure occurs in this conventional DC converter station. In this mode, baseline parameters for the low-voltage current limiting control parameters are designed. These baseline parameters are primarily determined by the strength of the receiving-end AC system. In actual engineering design, the baseline parameters for the low-voltage current limiting control parameters are typically applied using typical parameters from existing projects, followed by simulation verification and parameter fine-tuning based on the simulation results. Specifically, the operating characteristics of the DC transmission system containing the low-voltage current limiting control parameters are first analyzed based on the voltage / current characteristics of the low-voltage current limiting control parameters. Then, the setting range of the low-voltage current limiting control parameters is analyzed, using the low-voltage current limiting control parameters and the AC system bus voltage as independent variables and the reactive power exchange of the DC converter station as the dependent variable. Finally, simulation verification is performed on a DC model using commercial software. The simulation results are consistent with the analytical results, demonstrating the correctness and effectiveness of the analytical method.

[0063] Step 304 : Obtain a low-voltage current limiting control parameter correction value according to the reference value, the electrical coupling information, and the power information.

[0064] Optionally, the method for obtaining the correction value of the low-voltage current limiting control parameter based on the reference value, electrical coupling information, and power information refers to obtaining the correction value of the low-voltage current limiting control parameter based on the designed reference parameters of the low-voltage current limiting control parameter, the multi-feed interaction factor index, the active power support information of the flexible DC converter station, the reactive power support information of the flexible DC converter station, and the fixed parameters in the multi-terminal DC system.

[0065] The low-voltage current limiting control parameter optimization method provided in this embodiment obtains a reference value of the low-voltage current limiting control parameter, where the reference value is the low-voltage current limiting control parameter when the receiving-end converter station only includes a single conventional DC converter station in operation. The low-voltage current limiting control parameter correction value is obtained based on the reference value, electrical coupling information, and power information, thereby achieving rapid recovery of DC active power after a commutation failure in the DC converter station, providing sufficient reactive power, and effectively suppressing the occurrence of subsequent commutation failures in the DC system, thereby ensuring stable operation of the DC power supply and distribution system.

[0066] See Figure 4 , is a flowchart of the specific steps of step 104 in one embodiment. Figure 4 As shown, step 104 includes step 402 and step 404 .

[0067] Step 402: Acquire the maximum active power and actual active power of the flexible DC converter station.

[0068] Step 404: Obtain active power support information of the flexible HVDC converter station according to the maximum active power and the actual active power.

[0069] Optionally, the maximum active power is the maximum active power P of the unlocked valve group of the flexible DC converter station max , the actual active power refers to the actual active power P of the flexible DC converter station MMC The active power support information of the HVDC Flexible converter station is the active power support capability of the receiving-end HVDC Flexible converter station to the receiving-end conventional HVDC converter station. The active power support information of the HVDC Flexible converter station is represented as follows:

[0070] ΔP MMC =P max -P MMC

[0071] That is, the active power support information of the HVDC Flexible converter station is the difference between the maximum active power of the unlocked valve group of the HVDC Flexible converter station and the actual active power of the HVDC Flexible converter station.

[0072] After a conventional DC converter station fails, the Flexible DC converter station increases its active power to absorb some of the power transferred by the conventional DC converter station. This increased active power is factored into the correction value of the low-voltage current limiting control parameter. The active power output of the Flexible DC converter station after a conventional DC converter station failure depends on multiple factors, including the station's backup power capacity, DC control method, and fault type. However, the station's backup power is the primary determinant of its maximum output power. The greater the backup power capacity, the greater the acceptable active power transferred from the conventional DC converter station.

[0073] See Figure 5 , is a flowchart of the specific steps of step 104 in one embodiment. Figure 5 As shown, step 104 includes step 502 and step 504 .

[0074] Step 502: Acquire the maximum reactive power of the flexible DC converter station.

[0075] Step 504: Obtain reactive power support information of the flexible HVDC converter station according to the maximum reactive power.

[0076] Optionally, the maximum reactive power is the maximum reactive power Q of the unlocked valve group of the flexible DC converter station max , the reactive power support capability of the receiving-end flexible DC converter station to the conventional DC converter station. The reactive power support information of the flexible DC converter station indicates:

[0077] ΔQ MMC =Q max

[0078] That is, the reactive power support information of the flexible DC converter station is the reactive power support capability of the receiving-end flexible DC converter station to the conventional DC converter station.

[0079] Under low-voltage ride-through control, the Flexible DC converter station will output reactive power to the AC system, supporting voltage and power recovery at nearby conventional DC converter stations. In multi-terminal DC operation, the reactive power output by the Flexible DC converter station is factored into the correction value of the low-voltage current-limiting control parameters.

[0080] See Figure 6 , is a schematic diagram of calculating the correction value of the low-voltage current limiting control parameter through the steps in the above embodiment in one embodiment. Figure 6 As shown, in this embodiment, the method of translating the low-voltage current limiting control curve is used to adjust the baseline value of the low-voltage current limiting control parameter. Specifically, the low-voltage current limiting control parameter correction value in the multi-terminal DC system is as follows:

[0081]

[0082] Where U H ′ and U L ′ is the corrected low voltage current limiting control parameter, i.e. voltage threshold, M1=MIFF i,j is the multi-feed interaction factor between the conventional DC converter station and the flexible DC converter station. k1 and k2 are gain coefficients, which can be adjusted according to the simulation calculation after the DC connection system is connected. H 、U L , k1, k2, M1 are all fixed parameters, ΔP MMC and ΔQ MMC It is dynamically adjusted according to the operating conditions during operation.

[0083] The correction value of the low-voltage current limiting control parameter provided in this embodiment is applied to a multi-terminal DC system. After obtaining the active power support of the flexible DC converter station in the receiving-end converter station, the conventional DC converter station in the receiving-end converter station can increase the voltage threshold U based on the two-terminal operation mode. H and U L , that is, to reduce DC power more quickly after a fault occurs, and to reduce the DC power recovery speed during the fault recovery process, thereby reducing reactive power demand; after obtaining reactive power support from the receiving-end flexible DC converter station, the conventional DC converter station can reduce the voltage threshold U based on the operating mode at both ends. H and U L , that is, during the fault recovery process, increase the DC power recovery speed.

[0084] See Figure 7 , is a comparison diagram of characteristic curves of the original low-voltage current limiting control parameters and the optimized low-voltage current limiting control parameters in one embodiment. Figure 7 As shown, curve 1 is a characteristic curve using the original low-voltage current limiting control parameters, and curve 2 is a characteristic curve using the optimized low-voltage current limiting control parameters.

[0085] In this embodiment, during the occurrence and recovery of a commutation fault in a multi-terminal DC system, under the control and adjustment of the low-voltage current limiting control parameters, when the voltage drops to the starting voltage threshold U caused by the fault, H By reducing the current I delivered by the DC system H , limiting the DC power of the system, thereby reducing the reactive power required for the operation of the DC system; during the fault recovery process, when the voltage recovers to the voltage threshold U L At this time, the DC current I starts to increase L That is, the DC current increases with the DC voltage to ensure the smooth recovery of DC power. H and U L to U H ′ and U L′, the characteristic curve will shift to the right, that is, Figure 7 Curve 1 in the figure changes to curve 2. After a fault, the low voltage current limiting control parameter can be triggered more quickly, thereby limiting the DC current more quickly and reducing reactive power demand. At the initial moment of fault recovery, the larger recovery voltage starting value U L , which makes the reactive power provided by the filter device larger, and is also beneficial to the initial recovery of the DC system. H and U L , the operating conditions of the DC system are worse at the moment of fault occurrence and the initial moment of fault recovery, but more active power can be transmitted during the fault recovery period.

[0086] It should be understood that although Figure 2-Figure 5 The steps in the flowchart are shown in the order indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 2-Figure 5 At least some of the steps in the above process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but may be executed at different times. The order of execution of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps. It should be noted that the above different embodiments can be combined with each other.

[0087] See Figure 8 , is a structural block diagram of a low-voltage current limiting control parameter optimization device in an embodiment.

[0088] In this embodiment, the low-voltage current limiting control parameter optimization device is applied to a multi-terminal DC system, which includes a receiving-end converter station, which includes a conventional DC converter station and a flexible DC converter station. The device includes an electrical coupling information module 820, a power information module 840, and a parameter correction module 860.

[0089] The electrical coupling information module 820 is used to obtain electrical coupling information between conventional DC converter stations and flexible DC converter stations.

[0090] The power information module 840 is used to obtain power information of the flexible DC converter station.

[0091] The parameter correction module 860 is used to obtain a correction value of the low-voltage current limiting control parameter according to the electrical coupling information and the power information.

[0092] In this embodiment, each module is used to execute Figure 2 For details of the steps in the corresponding embodiment, please refer to Figure 2 as well as Figure 2 The relevant descriptions in the corresponding embodiments are not repeated here.

[0093] The low-voltage current limiting control parameter optimization device provided in this embodiment obtains the electrical coupling information between the conventional DC converter station and the flexible DC converter station through the electrical coupling information module 820, obtains the power information of the flexible DC converter station through the power information module 840, and obtains the correction value of the low-voltage current limiting control parameter based on the electrical coupling information and power information. This realizes the rapid recovery of DC active power after the commutation failure of the DC converter station, provides sufficient reactive power, effectively suppresses the occurrence of subsequent commutation failures in the DC system, and thus ensures the stable operation of the DC power supply and distribution system.

[0094] The division of the various modules in the above-mentioned low-voltage current limiting control parameter optimization device is only for illustration. In other embodiments, the low-voltage current limiting control parameter optimization device can be divided into different modules as needed to complete all or part of the functions of the above-mentioned low-voltage current limiting control parameter optimization device.

[0095] For the specific definition of the low-voltage current limiting control parameter optimization device, please refer to the definition of the low-voltage current limiting control parameter optimization method above, which will not be repeated here. The various modules in the above-mentioned low-voltage current limiting control parameter optimization device can be implemented in whole or in part by software, hardware, and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0096] A computer device is also provided in an embodiment of the present application, including a memory and a processor. A computer program is stored in the memory. When the computer program is executed by the processor, the processor executes the steps of the method in the above embodiment.

[0097] The present application also provides a computer-readable storage medium, one or more non-volatile computer-readable storage media containing computer-executable instructions, which, when executed by one or more processors, cause the processors to perform the steps of the low-voltage current limiting control parameter optimization method.

[0098] The low-voltage current limiting control parameter optimization method, device, computer equipment and storage medium provided in the above embodiments realize the rapid recovery of DC active power after commutation failure in the DC converter station, provide sufficient reactive power, effectively suppress the occurrence of subsequent commutation failures in the DC system, and thus ensure the stable operation of the DC power supply and distribution system, which has important economic value and promotional practical value.

[0099] As used herein, any reference to memory, storage, database, or other medium may include nonvolatile and / or volatile memory. Nonvolatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which serves as an external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0100] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A low-voltage current limiting control parameter optimization method, applied to a multi-terminal DC system, characterized in that: The multi-terminal DC system includes a receiving-end AC system and a receiving-end converter station, wherein the receiving-end converter station includes a conventional DC converter station and a flexible DC converter station, and the receiving-end AC system is connected to the conventional DC converter station and the flexible DC converter station respectively; the method includes: Acquiring electrical coupling information between the conventional DC converter station and the flexible DC converter station; Obtaining power information of the flexible DC converter station; Acquire a correction value of the low-voltage current limiting control parameter according to the electrical coupling information and the power information; Before obtaining the electrical coupling information between the conventional DC converter station and the flexible DC converter station, the method includes: The flexible DC converter station is set as a power transfer station of the conventional DC converter station, and the working mode of the flexible DC converter station is adjusted; the flexible DC converter station is used to provide active power support to the AC system during the fault period and the fault recovery process, and to provide reactive power to the AC system during the power recovery period after the fault.

2. The method according to claim 1, characterized in that The obtaining the low-voltage current limiting control parameter correction value according to the electrical coupling information and the power information includes: Obtaining a reference value of the low-voltage current limiting control parameter, where the reference value is the low-voltage current limiting control parameter when the receiving-end converter station includes only a single conventional DC converter station in operation; The low-voltage current limiting control parameter correction value is obtained according to the reference value, the electrical coupling information, and the power information.

3. The method according to claim 1, characterized in that The electrical coupling information includes: Multi-input interaction factor index between the conventional DC converter station and the flexible DC converter station.

4. The method according to claim 3, characterized in that The calculation formula of the multi-input interaction factor between the conventional DC converter station and the flexible DC converter station is as follows: MIIF j,i =ΔUj / ΔUi Wherein, ΔUi is the voltage change of the commutation busbar of a DC transmission inverter station in a certain loop when a voltage step change is applied; ΔUj is the response value of the voltage change of the commutation busbar of another DC transmission inverter station.

5. The method according to claim 1, wherein The acquiring power information of the flexible DC converter station includes: Obtaining active power support information of the flexible DC converter station; Obtain reactive power support information of the flexible DC converter station.

6. The method according to claim 5, characterized in that The obtaining of active power support information of the flexible DC converter station includes: Obtaining the maximum active power and actual active power of the flexible DC converter station; Active power support information of the flexible DC converter station is obtained according to the maximum active power and the actual active power.

7. The method according to claim 5, characterized in that The obtaining of reactive power support information of the flexible DC converter station includes: Obtaining the maximum reactive power of the flexible DC converter station; Reactive power support information of the flexible DC converter station is obtained according to the maximum reactive power.

8. A low-voltage current limiting control parameter optimization device, applied to a multi-terminal DC system, wherein the multi-terminal DC system includes a receiving-end AC system and a receiving-end converter station, wherein the receiving-end converter station includes a conventional DC converter station and a flexible DC converter station, wherein the receiving-end AC system is connected to the conventional DC converter station and the flexible DC converter station, respectively, and wherein: include: An electrical coupling information module, configured to obtain electrical coupling information between the conventional DC converter station and the flexible DC converter station; A power information module, configured to obtain power information of the flexible DC converter station; a parameter correction module, configured to obtain a correction value of the low-voltage current limiting control parameter according to the electrical coupling information and the power information; The electrical coupling information module is further used to set the flexible DC converter station as a power transfer station of the conventional DC converter station and adjust the operating mode of the flexible DC converter station; the flexible DC converter station is used to provide active power support to the AC system during a fault and a fault recovery process, and to provide reactive power to the AC system during the power recovery period after the fault.

9. A computer device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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