Auxiliary decision-making method and system for fault of submodule of flexible DC converter valve

Abstract

The invention relates to an auxiliary decision-making method and system for flexible direct current converter valve submodule faults, and belongs to the technical field of flexible direct current power transmission. The method comprises the following steps: matching to-be-detected fault information of a fault sub-module with historical fault information in a sub-module fault case library, and if matching succeeds, obtaining an auxiliary decision for assisting in solving the fault of the fault sub-module according to case information of the fault of the sub-module corresponding to the successfully matched historical fault information; and if the matching fails, storing the to-be-detected fault information of the fault sub-module and a final decision for solving the fault of the fault sub-module into a sub-module fault case library. According to the case information of the sub-module fault corresponding to the historical fault information successfully matched with the to-be-detected fault information of the fault sub-module, the auxiliary decision for assisting in solving the fault of the fault sub-module is obtained, the fault maintenance time can be effectively shortened, and the maintenance efficiency is improved.

Description

Technical Field

[0001] The invention relates to an auxiliary decision-making method and system for a flexible direct current converter valve submodule fault, belonging to the technical field of flexible direct current transmission. Background Art

[0002] With its significant technical advantages, flexible DC transmission technology plays a key role in many fields such as AC system interconnection, large-scale renewable energy grid connection, island power supply, and capacity expansion and transformation of urban distribution networks. It not only improves the efficiency of power transmission, but also improves the reliability and flexibility of the entire transmission and distribution system. It has become one of the core technologies in the current power transmission and distribution field.

[0003] Flexible DC transmission refers to high-voltage direct current transmission (HVDC) based on voltage source converter (VSC). It is a new type of DC transmission after AC transmission and conventional DC transmission. Its structure is similar to that of HVDC transmission. The main equipment of flexible DC transmission includes flexible DC converter valve, HVDC circuit breaker, converter transformer, flexible DC transmission control and protection system and DC reactor / smoothing reactor.

[0004] The flexible DC transmission valve is the core equipment of the flexible DC transmission system. Its main function is to convert AC power into DC power at the sending end and DC power into AC power at the receiving end, and to realize power control. The flexible DC transmission valve is realized by modular multilevel converter (MMC) technology composed of multiple submodules (SM) with the same structure and independent status. Modular multilevel converter technology combines the latest technologies and research results of power electronics technology, photoelectric conversion technology, high voltage technology, control technology, voltage balancing technology, cooling technology and high voltage insulation materials.

[0005] The flexible DC converter valve is a key device for realizing the conversion between AC and DC. It connects the sending-end converter station and the receiving-end converter station through DC cables or DC overhead lines to complete the power transmission from the sending end to the receiving end. Its value accounts for about 22% to 25% of the total price of the converter station equipment.

[0006] The number of flexible DC transmission converter valve sub-modules is huge. The previous fault detection method is that after the converter valve sub-module fails, relevant professional and technical personnel analyze the fault recording file and provide analysis results and solutions. It is difficult to quickly locate and analyze the cause of the fault, and the analysis time is long and the analysis efficiency is low. As a result, it is impossible to provide a decision to solve the fault in time according to the fault condition of the faulty sub-module. The fault inspection and repair time of the sub-module is long and the fault inspection and repair efficiency is low. Summary of the invention

[0007] The object of the present invention is to provide an auxiliary decision-making method and system for a flexible direct current converter valve submodule fault, so as to solve the problem of low fault inspection and repair efficiency of existing submodules.

[0008] To achieve the above object, the solution of the present invention includes: An auxiliary decision-making method for a flexible direct current converter valve submodule failure of the present invention comprises the following steps: Match the pending fault information of the fault submodule with the historical fault information in the submodule fault case library. If the match is successful, obtain an auxiliary decision for assisting in solving the fault of the fault submodule according to the case information of the submodule fault corresponding to the successfully matched historical fault information; if the match fails, store the pending fault information of the fault submodule and the final decision for solving the fault of the fault submodule in the submodule fault case library; The submodule failure case library includes case information of all submodule failures that have occurred at the flexible direct current converter valve project site. The case information of all submodule failures includes historical failure information of the submodule failures and corresponding recommended solutions as the final decision.

[0009] Furthermore, the case information of the submodule fault corresponding to the successfully matched historical fault information is obtained in the following manner: When the number of successfully matched historical fault information is equal to 1, the case information of the submodule fault corresponding to the successfully matched historical fault information is used as the case information of the submodule fault corresponding to the successfully matched historical fault information; When the number of successfully matched historical fault information is greater than 1, if the case information of the sub-module fault corresponding to the successfully matched historical fault information is repeated, the case information of the repeated sub-module fault in the case information of the sub-module fault corresponding to the successfully matched historical fault information is filtered out until only one is left, and the case information of the remaining sub-module fault after the filtering is used as the case information of the sub-module fault corresponding to the successfully matched historical fault information; if the case information of the sub-module fault corresponding to the successfully matched historical fault information is not repeated, the case information of the sub-module fault corresponding to all the successfully matched historical fault information is used as the case information of the sub-module fault corresponding to the successfully matched historical fault information; When the initial fault cause, fault description, and final fault cause of case information are the same, the case information is considered to be duplicated.

[0010] Furthermore, when there is information with a set value that is completely consistent in the to-be-detected fault information of the fault submodule and the historical fault information in the submodule fault case library, the match is considered successful, otherwise the match is considered failed; the set value is greater than or equal to 1.

[0011] Furthermore, the fault information to be detected is the fault information of all faulty submodules obtained by parsing the fault recording file of the converter valve submodule.

[0012] Furthermore, the analysis adopts a recording file analysis method obtained according to the fault recording file name.

[0013] Furthermore, the case information of all submodule failures also includes failure analysis results and / or case details.

[0014] Furthermore, the historical fault information includes the fault occurrence time, fault site, fault location, fault type, fault message and fault description.

[0015] Furthermore, a corresponding matching degree is obtained after the matching is successful.

[0016] An auxiliary decision-making system for a flexible direct current converter valve submodule failure of the present invention comprises a processor, and the processor is used to execute a computer program to implement the steps of the auxiliary decision-making method for a flexible direct current converter valve submodule failure as described above.

[0017] Beneficial effects of the present invention: The present invention is a pioneering invention, which provides an auxiliary decision-making method for a submodule fault of a flexible direct current converter valve, and obtains an auxiliary decision for assisting in solving the fault of the submodule according to the case information of the submodule fault corresponding to the historical fault information that successfully matches the fault information to be detected of the fault submodule, which can effectively shorten the fault troubleshooting time and improve the troubleshooting efficiency. The present invention also stores the fault information to be detected of the fault submodule that fails to match the historical fault information in the submodule fault case library and the final decision for solving the fault of the fault submodule in the aforementioned submodule fault case library, and can provide an auxiliary decision for assisting in solving the fault of the fault submodule that successfully matches the fault information to be detected, which can effectively shorten the fault troubleshooting time and improve the troubleshooting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the design flow chart of the decision support system; Figure 2 It is a functional flow chart of decision-making support software; Figure 3 It is a schematic diagram of the overall display interface of the decision support software. DETAILED DESCRIPTION

[0019] In order to solve the problems in the background technology, the present invention uses the historical failure cases of the sub-modules to assist relevant professional and technical personnel in performing fault analysis on the faulty sub-modules to be repaired, and provides decisions for solving the faults, which can effectively shorten the fault repair time and improve the repair efficiency.

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0021] An embodiment of an auxiliary decision-making method for a flexible direct current converter valve submodule failure: An auxiliary decision-making method for a flexible direct current converter valve submodule fault comprises the following steps: The fault information to be checked of the fault submodule is matched with the historical fault information in the submodule fault case library. If the match is successful, an auxiliary decision for assisting in solving the fault of the faulty submodule is obtained based on the case information of the submodule fault corresponding to the successfully matched historical fault information; if the match fails, the fault information to be checked of the faulty submodule and the final decision for solving the fault of the faulty submodule are stored in the submodule fault case library.

[0022] Among them, the submodule failure case library includes case information of all submodule failures that have occurred at the flexible direct current converter valve project site. The case information of all submodule failures includes historical failure information of submodule failures and corresponding recommended solutions as the final decision.

[0023] Specifically, the case information of the submodule fault corresponding to the successfully matched historical fault information is directly used as the case information of the submodule fault corresponding to the successfully matched historical fault information.

[0024] As another implementation method, the case information of the submodule fault corresponding to the successfully matched historical fault information is obtained in the following manner: When the number of successfully matched historical fault information is equal to 1, the case information of the submodule fault corresponding to the successfully matched historical fault information is used as the case information of the submodule fault corresponding to the successfully matched historical fault information.

[0025] When the number of successfully matched historical fault information is greater than 1, if the case information of the sub-module fault corresponding to the successfully matched historical fault information is repeated, the repeated case information of the sub-module fault in the case information of the sub-module fault corresponding to the successfully matched historical fault information is filtered out until only one remains, and the case information of the sub-module fault remaining after the filtering out is used as the case information of the sub-module fault corresponding to the successfully matched historical fault information. The repeated content is purposefully filtered out, so that the redundancy of the case information of the sub-module fault corresponding to the successfully matched historical fault information is relatively small, which can effectively shorten the fault repair time and improve the repair efficiency.

[0026] When the number of successfully matched historical fault information is greater than 1, if the case information of the sub-module fault corresponding to the successfully matched historical fault information does not exist in duplication, the case information of the sub-module fault corresponding to all the successfully matched historical fault information shall be regarded as the case information of the sub-module fault corresponding to the successfully matched historical fault information.

[0027] Among them, when the preliminary fault cause, fault description and final fault cause of the case information are the same, the case information is considered to be duplicated.

[0028] Specifically, the duplicated case information of submodule failures in the case information of submodule failures corresponding to the successfully matched historical failure information is filtered out to leave only one, and the duplicated case information is put into an array, and the first one is selected. Of course, any one of them can be selected as the remaining one.

[0029] Specifically, when there is information with a set value that is completely consistent in the to-be-detected fault information of the fault submodule and the historical fault information in the submodule fault case library, it is considered that the match is successful, otherwise it is considered that the match fails; the set value is greater than or equal to 1.

[0030] Among them, the set value is set according to actual needs. When there are more case information corresponding to the current successful match, the set value can be set relatively large to screen out the case information of sub-module failures corresponding to historical fault information with a relatively low matching degree, or when there are fewer case information corresponding to the successful match, the set value can be set relatively small to increase the number of case information corresponding to the successful match.

[0031] Specifically, the fault information to be detected can reflect the change process of the fault information of the submodule to be detected. The fault information to be detected is the fault information of all faulty submodules parsed from the fault recording file of the converter valve submodule. The fault information to be detected can also be the fault information of the faulty submodule directly obtained.

[0032] Specifically, considering that the configuration information of different flexible direct current projects is different, the analysis adopts the recording file analysis method obtained according to the fault recording file name, and the existing recording file analysis method may also be adopted.

[0033] The recording file parsing method obtained according to the fault recording file name specifically obtains the project name according to the fault recording file name, thereby using the configuration information of the corresponding project.

[0034] Specifically, the case information of all submodule failures also includes failure analysis results.

[0035] As another implementation manner, the case information of all submodule failures also includes case details.

[0036] As another implementation manner, the case information of all submodule failures also includes failure analysis results and case details.

[0037] As another implementation, the case information of all submodule failures also includes a troubleshooting solution for troubleshooting the failures.

[0038] Specifically, the historical fault information includes the fault occurrence time, fault site, fault location, fault type, fault message and fault description.

[0039] As another implementation method, the historical fault information may also include the fault occurrence time, fault site, fault location, fault type, fault level, device model, fault cause, fault message and fault description.

[0040] Specifically, the corresponding matching degree is obtained after the matching is successful. The matching degree is used as a reference to evaluate the reference value of the case information of the submodule fault corresponding to the historical fault information that successfully matches the to-be-detected fault information of the fault submodule, that is, the higher the matching degree, the higher the reference value. The matching degree is used to help relevant professional and technical personnel find the most appropriate case information of the submodule fault, so as to obtain the most appropriate auxiliary decision for assisting in solving the fault of the fault submodule more quickly, which can effectively shorten the fault repair time and improve the repair efficiency.

[0041] As another implementation method, the auxiliary decision method for the fault of the flexible direct current converter valve submodule is applied to the auxiliary decision system. The design process of the auxiliary decision system is as follows: Figure 1 As shown, the decision-making support system is mainly used to establish a fault case library and support the development of decision-making support software. The decision-making support software includes functions such as fault recording file reading, fault recording file parsing, fault case matching, and diagnostic information output. The decision-making support method includes the following steps: S1, establish a fault case library: All submodule fault case information that has occurred at the flexible DC converter valve project site is summarized and counted, and the same characteristic parameters in the case information are extracted as key fault features to form a fault case library as the aforementioned submodule fault case library. According to the module fault analysis report of the previous project site, key information is manually extracted and manually summarized into a table to achieve the summary statistics of all submodule fault case information that has occurred at the flexible DC converter valve project site.

[0042] S2, read the recording file and extract the fault information: The decision-making support software of the decision-making support system imports and parses the fault recording file of the converter valve submodule, detects all faulty submodules in the current recording file, and identifies and records (extracts) the faults and their evolution information (submodule fault change process information) of all submodules in the current recording file.

[0043] The faults and their evolution information of all submodules in the current recording file are used as the to-be-detected fault information of the aforementioned fault submodule.

[0044] S3, determine whether the fault module case matching is successful, and if the matching is successful, give a decision to solve the fault problem (i.e. output diagnostic information): By matching the fault evolution information of the selected fault module with the records in the fault case library, it is determined whether the match is successful, that is, matching the fault information to be detected of the fault submodule with the historical fault information in the submodule fault case library.

[0045] There are N fault information change processes (fault evolution information) of the submodule to be tested. If at least one fault information content is completely consistent with that of a case in the case library, the match is successful, otherwise the match is judged to have failed.

[0046] When the match is successful, the system will provide detailed information of similar cases, matching degree, submodule fault analysis results and corresponding solution suggestions (used to assist in making auxiliary decisions to solve the fault of the faulty submodule); when the match is unsuccessful, the new case, that is, the fault information to be detected of the faulty submodule and the final decision to solve the fault of the faulty submodule will be added to the fault case library for future reference.

[0047] Specifically, the corresponding fault change information is matched with the fault case library according to the selected fault module. When the match is successful, one or two or more cases that can successfully match the fault change information can be screened out.

[0048] When the number of successfully matched cases is greater than 1, the repeated cases are filtered out, that is, only 1 repeated case is retained, and the non-duplicate cases are also retained. Then, the matching case details, matching degree, sub-module fault analysis results and suggested solutions are given according to the retained matched fault cases.

[0049] Considering that the fault case analysis results of different successfully matched cases may be the same, it is necessary to filter out cases with duplicate results to avoid obtaining multiple duplicate analysis results and recommended solutions.

[0050] Specifically, when the number of retained matching fault cases is greater than 1, the repeated analysis results that are successfully matched are also screened out, that is, the repeated analysis results are retained as 1, and the non-duplicate ones are also retained. Then, the matching case details, matching degree, sub-module fault analysis results and suggested solutions are given according to the retained matching fault cases.

[0051] The submodule fault diagnosis and analysis process, submodule fault diagnosis and analysis results, and recommended measures (recommended solutions) can be found in Figure 3 .

[0052] Among them, the case information of submodule failure is composed of the submodule failure information actually generated at the flexible DC converter valve project site. The submodule failure information includes the fault occurrence time, fault site, fault location, fault type, fault message and fault description as fault characteristic parameters, as well as the corresponding fault recording file and fault analysis report.

[0053] That is, each submodule fault case (case information of submodule fault) has the same fault characteristic parameters such as fault occurrence time, fault site, fault location, fault type, fault message and fault description as historical fault information, as well as the corresponding fault recording file and fault analysis report.

[0054] Among them, the fault recording file of the converter valve submodule can find the corresponding file name in the recording storage directory according to the fault time and fault location and automatically import it.

[0055] Considering that the configuration information of the recording files of different flexible direct current projects is different, the flexible direct current project is judged according to the name of the recording file and the corresponding recording file parsing method is matched, and the recording file is parsed using the parsing method.

[0056] The present invention uses software technology to automatically identify and locate specific problems of the faulty module, thereby reducing the complexity of technical operations, and can assist operation and maintenance personnel in analyzing the faulty submodule, speed up the faulty submodule analysis process, shorten the fault repair time, and improve the operation and maintenance efficiency of the converter valve submodule. In addition, the functional flow of the auxiliary decision software of the auxiliary decision system is as follows: Figure 2 As shown in the figure, this method significantly improves the analysis speed and efficiency by optimizing the analysis process of the fault sub-module, and greatly improves the operation and maintenance efficiency of the flexible direct current sub-module.

[0057] The auxiliary decision-making method of the present invention first needs to establish a fault case library. The library (fault case library) integrates a wealth of fault analysis reports and recording files, extracts key fault characteristic parameters such as fault time, type, phenomenon, cause, alarm message, analysis process, processing results and recording information. This information is presented in a tabular form, forming the basis of the fault case library. The extraction of key fault characteristic parameters can be referred to in Table 1 below.

[0058] Table 1

[0059] In addition, it also includes detailed simulation of fault conditions, extraction of fault characteristic parameters, and recording of waveforms under different conditions to enrich the fault case library.

[0060] The second is the development of decision-making support software, including functions such as fault recording file reading and fault case matching. The software can automatically import and parse the fault recording file of the converter valve submodule, detect all fault submodules in the current recording file, and extract the change process information of all fault submodules in the file; according to the analysis results of the fault recording file, all fault modules and their change processes are carefully matched with the characteristic information in the fault case library.

[0061] By calculating the matching degree and eliminating the causes of repeated faults, it is possible to provide accurate fault analysis results, troubleshooting solutions, and practical solutions, greatly improving the efficiency and accuracy of fault handling. The present invention can quickly locate and trace the fault of the flexible direct current converter valve, improve the accuracy and efficiency of fault analysis, and assist operation and maintenance personnel to quickly solve problems. It has very important practical significance for improving the operation and maintenance control level of flexible direct current transmission and transformation equipment.

[0062] Among them, there are N fault information change processes of the submodule to be tested. If the fault information content of a case in the case library is consistent with the set value or more, the matching degree is set to 100%. For example, if the set value is 6, the matching degree = (number of consecutive matching items / 6)*100%. The setting value here can be selected according to actual needs, and the setting value is greater than or equal to 1.

[0063] An embodiment of an auxiliary decision-making system for a flexible direct current converter valve submodule failure: An auxiliary decision-making system for a flexible direct current converter valve submodule failure includes a processor, and the processor is used to execute a computer program to implement the steps of an auxiliary decision-making method for a flexible direct current converter valve submodule failure. Among them, an auxiliary decision-making method for a flexible direct current converter valve submodule failure has been described in detail in an embodiment of an auxiliary decision-making method for a flexible direct current converter valve submodule failure, and will not be repeated here.

Claims

1. An auxiliary decision-making method for flexible direct current converter valve submodule failure, characterized in that: The steps include: Match the pending fault information of the fault submodule with the historical fault information in the submodule fault case library. If the match is successful, obtain an auxiliary decision for assisting in solving the fault of the fault submodule according to the case information of the submodule fault corresponding to the successfully matched historical fault information; If the match fails, the to-be-detected fault information of the faulty submodule and the final decision on how to solve the fault of the faulty submodule are stored in the submodule fault case library; The submodule failure case library includes case information of all submodule failures that have occurred at the flexible direct current converter valve project site, and the case information of all submodule failures includes the historical failure information of the submodule failures and the corresponding recommended solutions as the final decision.

2. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: The case information of the submodule fault corresponding to the successfully matched historical fault information is obtained in the following manner: When the number of successfully matched historical fault information is equal to 1, the case information of the submodule fault corresponding to the successfully matched historical fault information is used as the case information of the submodule fault corresponding to the successfully matched historical fault information; When the number of successfully matched historical fault information is greater than 1, if the case information of the sub-module fault corresponding to the successfully matched historical fault information is repeated, the case information of the repeated sub-module fault in the case information of the sub-module fault corresponding to the successfully matched historical fault information is filtered out until only one is left, and the case information of the sub-module fault remaining after the filtering is used as the case information of the sub-module fault corresponding to the successfully matched historical fault information; If the case information of the submodule fault corresponding to the successfully matched historical fault information does not have duplication, the case information of the submodule fault corresponding to all the successfully matched historical fault information is used as the case information of the submodule fault corresponding to the successfully matched historical fault information; When the initial fault cause, fault description, and final fault cause of case information are the same, the case information is considered to be duplicated.

3. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: When there is information with a set value that is completely consistent in the to-be-detected fault information of the fault submodule and the historical fault information in the submodule fault case library, the match is considered successful, otherwise the match is considered failed; the set value is greater than or equal to 1.

4. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: The fault information to be detected is the fault information of all faulty submodules obtained by parsing the fault recording file of the converter valve submodule.

5. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 4, characterized in that: The analysis adopts a recording file analysis method obtained according to the fault recording file name.

6. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: The case information of all submodule failures also includes failure analysis results and / or case details.

7. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: The historical fault information includes the fault occurrence time, fault site, fault location, fault type, fault message and fault description.

8. The auxiliary decision-making method for flexible direct current converter valve submodule failure according to claim 1, characterized in that: The corresponding matching degree is also obtained after the matching is successful.

9. An auxiliary decision-making system for a flexible direct current converter valve submodule failure, comprising a processor, characterized in that: The processor is used to execute a computer program to implement the steps of the auxiliary decision-making method for flexible direct current converter valve submodule failure as described in any one of claims 1 to 8.

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