Transformer coil turn insulation strength cumulative damage evaluation method, device, equipment and medium

Abstract

This application discloses a method, apparatus, equipment, and medium for assessing the cumulative damage to transformer coil turn insulation strength, relating to the technical field of insulation degradation analysis. This application establishes a database of the correspondence between the compressive stress of transformer coil turn insulation and the number of damaged insulation paper layers based on a preset experimental model. The preset experimental model includes experimental models between conductors and between conductors and pads. The compressive stress of each coil coil section is calculated based on the transformer type when subjected to a short-circuit fault current impact. The database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of damaged insulation paper layers is queried based on the compressive stress to obtain the cumulative total number of damaged insulation layers for each coil section. The cumulative damage state of the transformer coil turn insulation is assessed based on the cumulative total number of damaged insulation layers, achieving early warning and predictive defense against latent faults in transformer coil turn insulation, solving the problem of difficulty in early detection of inter-turn short circuits, and improving the reliability and safety of transformer operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulation deterioration analysis, and particularly relates to a transformer coil turn insulation strength cumulative damage evaluation method, device, equipment and medium. BACKGROUND

[0002] The transformer is the core equipment of the power system, and its operation reliability is directly related to the safety and stability of the power grid. In the long-term operation process, the transformer will inevitably suffer multiple external short-circuit fault impacts and excitation inrush. The huge electric power generated by these impact currents repeatedly acts on the transformer winding, causing the inter-turn insulation (usually insulation paper) to gradually suffer mechanical damage and cumulative deterioration. When the insulation damage accumulates to a certain extent, it may eventually cause an inter-turn short circuit fault. Inter-turn short circuit is a serious form of transformer fault. Its initial characteristics are not obvious, and the sensitivity of traditional electrical quantity protection (such as differential protection) is insufficient, and it is difficult to detect slight insulation deterioration in time. However, once the inter-turn short circuit occurs, the short-circuit current is extremely large, and the fault develops extremely rapidly, which can cause local overheating of the winding, burning of the insulation, and even cause catastrophic accidents such as transformer fire and explosion, resulting in huge equipment loss, large-scale power outages, serious threats to the safety of the power system, and huge social and economic losses.

[0003] At present, the evaluation of the insulation state of the transformer winding mainly relies on offline preventive tests (such as winding direct current resistance measurement, insulation resistance test, dielectric loss factor measurement, etc.) or online monitoring methods. Although these methods can find some relatively serious insulation defects, they are difficult to evaluate the cumulative mechanical damage degree of the insulation material under multiple short-circuit impacts, and cannot early warn the latent insulation fault. For the fatigue damage process of the turn insulation under the repeated electric power, there is a lack of effective quantitative evaluation means, which makes the operation and maintenance personnel unable to accurately master the real health status and remaining life of the winding, and it is difficult to realize precise maintenance based on the state.

[0004] Therefore, how to predictively evaluate the latent fault of the transformer coil turn insulation is a problem to be solved at present. SUMMARY

[0005] The main purpose of the present application is to provide a transformer coil turn insulation strength cumulative damage evaluation method, device, equipment and medium, which aims to solve the technical problem of how to predictively evaluate the latent fault of the transformer coil turn insulation.

[0006] To achieve the above-mentioned purpose, the present application provides a transformer coil turn insulation strength cumulative damage evaluation method, which comprises the following steps:

[0007] A database of the correspondence between the compressive stress of transformer coil insulation and the number of layers of insulation paper damaged is established based on the preset experimental models. The preset experimental models include experimental models between conductors and between conductors and pads. Calculate the compressive stress of each coil in the transformer coil when a short-circuit fault current impacts the transformer type. By consulting the database of the correspondence between the compressive stress of the transformer coil insulation and the number of damaged insulation layers, the cumulative total number of damaged layers for each coil coil can be obtained. The cumulative damage status of transformer coil turn insulation is assessed based on the cumulative total number of damaged layers.

[0008] In one embodiment, the step of calculating the compressive stress of each coil of the transformer coil during a short-circuit fault current impact based on the transformer type includes: Based on the transformer type, determine the excitation parameters of the transformer coil and the boundary conditions of the solution domain; Based on the excitation parameters and boundary conditions, the leakage flux distribution of the transformer coil is calculated, and the radial magnetic flux density of each coil is obtained. Based on the radial magnetic flux density, calculate the compressive stress of each coil in the transformer coil when subjected to a short-circuit fault current impact.

[0009] In one embodiment, the step of determining the excitation parameters of the transformer coil according to the transformer type includes: Obtain the geometric and electrical parameters of the transformer coils based on the transformer type; The ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil are obtained from the number of turns in the geometric parameters and the fault current in the electrical parameters. The ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil are used as the excitation parameters of the transformer coil.

[0010] In one embodiment, the step of calculating the compressive stress of each coil of the transformer coil during a short-circuit fault current impact based on the radial magnetic flux density includes: Obtain the contact area of ​​the wire; Calculate the axial force on each disc based on the formulas for radial magnetic flux density and Lorentz force; The compressive stress of each coil in the transformer coil is calculated based on the axial force and contact area during a short-circuit fault current impact.

[0011] In one embodiment, the step of assessing the cumulative damage state of transformer coil turn insulation based on the cumulative total number of damaged layers includes: Obtain the maximum allowed number of destruction layers for each line pie; When the cumulative total number of damaged layers is less than the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a safe state. When the cumulative total number of damaged layers is greater than or equal to the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a risk state.

[0012] In one embodiment, the step of obtaining the maximum permissible number of damaged layers for each thread disc includes: High-voltage insulation tests were conducted on each coil under different experimental conditions with different numbers of insulation paper destruction layers. The test results of discharge of each coil under different numbers of insulation paper destruction layers were recorded. The high-voltage insulation tests included external withstand voltage test, induced withstand voltage test and impulse voltage test. Based on the test results, determine the maximum allowable number of damaged layers for each wire disc when it reaches the failure threshold.

[0013] In one embodiment, the step of establishing a database of the correspondence between the compressive stress of transformer coil turns insulation and the number of insulation paper failure layers based on a preset experimental model includes: Compression strength tests were performed on the first and second preset experimental models respectively to obtain the number of layers of the first and second insulating paper that were damaged. The first preset experimental model was a block-wire-block experimental model, and the second preset experimental model was a wire-wire experimental model. Statistical analysis was conducted based on the data of the number of damaged layers of the first and second insulating paper to obtain a database of the correspondence between the compressive stress of the transformer coil turns' insulation and the number of damaged insulating paper layers.

[0014] Furthermore, to achieve the above objectives, this application also proposes a device for assessing the cumulative damage to the insulation strength of transformer coil turns, the device comprising: The database construction module is used to establish a database of the correspondence between the compressive stress of the transformer coil coil insulation and the number of layers of insulation paper damaged, based on a preset experimental model. The preset experimental model includes experimental models between conductors and between conductors and pads. The stress calculation module is used to calculate the compressive stress of each coil of the transformer coil when a short-circuit fault current impacts, based on the transformer type. The failure layer prediction module is used to query the corresponding relationship database based on the compressive stress to obtain the cumulative total failure layer of each line disc; The damage assessment module is used to assess the cumulative damage status of the transformer coil turn insulation based on the cumulative total number of damaged layers, the cumulative damage status including a safe state and a dangerous state.

[0015] In addition, to achieve the above objectives, this application also proposes a device for assessing the cumulative damage to the insulation strength of transformer coil turns. The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program is configured to implement the steps of the method for assessing the cumulative damage to the insulation strength of transformer coil turns as described above.

[0016] In addition, to achieve the above objectives, this application also proposes a medium, which is a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the transformer coil turn insulation strength cumulative damage assessment method described above.

[0017] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the transformer coil turn insulation strength cumulative damage assessment method as described above.

[0018] This application provides a method for assessing the cumulative damage to the insulation strength of transformer coil turns. The method includes: establishing a database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of damaged insulation paper layers based on a preset experimental model, including experimental models between conductors and between conductors and pads; calculating the compressive stress of each coil coil under short-circuit fault current impact based on the transformer type; querying the database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of damaged insulation paper layers based on the compressive stress to obtain the cumulative total number of damaged insulation paper layers for each coil coil; and assessing the cumulative damage state of the transformer coil turn insulation based on the cumulative total number of damaged insulation paper layers. In summary, this application, by establishing a database of the correspondence between the compressive stress of the insulation paper and the number of damaged insulation paper layers, converts the fault current into the distribution of electromagnetic forces inside the coil to analyze the compressive stress of the turn insulation under multiple short-circuit impacts. Finally, by comparing the total number of damaged insulation paper layers with a preset threshold, it achieves early warning and predictive defense against latent faults in the transformer coil turn insulation, solving the problem of difficulty in early detection of inter-turn short circuits and improving the operational reliability and safety of transformers. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0020] Figure 1 A flowchart illustrating the first embodiment of the transformer coil turn insulation strength cumulative failure assessment method of this application; Figure 2 This is a schematic diagram of transformer coil turn insulation disassembly in one embodiment of the transformer coil turn insulation cumulative failure assessment method of this application; Figure 3 A flowchart illustrating the second embodiment of the transformer coil turn insulation strength cumulative failure assessment method of this application; Figure 4 This is a schematic diagram of the leakage flux distribution of a transformer coil in one embodiment of the method for assessing the cumulative damage of transformer coil insulation strength according to this application; Figure 5This is a schematic diagram of the module structure of the transformer coil turn insulation strength cumulative failure assessment device according to an embodiment of this application; Figure 6 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the cumulative damage assessment method for transformer coil turn insulation strength in this embodiment of the application. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0022] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Transformers are core equipment in power systems, and their operational reliability directly affects the safety and stability of the power grid. During long-term operation, transformers inevitably suffer from multiple external short-circuit faults and inrush currents. The enormous electrodynamic forces generated by these inrush currents repeatedly act on the transformer windings, causing gradual mechanical damage and cumulative deterioration of the inter-turn insulation (usually insulating paper). When the insulation damage accumulates to a certain extent, it may eventually lead to an inter-turn short-circuit fault. An inter-turn short circuit is a serious type of transformer fault. Its initial characteristics are not obvious, and traditional electrical quantity protection (such as differential protection) is insufficiently sensitive, making it difficult to detect even slight insulation deterioration in time. However, once an inter-turn short circuit occurs, the short-circuit current is extremely large, and the fault develops extremely rapidly. It can cause localized overheating of the windings, insulation burnout, and even catastrophic accidents such as transformer fires and explosions within a very short time. This not only causes huge equipment losses but also leads to large-scale power outages, seriously threatening the safety of the power system and resulting in enormous socio-economic losses.

[0024] Currently, the assessment of transformer winding insulation condition mainly relies on offline preventative tests (such as winding DC resistance measurement, insulation resistance testing, and dielectric loss factor measurement) or online monitoring methods. While these methods can detect some insulation defects that have already developed to a more serious level, they are insufficient for predicting the cumulative mechanical damage to insulation materials under repeated short-circuit impacts and cannot provide early warnings for latent insulation faults. Furthermore, there is a lack of effective quantitative assessment methods for the fatigue failure process of turn insulation under repeated electrodynamic forces, making it difficult for maintenance personnel to accurately grasp the true health status and remaining life of the windings, hindering condition-based precision maintenance. Therefore, how to effectively assess the cumulative damage to transformer coil turn insulation under repeated short-circuit impacts is a problem that urgently needs to be solved.

[0025] To address the aforementioned issues, this application establishes a database relating insulation paper compressive stress to the number of damaged layers. This database converts fault current into electromagnetic force distribution within the coil to analyze the turn insulation compressive stress under multiple short-circuit impacts. Finally, the total number of damaged insulation paper layers is compared with a preset threshold, enabling early warning and predictive defense against latent faults in transformer coil turn insulation. This solves the problem of early detection of inter-turn short circuits and improves the reliability and safety of transformer operation.

[0026] The executing entity in this embodiment can be a transformer coil turn insulation strength cumulative failure assessment system, or a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device capable of performing the aforementioned transformer coil turn insulation strength cumulative failure assessment function. This embodiment does not specifically limit it in this way. The following uses a transformer coil turn insulation strength cumulative failure assessment system as an example to describe this embodiment and the following embodiments.

[0027] Based on this, the embodiments of this application provide a method for assessing the cumulative damage of transformer coil turn insulation strength, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the transformer coil turn insulation strength cumulative damage assessment method of this application.

[0028] In this embodiment, the method for assessing the cumulative damage to the insulation strength of transformer coil turns includes steps S10 to S40: Step S10: Establish a database of the correspondence between the compressive stress of the transformer coil insulation and the number of layers of insulation paper damaged, based on the preset experimental model. The preset experimental model includes experimental models between conductors and between conductors and pads.

[0029] In one feasible implementation, step S10 specifically includes: Step S101: Perform compression strength tests on the preset first experimental model and the preset second experimental model respectively to obtain the data on the number of layers of the first insulating paper that are damaged and the data on the number of layers of the second insulating paper that are damaged. The preset first experimental model is an experimental model of pad-wire-pad, and the preset second experimental model is an experimental model of wire-wire.

[0030] Specifically, such as Figure 2As shown, for the "pad-wire-pad" model, the same pad material and wire (outer insulating paper) as the actual transformer are selected. The wire is placed between two pads, and a pressure of 20~120MPa is applied on a material testing machine to simulate the stress state when the insulation of a continuous or spiral coil comes into contact with the pad. After each compression, the system analyzes and records the number of layers of mechanical damage such as cracking and delamination after the outer insulation paper of the wire is removed. For the "wire-wire" model, two wires with outer insulating paper are placed crosswise or parallel and a pressure of 20~120MPa is applied to simulate the stress state when there is no pad in the direct contact between the turns in a cylindrical coil. The number of damaged layers is also recorded. To ensure data reliability, the experiment is repeated multiple times for each model, and outliers are removed.

[0031] The number of insulation paper failure layers refers to the number of layers of insulation paper material that show visible mechanical damage (such as cracks, delamination, and crushing) under external force. The two models correspond to two typical contact forms in a coil, helping to comprehensively cover the stress conditions in actual operation.

[0032] Step S102: Statistical analysis is performed based on the data of the number of damaged layers of the first insulating paper and the data of the number of damaged layers of the second insulating paper to obtain a database of the correspondence between the compressive stress of the insulation of the transformer coil turns and the number of damaged layers of the insulating paper.

[0033] In the process, the system organizes the discrete data obtained from the experiment into a queryable mapping relationship.

[0034] Specifically, the number of insulation paper damage layers corresponding to different pressure levels in step S101 is statistically analyzed, the average number of damage layers under the same pressure is calculated, and the data dispersion is considered to form a pressure-damage layer comparison table or fitting curve. This database can be established separately for different coil structures, such as a database for the "pad-wire-pad" contact type and a database for the "wire-wire" contact type, so that it can be selected according to the actual transformer type in subsequent evaluation.

[0035] Step S20: Calculate the compressive stress of each coil of the transformer coil when the short-circuit fault current impacts the transformer type.

[0036] Transformer types include, but are not limited to, continuous coils, helical coils, and cylindrical coils. Different types of coils have different structural characteristics and stress distribution methods. Therefore, it is necessary to select appropriate simulation models and contact area calculation methods according to the specific type.

[0037] Compressive stress refers to the pressure exerted on the inter-turn insulation material (insulating paper) by short-circuit electrodynamic forces, and its magnitude directly affects the degree of mechanical damage to the insulating paper.

[0038] Specifically, in this step, the system will establish an electromagnetic field simulation calculation model of the transformer coil, analyze the electromagnetic force borne by each coil under the impact of short-circuit fault current, and further calculate the compressive stress value of the turn insulation, thereby providing key stress input data for subsequent assessment of cumulative insulation damage.

[0039] Step S30: Based on the compressive stress, query the database of the correspondence between the compressive stress of the transformer coil insulation and the number of damaged insulation paper layers to obtain the cumulative total number of damaged layers for each coil.

[0040] In this step, the system matches the compressive stress value under each short-circuit impact obtained from the simulation calculation with the corresponding relationship database obtained from the experiment, and successively accumulates the total number of insulation paper layers damaged for each coil.

[0041] The specific process is as follows: For the first impact, based on the calculated compressive stress of each coil, the corresponding number of insulation paper layers damaged is retrieved from the established relational database and recorded; for the second impact, the number of damaged layers is retrieved in the same way and added to the first impact; this process continues until all impacts have been accumulated, ultimately obtaining the total cumulative number of damaged layers for each coil. This process is performed separately for high-voltage and low-voltage coils, and differentiates between different contact types. Specifically, the database corresponding to the compressive stress of transformer coil insulation turns and the number of insulation paper layers damaged is shown in Table 1: Table 1

[0042] In addition, the cumulative total number of damaged layers reflects the cumulative mechanical damage to the insulating paper under multiple short-circuit impacts, and is an indicator used to assess the remaining life and failure risk of the insulation. Since the stress magnitude of each impact may be different, the number of damaged layers may also be different, and the accumulation process reflects the irreversibility and cumulative effect of the damage.

[0043] Step S40: Assess the cumulative failure status of the transformer coil turns insulation based on the cumulative total number of failure layers. The cumulative failure status includes a safe state and a dangerous state.

[0044] In this step, the system compares the cumulative total number of damaged layers with a pre-set safety threshold to determine the current health status and failure risk of the insulation. This assessment allows for real-time monitoring of the damage level and trend of the insulation layers, providing a basis for decision-making in condition-based maintenance and proactive defense. Furthermore, the cumulative damage state refers to the stage of damage to the insulation paper, typically categorized as safe or dangerous. In this embodiment, it is primarily determined by comparing the cumulative damage state with the maximum permissible number of damaged layers.

[0045] In one feasible implementation, step S40 specifically includes: Step S401: Obtain the maximum allowed number of destruction layers for each line pie.

[0046] The maximum permissible number of damaged layers is a threshold; exceeding this threshold indicates a risk of inter-turn discharge in the insulation, requiring maintenance or replacement. In this step, the system simulates or experiments the insulation strength under applied withstand voltage, induced withstand voltage, and impulse voltage to study the impact of different numbers of damaged insulation layers on the electrical performance of the inter-turn insulation. For example, standard lightning impulse voltage or power frequency withstand voltage is applied to insulation paper samples with different numbers of damaged layers, and the changes in their breakdown voltage or partial discharge initiation voltage are observed to determine the maximum permissible number of damaged layers that each coil can withstand while ensuring reliable insulation operation. This criterion can be formulated separately for transformers of different voltage levels and coil structures, and used as a benchmark for subsequent comparisons.

[0047] Step S402: When the cumulative total number of damaged layers is less than the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a safe state.

[0048] If the cumulative total number of damaged layers in a transformer coil does not exceed the maximum permissible number of damaged layers, it indicates that although the insulation paper of that coil has undergone multiple impact damages, the remaining insulation strength still meets the operational requirements, the risk of inter-turn discharge is low, and operation can continue without immediate intervention. This state indicates that the transformer is currently in a safe operating range. It is understood that a safe state does not mean the insulation is completely intact, but rather that the degree of damage is still within a controllable range and will not immediately cause a fault, but continuous monitoring is required.

[0049] Step S403: When the cumulative total number of damaged layers is greater than or equal to the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a risk state.

[0050] If the cumulative total number of damaged layers in a transformer coil reaches or exceeds the maximum permissible number of damaged layers, it indicates that the insulation paper damage has accumulated to a critical level, and the inter-turn insulation strength has significantly decreased. This could lead to inter-turn discharge or even short-circuit faults during subsequent operation. In this case, an immediate warning should be issued, and it should be recommended to arrange power outage maintenance or take other proactive preventative measures to avoid escalation of the accident. Understandably, a risk status indicates that the insulation has entered the pre-failure stage, requiring close monitoring and timely handling. By linking the assessment results with maintenance strategies, condition-based maintenance and predictive maintenance of transformers can be achieved.

[0051] In one feasible implementation, step S401 specifically includes: Step A10: Apply high-voltage insulation tests under different experimental conditions to each coil under different numbers of insulation paper destruction layers, and record the test results of discharge of each coil under different numbers of insulation paper destruction layers. The high-voltage insulation tests include external withstand voltage test, induced withstand voltage test and impulse voltage test.

[0052] In this step, the system establishes a correlation between the number of insulation layers damaged and electrical performance. Specifically, for wire disc samples with different numbers of insulation paper layers damaged, external withstand voltage tests, induced withstand voltage tests, and impulse voltage tests are conducted, and the voltage values ​​or phenomena at the occurrence of discharges (such as breakdown or partial discharge initiation) are observed and recorded. Through these tests, the law of decrease in electrical strength of insulation under different degrees of damage can be clarified, providing data support for determining the maximum allowable number of layers damaged.

[0053] In addition, the applied withstand voltage test mainly assesses the insulation's ability to withstand power frequency overvoltages; the induced withstand voltage test is used to verify the strength of longitudinal insulation (inter-turn and inter-layer insulation); and the impulse voltage test is used to simulate the effects of lightning or switching overvoltages. These three tests comprehensively reflect the insulation's performance under different types of voltage stresses.

[0054] Step A20: Determine the maximum number of permissible damage layers for each wire disc when it reaches the failure threshold based on the test results.

[0055] In this step, the system analyzes the test data to identify the critical number of layers where unacceptable discharge phenomena begin to appear in the insulation (such as a significant drop in breakdown voltage or excessive partial discharge). Typically, a safety margin (e.g., 50% to 70% of the measured number of broken layers) is used as the maximum allowable number of broken layers. This maximum allowable number of broken layers can be determined separately for transformers of different voltage levels and coil structures, and serves as a benchmark for subsequent steps.

[0056] Furthermore, the failure threshold can be determined based on relevant standards or engineering experience. For example, when the number of damaged insulation layers reaches a certain percentage of the total number of layers, a high risk of failure is considered to exist. The setting of the maximum allowable number of damaged layers must balance safety and economy, avoiding both overly conservative approaches that lead to frequent maintenance and ensuring reliable operation of the insulation within its expected lifespan.

[0057] This embodiment provides a method for assessing the cumulative damage to the insulation strength of transformer coil turns. The method includes: establishing a database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of damaged insulation paper layers based on a preset experimental model, including experimental models between conductors and between conductors and pads; calculating the compressive stress of each coil coil under short-circuit fault current impact based on the transformer type; querying the database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of damaged insulation paper layers based on the compressive stress to obtain the cumulative total number of damaged insulation paper layers for each coil coil; and assessing the cumulative damage state of the transformer coil turn insulation based on the cumulative total number of damaged insulation paper layers. In summary, this embodiment, by establishing a database of the correspondence between the compressive stress of the insulation paper and the number of damaged insulation paper layers, converts the fault current into the distribution of electromagnetic forces inside the coil to analyze the compressive stress of the turn insulation under multiple short-circuit impacts. Finally, by comparing the total number of damaged insulation paper layers with a preset threshold, it achieves early warning and predictive defense against latent faults in the transformer coil turn insulation, solving the problem of difficulty in early detection of inter-turn short circuits and improving the reliability and safety of transformer operation.

[0058] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 , Figure 3 This is a flowchart illustrating the second embodiment of the transformer coil turn insulation strength cumulative failure assessment method of this application. Step S20 specifically includes: Step S201: Determine the excitation parameters of the transformer coil and the boundary conditions of the solution domain according to the transformer type.

[0059] In this step, the system sets the correct input conditions and computational domain constraints for the electromagnetic field simulation. Specifically, the system first obtains the geometric parameters (such as inner radius, outer radius, reactance height, number of turns, etc.) and electrical parameters (such as rated current, short-circuit fault current, etc.) of the coils based on the model and structure of the target transformer. Then, based on these parameters, it calculates the ampere-turns of the high-voltage and low-voltage coils (e.g., ampere-turns = number of turns × fault current) and applies them as excitation sources to the model. Simultaneously, based on the actual magnetic circuit structure of the transformer, it sets the boundary conditions of the solution domain, typically including parallel or perpendicular boundaries of magnetic field lines, to simulate the influence of the yoke and air domain on the magnetic field.

[0060] Understandably, the excitation parameters mainly include the ampere-turn distribution of the coil, which determines the source strength of the magnetic field. Boundary conditions are constraints on the boundaries of the computational domain when solving partial differential equations. Common examples include magnetic field lines perpendicular or parallel boundaries, used to simulate planes of symmetry or boundaries at infinity. For instance, the boundary conditions of the solution domain set for an SZ11-125000 / 220 transformer are shown in Table 2: Table 2

[0061] In one feasible implementation, the step of determining the excitation parameters of the transformer coil according to the transformer type includes: Step B10: Obtain the geometric and electrical parameters of the transformer coil according to the transformer type.

[0062] In this step, geometric parameters determine the spatial layout of the coils, while electrical parameters determine the magnitude and distribution of the fault current. Specifically, the system obtains the corresponding coil's geometric dimensions (such as inner radius, outer radius, height from the lower yoke, reactance height, number of turns, etc.) and electrical parameters (such as fault current) based on the transformer type. These parameters form the basis for establishing an accurate model. For example, taking an SZ11-125000 / 220 transformer as an example, the transformer coil parameters for establishing the transformer coil simulation calculation model are shown in Table 3: Table 3

[0063] Step B20: Obtain the ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil based on the number of turns in the geometric parameters and the fault current in the electrical parameters.

[0064] In this step, the system multiplies the number of turns of the high-voltage coil by the fault current on the high-voltage side to obtain the ampere-turns of the high-voltage coil; similarly, it multiplies the number of turns of the low-voltage coil by the fault current on the low-voltage side to obtain the ampere-turns of the low-voltage coil. Since the ampere-turns of the high-voltage and low-voltage coils are in opposite directions, they must be assigned opposite signs during excitation settings to simulate a balanced state. It can be understood that ampere-turns are the unit of magnetomotive force, representing the coil's ability to generate a magnetic field; their magnitude and direction directly affect the distribution of the leakage magnetic field.

[0065] Step B30: Use the ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil as the excitation parameters of the transformer coil.

[0066] In this step, the system applies the calculated ampere-turn value to the corresponding coil region in the simulation model as the excitation source for magnetic field analysis. In this way, the model can accurately reflect the leakage magnetic field generated by the coil during a short-circuit fault. For example, taking an SZ11-125000 / 220 transformer as an example, its coil ampere-turn excitation is shown in Table 4: Table 4

[0067] Step S202: Calculate the leakage flux distribution of the transformer coil based on the excitation parameters and boundary conditions to obtain the radial magnetic flux density of each coil.

[0068] In this step, the system obtains the leakage magnetic field distribution inside the coil by numerically solving Maxwell's equations (e.g.,Figure 4 (As shown). Specifically, the magnetic vector potential is solved using the finite element method or other numerical methods under set excitation and boundary conditions, thereby obtaining the magnetic flux density at each location. The focus is on extracting the radial magnetic flux density component at each coil, as this component is directly related to the axial electrodynamic force. It can be understood that the radial magnetic flux density is the radial component of the magnetic flux density, measured in Tesla (T), and its magnitude varies with the coil position. For example, taking an SZ11-125000 / 220 transformer as an example, its radial magnetic flux density is shown in Table 5. Table 5

[0069] Step S203: Calculate the compressive stress of each coil of the transformer coil when the short-circuit fault current impacts based on the radial magnetic flux density.

[0070] In this step, the magnetic field calculation results are converted into mechanical stress. First, according to the Lorentz force formula... Where B is the radial magnetic flux density, I is the current in the conductor (fault current), and L is the effective length of the conductor (usually the circumference of the coil). The axial electrodynamic force on each coil is calculated. Then, the contact area between the conductor and the pad or adjacent conductors is determined: for continuous or helical coils, the actual contact area after removing the chamfer needs to be considered; for cylindrical coils, it is the direct contact area between the conductors. Finally, the axial force is divided by the contact area to obtain the compressive stress value (in MPa) of the coil coil's insulation. Repeating this process yields the compressive stress of each coil under each short-circuit impact.

[0071] In addition, the contact area is a key parameter affecting the accuracy of stress calculation and needs to be determined reasonably based on the coil structure and the stress form. For coils with spacers, the contact occurs between the conductor and the spacer; for coils without spacers, the contact occurs between adjacent conductors.

[0072] In one feasible implementation, step S203 specifically includes: Step C10: Obtain the contact area of ​​the wire.

[0073] In this step, the system uses geometric calculations or finite element contact analysis to obtain the contact area based on the coil structure type. For coils with spacers, the contact area between the flat portion of the wire after chamfering and the spacer needs to be considered; for coils without spacers, the contact area between adjacent wires is taken, taking into account the wire cross-sectional shape and the degree of compression. This can be estimated based on typical spacer dimensions and wire specifications, or obtained through microscopic measurements and statistics.

[0074] Step C20: Calculate the axial force on each coil according to the formulas for radial magnetic flux density and Lorentz force.

[0075] In this step, the system couples the magnetic field and current using the Lorentz force formula to obtain the mechanical force acting on the coil. Specifically, for each coil, the axial force is obtained by multiplying its radial magnetic flux density, the fault current in the conductor, and the effective length of the conductor (usually the average circumference of the coil) (as shown in Table 6). It can be understood that the axial force is the electrodynamic force along the coil axis generated by the interaction of the leakage magnetic field and the current; it is the direct cause of turn insulation compression. For multiple impacts, the axial force under each impact needs to be calculated separately.

[0076] Table 6

[0077] Step C30: Calculate the compressive stress of each coil of the transformer coil when the short-circuit fault current impacts, based on the axial force and contact area.

[0078] In this step, the system divides the axial force by the contact area to obtain the compressive stress borne by each coil of insulation, as shown in Table 7. This stress value reflects the mechanical strength of the short-circuit impact on the insulating paper and will be used to subsequently query the database to determine the number of insulation layers damaged. For multiple impacts, the stress value under each impact needs to be calculated separately, taking into account the irreversible cumulative effect of stress. It is understandable that compressive stress is the core indicator for assessing insulation damage; that is, under multiple impacts, even if the stress of a single impact does not exceed the material's strength limit, multiple accumulations may lead to fatigue failure. Therefore, a comprehensive assessment is needed, taking into account the cumulative number of damaged layers.

[0079] Table 7

[0080] In this embodiment, by establishing an electromagnetic field simulation model and calculating the leakage magnetic field distribution, combined with the Lorentz force formula and contact area analysis, the quantitative calculation of the compressive stress of each coil of the transformer coil under multiple short-circuit impacts was realized. This solved the problem of the difficulty in obtaining the mechanical stress of the turn insulation and improved the accuracy and reliability of the cumulative damage assessment.

[0081] This application also provides a device for assessing the cumulative damage to the insulation strength of transformer coil turns. Please refer to [reference needed]. Figure 5 The transformer coil turn insulation strength cumulative damage assessment device includes: The database construction module 10 is used to establish a database of the correspondence between the compressive stress of the transformer coil coil insulation and the number of layers of insulation paper damaged, based on the preset experimental models. The preset experimental models include experimental models between conductors and between conductors and pads. The stress calculation module 20 is used to calculate the compressive stress of each coil of the transformer coil when a short-circuit fault current impacts, based on the transformer type. The damage layer estimation module 30 is used to query the database of the correspondence between the compressive stress of the transformer coil coil insulation and the number of damaged insulation layers based on the compressive stress, and obtain the cumulative total number of damaged layers for each coil. The damage assessment module 40 is used to assess the cumulative damage status of the transformer coil turn insulation based on the cumulative total number of damaged layers.

[0082] The transformer coil turn insulation strength cumulative failure assessment device provided in this application, employing the transformer coil turn insulation strength cumulative failure assessment method in the above embodiments, can solve the technical problem of how to predictively assess latent faults in transformer coil turn insulation. Compared with the prior art, the beneficial effects of the transformer coil turn insulation strength cumulative failure assessment device provided in this application are the same as those of the transformer coil turn insulation strength cumulative failure assessment method provided in the above embodiments, and other technical features in the transformer coil turn insulation strength cumulative failure assessment device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0083] In one embodiment, the database construction module 10 is further configured to perform compression strength tests on a preset first experimental model and a preset second experimental model respectively, to obtain data on the number of first insulation paper failure layers and data on the number of second insulation paper failure layers. The preset first experimental model is an experimental model of pad-wire-pad, and the preset second experimental model is an experimental model of wire-wire. Statistical analysis is performed based on the data on the number of first insulation paper failure layers and the data on the number of second insulation paper failure layers to obtain a database of the correspondence between the compressive stress of the insulation of the transformer coil turns and the number of insulation paper failure layers.

[0084] In one embodiment, the stress calculation module 20 is further configured to determine the excitation parameters of the transformer coil and the boundary conditions of the solution domain according to the transformer type; calculate the leakage flux distribution of the transformer coil according to the excitation parameters and boundary conditions to obtain the radial magnetic flux density of each coil; and calculate the compressive stress of each coil of the transformer coil when the short-circuit fault current impacts according to the radial magnetic flux density.

[0085] In one embodiment, the stress calculation module 20 is further configured to obtain the geometric and electrical parameters of the transformer coil according to the transformer type; obtain the ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil according to the number of turns in the geometric parameters and the fault current in the electrical parameters; and use the ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil as excitation parameters of the transformer coil.

[0086] In one embodiment, the stress calculation module 20 is also used to obtain the contact area of ​​the conductor; calculate the axial force on each coil according to the formulas for radial magnetic flux density and Lorentz force; and calculate the compressive stress of each coil of the transformer coil when impacted by a short-circuit fault current according to the axial force and the contact area.

[0087] In one embodiment, the damage assessment module 40 is further configured to obtain the maximum allowable number of damaged layers for each coil; when the cumulative total number of damaged layers is less than the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a safe state; when the cumulative total number of damaged layers is greater than or equal to the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a risk state.

[0088] In one embodiment, the damage assessment module 40 is also used to apply high-voltage insulation tests under different experimental conditions to each coil under different numbers of insulation paper damage layers, and record the test results of discharge of each coil under different numbers of insulation paper damage layers. The high-voltage insulation test includes external withstand voltage test, induced withstand voltage test and impulse voltage test; and determine the maximum allowable number of damage layers corresponding to each coil when it reaches the failure critical point based on the test results.

[0089] This application provides a transformer coil turn insulation strength cumulative damage assessment device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the transformer coil turn insulation strength cumulative damage assessment method in the above embodiment 1.

[0090] The following is for reference. Figure 6 This document illustrates a structural schematic diagram of a transformer coil turn insulation strength cumulative damage assessment device suitable for implementing embodiments of this application. The transformer coil turn insulation strength cumulative damage assessment device in embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 6 The transformer coil turn insulation strength cumulative damage assessment device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0091] like Figure 6As shown, the transformer coil turn insulation strength cumulative damage assessment device may include a processing unit 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in ROM (Read Only Memory) 1002 or a program loaded from storage device 1003 into RAM (Random Access Memory) 1004. RAM 1004 also stores various programs and data required for the operation of the transformer coil turn insulation strength cumulative damage assessment device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. Input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, LCDs (Liquid Crystal Displays), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the transformer coil turn insulation strength cumulative failure assessment device to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows a transformer coil turn insulation strength cumulative failure assessment device with various systems, it should be understood that it is not required to implement or possess all the systems shown. More or fewer systems can be implemented alternatively.

[0092] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0093] The transformer coil turn insulation strength cumulative failure assessment device provided in this application, employing the transformer coil turn insulation strength cumulative failure assessment method in the above embodiments, can solve the technical problem of how to predictively assess latent faults in transformer coil turn insulation. Compared with the prior art, the beneficial effects of the transformer coil turn insulation strength cumulative failure assessment device provided in this application are the same as those of the transformer coil turn insulation strength cumulative failure assessment method provided in the above embodiments, and other technical features in this transformer coil turn insulation strength cumulative failure assessment device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0094] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0095] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0096] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the transformer coil turn insulation strength cumulative failure assessment method in the above embodiments.

[0097] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory or Flash Memory), optical fibers, CD-ROM (CD-Read Only Memory), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0098] The aforementioned computer-readable storage medium may be included in the transformer coil turn insulation strength cumulative failure assessment device; or it may exist independently and not assembled into the transformer coil turn insulation strength cumulative failure assessment device.

[0099] The aforementioned computer-readable storage medium carries one or more programs that, when executed by the transformer coil turn insulation strength cumulative damage assessment device, cause the transformer coil turn insulation strength cumulative damage assessment device to: calculate the compressive stress of each coil of the transformer coil under short-circuit fault current impact according to the transformer type; query the database of the correspondence between the compressive stress of the transformer coil turn insulation and the number of insulation paper damage layers according to the compressive stress to obtain the cumulative total number of damage layers of each coil; and assess the cumulative damage state of the transformer coil turn insulation according to the cumulative total number of damage layers.

[0100] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including LAN (Local Area Network) or WAN (Wide Area Network)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0101] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0102] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0103] The medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described method for assessing the cumulative damage to the insulation strength of transformer coil turns. This solves the technical problem of how to predictively assess latent insulation faults in transformer coil turns. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the method for assessing the cumulative damage to the insulation strength of transformer coil turns provided in the above embodiments, and will not be repeated here.

[0104] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method for assessing the cumulative damage to the insulation strength of transformer coil turns.

[0105] The computer program product provided in this application can solve the technical problem of how to predictively assess latent faults in transformer coil insulation. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the transformer coil insulation strength cumulative damage assessment method provided in the above embodiments, and will not be repeated here.

[0106] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for assessing the cumulative failure of transformer coil coil insulation strength, characterized in that, The method includes: Based on the preset experimental model, a database of the correspondence between the compressive stress of the transformer coil coil insulation and the number of layers of insulation paper damaged is established. The preset experimental model includes experimental models between conductors and between conductors and pads. Calculate the compressive stress of each coil in the transformer coil when a short-circuit fault current impacts the transformer, based on the transformer type. The cumulative total number of failure layers for each line disc is obtained by querying the corresponding relationship database based on the compressive stress. The cumulative damage status of the transformer coil turns insulation is assessed based on the cumulative total number of damaged layers, and the cumulative damage status includes a safe state and a dangerous state.

2. The method as described in claim 1, characterized in that, The step of calculating the compressive stress of each coil in the transformer coil during a short-circuit fault current impact, based on the transformer type, includes: Based on the transformer type, determine the excitation parameters of the transformer coil and the boundary conditions of the solution domain; Based on the excitation parameters and the boundary conditions, the leakage flux distribution of the transformer coil is calculated to obtain the radial magnetic flux density of each coil. Based on the radial magnetic flux density, calculate the compressive stress of each coil in the transformer coil when subjected to a short-circuit fault current impact.

3. The method as described in claim 2, characterized in that, The steps for determining the excitation parameters of a transformer coil based on the transformer type include: Obtain the geometric and electrical parameters of the transformer coils based on the transformer type; The ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil are obtained based on the number of turns in the geometric parameters and the fault current in the electrical parameters. The ampere-turns of the high-voltage coil and the ampere-turns of the low-voltage coil are used as the excitation parameters of the transformer coil.

4. The method as described in claim 2, characterized in that, The step of calculating the compressive stress of each coil in the transformer coil during a short-circuit fault current impact based on the radial magnetic flux density includes: Obtain the contact area of ​​the wire; Calculate the axial force on each disc according to the formulas for radial magnetic flux density and Lorentz force; The compressive stress of each coil of the transformer coil is calculated based on the axial force and the contact area during the short-circuit fault current impact.

5. The method as described in claim 1, characterized in that, The step of assessing the cumulative damage state of the transformer coil turn insulation based on the cumulative total number of damaged layers includes: Obtain the maximum allowed number of destruction layers for each line pie; When the cumulative total number of damaged layers is less than the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a safe state. When the cumulative total number of damaged layers is greater than or equal to the maximum allowable number of damaged layers, the cumulative damage state of the transformer coil insulation is determined to be a risk state.

6. The method as described in claim 5, characterized in that, The step of obtaining the maximum allowable number of destruction layers for each line cake includes: High-voltage insulation tests were conducted on each coil under different experimental conditions with different numbers of insulation paper destruction layers, and the test results of discharge of each coil under different numbers of insulation paper destruction layers were recorded. The high-voltage insulation tests included external withstand voltage test, induced withstand voltage test and impulse voltage test. Based on the test results, determine the maximum allowable number of damaged layers for each thread when it reaches the failure threshold.

7. The method as described in claim 1, characterized in that, The steps for establishing a database of the correspondence between the compressive stress of transformer coil insulation turns and the number of insulation paper layers damaged, based on a preset experimental model, include: Compression strength tests were performed on the first and second preset experimental models respectively to obtain data on the number of layers of first and second insulating paper that were damaged. The first preset experimental model was a block-wire-block experimental model, and the second preset experimental model was a wire-wire experimental model. Statistical analysis was performed based on the data on the number of damaged insulation layers of the first and second insulating papers to obtain a database of the correspondence between the compressive stress of the insulation of the transformer coil turns and the number of damaged insulation layers.

8. A device for assessing the cumulative damage to the insulation strength of transformer coil turns, characterized in that, The device includes: The database construction module is used to establish a database of the correspondence between the compressive stress of the transformer coil coil insulation and the number of layers of insulation paper damaged, based on a preset experimental model. The preset experimental model includes experimental models between conductors and between conductors and pads. The stress calculation module is used to calculate the compressive stress of each coil in the transformer coil when a short-circuit fault current impacts the transformer, based on the transformer type. The failure layer prediction module is used to query the corresponding relationship database based on the compressive stress to obtain the cumulative total failure layer of each line disc; The damage assessment module is used to assess the cumulative damage status of the transformer coil turn insulation based on the cumulative total number of damaged layers, the cumulative damage status including a safe state and a dangerous state.

9. A device for assessing the cumulative damage to the insulation strength of transformer coil turns, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the method for assessing the cumulative failure of transformer coil turn insulation strength as claimed in any one of claims 1 to 7.

10. A medium, characterized in that, The medium is a computer-readable storage medium, on which a computer program is stored, which, when executed by a processor, implements the steps of the method for assessing the cumulative damage to the insulation strength of transformer coil turns as described in any one of claims 1 to 7.

Images