A reliability evaluation method and device for a converter valve considering the operation and maintenance cycle

Abstract

The present invention discloses a method and device for evaluating the reliability of a converter valve considering the operation and maintenance cycle. The method includes the following steps: obtaining the initial failure rates of a plurality of thyristor levels or sub-modules in the converter valve; calculating the equivalent failure rates of the sub-modules after a plurality of secondary operations according to the initial failure rates; and calculating the reliability value of the converter valve according to the type of the converter valve in combination with the equivalent failure rates of the sub-modules. By fully considering the influence of each operation and maintenance on the reliability of the converter valve, when modeling the reliability of the converter valve, according to the conversion coefficient of the conversion system equivalent to the thyristor level or sub-module, it is applicable to the reliability evaluation of existing flexible DC converter valves and conventional DC converter valves, and fully reflects the influence of operation and maintenance on the equivalent failure rates of the thyristor level or sub-module.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage direct current transmission, and particularly relates to a reliability evaluation method and device for a converter valve considering the operation and maintenance cycle. Background Art

[0002] Since the first ultra-high voltage direct current project in China - the Gezhouba-Shanghai Nanqiao direct current transmission project was put into operation in September 1989 for pole I and was fully commissioned in August 1990, China has had more than 30 years of application experience in the field of conventional direct current transmission, and in 2022, the overall upgrade and transformation of the converter valves at the sending and receiving ends was ushered in. Since July 2011, when the first flexible direct current project in Asia - the Shanghai Nanhui flexible direct current project was put into operation, China has had more than 10 years of application experience in flexible direct current projects. With the rapid construction of conventional direct current and flexible direct current in China, the research on the reliability of the converter valve body is also being carried out synchronously. However, at present, it mainly focuses on the failure analysis of key components under different electrical stresses, and the reliability research of converter valve equipment is carried out based on this. However, in actual projects, the converter valves are overhauled and maintained according to a certain cycle during operation, and the existing research results have deficiencies in considering the impact and analysis of operation and maintenance on reliability, and there are obvious deficiencies in analyzing the reliability of flexible direct current converter valves. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide a reliability evaluation method and device for a converter valve considering the operation and maintenance cycle. By fully considering the impact of each operation and maintenance on the reliability of the converter valve, when building the reliability model of the converter valve, according to the conversion coefficient of the conversion system equivalent to the thyristor level or sub-module, it is applicable to the reliability evaluation of existing flexible direct current converter valves and conventional direct current converter valves, and fully reflects the impact of operation and maintenance on the equivalent failure rate of the thyristor level or sub-module.

[0004] To solve the above technical problems, the first aspect of the embodiments of the present invention provides a reliability evaluation method for a converter valve considering the operation and maintenance cycle, including the following steps:

[0005] Obtain the initial failure rate of several thyristor levels or sub-modules in the converter valve;

[0006] Calculate the equivalent failure rate of the sub-module after several operations and maintenances according to the initial failure rate;

[0007] Calculate the reliability value of the converter valve according to the converter valve type and in combination with the equivalent failure rate of the sub-module.

[0008] Further, the calculation formula for the equivalent failure rate λ′ is:

[0009]

[0010] Among them, T0 is the maintenance period of the converter valve, k0 is the conversion coefficient, t is the operation time, floor is the floor function, and λ0 is the initial failure rate.

[0011] Further, calculating the reliability value of the converter valve includes:

[0012] Calculating the reliability value of a single arm of the converter valve according to the reliability model of the sub-module;

[0013] Calculating the reliability value of the converter valve according to the reliability value of the single arm.

[0014] Further, the reliability value R of the single arm arm The calculation formula is:

[0015]

[0016] R sm = e -λ′ ,

[0017] Among them, R sm is the reliability function of the thyristor level or the sub-module, N is the number of the thyristor level or the sub-module, is the combination number of taking i from N elements each time.

[0018] Further, the reliability value R of the converter valve valve The calculation formula is:

[0019]

[0020] Among them, is the combination number of taking 1 from P0 elements each time, is the combination number of taking 1 from P elements each time, is the reliability of a single valve including 6 arms.

[0021] Further, before the type of the converter valve is determined, it also includes:

[0022] Obtaining the type of the converter valve to get the corresponding P value and P0 value;

[0023] Among them, the P value represents the number of valve groups in a monopolar converter valve; the P0 value is related to the main wiring mode of the high-voltage DC transmission system and represents the number of valve groups in a single-end converter.

[0024] Correspondingly, a second aspect of the embodiments of the present invention provides a converter valve reliability evaluation device considering the operation and maintenance period, including:

[0025] A data acquisition module for acquiring the initial failure rates of several thyristor levels or sub - modules in a converter valve;

[0026] A first calculation module for calculating the equivalent failure rate of the sub - modules after several maintenance operations based on the initial failure rate;

[0027] A second calculation module for calculating the reliability value of the converter valve by combining the equivalent failure rate of the sub - modules according to the type of the converter valve;

[0028] Further, the calculation formula for the equivalent failure rate λ′ is:

[0029]

[0030] where T0 is the maintenance period of the converter valve, k0 is the conversion coefficient, t is the operating time, floor is the floor function, and λ0 is the initial failure rate.

[0031] Further, the second calculation module includes:

[0032] A first calculation unit for calculating the reliability value of a single arm of the converter valve according to the reliability model of the sub - module;

[0033] A second calculation unit for calculating the reliability value of the converter valve according to the reliability value of the single arm.

[0034] Further, the reliability value R arm of a single arm is calculated as:

[0035]

[0036] R sm = e -λ′ ,

[0037] where R sm is the reliability function of the thyristor level or the sub - module, N is the number of the thyristor levels or the sub - modules, is the combination number of taking i elements each time from N elements.

[0038] Further, the calculation formula for the reliability value R valve of the converter valve is:

[0039]

[0040] where, is the combination number of taking 1 element each time from P0 elements, is the combination number of taking 1 element each time from P elements, For the reliability of a single valve with 6 arms.

[0041] Furthermore, the second calculation module further includes:

[0042] A data acquisition unit, which is used to acquire the converter valve type and obtain the P value and P0 value corresponding to the converter valve type;

[0043] Wherein, the P value represents the number of valve groups in a monopole converter valve; the P0 value is related to the main wiring mode of the HVDC transmission system and represents the number of valve groups in a single-end converter.

[0044] The above technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0045] By fully considering the impact of each operation and maintenance on the reliability of the converter valve, when modeling the reliability of the converter valve, according to the conversion coefficient of the equivalent system to the thyristor level or sub-module, it is applicable to the reliability assessment of existing flexible DC converter valves and conventional DC converter valves, and fully reflects the impact of operation and maintenance on the equivalent failure rate of the thyristor level or sub-module. Description of the Drawings

[0046] Figure 1 is the flowchart of the converter valve reliability assessment method considering the operation and maintenance cycle provided by the embodiments of the present invention;

[0047] Figure 2 is the logic diagram of the converter valve reliability assessment method considering the operation and maintenance cycle provided by the embodiments of the present invention;

[0048] Figure 3 is the wiring diagram of the flexible DC converter with a typical high and low valve group configuration provided by the embodiments of the present invention;

[0049] Figure 4 is the schematic diagram of the typical MMC topology flexible DC converter valve and sub-module provided by the embodiments of the present invention;

[0050] Figure 5 is the wiring diagram of the typical single twelve-pulse monopole conventional DC converter provided by the embodiments of the present invention;

[0051] Figure 6 is the schematic diagram of the thyristor level provided by the embodiments of the present invention;

[0052] Figure 7 is the schematic diagram of the reliability analysis of the converter valve during the whole life cycle considering the impact of operation and maintenance provided by the embodiments of the present invention;

[0053] Figure 8 is the block diagram of the converter valve reliability assessment device considering the operation and maintenance cycle provided by the embodiments of the present invention;

[0054] Figure 9It is the block diagram of the second calculation module provided by the embodiment of the present invention.

[0055] Reference numerals:

[0056] 1. Data acquisition module, 2. First calculation module, 3. Second calculation module, 31. First calculation unit, 32. Second calculation unit, 33. Data acquisition unit. Detailed implementation manners

[0057] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific implementation manners and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0058] Please refer to Figure 1 and Figure 2 , the first aspect of the embodiment of the present invention provides a method for evaluating the reliability of a converter valve considering the operation and maintenance cycle, including the following steps:

[0059] S100. Obtain the initial failure rates of several thyristor levels or sub-modules in the converter valve.

[0060] S200. Calculate the equivalent failure rates of the sub-modules after several times of operation and maintenance based on the initial failure rates.

[0061] S300. Calculate the reliability value of the converter valve according to the type of the converter valve and in combination with the equivalent failure rates of the sub-modules.

[0062] Specifically, in step S200, the calculation formula for the equivalent failure rate λ′ is:

[0063]

[0064] where T0 is the maintenance cycle of the converter valve, k0 is the conversion coefficient, t is the operation time, floor is the floor function, and λ0 is the initial failure rate.

[0065] Specifically, in step S300, calculating the reliability value of the converter valve further includes:

[0066] S320. Calculate the reliability value of a single bridge arm of the converter valve according to the reliability model of the sub-module.

[0067] S330. Calculate the reliability value of the converter valve according to the reliability value of a single bridge arm.

[0068] Further, in step 310, the reliability value R arm of a single bridge arm is calculated by the formula:

[0069]

[0070] R sm = e -λ′ ,

[0071] wherein, R sm is the reliability function of the thyristor level or sub-module, N is the number of thyristor levels or sub-modules, is the combination number of taking i from N elements each time.

[0072] Furthermore, in step 320, the reliability value R valve of the commutation valve is calculated as follows:

[0073]

[0074] wherein, is the combination number of taking 1 from P0 elements each time, is the combination number of taking 1 from P elements each time, is the reliability of a single valve including 6 bridge arms.

[0075] Furthermore, before determining the type of the commutation valve, it further includes:

[0076] S310, obtaining the type of the commutation valve, and getting the corresponding P value and P0 value for the type of the commutation valve.

[0077] wherein, the P value represents the number of valve groups in a monopolar commutation valve. For thyristor valves, P = 4 for double twelve-pulse, and P = 2 for single twelve-pulse thyristor valves; for IGBT valves, P = 2 for high-low valve groups, and P = 1 for a single valve group. The P0 value is related to the main wiring mode of the HVDC transmission system and represents the number of valve group sets in a single-end converter. For a bipolar system, P0 = 2, and for a pseudo-bipolar system, P0 = 1.

[0078] Please refer to Figure 4 , for the ±500kV EHV DC project, adopting a single twelve-pulse true bipolar wiring mode (specifically as Figure 4 shown, that is, P = 2, P0 = 2), there are N = 120 thyristor levels in a single valve (i.e., a single bridge arm) (specifically as Figure 5 shown), among which the non-redundant number N0 = 116, and the number of redundant sub-modules is N - N0 = 4.

[0079] The initial annual failure rate of the thyristor level is 0.2%, and the initial failure rate is λ0 = 228.31 FIT, where 1 FIT = 1×10 -9 / h. Then, at time t, the failure rate of the sub-module The reliability of the sub-module is R sm = e -λ′According to the maintenance once every T0 = 1 year, the reliability of the converter valve is analyzed.

[0080] For the single twelve-pulse true bipolar connection converter valve, the reliability of the converter valve body is:

[0081] The conversion coefficient k0 is calculated according to the physical environment, time, electrical stress within the cycle, etc. of the equipment application. In this example, it is calculated according to 0.1, and the reliability within the whole life cycle of the converter valve as shown can be obtained. And the early operation and maintenance cycle can be appropriately extended to further reduce the operation and maintenance cost. After running for about 30 years, the reliability of the converter decreases rapidly, and the operation and maintenance is only effective for the reliability in the short term. At this time, a major overhaul of the converter valve is required to fundamentally improve the reliability of the converter valve so as to meet the availability requirements of the system operation. Figure 6

[0082] Correspondingly, the second aspect of the embodiment of the present invention provides a converter valve reliability evaluation device considering the operation and maintenance cycle, including:

[0083] A data acquisition module 1, which is used to acquire the initial failure rates of several thyristor levels or sub-modules in the converter valve;

[0084] A first calculation module 2, which is used to calculate the equivalent failure rates of the sub-modules after several operations and maintenances according to the initial failure rates;

[0085] A second calculation module 3, which is used to calculate the reliability value of the converter valve according to the converter valve type and in combination with the equivalent failure rates of the sub-modules.

[0086] Further, the calculation formula of the equivalent failure rate λ′ is:

[0087]

[0088] where T0 is the maintenance cycle of the converter valve, k0 is the conversion coefficient, t is the operation time, floor is the floor function, and λ0 is the initial failure rate.

[0089] Further, the second calculation module 3 includes:

[0090] A first calculation unit 31, which is used to calculate the reliability value of a single bridge arm of the converter valve according to the reliability model of the sub-module;

[0091] A second calculation unit 32, which is used to calculate the reliability value of the converter valve according to the reliability value of the single bridge arm.

[0092] Further, the calculation formula of the reliability value R of a single bridge arm arm is:

[0093] ​

[0094] R sm = e -λ′ ,

[0095] wherein, R sm is the reliability function of the thyristor stage or sub-module, N is the number of thyristor stages or sub-modules, is the combination number of taking i from N elements each time.

[0096] Furthermore, the reliability value R valve of the commutation valve is calculated as follows:

[0097]

[0098] wherein, is the combination number of taking 1 from P0 elements each time, is the combination number of taking 1 from P elements each time, is the reliability of a single valve including 6 bridge arms.

[0099] Furthermore, the second calculation module 3 further includes:

[0100] A data acquisition unit 33, which is used to acquire the type of the commutation valve and obtain the P value and P0 value corresponding to the type of the commutation valve.

[0101] wherein, the P value represents the number of valve groups in a monopolar commutation valve. For thyristor valves, P = 4 for double twelve-pulse, and P = 2 for single twelve-pulse thyristor valves; for IGBT valves, P = 2 for high-low valve groups, and P = 1 for a single valve group. The P0 value is related to the main wiring mode of the HVDC transmission system and represents the number of valve group sets in a single-end converter. For a bipolar system, P0 = 2, and for a pseudo-bipolar system, P0 = 1.

[0102] Correspondingly, a third aspect of the embodiments of the present invention further provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein, the memory stores instructions executable by the one processor, and the instructions are executed by the one processor to enable the at least one processor to execute the above-mentioned commutation valve reliability evaluation method considering the operation and maintenance cycle.

[0103] In addition, a fourth aspect of the embodiments of the present invention further provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the above-mentioned commutation valve reliability evaluation method considering the operation and maintenance cycle is implemented.

[0104] The embodiments of the present invention aim to protect a commutation valve reliability evaluation method and device considering the operation and maintenance cycle, and have the following effects:

[0105] By fully considering the impact of each operation and maintenance on the reliability of the converter valve, when modeling the reliability of the converter valve, according to the conversion coefficient that converts the system equivalently to the thyristor level or sub-module, it is applicable to the reliability assessment of existing flexible DC converter valves and conventional DC converter valves, and fully reflects the impact of operation and maintenance on the equivalent failure rate of the thyristor level or sub-module.

[0106] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0107] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0108] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0109] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent substitutions can still be made to the specific implementation manners of the present invention, and any modification or equivalent substitution that does not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A reliability evaluation method for a converter valve considering the operation and maintenance cycle, characterized in that It includes the following steps: Obtain the initial failure rates of several sub-modules in the converter valve; Calculate the equivalent failure rates of the sub-modules after several operations and maintenances based on the initial failure rates; Calculate the reliability value of the converter valve based on the converter valve type and in combination with the equivalent failure rates of the sub-modules; The equivalent failure rate is calculated by the following formula: ， Among them, T0 is the maintenance period of the commutation valve, is the conversion coefficient, t is the operation time, floor is the floor function, is the initial failure rate; The calculation of the reliability value of the converter valve includes: Calculate the reliability value of a single arm of the converter valve based on the reliability model of the sub-module; Calculate the reliability value of the converter valve based on the reliability value of the single arm; The reliability value of the single arm The calculation formula is as follows: ， ， Among them, is the reliability function of the sub-module, N is the number of the sub-modules, is the combination number of taking i from N sub-modules each time; The reliability value of the converter valve The calculation formula is as follows: ， Among them, is the combination number of taking 1 from P0 sub-modules each time, is the combination number of taking 1 from P sub-modules each time, is the reliability of a single valve with 6 arms; Before the step of based on the converter valve type, it also includes: Obtain the converter valve type to obtain the P value and P0 value corresponding to the converter valve type; Wherein, the P value represents the number of valve groups in a monopolar converter valve; the P0 value is related to the main wiring mode of the high-voltage DC transmission system and represents the number of valve group sets in a single-end converter; 2. A converter valve reliability evaluation device considering the operation and maintenance cycle, characterized in that It includes: A data acquisition module, which is used to obtain the initial failure rates of several sub-modules in the converter valve; A first calculation module, which is used to calculate the equivalent failure rates of the sub-modules after several operations and maintenances based on the initial failure rates; A second calculation module, which is used to calculate the reliability value of the converter valve based on the converter valve type and in combination with the equivalent failure rates of the sub-modules; The equivalent failure rate is calculated by the following formula: ， Among them, T0 is the maintenance period of the converter valve, is the conversion coefficient, t is the operating time, floor is the floor function, is the initial failure rate; The second calculation module includes: A first calculation unit, which is used to calculate the reliability value of a single arm of the converter valve based on the reliability model of the sub-module; A second calculation unit, which is used to calculate the reliability value of the converter valve based on the reliability value of the single arm; Reliability value of the single arm The calculation formula is as follows: ， ， Among them, is the reliability function of the sub-module, N is the number of the sub-modules, is the combination number of taking i from N sub-modules each time; The reliability value of the converter valve The calculation formula is as follows: ， Among them, is the combination number of taking 1 from P0 sub-modules each time, is the combination number of taking 1 from P sub-modules each time, is the reliability of a single valve containing 6 bridge arms; The second calculation module further includes: A data acquisition unit, which is used to obtain the converter valve type to obtain the P value and P0 value corresponding to the converter valve type; Wherein, the P value represents the number of valve groups in a monopolar converter valve; the P0 value is related to the main wiring mode of the high-voltage DC transmission system and represents the number of valve group sets in a single-end converter;

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