Oil paper insulation life evaluation method, device and equipment of converter transformer and medium

Abstract

The invention discloses an oil paper insulation life evaluation method, device and equipment of a converter transformer and a medium, and relates to the technical field of electric power engineering, and the method comprises the steps: building an insulation life improvement model based on a linear cumulative damage theory and a thermal aging model; carrying out numerical solution on the electromagnetic field and the solid force field to obtain Lorentz force density and mechanical damage accumulation equivalent stress distribution, and determining an equivalent stress translation factor by utilizing the mechanical damage accumulation equivalent stress distribution; solving numerical values of the oil paper insulation space temperature field and the electromagnetic field to obtain total eddy current loss, and determining a temperature translation factor based on the Lorentz force density, the total eddy current loss and the oil paper insulation space temperature field; calculating total acceleration factor distribution by using the equivalent stress translation factor and the temperature translation factor, inputting the total acceleration factor distribution into the insulation life improvement model, and outputting space life distribution; and carrying out oil paper insulation life evaluation on the converter transformer, realizing quantitative evaluation on insulation fatigue damage under the action of cyclic load, and comprehensively evaluating the life of an insulation material.

Description

Technical Field

[0001] This invention relates to the field of power engineering technology, and in particular to a method, apparatus, equipment and medium for assessing the life of oil-paper insulation of converter transformers. Background Technology

[0002] Converter transformers are core equipment in DC transmission systems, and their operational reliability directly affects the safety and stability of the entire power grid. Oil-paper insulation, as the core medium for inter-turn and inter-layer insulation in converter transformer windings, has a remaining life that is a key indicator for assessing the service status of converter transformers. Existing research simplifies the cyclic mechanical stress on oil-paper insulation as a static load, failing to accurately characterize the cumulative effect of fatigue damage to the insulation material caused by cyclic stress. Furthermore, existing research struggles to characterize the non-uniform lifespan characteristics caused by uneven field distribution within the insulation system, making it impossible to accurately locate aging and weakened areas.

[0003] As can be seen from the above, how to achieve quantitative assessment of insulation fatigue damage under cyclic loading, accurately characterize the non-uniform distribution of the spatial lifetime of oil-paper insulation, accurately predict the spatial distribution of the lifetime of converter transformer insulation system, and comprehensively evaluate the lifetime characteristics of insulation materials under complex working conditions are problems to be solved in this field. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method, apparatus, equipment, and medium for assessing the lifespan of oil-paper insulation in converter transformers. This method enables quantitative assessment of insulation fatigue damage under cyclic loading, accurately characterizes the non-uniform distribution of the spatial lifespan of oil-paper insulation, achieves accurate prediction of the spatial distribution of the lifespan of the converter transformer insulation system, and comprehensively evaluates the lifespan characteristics of insulation materials under complex operating conditions. The specific solution is as follows: In a first aspect, this application discloses a method for evaluating the lifespan of the oil-paper insulation of a converter transformer, including: An improved insulation life model considering the cumulative effect of mechanical damage is constructed based on the linear cumulative damage theory and thermal aging model. The electromagnetic field and solid force field of the converter transformer are numerically solved to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The equivalent stress translation factor is determined using the cumulative equivalent stress distribution of mechanical damage. The temperature field and electromagnetic field of the oil-paper insulation space of the converter transformer are numerically solved to obtain the total eddy current loss. The temperature shift factor is determined based on the Lorentz force density, the total eddy current loss and the temperature field of the oil-paper insulation space. The total acceleration factor distribution is calculated using the equivalent stress translation factor and the temperature translation factor. The total acceleration factor distribution is then input into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation life of the converter transformer is evaluated based on the spatial lifetime distribution.

[0005] Optionally, the improved insulation life model considering the cumulative effect of mechanical damage, based on linear cumulative damage theory and thermal aging model, includes: Based on Miner's fatigue damage accumulation theory, and by introducing a time-varying stress function, the damage degree and fatigue life functions of the material are constructed. The constant stress value equivalent to the cumulative mechanical damage is calculated using the damage degree and fatigue life function of the material. The material's damage degree and fatigue life function, the constant stress value equivalent to the mechanical damage accumulation, and the Arrhenius thermal aging model are combined to construct an improved insulation life model that considers the cumulative effect of mechanical damage.

[0006] Optionally, the improved insulation life model considering the cumulative effect of mechanical damage is as follows: ; in, Equivalent stress intensity R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress, Equivalent stress-time shift factor This is the temperature-time shift factor. The activation energy of the reaction. For reference temperature value, This is the temperature-equivalent stress-time shift factor. This is an indicator of the aging status of insulating paper. This represents the current degree of polymerization of the insulating paper. This represents the initial degree of polymerization of the insulating paper. This refers to the time required to reach the critical aging state under reference temperature and reference stress. This represents the average value of the critical aging state value. This refers to the time required to reach the critical aging state under actual temperature and reference stress.

[0007] Optionally, the step of numerically solving the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer, and determining the equivalent stress translation factor using the cumulative equivalent stress distribution of mechanical damage, includes: Time-varying simulations were performed on the internal space of the converter transformer to obtain the electromagnetic field and solid force field; The electromagnetic field is numerically solved using a sequential coupling solution method to obtain the Lorentz force density; The Lorentz force density is used as a structural load to transfer to the solid force field in order to construct the time-varying stress function of the oil-paper insulation; A damage integral equation is constructed based on Miner's fatigue damage accumulation theory and the time-varying stress function. Under the critical condition of insulation failure, the damage integral equation is solved to obtain the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The cumulative equivalent stress distribution of mechanical damage is substituted into the formula for calculating the equivalent stress translation factor to obtain the equivalent stress translation factor.

[0008] Optionally, the formula for calculating the cumulative equivalent stress distribution of mechanical damage is: ; in, For the cumulative equivalent stress distribution of mechanical damage, R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress; The formula for calculating the equivalent stress translation factor is as follows: ; in, This is the equivalent stress shift factor.

[0009] Optionally, determining the temperature translation factor based on the Lorentz force density, the total eddy current loss, and the temperature field of the oil-paper insulation space includes: The Lorentz force density is transferred to the heat flow field as a heat source term, and the temperature distribution of the oil-paper insulation space is calculated based on the total eddy current loss and the temperature field of the oil-paper insulation space. The temperature shift factor is determined using the temperature distribution in the oil-paper insulation space.

[0010] Optionally, the step of calculating the total acceleration factor distribution using the equivalent stress translation factor and the temperature translation factor, and inputting the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation, includes: Calculate the product between the equivalent stress translation factor and the temperature translation factor, and use the product as the total acceleration factor distribution; The total acceleration factor distribution is input into the insulation lifetime improvement model to output the spatial lifetime distribution of the paper insulation.

[0011] Secondly, this application discloses a device for evaluating the life of oil-paper insulation of a converter transformer, comprising: The step of calculating the total acceleration factor distribution using the equivalent stress shift factor and the temperature shift factor, and inputting the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation includes: Calculate the product between the equivalent stress translation factor and the temperature translation factor, and use the product as the total acceleration factor distribution; The total acceleration factor distribution is input into the insulation lifetime improvement model to output the spatial lifetime distribution of the paper insulation.

[0012] Thirdly, this application discloses an electronic device, including: Memory, used to store computer programs; A processor is used to execute the computer program to implement the aforementioned method for evaluating the life of oil-paper insulation of converter transformers.

[0013] Fourthly, this application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned disclosed method for evaluating the life of oil-paper insulation of converter transformers.

[0014] As can be seen, this application provides a method for assessing the lifespan of the oil-paper insulation of a converter transformer, including: constructing an improved insulation lifespan model considering the cumulative effect of mechanical damage based on linear cumulative damage theory and thermal aging model; numerically solving the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer; determining the equivalent stress shifting factor using the equivalent stress distribution of mechanical damage accumulation; numerically solving the spatial temperature field of the oil-paper insulation and the electromagnetic field of the converter transformer to obtain the total eddy current loss; determining the temperature shifting factor based on the Lorentz force density, the total eddy current loss, and the spatial temperature field of the oil-paper insulation; calculating the total acceleration factor distribution using the equivalent stress shifting factor and the temperature shifting factor; inputting the total acceleration factor distribution into the improved insulation lifespan model to output the spatial lifespan distribution of the oil-paper insulation; and assessing the lifespan of the oil-paper insulation of the converter transformer based on the spatial lifespan distribution. This application constructs an improved insulation life model considering the cumulative effect of mechanical damage based on linear cumulative damage theory and thermal aging model. This model avoids inaccurate life assessments caused by omitting mechanical damage factors, improving the comprehensiveness and accuracy of insulation life prediction. Numerical solutions are performed on the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer. The equivalent stress shift factor is determined using the equivalent stress distribution of mechanical damage accumulation, transforming mechanical damage into a calculable equivalent stress shift factor, thus achieving a quantitative characterization of the accelerating effect of mechanical damage on insulation aging. Numerical solutions are also performed on the spatial temperature field and electromagnetic field of the oil-paper insulation of the converter transformer to obtain the total eddy current loss. The temperature shift factor is determined by the Lorentz force density, total eddy current loss, and spatial temperature field of the oil-paper insulation. This solves the problems of neglecting eddy current loss and uneven temperature distribution in traditional temperature factor calculations, and avoids life prediction deviations caused by inaccurate temperature calculations. The total acceleration factor distribution is calculated using the equivalent stress shift factor and temperature shift factor. The total acceleration factor distribution is input into the insulation life improvement model to output the spatial life distribution of the oil-paper insulation. Based on the spatial life distribution, the life of the oil-paper insulation of the converter transformer is evaluated. This comprehensively assesses the life characteristics of the insulation material under complex operating conditions, realizes the quantitative assessment of insulation fatigue damage under cyclic loading, accurately characterizes the non-uniform distribution of the spatial life of the oil-paper insulation, and achieves accurate prediction of the spatial distribution of the life of the converter transformer insulation system. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This application discloses a flowchart of a method for assessing the lifespan of oil-paper insulation in a converter transformer. Figure 2 This application discloses a specific flowchart for assessing the lifespan of the oil-paper insulation of a converter transformer. Figure 3 This is a structural diagram of a two-dimensional axisymmetric finite element model disclosed in this application; Figure 4 This application discloses an instantaneous mechanical stress distribution diagram; Figure 5 This application discloses a distribution diagram of instantaneous stress, effective stress, and translation factor of a converter transformer under rated load. Figure 6 This application discloses an equivalent stress distribution diagram; Figure 7 This is an equivalent stress shift factor distribution diagram disclosed in this application; Figure 8 This application discloses a temperature distribution map; Figure 9 This application discloses a temperature translation factor distribution map; Figure 10 This application discloses a total translation factor distribution map; Figure 11 This application discloses a remaining lifetime distribution map; Figure 12 This is a diagram showing the axial distribution of the lifespan of an oil-paper insulation system disclosed in this application. Figure 13 This is a schematic diagram of the structure of a converter transformer oil-paper insulation life assessment device disclosed in this application; Figure 14 This application provides a structural diagram of an electronic device. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Converter transformers are core equipment in DC transmission systems, and their operational reliability directly affects the safety and stability of the entire power grid. Oil-paper insulation, as the core medium for inter-turn and inter-layer insulation in converter transformer windings, has a remaining lifespan that is a key indicator for assessing the service status of converter transformers. Existing research simplifies the cyclic mechanical stress on oil-paper insulation as a static load, failing to accurately characterize the cumulative effect of fatigue damage to insulation materials caused by cyclic stress. Furthermore, existing research struggles to characterize the non-uniform lifespan characteristics caused by uneven field distribution within the insulation system, making it impossible to accurately locate aging and weakened areas. Therefore, how to quantitatively assess insulation fatigue damage under cyclic loading, accurately characterize the non-uniform spatial lifespan distribution of oil-paper insulation, accurately predict the spatial lifespan distribution of converter transformer insulation systems, and comprehensively evaluate the lifespan characteristics of insulation materials under complex operating conditions are problems that need to be solved in this field.

[0019] See Figure 1 As shown in the figure, this invention discloses a method for evaluating the lifespan of the oil-paper insulation of a converter transformer, which may specifically include: Step S11: Construct an improved insulation life model that considers the cumulative effect of mechanical damage based on the linear cumulative damage theory and thermal aging model.

[0020] In this embodiment, based on Miner's fatigue damage accumulation theory, a time-varying stress function is introduced to construct the material's damage degree and fatigue life function; the material's damage degree and fatigue life function are used to calculate the constant stress value equivalent to mechanical damage accumulation; the material's damage degree and fatigue life function, the constant stress value equivalent to mechanical damage accumulation, are combined with the Arrhenius thermal aging model to construct an improved insulation life model considering the mechanical damage accumulation effect; the improved insulation life model considering the mechanical damage accumulation effect is as follows: ; in, Equivalent stress intensity R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress, Equivalent stress-time shift factor This is the temperature-time shift factor. The activation energy of the reaction. For reference temperature value, This is the temperature-equivalent stress-time shift factor. This is an indicator of the aging status of insulating paper. This represents the current degree of polymerization of the insulating paper. This represents the initial degree of polymerization of the insulating paper. This refers to the time required to reach the critical aging state under reference temperature and reference stress. This represents the average value of the critical aging state value. This refers to the time required to reach the critical aging state under actual temperature and reference stress.

[0021] Microscopic mechanism studies show that the aging of oil-paper insulation under alternating stress is essentially a fatigue damage accumulation process following Miner's fatigue damage accumulation theory. Based on this, this patent proposes an improved insulation life model that considers the mechanical damage accumulation effect. First, a time-varying stress function is introduced. This characterizes the time-varying properties of mechanical stress during actual operation. Based on Miner's fatigue damage accumulation theory, the damage degree and fatigue life functions of a material are as follows: ; in, D For the degree of damage to the material, t The time during which the load is applied. This is a lifetime function of paper insulation under instantaneous stress.

[0022] Substitute the above lifetime function into the damage integral, and let D =1 (corresponding to insulation failure), equating time-varying stress to constant stress. The formula is as follows, from which the equivalent constant stress value of mechanical damage accumulation can be obtained. : ; Based on this, an improved insulation life model was established by combining the Arrhenius thermal aging model and simultaneously considering the cumulative effect of mechanical damage. Compared with the traditional model, the advantages of the improved insulation life model lie in its comprehensive consideration of the coupling effect of the temperature field and the time-varying mechanical stress field, and in achieving accurate quantitative assessment of the spatial distribution of insulation life. Specific comparisons are shown in Table 1. Table 1. Comparison between the improved insulation life model and the traditional thermal aging model.

[0023] Step S12: Numerically solve the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer, and use the cumulative equivalent stress distribution of mechanical damage to determine the equivalent stress translation factor.

[0024] In this embodiment, time-varying simulation is performed on the internal space of the converter transformer to obtain the electromagnetic field and solid force field; the electromagnetic field is numerically solved using a sequential coupling solution method to obtain the Lorentz force density; the Lorentz force density is transferred as a structural load to the solid force field to construct the time-varying stress function of the oil-paper insulation; a damage integral equation is constructed based on Miner's fatigue damage accumulation theory and the time-varying stress function; under the critical condition of insulation failure, the damage integral equation is solved to obtain the mechanical damage accumulation equivalent stress distribution of the oil-paper insulation of the converter transformer; the mechanical damage accumulation equivalent stress distribution is substituted into the equivalent stress translation factor calculation formula to obtain the equivalent stress translation factor; the calculation formula for the mechanical damage accumulation equivalent stress distribution is: ; in, For the cumulative equivalent stress distribution of mechanical damage, R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress; The formula for calculating the equivalent stress translation factor is as follows: ; in, This is the equivalent stress shift factor.

[0025] Specifically, firstly, the electromagnetic field analysis employs a quasi-static approximation method based on the magnetic vector potential (A), and its governing equations are as follows: ; in, The material's magnetic permeability, A three-dimensional current density source is applied to the winding region, with the outer boundary set as a magnetically insulating condition. ); Secondly, the electromagnetic field is calculated to obtain the Lorentz force density. This Lorentz force density is then used as a structural load transferred to the solid force field to solve for the stress distribution of the oil-paper insulation. The solid force field structural response analysis is based on linear elasticity theory and is solved using equilibrium equations, geometric equations, and the constitutive relation of the generalized Hooke's law. The formulas are as follows: ; ; .

[0026] in, For the three-dimensional stress tensor in space, It is a three-dimensional volume force vector. For the three-dimensional strain tensor, It is a three-dimensional displacement field. It is a fourth-order elastic tensor.

[0027] Next, based on Miner's fatigue damage accumulation theory, a damage integral equation under time-varying stress field is established, as follows: ; in, For the degree of damage to the material, The stress function is the time-varying stress function of the oil-paper insulation. For the cumulative equivalent stress distribution of mechanical damage, This is a function of the spatial lifetime of paper insulation under instantaneous stress. The characteristic lifetime is under reference stress.

[0028] Critical conditions for insulation failure ( D Under condition =1), by solving the damage integral equation, the cumulative equivalent stress distribution of mechanical damage at each point in space is obtained. Finally, the cumulative equivalent stress distribution of mechanical damage is... Substituting into the formula for calculating the equivalent stress translation factor, the equivalent stress translation factor at each point is obtained. This translation factor enables a quantitative characterization of the damage effect of cyclic mechanical stress.

[0029] Step S13: Numerically solve the temperature field and electromagnetic field of the oil-paper insulation space of the converter transformer to obtain the total eddy current loss, and determine the temperature shift factor based on the Lorentz force density, the total eddy current loss and the temperature field of the oil-paper insulation space.

[0030] In this embodiment, the temperature field and electromagnetic field of the oil-paper insulation space of the converter transformer are numerically solved to obtain the total eddy current loss. The Lorentz force density is transferred to the heat flow field as a heat source term. The temperature distribution of the oil-paper insulation space is calculated based on the total eddy current loss and the temperature field of the oil-paper insulation space. The temperature shift factor is determined using the temperature distribution of the oil-paper insulation space.

[0031] This application determines the temperature translation factor by constructing a sequential coupling of electromagnetic and thermal flow fields. First, based on the formula... Obtain the spatial magnetic flux density distribution and winding eddy current loss density. Calculate the total eddy current loss. The formula is as follows: ; in, For electrical conductivity, The region is a conductor, and T is the current period. Secondly, the eddy current loss density of the winding obtained from electromagnetic field calculations is used as a heat source term and transferred to the heat flow field to solve for the temperature distribution in the oil-paper insulation space. The fluid flow and heat transfer process in the insulating oil domain satisfies the continuity equation, and the formulas for the momentum conservation equation and energy conservation equation are as follows: ; ; ; in, For fluid density, For the velocity field, For pressure, For dynamic viscosity, Where k is the specific heat capacity at constant pressure and k is the thermal conductivity. For temperature, The total heat source term includes winding losses coupled from the electromagnetic field. and core loss.

[0032] Finally, based on the temperature field of the oil-paper insulation space The distribution of the temperature shift factor at each point in space is calculated by substituting it into the improved insulation life model. The formula is as follows: .

[0033] Step S14: Calculate the total acceleration factor distribution using the equivalent stress translation factor and the temperature translation factor, and input the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation.

[0034] In this embodiment, the product between the equivalent stress translation factor and the temperature translation factor is calculated, and the product is used as the total acceleration factor distribution; the total acceleration factor distribution is input into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation.

[0035] To achieve accurate assessment of the lifespan of the converter transformer insulation system, this application integrates the aforementioned multiphysics simulation and damage equivalent calculation results to perform spatial non-uniform distribution calculation of the insulation lifespan. First, it integrates the synergistic effects of temperature and stress, multiplying the equivalent stress translation factor by the temperature translation factor to calculate the total acceleration factor distribution at each point in space. The formula is as follows: ; Finally, the total translation factor was substituted into the improved insulation lifetime model to obtain the spatial lifetime distribution, which is the characteristic lifetime of the insulating paper measured at the laboratory reference aging temperature of 130°C. As a reference lifetime, the spatial lifetime distribution of the paper insulation was calculated. This lifetime distribution can directly guide the accurate assessment of insulation reliability and the location of weak areas, providing a key basis for the reliability assessment of converter transformers.

[0036] This application proposes an improved lifespan model for oil-paper insulation that considers the cumulative effect of mechanical damage. It transforms the time-varying mechanical stress field into an equivalent damage factor and employs electromagnetic-thermal-solid force multiphysics coupling simulation technology to achieve accurate prediction of the lifespan distribution of oil-paper insulation systems. By comprehensively considering the synergistic effect of mechanical damage and thermal aging, this method can more comprehensively evaluate the lifespan characteristics of insulation materials under complex operating conditions. It provides a theoretical basis for accurate assessment of transformer insulation status, prediction of remaining lifespan, and formulation of differentiated operation and maintenance strategies, and has significant engineering application value.

[0037] Step S15: Evaluate the oil-paper insulation life of the converter transformer based on the spatial lifetime distribution.

[0038] The specific process for assessing the lifespan of the oil-paper insulation of the converter transformer in this application is as follows: Figure 2 As shown, firstly, an improved insulation life model considering the cumulative effect of mechanical damage is established; secondly, an electromagnetic-solid mechanics sequential coupling method is used to simulate and obtain the time-varying solid force field distribution inside the transformer, and convert it into an effective stress distribution to calculate the equivalent stress translation factor; nextly, the temperature distribution inside the transformer is obtained through electromagnetic-thermal-fluid sequential coupling simulation, and the temperature translation factor is calculated based on this distribution; finally, the total acceleration factor distribution is calculated by combining the mechanical and temperature translation factors, and the total acceleration factor distribution is input into the improved insulation life model to output the spatial life distribution of the oil-paper insulation, thereby achieving an accurate assessment of the non-uniform characteristics of insulation life.

[0039] This application has two main advantages: First, by introducing an equivalent characterization method for mechanical dynamic damage, time-varying mechanical stress is equivalent to constant stress, enabling a quantitative assessment of insulation fatigue damage under cyclic loading. Second, an improved insulation lifetime model considering the cumulative effect of mechanical damage is established, achieving accurate characterization of the non-uniform distribution of the spatial lifetime of oil-paper insulation. The main innovation of this application is to first perform damage equivalence on the temperature field and time-varying mechanical stress field obtained from multi-physics coupling simulation, and then calculate the non-uniform distribution of the spatial lifetime of the oil-paper insulation system through the improved lifetime model.

[0040] Taking a 220 kV converter transformer as an example, the implementation method and specific operation process are as follows, based on the technical solution of this invention: (1) Construction of a two-dimensional axisymmetric finite element model of the converter transformer: A two-dimensional axisymmetric finite element model is established by scaling the actual size proportionally. The structure of the two-dimensional axisymmetric finite element model is as follows: Figure 3 As shown in Table 2, the performance parameters of the key materials in the model are as follows: Table 2 Basic Parameters of Converter Transformer

[0041] The converter transformer core model is a single-phase four-column structure, consisting of two main columns and two side columns, with the windings wound on the main columns. The two sets of windings are connected in parallel, with the same structure but opposite winding directions. From the inside out, they are the voltage regulating winding, the grid-side winding, and the valve-side winding. The winding structure includes components such as copper conductors, insulating paper, oil baffles, equalizing rings, phase spacers, and corner rings. The horizontal and vertical oil passages are mechanically supported and guided by pads and support bars, respectively.

[0042] (2) Spatial distribution characteristics of equivalent translation factor of mechanical stress: First, based on the sequential coupling simulation of electromagnetic-solid force field, the instantaneous mechanical stress distribution of converter transformer under rated load is obtained. Instantaneous mechanical stress distribution as Figure 4 As shown in the figure. Simulation results show that under rated load, the mechanical stress amplitude of the converter transformer windings varies periodically with time due to alternating electromagnetic forces. The grid-side winding exhibits periodic stretching, while the valve-side winding exhibits periodic compression. The winding region shows significant spatial non-uniformity and time-varying characteristics with time-periodic variation, especially at the winding ends and in the middle region, due to the interaction between electromagnetic forces and structural constraints, and fluctuating periodically with the load current. The instantaneous stress, effective stress, and translation factor distribution of the converter transformer under rated load are shown in the figure. Figure 5 As shown, the grid-side winding exhibits periodic stretching, with a maximum tensile stress of 11.4 MPa and an equivalent stress of 10.3 MPa after mechanical damage accumulation; while the valve-side winding exhibits periodic compression, with a maximum compressive stress of 11.3 MPa and an equivalent stress of 10.1 MPa.

[0043] Then, based on the cumulative effect of mechanical damage, the above-mentioned instantaneous stress distribution results are substituted into... Obtain the equivalent stress distribution Equivalent stress distribution as Figure 6 As shown in the figure. The equivalent calculation results show that the equivalent stress still maintains a non-uniform distribution in space. The maximum equivalent stress value is 17.6 MPa, which appears in the middle region of the two windings, while the equivalent stress in the regions on both sides of the windings is relatively low, remaining in the range of 1.2-1.5 MPa.

[0044] Finally, substitute the equivalent stress values ​​into... Obtain the equivalent stress shift factor The distribution results, the equivalent stress shift factor distribution is as follows: Figure 7As shown, the calculation results show that the numerical range of the mechanical damage equivalent translation factor is between 1 and 1.38, and the spatial distribution of the mechanical damage equivalent translation factor is consistent with the equivalent stress distribution, mainly concentrated in the winding end and middle regions.

[0045] (3) Spatial distribution characteristics analysis of temperature translation factor: In order to further quantify the impact of thermal aging on insulation life, this patent obtained the temperature field distribution T(x,y,z) of the converter transformer under rated load based on electromagnetic-thermal-fluid multiphysics field coupling simulation. The temperature distribution is as follows: Figure 8 As shown, the internal temperature of the transformer exhibits a significant spatial gradient, gradually increasing from the bottom to the top of the winding, ranging from 24.3°C to 65.2°C. The high-temperature region is mainly concentrated in the upper part of the winding, reaching a maximum of 65.2°C. Substituting the spatial temperature distribution into... Further obtain the temperature translation factor Distribution, temperature translation factor distribution as follows Figure 9 As shown, from a spatial distribution perspective, the temperature translation factor follows the same pattern as the temperature field numerical distribution, gradually increasing from the bottom to the top, with the numerical range of the temperature translation factor being... to Between these values, the maximum value is located at the hot spot temperature.

[0046] Based on the equivalent stress shift factor obtained above With temperature translation factor Spatial distribution, through The total translation factor was calculated. Spatial distribution, total translation factor distribution as follows Figure 10 As shown. The maximum total translation factor is 0.01488, located in the upper part of the winding; the translation factor is smaller in the oil ducts and peripheral insulation areas. The characteristic life of the insulating paper was measured at a laboratory reference aging temperature of 130℃. =30.24 (days) was used as the reference lifetime to obtain the remaining lifetime distribution of the oil-paper insulation system. The remaining lifetime distribution is as follows: Figure 11 As shown. The minimum lifetime distribution is 5582 days, and the weakest point in lifetime is the location with the maximum total translation factor. Using the longitudinal axis LV of this location as a reference line, the distribution law of oil-paper insulation lifetime along the winding height under different loads was studied. The overall oil-paper insulation lifetime on the valve side exhibits a gradient distribution along the winding height direction, with higher values ​​at the bottom and lower values ​​at the top. The axial distribution law of the oil-paper insulation system lifetime is shown below. Figure 12 As shown in the figure. The method proposed in this patent enables a visual representation of the lifetime distribution of the converter transformer insulation system. By identifying weak areas in the insulation lifetime, it provides a scientific basis for formulating differentiated operation and maintenance strategies, and has significant engineering value for improving the operational reliability of converter transformers.

[0047] In this embodiment, an improved insulation life model considering the cumulative effect of mechanical damage is constructed based on the linear cumulative damage theory and the thermal aging model. The electromagnetic field and solid force field of the converter transformer are numerically solved to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer. The equivalent stress shift factor is determined using the equivalent stress distribution of mechanical damage accumulation. The spatial temperature field of the oil-paper insulation and the electromagnetic field of the converter transformer are numerically solved to obtain the total eddy current loss. The temperature shift factor is determined based on the Lorentz force density, the total eddy current loss, and the spatial temperature field of the oil-paper insulation. The total acceleration factor distribution is calculated using the equivalent stress shift factor and the temperature shift factor. The total acceleration factor distribution is input into the improved insulation life model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation lifetime of the converter transformer is evaluated based on the spatial lifetime distribution. This application constructs an improved insulation life model considering the cumulative effect of mechanical damage based on linear cumulative damage theory and thermal aging model. This model avoids inaccurate life assessments caused by omitting mechanical damage factors, improving the comprehensiveness and accuracy of insulation life prediction. Numerical solutions are performed on the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer. The equivalent stress shift factor is determined using the equivalent stress distribution of mechanical damage accumulation, transforming mechanical damage into a calculable equivalent stress shift factor, thus achieving a quantitative characterization of the accelerating effect of mechanical damage on insulation aging. Numerical solutions are also performed on the spatial temperature field and electromagnetic field of the oil-paper insulation of the converter transformer to obtain the total eddy current loss. The temperature shift factor is determined by the Lorentz force density, total eddy current loss, and spatial temperature field of the oil-paper insulation. This solves the problems of neglecting eddy current loss and uneven temperature distribution in traditional temperature factor calculations, and avoids life prediction deviations caused by inaccurate temperature calculations. The total acceleration factor distribution is calculated using the equivalent stress shift factor and temperature shift factor. The total acceleration factor distribution is input into the insulation life improvement model to output the spatial life distribution of the oil-paper insulation. Based on the spatial life distribution, the life of the oil-paper insulation of the converter transformer is evaluated. This comprehensively assesses the life characteristics of the insulation material under complex operating conditions, realizes the quantitative assessment of insulation fatigue damage under cyclic loading, accurately characterizes the non-uniform distribution of the spatial life of the oil-paper insulation, and achieves accurate prediction of the spatial distribution of the life of the converter transformer insulation system.

[0048] See Figure 13 As shown in the figure, an embodiment of the present invention discloses a device for evaluating the life of oil-paper insulation of a converter transformer, which may specifically include: Model building module 11 is used to build an improved insulation life model that considers the cumulative effect of mechanical damage based on linear cumulative damage theory and thermal aging model; The equivalent stress translation factor determination module 12 is used to numerically solve the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer, and to determine the equivalent stress translation factor using the cumulative equivalent stress distribution of mechanical damage. Temperature shift factor determination module 13 is used to numerically solve the temperature field of the oil-paper insulation space and the electromagnetic field of the converter transformer to obtain the total eddy current loss, and to determine the temperature shift factor based on the Lorentz force density, the total eddy current loss and the temperature field of the oil-paper insulation space. The spatial lifetime distribution determination module 14 is used to calculate the total acceleration factor distribution using the equivalent stress translation factor and the temperature translation factor, and input the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation life assessment module 15 is used to assess the oil-paper insulation life of the converter transformer based on the spatial life distribution.

[0049] In this embodiment, an improved insulation life model considering the cumulative effect of mechanical damage is constructed based on the linear cumulative damage theory and the thermal aging model. The electromagnetic field and solid force field of the converter transformer are numerically solved to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer. The equivalent stress shift factor is determined using the equivalent stress distribution of mechanical damage accumulation. The spatial temperature field of the oil-paper insulation and the electromagnetic field of the converter transformer are numerically solved to obtain the total eddy current loss. The temperature shift factor is determined based on the Lorentz force density, the total eddy current loss, and the spatial temperature field of the oil-paper insulation. The total acceleration factor distribution is calculated using the equivalent stress shift factor and the temperature shift factor. The total acceleration factor distribution is input into the improved insulation life model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation lifetime of the converter transformer is evaluated based on the spatial lifetime distribution. This application constructs an improved insulation life model considering the cumulative effect of mechanical damage based on linear cumulative damage theory and thermal aging model. This model avoids inaccurate life assessments caused by omitting mechanical damage factors, improving the comprehensiveness and accuracy of insulation life prediction. Numerical solutions are performed on the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the equivalent stress distribution of mechanical damage accumulation on the oil-paper insulation of the converter transformer. The equivalent stress shift factor is determined using the equivalent stress distribution of mechanical damage accumulation, transforming mechanical damage into a calculable equivalent stress shift factor, thus achieving a quantitative characterization of the accelerating effect of mechanical damage on insulation aging. Numerical solutions are also performed on the spatial temperature field and electromagnetic field of the oil-paper insulation of the converter transformer to obtain the total eddy current loss. The temperature shift factor is determined by the Lorentz force density, total eddy current loss, and spatial temperature field of the oil-paper insulation. This solves the problems of neglecting eddy current loss and uneven temperature distribution in traditional temperature factor calculations, and avoids life prediction deviations caused by inaccurate temperature calculations. The total acceleration factor distribution is calculated using the equivalent stress shift factor and temperature shift factor. The total acceleration factor distribution is input into the insulation life improvement model to output the spatial life distribution of the oil-paper insulation. Based on the spatial life distribution, the life of the oil-paper insulation of the converter transformer is evaluated. This comprehensively assesses the life characteristics of the insulation material under complex operating conditions, realizes the quantitative assessment of insulation fatigue damage under cyclic loading, accurately characterizes the non-uniform distribution of the spatial life of the oil-paper insulation, and achieves accurate prediction of the spatial distribution of the life of the converter transformer insulation system.

[0050] In some specific embodiments, the model building module 11 may specifically include: The module for constructing damage degree and fatigue life functions is used to construct the damage degree and fatigue life functions of materials based on Miner's fatigue damage accumulation theory and by introducing time-varying stress functions. A constant stress value calculation module is used to calculate the constant stress value equivalent to the cumulative mechanical damage using the damage degree and fatigue life function of the material; The specific construction module of the insulation life improvement model is used to combine the damage degree and fatigue life function of the material, the constant stress value equivalent to the mechanical damage accumulation, and the Arrhenius thermal aging model to construct an insulation life improvement model that considers the mechanical damage accumulation effect.

[0051] In some specific embodiments, the improved insulation life model considering the cumulative effect of mechanical damage is as follows: ; in, Equivalent stress intensity R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress, Equivalent stress-time shift factor This is the temperature-time shift factor. The activation energy of the reaction. For reference temperature value, This is the temperature-equivalent stress-time shift factor. This is an indicator of the aging status of insulating paper. This represents the current degree of polymerization of the insulating paper. This represents the initial degree of polymerization of the insulating paper. This refers to the time required to reach the critical aging state under reference temperature and reference stress. This represents the average value of the critical aging state value. This refers to the time required to reach the critical aging state under actual temperature and reference stress.

[0052] In some specific embodiments, the equivalent stress translation factor determination module 12 may specifically include: The time-varying simulation module is used to perform time-varying simulations of the internal space of the converter transformer in order to obtain the electromagnetic field and solid force field. The numerical solution module is used to numerically solve the electromagnetic field using a sequential coupling solution method to obtain the Lorentz force density; The time-varying stress function construction module is used to transfer the Lorentz force density as a structural load to the solid force field in order to construct the time-varying stress function of the oil-paper insulation. The damage integral equation construction module is used to construct the damage integral equation based on Miner's fatigue damage accumulation theory and the time-varying stress function. The damage integral equation solving module is used to solve the damage integral equation under the critical condition of insulation failure, so as to obtain the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The equivalent stress translation factor calculation module is used to substitute the cumulative equivalent stress distribution of mechanical damage into the equivalent stress translation factor calculation formula to obtain the equivalent stress translation factor.

[0053] In some specific embodiments, the formula for calculating the cumulative equivalent stress distribution of mechanical damage is as follows: ; in, For the cumulative equivalent stress distribution of mechanical damage, R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress; The formula for calculating the equivalent stress translation factor is as follows: ; in, This is the equivalent stress shift factor.

[0054] In some specific embodiments, the temperature translation factor determination module 13 may specifically include: The oil-paper insulation space temperature distribution calculation module is used to transfer the Lorentz force density as a heat source term to the heat flow field, and calculate the oil-paper insulation space temperature distribution based on the total eddy current loss and the oil-paper insulation space temperature field. The temperature shift factor determination module is used to determine the temperature shift factor using the temperature distribution of the oil-paper insulation space.

[0055] In some specific embodiments, the spatial lifetime distribution determination module 14 may specifically include: The total acceleration factor distribution calculation module is used to calculate the product between the equivalent stress translation factor and the temperature translation factor, and to use the product as the total acceleration factor distribution. The total acceleration factor distribution input module is used to input the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation.

[0056] Figure 14This is a schematic diagram of an electronic device provided in an embodiment of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the method for evaluating the oil-paper insulation life of a converter transformer, as disclosed in any of the foregoing embodiments.

[0057] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0058] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored on it include operating system 221, computer program 222 and data 223, etc., and the storage method can be temporary storage or permanent storage.

[0059] The operating system 221 manages and controls the various hardware devices on the electronic device 20 and the computer program 222 to enable the processor 21 to perform calculations and processing on the data 223 in the memory 22. It can be Windows, Unix, Linux, etc. The computer program 222, in addition to including a computer program capable of performing the oil-paper insulation life assessment method for converter transformers executed by the electronic device 20 as disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the oil-paper insulation life assessment device for converter transformers from external devices, as well as data collected by its own input / output interface 25.

[0060] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0061] Furthermore, this application also discloses a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, it implements the steps of the method for evaluating the life of oil-paper insulation of converter transformers disclosed in any of the foregoing embodiments.

[0062] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0063] The above provides a detailed description of the method, apparatus, equipment, and storage medium for evaluating the lifespan of oil-paper insulation in a converter transformer. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the invention. At the same time, those skilled in the art will recognize that, based on the ideas of the invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the invention.

Claims

1. A method for evaluating the lifespan of oil-paper insulation in a converter transformer, characterized in that, include: An improved insulation life model considering the cumulative effect of mechanical damage is constructed based on the linear cumulative damage theory and thermal aging model. The electromagnetic field and solid force field of the converter transformer are numerically solved to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The equivalent stress translation factor is determined using the cumulative equivalent stress distribution of mechanical damage. The temperature field and electromagnetic field of the oil-paper insulation space of the converter transformer are numerically solved to obtain the total eddy current loss. The temperature shift factor is determined based on the Lorentz force density, the total eddy current loss and the temperature field of the oil-paper insulation space. The total acceleration factor distribution is calculated using the equivalent stress translation factor and the temperature translation factor. The total acceleration factor distribution is then input into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation life of the converter transformer is evaluated based on the spatial lifetime distribution.

2. The method for evaluating the lifespan of the oil-paper insulation of a converter transformer according to claim 1, characterized in that, The improved insulation life model, which considers the cumulative effect of mechanical damage and is based on linear cumulative damage theory and thermal aging model, includes: Based on Miner's fatigue damage accumulation theory, and by introducing a time-varying stress function, the damage degree and fatigue life functions of the material are constructed. The constant stress value equivalent to the cumulative mechanical damage is calculated using the damage degree and fatigue life function of the material. The material's damage degree and fatigue life function, the constant stress value equivalent to the mechanical damage accumulation, and the Arrhenius thermal aging model are combined to construct an improved insulation life model that considers the cumulative effect of mechanical damage.

3. The method for evaluating the lifespan of the oil-paper insulation of a converter transformer according to claim 1, characterized in that, The improved insulation life model considering the cumulative effect of mechanical damage is as follows: ； in, Equivalent stress intensity R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress, The equivalent stress-time shift factor, This is the temperature-time shift factor. The activation energy of the reaction. For reference temperature value, This is the temperature-equivalent stress-time shift factor. This is an indicator of the aging status of insulating paper. This represents the current degree of polymerization of the insulating paper. This represents the initial degree of polymerization of the insulating paper. This refers to the time required to reach the critical aging state under reference temperature and reference stress. This represents the average value of the critical aging state value. This refers to the time required to reach the critical aging state under actual temperature and reference stress.

4. The method for evaluating the lifespan of the oil-paper insulation of a converter transformer according to claim 1, characterized in that, The numerical solution of the electromagnetic field and solid force field of the converter transformer is performed to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The equivalent stress translation factor is determined using the cumulative equivalent stress distribution of mechanical damage, including: Time-varying simulations were performed on the internal space of the converter transformer to obtain the electromagnetic field and solid force field; The electromagnetic field is numerically solved using a sequential coupling solution method to obtain the Lorentz force density; The Lorentz force density is used as a structural load to transfer to the solid force field in order to construct the time-varying stress function of the oil-paper insulation; A damage integral equation is constructed based on Miner's fatigue damage accumulation theory and the time-varying stress function. Under the critical condition of insulation failure, the damage integral equation is solved to obtain the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer. The cumulative equivalent stress distribution of mechanical damage is substituted into the formula for calculating the equivalent stress translation factor to obtain the equivalent stress translation factor.

5. The method for evaluating the lifespan of the oil-paper insulation of a converter transformer according to claim 4, characterized in that, The formula for calculating the cumulative equivalent stress distribution of mechanical damage is as follows: ； in, For the cumulative equivalent stress distribution of mechanical damage, R The gas constant is... T This represents the actual temperature value of the paper insulation. Stress coefficient, Total lifespan. The stress function is the time-varying stress function of the oil-paper insulation. Characteristic lifetime under reference stress; The formula for calculating the equivalent stress translation factor is as follows: ； in, This is the equivalent stress shift factor.

6. The method for evaluating the lifespan of the oil-paper insulation of a converter transformer according to claim 1, characterized in that, The determination of the temperature translation factor based on the Lorentz force density, the total eddy current loss, and the temperature field of the oil-paper insulation space includes: The Lorentz force density is transferred to the heat flow field as a heat source term, and the temperature distribution of the oil-paper insulation space is calculated based on the total eddy current loss and the temperature field of the oil-paper insulation space. The temperature shift factor is determined using the temperature distribution in the oil-paper insulation space.

7. The method for evaluating the life of oil-paper insulation of a converter transformer according to any one of claims 1 to 6, characterized in that, The step of calculating the total acceleration factor distribution using the equivalent stress shift factor and the temperature shift factor, and inputting the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation includes: Calculate the product between the equivalent stress translation factor and the temperature translation factor, and use the product as the total acceleration factor distribution; The total acceleration factor distribution is input into the insulation lifetime improvement model to output the spatial lifetime distribution of the paper insulation.

8. A device for evaluating the lifespan of oil-paper insulation in a converter transformer, characterized in that, include: The model building module is used to build an improved insulation life model that considers the cumulative effect of mechanical damage based on the linear cumulative damage theory and the thermal aging model. The equivalent stress translation factor determination module is used to numerically solve the electromagnetic field and solid force field of the converter transformer to obtain the Lorentz force density and the cumulative equivalent stress distribution of mechanical damage to the oil-paper insulation of the converter transformer, and to determine the equivalent stress translation factor using the cumulative equivalent stress distribution of mechanical damage. The temperature shift factor determination module is used to numerically solve the temperature field of the oil-paper insulation space and the electromagnetic field of the converter transformer to obtain the total eddy current loss, and to determine the temperature shift factor based on the Lorentz force density, the total eddy current loss and the temperature field of the oil-paper insulation space. The spatial lifetime distribution determination module is used to calculate the total acceleration factor distribution using the equivalent stress translation factor and the temperature translation factor, and input the total acceleration factor distribution into the insulation lifetime improvement model to output the spatial lifetime distribution of the oil-paper insulation. The oil-paper insulation life assessment module is used to assess the oil-paper insulation life of the converter transformer based on the spatial life distribution.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the method for evaluating the life of oil-paper insulation of a converter transformer as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store a computer program; wherein, when the computer program is executed by a processor, it implements the method for evaluating the oil-paper insulation life of a converter transformer as described in any one of claims 1 to 7.

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