Transformer risk assessment method and system

Abstract

The invention discloses a transformer risk assessment method and system, and belongs to the technical field of power grid risk assessment, and the method comprises the steps: calculating the fault rate of equipment of the same model of each manufacturer according to the model, manufacturer, number and fault type information of in-operation equipment of a power grid company obtained through statistics; according to the corresponding relation between the equipment fault rate and the fault occurrence degree, the equipment fault rate is converted into the fault occurrence degree; analyzing the structure, the function and the failure of the equipment to obtain fault types and the severity and the undetectability of each fault type; and calculating the risk index of each fault type according to the fault occurrence degree, the severity and the undetectability, and taking the maximum value of the risk index of each fault type as the equipment risk index. Furthermore, the method also comprises the step of determining the maintenance priority of the equipment according to the equipment risk index. According to the method, the statistical rule and the fault mode and effect analysis technology are fused, the fault frequency and the risk index of the transformer are accurately quantified, and distribution of operation and inspection resources is optimized.

Description

Technical Field

[0001] This application belongs to the field of power grid risk assessment technology, and in particular relates to a transformer risk assessment method and system. Background Technology

[0002] The challenges faced in transformer operation and maintenance are mainly reflected in the following aspects:

[0003] There is a mismatch between the workload of operation and maintenance and the staffing: Some municipal power grids undertake more than 20% of the equipment operation and maintenance work in the province, while operation and maintenance personnel account for only 5.6% of the province's total. This mismatch leads to enormous workload for operation and maintenance personnel, making it difficult for them to cope with the heavy equipment maintenance and repair tasks.

[0004] Limitations of traditional maintenance models: The traditional condition-based maintenance business model, which focuses on "extra-cycle management," is no longer suitable for current needs. Furthermore, this model lacks the ability to provide early warnings of similar defects in similar equipment from the same factory, and maintenance decisions lack foresight and specificity.

[0005] With the continuous improvement of the smart grid system, the types, quantities, and operational complexities of power equipment have increased significantly. This makes high-quality and efficient data analysis models particularly important in power equipment risk assessment and response, necessitating the development of a forward-looking and targeted risk assessment method. This method should be able to provide operation and maintenance personnel with differentiated maintenance strategies to optimize resource allocation and improve the efficiency and effectiveness of maintenance work. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the existing technology. In order to overcome the uneven distribution of power grid operation and maintenance resources and the insufficient early warning capability of current operation and maintenance strategies for similar defects of equipment from the same manufacturer and of the same type, a transformer risk assessment method and system is provided. Based on statistical rules, the failure rate of all operating equipment from different manufacturers and models is obtained. Then, the FMEA method is combined to calculate the risk index of the transformer, classify the equipment into different risk levels, implement differentiated maintenance strategies, and thus effectively optimize the allocation of operation and maintenance resources and improve the foresight and pertinence of operation and maintenance decisions.

[0007] To achieve the above objectives, this application employs the following technical solution:

[0008] Firstly, this application provides a transformer risk assessment method, including:

[0009] Based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, the failure rate of the same model of equipment from each manufacturer was calculated.

[0010] Based on the correlation between equipment failure rate and failure occurrence rate, the equipment failure rate is converted into failure occurrence rate.

[0011] The analysis of equipment structure, function and failure results in the types of failures, as well as the severity and undetectability of each type of failure.

[0012] The risk index for each fault type is calculated based on the fault occurrence, severity, and undetectability. The maximum value of the risk index for each fault type is taken as the equipment risk index.

[0013] Furthermore, the transformer risk assessment method also includes: determining the maintenance priority of the equipment based on the equipment risk index.

[0014] Furthermore, the fault types include current circuit overheating, winding deformation, abnormal partial discharge in winding, aging of winding insulation, dampness in winding insulation, excessive impurities in oil, abnormal oil level, damp insulating oil, abnormal partial discharge in oil, aging of insulating oil, discharge of core clamps, overheating of core clamps, loosening of core clamps, oil leakage from the oil tank, overheating of metal parts in the oil tank, discharge of metal parts in the oil tank, abnormal insulation of the tap changer, overheating of the tap changer, abnormal switching function of the tap changer, abnormal secondary circuit of the tap changer, abnormal bushing insulation, overheating of the bushing, damage to the bushing, and abnormal cooling system.

[0015] Furthermore, based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, the failure rate of the same model of equipment from each manufacturer is calculated, including:

[0016] ;

[0017] PoF stands for Equipment Failure Rate.

[0018] Furthermore, the correspondence between the equipment failure rate and the degree of failure occurrence includes:

[0019] The equipment failure rate is in the range [0, 0.001], and the failure occurrence degree is 1;

[0020] The equipment failure rate is in the range of (0.001, 0.005), and the failure occurrence degree is 2.

[0021] The equipment failure rate is in the range of (0.005, 0.01), and the failure occurrence rate is 3.

[0022] The equipment failure rate is in the range of (0.01, 0.02), and the failure occurrence rate is 4.

[0023] The equipment failure rate is within the range of (0.02, 0.05), and the failure occurrence rate is 5.

[0024] The equipment failure rate is in the range of (0.05, 0.1], and the failure occurrence rate is 6.

[0025] The equipment failure rate is in the range of (0.1, 0.2], and the failure occurrence rate is 7.

[0026] The equipment failure rate is in the range of (0.2, 0.4], and the failure occurrence rate is 8.

[0027] The equipment failure rate is in the range of (0.4, 0.75), and the failure occurrence rate is 9.

[0028] The equipment failure rate is located in (0.75, 1], and the failure occurrence degree is 10.

[0029] Furthermore, the occurrence, severity, and undetectability of the faults are all divided into ten levels.

[0030] Furthermore, the calculation of the risk index for each fault type based on fault occurrence, severity, and undetectability includes:

[0031] The risk index for each fault type is obtained by producting the fault occurrence rate, severity rate, and undetectability rate, and then normalizing the product.

[0032] ;

[0033] in, Risk indices for each type of failure.

[0034] Furthermore, the step of determining the maintenance priority of equipment based on the equipment risk index includes:

[0035] If the equipment risk index is in the range [0, 0.1), the equipment maintenance priority is Level 1 (Ⅰ).

[0036] If the equipment risk index is in the range of [0.1, 0.3), the equipment maintenance priority is Level II.

[0037] If the equipment risk index is in the range of [0.3, 0.6), the equipment maintenance priority is Level III.

[0038] If the equipment risk index is in the range of [0.6, 0.85), the equipment maintenance priority is Level IV;

[0039] If the equipment risk index is in the range of [0.85, 1], the equipment maintenance priority is Level V.

[0040] Secondly, this application provides a transformer risk assessment system, comprising:

[0041] The first calculation module is used to calculate the failure rate of the same model of equipment from each manufacturer based on the statistical information on the model, manufacturer, quantity and failure type of the equipment in operation of the power grid company.

[0042] The conversion module is used to convert the equipment failure rate into the failure occurrence rate based on the correspondence between the equipment failure rate and the failure occurrence rate.

[0043] The analysis module is used to: analyze the equipment structure, function, and failures to obtain the fault types, as well as the severity and undetectability of each fault type;

[0044] The second calculation module is used to calculate the risk index of each fault type based on the fault occurrence, severity, and undetectability, and to take the maximum value of the risk index of each fault type as the equipment risk index.

[0045] Thirdly, this application provides a computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the transformer risk assessment method as described in any step of the first aspect.

[0046] Compared with existing technologies, the beneficial effects achieved by this application are as follows: This application integrates statistical rule analysis with Failure Mode and Effects Analysis (FMEA) technology to accurately quantify the failure frequency and risk index of transformers, optimizing the allocation of operation and maintenance resources. This allows operation and maintenance work to be more efficiently focused on high-risk equipment, thereby improving operation and maintenance efficiency. Simultaneously, this method enhances the foresight and targeting of maintenance decisions, enabling maintenance work to more accurately target potential fault points, reducing the risk of unexpected downtime due to equipment failure, and enhancing the stability and security of the power grid. Furthermore, through differentiated maintenance strategies, unnecessary maintenance work is reduced, effectively lowering long-term maintenance costs. This application also improves the response speed to equipment failures, increases the flexibility of operation and maintenance work, and can quickly adapt to various emergencies in power grid operation. Finally, this application supports the development of smart grid technology, providing an efficient data analysis model for risk assessment and response of power equipment under the smart grid system, and promoting the healthy development of the smart grid. Attached Figure Description

[0047] Figure 1 The diagram shown is a flowchart of a transformer risk assessment method in one embodiment of this application;

[0048] Figure 2 The diagram shown is a flowchart of a transformer risk assessment method in another embodiment of this application;

[0049] Figure 3 The diagram shown is a schematic of a transformer risk assessment system in one embodiment of this application. Detailed Implementation

[0050] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and should not be used to limit the scope of protection of the present application.

[0051] Example 1: As Figure 1 As shown, this embodiment provides a transformer risk assessment method, including:

[0052] S1. Based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, calculate the fault rate of the same model of equipment from each manufacturer.

[0053] It should be noted that the fault types include overheating of the current circuit, winding deformation, abnormal partial discharge of the winding, aging of the winding insulation, dampness of the winding insulation, excessive impurities in the oil, abnormal oil level, damp insulating oil, abnormal partial discharge in the oil, aging of the insulating oil, discharge of the core clamps, overheating of the core clamps, loosening of the core clamps, oil leakage from the oil tank, overheating of the metal parts of the oil tank, discharge of the metal parts of the oil tank, abnormal insulation of the tap changer, overheating of the tap changer, abnormal switching function of the tap changer, abnormal secondary circuit of the tap changer, abnormal bushing insulation, overheating of the bushing, damage to the bushing, and abnormal cooling system.

[0054] Furthermore, based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, the failure rate of the same model of equipment from each manufacturer is calculated, including:

[0055] ;

[0056] PoF stands for Equipment Failure Rate.

[0057] S2. Based on the correspondence between equipment failure rate and failure occurrence rate, convert the equipment failure rate into failure occurrence rate.

[0058] Furthermore, the correspondence between the equipment failure rate and the degree of failure occurrence includes:

[0059] The equipment failure rate is in the range [0, 0.001], and the failure occurrence degree is 1;

[0060] The equipment failure rate is in the range of (0.001, 0.005), and the failure occurrence degree is 2.

[0061] The equipment failure rate is in the range of (0.005, 0.01), and the failure occurrence rate is 3.

[0062] The equipment failure rate is in the range of (0.01, 0.02), and the failure occurrence rate is 4.

[0063] The equipment failure rate is within the range of (0.02, 0.05), and the failure occurrence rate is 5.

[0064] The equipment failure rate is in the range of (0.05, 0.1], and the failure occurrence rate is 6.

[0065] The equipment failure rate is in the range of (0.1, 0.2], and the failure occurrence rate is 7.

[0066] The equipment failure rate is in the range of (0.2, 0.4], and the failure occurrence rate is 8.

[0067] The equipment failure rate is in the range of (0.4, 0.75), and the failure occurrence rate is 9.

[0068] The equipment failure rate is located in (0.75, 1], and the failure occurrence degree is 10.

[0069] The occurrence rate is obtained by converting the equipment failure rate into a calculation, and the conversion process is shown in Table 1.

[0070] Table 1: Failure Rate to Occurrence Conversion

[0071]

[0072] S3. Analyze the equipment structure, function and failure to obtain the fault types, as well as the severity and undetectability of each fault type;

[0073] S4. Calculate the risk index for each fault type based on the fault occurrence, severity, and undetectability, and take the maximum value of the risk index for each fault type as the equipment risk index.

[0074] Furthermore, the occurrence, severity, and undetectability of the faults are all divided into ten levels.

[0075] Furthermore, the calculation of the equipment risk index based on the occurrence, severity, and undetectability of the failure includes:

[0076] The risk index for each fault type is obtained by producting the fault occurrence rate, severity rate, and undetectability rate, and then normalizing the product.

[0077] ;

[0078] in, Risk indices for each type of failure.

[0079] In some embodiments, the transformer risk assessment method further includes: S5, determining the maintenance priority of the equipment based on the equipment risk index.

[0080] Furthermore, the step of determining the maintenance priority of equipment based on the equipment risk index includes:

[0081] If the equipment risk index is in the range [0, 0.1), the equipment maintenance priority is Level 1 (Ⅰ), and the maintenance cycle can be appropriately extended.

[0082] If the equipment risk index is in the range of [0.1, 0.3), the equipment maintenance priority is Level II, with fixed-cycle maintenance.

[0083] If the equipment risk index is in the range of [0.3, 0.6), the equipment maintenance priority is Level III, and maintenance should be carried out in a timely manner.

[0084] If the equipment risk index is in the range of [0.6, 0.85), the equipment maintenance priority is Level IV, and maintenance should be carried out as soon as possible;

[0085] If the equipment risk index is in the range of [0.85, 1], the equipment maintenance priority is Level V, and maintenance should be carried out immediately.

[0086] It should be noted that the maintenance priority increases sequentially from Level I to Level V, with the corresponding maintenance cycles becoming increasingly shorter. The appropriately extended maintenance cycle should be longer than the maintenance frequency under fixed-cycle maintenance, and the frequency of timely maintenance should be lower than the maintenance frequency under fixed-cycle maintenance. Furthermore, the frequency of immediate maintenance is lower than the frequency of timely maintenance. Among these, the frequency of immediate maintenance is the lowest, and the speed of immediate maintenance must be faster than the speed of timely maintenance.

[0087] Based on the risk index calculation results, the maintenance priorities of the equipment are divided, and maintenance suggestions are given. The division method is shown in Table 2.

[0088] Table 2: Determination of Equipment Maintenance Priority

[0089]

[0090] Example 2: Based on Example 1, to further illustrate the detailed application process of the method of this application, a risk assessment was conducted on a 500kV main transformer of a substation in a certain region that was put into operation in 2000. For example... Figure 2 As shown, according to statistics, there are a total of 3 main transformers of the same type and from the same factory in operation in this region. These 3 main transformers have experienced a total of 1 winding partial discharge abnormality fault within 5 years.

[0091] First, based on the equipment failure rate calculation method, the partial discharge abnormality failure rate of this main transformer winding is the ratio of the failure frequency to the number of operating equipment, PoF. 绕组局放异常 =0.33; Secondly, referring to the occurrence degree conversion method, it can be seen that when PoF 绕组局放异常 =0.33, the occurrence degree of partial discharge anomaly of the main transformer winding is 8; finally, the risk index of the main transformer is calculated by combining the occurrence degree, severity and undetectability.

[0092]

[0093] The main transformer's risk index (RPN) is 0.504. According to the risk priority classification method, the main transformer's maintenance priority is Level III (Level 3), and maintenance should be carried out in a timely manner.

[0094] In summary, this method, by combining statistical rules with FMEA theory, can effectively quantify the transformer risk index and provide differentiated operation and maintenance recommendations for the main transformer.

[0095] Example 3: Based on Example 1, this example provides a transformer risk assessment system, such as... Figure 3 As shown, it includes:

[0096] The first calculation module is used to calculate the failure rate of the same model of equipment from each manufacturer based on the statistical information on the model, manufacturer, quantity and failure type of the equipment in operation of the power grid company.

[0097] The conversion module is used to convert the equipment failure rate into the failure occurrence rate based on the correspondence between the equipment failure rate and the failure occurrence rate.

[0098] The analysis module is used to: analyze the equipment structure, function, and failures to obtain the fault types, as well as the severity and undetectability of each fault type;

[0099] The second calculation module is used to calculate the risk index of each fault type based on the fault occurrence, severity, and undetectability, and to take the maximum value of the risk index of each fault type as the equipment risk index.

[0100] Furthermore, the transformer risk assessment system also includes:

[0101] The maintenance priority determination module is used to determine the maintenance priority of equipment based on the equipment risk index.

[0102] It should be noted that the fault types include overheating of the current circuit, winding deformation, abnormal partial discharge of the winding, aging of the winding insulation, dampness of the winding insulation, excessive impurities in the oil, abnormal oil level, damp insulating oil, abnormal partial discharge in the oil, aging of the insulating oil, discharge of the core clamps, overheating of the core clamps, loosening of the core clamps, oil leakage from the oil tank, overheating of the metal parts of the oil tank, discharge of the metal parts of the oil tank, abnormal insulation of the tap changer, overheating of the tap changer, abnormal switching function of the tap changer, abnormal secondary circuit of the tap changer, abnormal bushing insulation, overheating of the bushing, damage to the bushing, and abnormal cooling system.

[0103] Example 4: Based on Example 1, this example provides a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the transformer risk assessment method described in any step of Example 1 is implemented.

[0104] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A method for assessing the risk of a transformer, characterized in that, include: Based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, the failure rate of the same model of equipment from each manufacturer was calculated. Based on the correlation between equipment failure rate and failure occurrence rate, the equipment failure rate is converted into failure occurrence rate. The analysis of equipment structure, function and failure results in the types of failures, as well as the severity and undetectability of each type of failure. The risk index for each fault type is calculated based on the fault occurrence, severity, and undetectability. The maximum value of the risk index for each fault type is taken as the equipment risk index.

2. The transformer risk assessment method according to claim 1, characterized in that, Also includes: The maintenance priority of equipment is determined based on the equipment risk index.

3. The transformer risk assessment method according to claim 1, characterized in that, The fault types include current circuit overheating, winding deformation, abnormal winding partial discharge, winding insulation aging, winding insulation dampness, excessive impurities in oil, abnormal oil level, damp insulating oil, abnormal partial discharge in oil, aging insulating oil, core clamp discharge, core clamp overheating, core clamp loosening, oil tank leakage, oil tank metal parts overheating, oil tank metal parts discharge, tap changer insulation abnormality, tap changer overheating, tap changer switching function abnormality, tap changer secondary circuit abnormality, bushing insulation abnormality, bushing overheating, bushing damage, and cooling system abnormality.

4. The transformer risk assessment method according to claim 1, characterized in that, The failure rate of the same model of equipment from each manufacturer is calculated based on the statistical information on the model, manufacturer, quantity, and fault type of the power grid company's operating equipment, including: ； PoF stands for Equipment Failure Rate.

5. The transformer risk assessment method according to claim 1, characterized in that, The relationship between the equipment failure rate and the degree of failure includes: The equipment failure rate is in the range [0, 0.001], and the failure occurrence degree is 1; The equipment failure rate is in the range of (0.001, 0.005), and the failure occurrence degree is 2. The equipment failure rate is in the range of (0.005, 0.01), and the failure occurrence rate is 3. The equipment failure rate is in the range of (0.01, 0.02), and the failure occurrence rate is 4. The equipment failure rate is within the range of (0.02, 0.05), and the failure occurrence rate is 5. The equipment failure rate is in the range of (0.05, 0.1], and the failure occurrence rate is 6. The equipment failure rate is in the range of (0.1, 0.2], and the failure occurrence rate is 7. The equipment failure rate is in the range of (0.2, 0.4], and the failure occurrence rate is 8. The equipment failure rate is in the range of (0.4, 0.75), and the failure occurrence rate is 9. The equipment failure rate is located in (0.75, 1], and the failure occurrence degree is 10.

6. The transformer risk assessment method according to claim 1, characterized in that, The occurrence, severity, and undetectability of the faults are all classified into ten levels.

7. The transformer risk assessment method according to claim 1, characterized in that, The calculation of risk indices for each fault type based on fault occurrence, severity, and undetectability includes: The risk index for each fault type is obtained by producting the fault occurrence rate, severity rate, and undetectability rate, and then normalizing the product. ； in, Risk indices for each type of failure.

8. The transformer risk assessment method according to claim 2, characterized in that, The process of determining equipment maintenance priority based on equipment risk index includes: If the equipment risk index is in the range [0, 0.1), the equipment maintenance priority is Level 1 (Ⅰ). If the equipment risk index is in the range of [0.1, 0.3), the equipment maintenance priority is Level II. If the equipment risk index is in the range of [0.3, 0.6), the equipment maintenance priority is Level III. If the equipment risk index is in the range of [0.6, 0.85), the equipment maintenance priority is Level IV; If the equipment risk index is in the range of [0.85, 1], the equipment maintenance priority is Level V.

9. A transformer risk assessment system, characterized in that, include: The first calculation module is used to calculate the failure rate of the same model of equipment from each manufacturer based on the statistical information on the model, manufacturer, quantity and failure type of the equipment in operation of the power grid company. The conversion module is used to convert the equipment failure rate into the failure occurrence rate based on the correspondence between the equipment failure rate and the failure occurrence rate. The analysis module is used to: analyze the equipment structure, function, and failures to obtain the fault types, as well as the severity and undetectability of each fault type; The second calculation module is used to calculate the risk index of each fault type based on the fault occurrence, severity, and undetectability, and to take the maximum value of the risk index of each fault type as the equipment risk index.

10. The transformer risk assessment system according to claim 9, characterized in that, Also includes: The maintenance priority determination module is used to determine the maintenance priority of equipment based on the equipment risk index.

11. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the transformer risk assessment method as described in any one of claims 1-8.

Images