Substation maintenance and replacement method and system considering time value

Abstract

The invention discloses a transformer substation maintenance and replacement method and system considering time value, and belongs to the technical field of transformer substation maintenance. Based on the economic life condition of the transformer, constructing a maintenance annual average net income model considering the time value, and outputting the maximum annual average net income # imgabs0 # under the maintenance condition; a replacement annual average net income model considering time value is constructed based on the economic life condition of the transformer, and the maximum annual average net income # imgabs1 # under the replacement condition is output; when # imgabs2, the power grid equipment is not replaced; and when the # imgabs3 # is adopted, the power grid equipment is replaced, and the replacement moment # imgabs5 # corresponding to the # imgabs4 # is the economic life of the equipment. The method has practical significance in realizing lean management of power equipment operation and reasonably prolonging the service life of the power equipment for a power grid enterprise.

Description

Background Art

[0002] At present, some achievements have been made in the research on the economic life of power grid equipment. Most of them are based on the asset life cycle management method, using different methods to calculate the comprehensive cost or the maximum comprehensive benefit, so as to determine the economic life. Luo Xiaochu et al., Yin Laibin et al., Xu Chong et al. considered the initial investment, operation and maintenance, failure loss and scrapping cost of the transformer during the life cycle, but did not give a specific mathematical model of social responsibility cost in the failure loss cost model. The economic life calculation only considered the economic issues in the operation of the equipment, and did not consider the impact of environmental responsibility cost. On this basis, Jiang Xiubo et al. considered the environmental cost and established a transformer life cycle cost estimation model based on interval analysis. Li Ran et al., guided by the life cycle cost theory, incorporated environmental and social responsibility costs into the life cycle cost of the transformer, introduced the random fuzzy theory that can handle these two uncertainties at the same time to handle the evaluation parameters, and established a new transformer economic life evaluation model, obtained the economic life intervals at different confidence levels and the economic life interval with the largest opportunity measure in the interval of the same span, but did not consider the time value of cost, and the power supply income is difficult to calculate in actual evaluation. Li Na et al., Wang Huifang et al. considered the time value of investment cost and established a full life cycle cost model for transformer economic life management considering the probability of failure. On this basis, the cost annuity method was used to evaluate the economic life of distribution transformers. However, the optimal or economic update time of transformers and the benefits of updating at different times have not been solved. Yu Jilai et al. comprehensively considered the impact of factors such as energy conservation, environment and society, capacity subsidies, depreciation, and loans on the economic performance of in-service transformers, and quantitatively evaluated the economic life of transformers through optimized comprehensive economic benefit indicators. Not only the time value of funds was taken into account, but also the differences in various economic indicators between in-service transformers and reference transformers with planned updates were considered. In particular, the optimal or economic update time of in-service transformers and the benefits of updating at different times can be answered. On the basis of the above literature, Liu Youwei et al. comprehensively considered the power supply income and various cost expenditures of transformers, and took the maximum annual net income as the optimization goal, and established a mathematical model of the average annual net income for the two cases of maintenance and replacement. By comparing the maximum annual net income under maintenance and replacement, a decision is made on whether maintenance or replacement is applicable.

[0003] In summary, the application of the life cycle method to transmission lines and power grid equipment has achieved certain results, but the models established by predecessors are not universal. There is no unified method for deciding the method and timing of equipment renewal in power companies. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a substation maintenance and replacement method and system that takes time value into consideration in view of the deficiencies in the above-mentioned prior art, so as to solve the technical problems of aging of substation equipment, increased failure rate and low maintenance and replacement efficiency; by optimizing the maintenance and replacement plan, the operating risk of the substation is reduced, the service life of the equipment is extended, while the power outage time caused by maintenance and replacement is reduced, and the reliability and economy of the power system are improved; by considering the time value, the economic performance of the transformer during its life cycle can be more accurately evaluated, thereby ensuring the most effective utilization of assets; by calculating the economic life, the best replacement time point can be determined to avoid replacing equipment too early or too late, thereby reducing long-term maintenance and replacement costs; the consideration of time value helps to weigh the initial investment cost against future operating costs in investment decisions, and ensure the rational allocation and use of funds.

[0005] The present invention adopts the following technical solutions: A method for substation maintenance and replacement considering time value comprises the following steps: Set transformer economic life conditions; Based on the economic life of the transformer, an annual average net profit model considering the time value is constructed, and the maximum annual average net profit under maintenance is output. ; Based on the economic life of the transformer, a replacement annual net profit model considering the time value is constructed, and the maximum annual net profit under replacement is output. ; when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

[0006] Preferably, the transformer economic life condition is specifically: The annual operation and maintenance cost increases with the age of power transformers; Maintenance costs increase with the age of power transformers; Taking into account the time value, the annual interest rate is 6%~10%; Maintenance reduces the probability of failure and extends the economic life of the transformer; There is a baseline aging curve for power transformers; The older the power transformer is, the more difficult it is to repair it to the same benchmark aging curve as it was at the same time. The maximum life of a power transformer is calculated as T=80 years.

[0007] Preferably, the reduction in the probability of power transformer failure after maintenance for:

[0008] in, and are the actual power transformer failure probability and the benchmark failure probability respectively; k is a constant greater than 1, is the transformer in-service life, is the maximum life of the transformer.

[0009] Preferably, the maximum annual net profit under maintenance The average annual net income under maintenance The corresponding profit when the maximum value is reached.

[0010] Preferably, the average annual net profit under maintenance for:

[0011] in, is the total revenue from electricity supply, is the total cost in the case of overhaul, For time period.

[0012] Preferably, the total power supply income for:

[0013] in, is the contribution rate of the power transformer in the entire power supply chain; P is the price difference between buying and selling electricity; is the capacity of the power transformer; is the average load factor of the power transformer, is the annual interest rate; Total Cost for:

[0014] in, is the initial investment cost, Transformer service time During this period, the time value and operation and maintenance costs are considered. The total maintenance cost during service life considering the time value is: is the total failure risk cost during service considering the time value, The decommissioning disposal cost takes into account the time value.

[0015] Preferably, the maximum annual net benefit under replacement conditions Average annual net income under replacement The corresponding profit when the maximum value is reached.

[0016] Preferably, the average annual net income under replacement for: still

[0017] in, The power transformer from time 0 to the Operating income during the year taking into account the time value, is the total cost in the case of replacement, For the number of years.

[0018] Preferably, the power transformer is Operating income taking into account time value during the year for:

[0019] in, is the contribution rate of the power transformer in the entire power supply chain; P is the price difference between buying and selling electricity; is the capacity of the power transformer; is the average load factor of the power transformer, is the annual interest rate; Total cost in case of replacement for:

[0020] in, is the initial investment cost, To consider the time value of operation and maintenance costs, is the total failure risk cost during service considering the time value, The decommissioning disposal cost takes into account the time value.

[0021] In a second aspect, an embodiment of the present invention provides a substation maintenance and replacement system considering time value, including: Setting module, setting transformer economic life conditions; The first building block is to build an annual average net profit model for maintenance considering the time value based on the economic life of the transformer, and output the maximum annual average net profit under maintenance. ; The second building block is to build an annual average net profit model for replacement based on the economic life of the transformer, taking into account the time value, and output the maximum annual average net profit under replacement conditions. ; Replace the module when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

[0022] In a third aspect, a computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for substation maintenance and replacement considering time value when executing the computer program.

[0023] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned substation maintenance and replacement method considering time value.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects: A substation maintenance and replacement method considering time value is proposed. By considering time value, the economic benefits of maintenance and replacement of substation transformers are optimized to achieve the best balance between cost and benefit. By setting the economic life condition of the transformer, it is helpful to clarify the optimal service life of the equipment from a financial perspective, guide decision makers to conduct cost-benefit analysis, and avoid inefficient resource waste. By constructing an average annual net income model and integrating the time value factor into the economic evaluation of maintenance and replacement, it can provide a quantitative decision-making basis and help decision makers to intuitively compare the financial performance of different maintenance strategies. By comparing the maximum average annual net income of maintenance and replacement, it can assist decision makers in making maintenance decisions based on economic benefits and optimize asset utilization efficiency. By determining the economic life moment, a clear time node is provided for the maintenance and replacement of substation equipment, which helps to achieve the reasonable allocation of resources and effective control of risks. Among them, considering time value is an important principle in financial decision-making, which means that future cash flows need to be discounted to the current time point to reflect the time value of money and ensure that the comparison of funds at different time points is fair and reasonable. The determination of economic life is based on the cost-benefit analysis of the equipment, which takes into account the costs and benefits of the equipment throughout its life cycle, including acquisition cost, maintenance cost, failure risk cost, and equipment residual value. The average annual net income model provides decision makers with a tool to evaluate the economic benefits of equipment maintenance strategies by evenly allocating the total cost and total income of the equipment on an annual basis, combined with the discount effect of the time value. The determination of economic life is based on the comparison of average annual net income. When the average annual net income of maintenance is higher than that of replacement, it indicates that the current equipment maintenance is economically reasonable; conversely, replacing the equipment will bring greater economic benefits. This determination helps decision makers formulate scientific maintenance plans and optimize asset management and operational efficiency.

[0025] Furthermore, the setting of the economic life condition of the transformer aims to balance the operation cost and maintenance cost of the transformer to maximize the long-term economic benefits. Specific benefits include: by considering the trend of annual operation and maintenance costs and overhaul costs increasing with the age of the transformer, future maintenance and replacement strategies can be predicted and planned to avoid sudden high maintenance costs. Considering the time value, that is, the time cost of funds, by setting the annual interest rate to 6%-8%, the relative value of investment at different time points can be evaluated, so as to make more reasonable financial decisions. Overhaul can reduce the probability of failure and extend the economic life of the transformer, which helps to reduce the power outage losses and emergency repair costs caused by failures. The benchmark aging curve provides a reference standard for the health status of the transformer. By comparing the actual aging situation with the benchmark curve, the remaining life and maintenance needs of the transformer can be more accurately assessed. As the age of the transformer increases, it becomes more difficult to repair it to the same moment as the benchmark aging curve, which indicates that early maintenance and timely replacement can reduce the difficulty and cost of later maintenance. Setting the maximum life of the power transformer to 80 years provides a clear time frame for the use and replacement of the transformer, which is conducive to long-term asset management and planning. In summary, the setting of transformer economic life conditions is helpful to formulate an economical and reliable substation maintenance and replacement plan to ensure the stable operation of the power system and maximize cost-effectiveness.

[0026] Furthermore, the purpose of constructing an annual average net income model for maintenance considering the time value is to optimize the maintenance and replacement strategy of the substation to maximize economic benefits. Through this model, the annual average net income of the substation under different maintenance strategies can be evaluated, and the maintenance time and method that can bring the maximum annual average net income can be determined. The benefits include: Improving the efficiency of capital use: By calculating the maintenance costs and benefits at different time points, funds can be reasonably arranged to avoid maintenance too early or too late, thereby improving the efficiency of capital use. Maximizing long-term economic benefits: Models considering the time value can help decision makers choose maintenance strategies that can bring the greatest long-term benefits from a long-term perspective. Risk management: Through model analysis, the risks that may be brought about by different maintenance strategies can be predicted and evaluated, so as to take measures to reduce risks and ensure the stable operation of the substation. The principle is as follows: Consideration of time value: When calculating the annual average net income, future income and costs need to be discounted to current value. This is because the current value of a future income or cost will be lower than its future value due to the time value of money. Calculation of average annual net income: Average annual net income refers to the average annual income after deducting maintenance costs within a certain period of time. The calculation needs to take into account the substation's operating income, maintenance costs, replacement costs, and possible failure losses. Maximizing average annual net income: Through model calculation, you can find the time and method of maintenance that maximizes the average annual net income. This usually involves comparing the benefits and costs of different maintenance strategies and selecting the best option. In summary, constructing an average annual net income model for maintenance that takes into account the value of time can help substation managers maximize economic benefits while ensuring the safe and reliable operation of equipment.

[0027] Furthermore, the purpose of constructing an annual average net benefit model for replacement considering time value is to optimize the maintenance and replacement decision of substation transformers and ensure the maximization of cost-effectiveness throughout the entire service life of the transformer. By considering the time value of money, this model can more accurately evaluate the economic benefits of different maintenance and replacement strategies, thereby guiding decision makers to choose the best time for maintenance or replacement. The principle analysis is explained as follows: Time value of money: Money has time value, that is, a certain amount of money has different values ​​at different time points. Generally, the current value of a sum of money is higher than the future value because the current money can be invested to generate income. In the maintenance and replacement decision of substation transformers, considering the time value of money means that future costs and benefits need to be discounted to the current value for comparison. Economic life condition: The economic life of the transformer refers to the number of years during its service life that can obtain the maximum economic benefit through maintenance and replacement strategies. The purpose of setting the economic life condition of the transformer is to determine a time frame within which the economic effects of different strategies are evaluated. Annual average net benefit model: By constructing an annual average net benefit model for maintenance and replacement, the annual average net benefit under different strategies can be calculated. The model will take into account all relevant costs (such as maintenance costs, replacement costs, operating costs, etc.) and benefits (such as saved operating costs, improved power supply reliability, etc.) and discount them to annual average values ​​for easy comparison. Maximum annual average net benefit: The model outputs the maximum annual average net benefit under maintenance and replacement conditions, that is, and By comparing these two values, a decision can be made whether to proceed with repair or to replace the product. Greater than , indicating that it is more economical to continue repairing; otherwise, it is more reasonable to replace the transformer. Economic life determination: When deciding to replace the transformer, the model outputs The corresponding replacement time t is the economic life of the transformer. This time point is based on economic analysis, which means that replacing the transformer at this time can maximize cost-effectiveness. In summary, the annual average net benefit model of replacement considering the time value can help decision makers make economically reasonable maintenance and replacement decisions throughout the life cycle of the transformer, thereby improving the efficiency of capital use, reducing long-term operating costs, and ensuring the reliability and safety of power grid equipment.

[0028] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0029] In summary, the economic life assessment considering the time value of the present invention can better adapt to changes in the market and technology, allowing enterprises to flexibly adjust their asset strategies to cope with market fluctuations. The present invention incorporates the time value in the economic life assessment, which helps to more accurately identify the best time for replacement and avoid replacing equipment too early or too late, thereby reducing unnecessary maintenance and replacement costs. Under the premise of considering the time value, a method for determining the economic life of a transformer is proposed; by comparing the two situations of maintenance and replacement, an economic life model for the power transformer is established based on the principle of maximum annual return. The present invention can determine the optimal replacement time for the power transformer, and can provide a reference basis for enterprises to formulate reasonable maintenance strategies or replacement strategies, thereby achieving maximum economic benefits.

[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the process of the present invention; Figure 2 Schematic diagram of output results in the empirical analysis of the present invention; Figure 3 A schematic diagram of a computer device provided by an embodiment of the present invention; Figure 4 The present invention is a block diagram of an electronic device provided according to an embodiment. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0034] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0035] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0036] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0037] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0038] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0039] The present invention provides a substation maintenance and replacement method that takes time value into consideration, introduces the concept of time value, and optimizes the maintenance and replacement work of substations. Compared with the prior art, the present invention not only takes into account the direct cost of maintenance and replacement, but also takes into account the power outage time caused by maintenance and replacement, the speed of equipment aging, and the impact of maintenance and replacement timing on power grid stability and power supply reliability. Through this method, the economy and necessity of maintenance and replacement can be more accurately evaluated, thereby minimizing costs while ensuring the safe and stable operation of the power grid.

[0040] 1. Improve the decision-making efficiency of substation maintenance and replacement. By comprehensively considering the value of time, the maintenance and replacement plan can be arranged more reasonably, avoiding unnecessary emergency maintenance, reducing power outage time, and improving power supply reliability.

[0041] 2. Optimized resource allocation. By accurately calculating the best time for maintenance and replacement, maintenance resources can be allocated more reasonably, avoiding resource waste and reducing overall operating costs.

[0042] 3. Enhanced stability and security of the power grid. By considering equipment aging and power grid operating status, the present invention helps to prevent potential failure risks in advance and reduce power grid accidents caused by equipment failure.

[0043] 4. Improved economic benefits: By reducing power outage losses and optimizing maintenance costs, the present invention helps to improve the economic benefits of substations and create greater value for power companies.

[0044] See also Figure 1 The present invention provides a substation maintenance and replacement method considering time value, comprising the following steps: S1. Set the economic life condition of the transformer; (1) The annual operation and maintenance cost will increase with the age of the power transformer; (2) The maintenance cost will increase with the age of the power transformer; (3) Taking into account the time value, the annual interest rate is 8%; (4) Maintenance will reduce the probability of failure and extend the economic life of the transformer; (5) There is a baseline aging curve for power transformers; (6) The older the power transformer is, the more difficult it is to repair it to the same benchmark aging curve as the current one. (7) The theoretical maximum life of a power transformer is T=80 years.

[0045] According to (6) combined with actual maintenance experience, the maintenance effect is expressed as a decreasing function of the service age t. The older the service age, the worse the maintenance effect. Therefore, the decrease in the failure probability of the power transformer after maintenance is: (1) in, and are the actual failure probability and benchmark failure probability of power transformers respectively; k is a constant greater than 1. When there is no more accurate empirical data, it is recommended to take 3.

[0046] (2) in, for, for, is the service life of the transformer.

[0047] S2, annual average net income model for maintenance considering time value; The economic life of a transformer is the most reasonable life span of a converter station from an economic perspective. Specifically, it refers to the number of years during the entire life cycle that can make the annual average cost of a power grid equipment the lowest. The cost of power grid equipment consists of two parts: First, the annual amortization of the initial investment in the equipment, which decreases as the equipment ages; The second is the annual operating cost of the equipment (including daily inspections, maintenance, overhauls and emergency repairs). This part of the cost will increase as the service life increases.

[0048] Therefore, during the entire life cycle of power grid equipment, its annual average total cost will change with the use time of the equipment, and the years with the lowest average total cost are the economic life. Proposing a strategy for replacing power grid equipment in appropriate years can not only save data, but also improve economic benefits, and achieve the goal of maximizing investment benefits for power grid enterprises.

[0049] The economic life of the transformer is t. After the maintenance at time point t, the equivalent service life of the transformer is extended by Therefore, for maintenance, the time period involved in the economic model is .

[0050] During the above period, the total income from the transformer's power supply is: (3) in, is the contribution rate of the power transformer in the entire power supply chain; P is the price difference between buying and selling electricity; is the capacity of the power transformer; is the average load factor of the power transformer.

[0051] Considering the time value, the annual interest rate is 8%, and the service life of the power transformer is In 2017, the total electricity supply revenue is expressed as: (4) The initial investment cost includes the equipment purchase cost and disposal and installation fees: = (5) Transformer service time During this period, the operation and maintenance cost considering the time value is expressed as: (6) in, is the annual basic operation and maintenance cost, and T is the theoretical maximum lifespan.

[0052] Total in-service maintenance cost considering the value of time: (7) in is the basic cost of a single overhaul, which is an average value determined based on long-term experience accumulation; t is the service life.

[0053] The total failure risk cost during service considering the time value is: (8) Taking into account the residual value of the transformer after retirement, the retirement disposal cost is calculated based on 5% of the original value of the asset.

[0054] (9) The decommissioning cost considering the time value is: (10) In summary, in the case of maintenance, the total cost is: (11) Based on this, the average annual net profit under maintenance is expressed as: (12) From formulas (1) to (12), we can see that It is usually a function that increases monotonically with time, reaches a maximum value, and then decreases monotonically with time. , we can get The time t to reach the maximum value (i.e. the optimal maintenance time) and the corresponding maximum annual net profit .

[0055] S3. Annual average net income model considering replacement of time value.

[0056] The annual average net profit model for replacement also takes into account the two major items of income and cost, and the time period involved is from the start of operation to the time of replacement. between.

[0057] Assume that the power transformer is replaced in the tth year. The operating income taking into account the time value during the year is: (13) When replacing, the cost includes 4 items of routine operation and maintenance costs. Among them, the initial investment cost is the same as (5); The operation and maintenance cost considering the time value is expressed as: (14) The total failure risk cost during service considering the time value is: (15) The decommissioning cost considering the time value is: (16) In summary, in the case of replacement, the total cost is: (17) Accordingly, the average annual net benefit under replacement conditions is expressed as: (18) Combining formulas (13)-(18), we know that is a function that increases monotonically with time, reaches a maximum value, and then decreases monotonically with time; let , that is, to obtain The time t to reach the maximum value (i.e. the optimal maintenance time) and the corresponding maximum annual net profit .

[0058] According to the above, the economic life of power equipment is determined by the maximum average annual net income during the life cycle; two scenarios need to be considered, namely whether to replace the equipment: (1) If , indicating that choosing not to replace the equipment can obtain a greater average annual net profit, so it is advisable not to replace it in this case.

[0059] (2) If , indicating that replacing equipment can obtain a greater average annual net profit. In this case, it is advisable to replace equipment, and Corresponding replacement time This is the economic life of the equipment.

[0060] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as systems, methods or program products. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: complete hardware implementation, complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, which may be collectively referred to herein as "circuits", "modules" or "platforms".

[0061] In yet another embodiment of the present invention, a substation maintenance and replacement system taking time value into consideration is provided, and the system can be used to implement the above-mentioned substation maintenance and replacement method taking time value into consideration. Specifically, the substation maintenance and replacement system taking time value into consideration includes a setting module, a first building module, a second building module and a replacement module.

[0062] Among them, a setting module is used to set the economic life conditions of the transformer; The first building block is to build an annual average net profit model for maintenance considering the time value based on the economic life of the transformer, and output the maximum annual average net profit under maintenance. ; The second building block is to build an annual average net profit model for replacement based on the economic life of the transformer, taking into account the time value, and output the maximum annual average net profit under replacement conditions. ; Replace the module when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

[0063] In another embodiment of the present invention, a terminal device is provided, the terminal device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the substation maintenance and replacement method considering the time value, including: Set the economic life conditions of the transformer; build an annual average net profit model for maintenance considering the time value based on the economic life conditions of the transformer, and output the maximum annual average net profit under maintenance ; Based on the economic life of the transformer, a replacement annual net income model considering the time value is constructed, and the maximum annual net income under replacement is output ;when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

[0064] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device, and can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that more specific examples (non-exhaustive list) of the computer-readable storage medium here include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0065] Computer readable storage media also include data signals propagated in baseband or as part of a carrier wave, which carry readable program codes. Such propagated data signals can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than a readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or device. The program code contained on the readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0066] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0067] The processor may load and execute one or more instructions stored in a computer-readable storage medium to implement the corresponding steps of the substation maintenance and replacement method considering time value in the above embodiment; the processor may load and execute the following steps: Set the economic life conditions of the transformer; build an annual average net profit model for maintenance considering the time value based on the economic life conditions of the transformer, and output the maximum annual average net profit under maintenance ; Based on the economic life of the transformer, a replacement annual net income model considering the time value is constructed, and the maximum annual net income under replacement is output ;when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

[0068] See also Figure 3 , the terminal device is a computer device, and the computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, the substation maintenance and replacement method considering the time value in the embodiment is implemented. To avoid repetition, it is not described one by one here. Alternatively, when the computer program 63 is executed by the processor 61, the functions of each model / unit in the substation maintenance and replacement system considering the time value in the embodiment are implemented. To avoid repetition, it is not described one by one here.

[0069] The computer device 60 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Figure 3 This is only an example of the computer device 60 and does not constitute a limitation of the computer device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.

[0070] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, central processing units, graphics processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, data processing logic based on quantum computing, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0071] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the computer device 60.

[0072] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is to be output.

[0073] Any reference to a memory, database or other medium used in the embodiments provided in the present application may include at least one of a non-volatile and a volatile memory. Non-volatile memory may include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory, an optical memory, a high-density embedded non-volatile memory, a resistive random access memory (ReRAM), a magnetic random access memory (MRAM), a ferroelectric random access memory (FRAM), a phase change memory (PCM), a graphene memory, etc. Volatile memory may include a random access memory (RAM) or an external cache memory, etc. As an illustration and not limitation, RAM may be in various forms, such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), etc.

[0074] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0075] See also Figure 4 The terminal device 600 is an electronic device, and the electronic device is in the form of a general computing device. The components of the electronic device may include but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0076] The storage unit stores program codes, which can be executed by the processing unit 610, so that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention described in the above method section of this specification. For example, the processing unit 610 can perform the following steps: Figure 1 Follow the steps shown in .

[0077] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 6201 and / or a cache memory unit 6202 , and may further include a read-only memory unit (ROM) 6203 .

[0078] The storage unit 620 may also include a program / utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0079] Bus 630 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0080] The electronic device 600 may also communicate with one or more external devices 700 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 650. Furthermore, the electronic device 600 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 via a bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0081] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0082] Taking a 220 kV power transformer as an example, the following data related to economic life are obtained, see Table 1 for details.

[0083] Table 1 Related information of a 220KV transformer

[0084] According to reliability prediction, the actual aging curve of the power transformer is known to be: (19) According to the aging life of the main insulation of power transformers being greater than 80 years and the existing operating experience abroad, the benchmark aging curve can be estimated as: (20) The maintenance reduces the failure probability at time t, which is equivalent to extending the life of the power transformer. The failure probability of the power transformer after maintenance is subject to = distribution.

[0085] Combining equations (1), (2) and (19) and (20), we can obtain the Δt value corresponding to any maintenance time t; (twenty one) Combining equations (1)-(12) and Table 1, we can calculate the average annual net income during maintenance. and the best maintenance time; according to formula (19)-(21) and Table 1, the average annual net profit when replacing is obtained and the best time to replace; The relationship with time t is as follows Figure 2 shown.

[0086] according to Figure 2 see, and The horizontal coordinate time corresponding to the intersection of hour, , that is, the average annual net income under maintenance is greater than the average annual net income under replacement; when hour, That is, the average annual net income under maintenance is less than that under replacement, and the average annual net income of replacement is monotonically decreasing, indicating that it should be replaced immediately at 25.82 years.

[0087] In summary, the present invention provides a method and system for substation maintenance and replacement that takes time value into consideration, takes the maximum annual net profit as the optimization goal, and makes a decision on whether to apply maintenance or replacement by comparing the maximum annual average net profits under the two situations; by analyzing various economic factors and laws within the life cycle of the converter station, including power supply income, various actual costs, and risk costs, a mathematical model of the average annual net profit is established for the two situations of maintenance and replacement respectively; finally, the results of empirical research show that the model is highly operational, and the prediction results are in line with reality, which is of practical significance for power grid companies to achieve lean management of power equipment operations and reasonably extend the life of power equipment.

[0088] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0089] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0091] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0092] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0093] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0094] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0095] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0098] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for substation maintenance and replacement considering time value, characterized in that: The following steps are involved: Set transformer economic life conditions; Based on the economic life of the transformer, an annual average net profit model considering the time value is constructed, and the maximum annual average net profit under maintenance is output. ; Based on the economic life of the transformer, a replacement annual net profit model considering the time value is constructed, and the maximum annual net profit under replacement is output. ; when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

2. The substation maintenance and replacement method considering time value according to claim 1 is characterized in that: The economic life conditions of transformers are as follows: The annual operation and maintenance cost increases with the age of power transformers; Maintenance costs increase with the age of power transformers; Taking into account the time value, the annual interest rate is 6%~10%; Maintenance reduces the probability of failure and extends the economic life of the transformer; There is a baseline aging curve for power transformers; The older the power transformer is, the more difficult it is to repair it to the same benchmark aging curve as it was at the same time. The maximum life of a power transformer is calculated as T=80 years.

3. The substation maintenance and replacement method considering time value according to claim 2 is characterized in that: The reduction in the probability of power transformer failure after maintenance for: in, and are the actual power transformer failure probability and the benchmark failure probability respectively; k is a constant greater than 1, is the transformer in-service life, is the maximum life of the transformer.

4. The substation maintenance and replacement method considering time value according to claim 1 is characterized in that: Maximum annual net profit under maintenance The average annual net income under maintenance The corresponding profit when the maximum value is reached.

5. The method for substation maintenance and replacement considering time value according to claim 4 is characterized in that: Average annual net income under maintenance for: in, is the total revenue from electricity supply, is the total cost in the case of overhaul, For time period.

6. The substation maintenance and replacement method considering time value according to claim 5 is characterized in that: Total power supply revenue for: in, is the contribution rate of the power transformer in the entire power supply chain; P is the price difference between buying and selling electricity; is the capacity of the power transformer; is the average load factor of the power transformer, is the annual interest rate; Total Cost for: in, is the initial investment cost, Transformer service time During this period, the time value and operation and maintenance costs are considered. The total maintenance cost during service life considering the time value is: is the total failure risk cost during service considering the time value, The decommissioning disposal cost takes into account the time value.

7. The substation maintenance and replacement method considering time value according to claim 1 is characterized in that: Maximum annual net income under replacement conditions Average annual net income under replacement The corresponding profit when the maximum value is reached.

8. The method for substation maintenance and replacement considering time value according to claim 7, characterized in that: Average annual net income under replacement for: still in, The power transformer from time 0 to the Operating income during the year taking into account the time value, is the total cost in the case of replacement, For the number of years.

9. The method for substation maintenance and replacement considering time value according to claim 8, characterized in that: The power transformer is at time 0 to Operating income taking into account time value during the year for: in, is the contribution rate of the power transformer in the entire power supply chain; P is the price difference between buying and selling electricity; is the capacity of the power transformer; is the average load factor of the power transformer, is the annual interest rate; Total cost in case of replacement for: in, is the initial investment cost, To consider the time value of operation and maintenance costs, is the total failure risk cost during service considering the time value, The decommissioning disposal cost takes into account the time value.

10. A substation maintenance and replacement system considering time value, characterized in that: include: Setting module, setting transformer economic life conditions; The first building block is to build an annual average net profit model for maintenance considering the time value based on the economic life of the transformer, and output the maximum annual average net profit under maintenance. ; The second building block is to build an annual average net profit model for replacement based on the economic life of the transformer, taking into account the time value, and output the maximum annual average net profit under replacement conditions. ; Replace the module when , do not replace the power grid equipment; when , replace power grid equipment, Corresponding replacement time This is the economic life of the equipment.

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