Parameter determination method and device of enameled wire, and storage medium

Abstract

The invention discloses a parameter determination method and device of an enameled wire and a storage medium. The method for determining the parameters of the enamelled wires comprises the following steps: acquiring corona resistance time, paint film thickness and surface paint proportion of a plurality of groups of enamelled wires; constructing a fitting equation model of the logarithm value of the corona-resistant time, the paint film thickness and the surface paint proportional relation curve; performing fitting analysis on each group of corona-resistant time logarithm values, the paint film thickness and the surface paint proportion, and determining constant values of a fitting equation model; and when the parameters of the enameled wire need to be determined, obtaining the parameters of the corresponding enameled wire based on the corona resistance time demand of a user and the fitting equation model. Statistical modeling is carried out on corona-resistant test data of multiple groups of enameled wire samples to obtain a function relationship among corona-resistant time, paint film thickness and surface paint proportion, so that parameters of the enameled wire can be accurately and quickly determined.

Description

Technical Field

[0001] This invention relates to the technical field of electromagnetic wire insulation performance evaluation and design, and in particular to a curve fitting method for the relationship between corona resistance time, varnish thickness and surface varnish ratio. Background Technology

[0002] With the widespread application of variable frequency motors, electric vehicle drive motors, and high-voltage power supplies, motor windings operate under conditions of high voltage, high frequency, and steep voltage rise times. This makes the winding insulation susceptible to continuous erosion from partial discharge and corona discharge, leading to insulation aging and even breakdown failure. As a key component of winding insulation, the corona resistance of the enameled wire directly affects the reliability and lifespan of the entire device.

[0003] In existing technologies, to meet the different customers' requirements for corona resistance time, empirical design or large-scale trial production and repeated testing are commonly used to adjust the coating thickness and topcoat ratio. On the one hand, empirical design makes it difficult to quantify the relationship between coating thickness, topcoat ratio and corona resistance time, and the design margin is often too large, resulting in material waste and increased production costs. On the other hand, the iterative approach of trial production and testing is time-consuming, costly, and lacks a unified quantitative design basis, which is not conducive to the rapid development and promotion of corona-resistant enameled wire products of different specifications and varieties.

[0004] Therefore, there is an urgent need for a method that can determine the corresponding enameled wire parameters based on existing test data, so as to reduce material and production costs and improve the accuracy and efficiency of product design while ensuring performance. Summary of the Invention

[0005] In order to solve the technical problem that existing technologies rely on empirical design or repeated testing when determining the parameters of enameled wires, this invention proposes a method, apparatus, and storage medium for determining the parameters of enameled wires.

[0006] The method for determining the parameters of enameled wire proposed in this invention includes:

[0007] Obtain the corona resistance time, coating thickness, and surface coating ratio of multiple sets of enameled wires;

[0008] A fitting equation model was constructed to fit the relationship curve between the logarithm of corona resistance time, film thickness, and surface paint ratio.

[0009] The constant values ​​of the fitting equation model were determined by fitting the logarithmic values ​​of the corona resistance time of each group with the coating thickness and the topcoat ratio.

[0010] When it is necessary to determine the parameters of the enameled wire, the parameters of the corresponding enameled wire are obtained based on the user's corona resistance time requirements and the fitted equation model.

[0011] Furthermore, the fitted equation model is as follows:

[0012]

[0013] Where A, B, and D are constants, T is the corona resistance time, H is the paint film thickness, P is the paint ratio, and e is the base of the natural logarithm or any positive integer.

[0014] Furthermore, the constant values ​​of the fitting equation model, determined by fitting the logarithmic values ​​of each group of corona resistance times with the film thickness and the topcoat ratio, include:

[0015] Importing the n sets of data {Hn, Pn, Tn} into the fitted equation model, and taking the logarithm to the base e of both sides of the equation, we get:

[0016]

[0017] Multiple sets of data were calculated: {Hn, Pn, Tn, \ln(Tn)}, where Hn is the paint film thickness of the nth set, Pn is the topcoat ratio of the nth set, and Tn is the corona resistance time of the nth set.

[0018] The data set {Hn, Pn, Tn, \ln(Tn)} was fitted using fitting analysis software to determine the constant values ​​A, B, and D.

[0019] Furthermore, based on the user's corona resistance time requirements and the fitted equation model, the parameters of the corresponding enameled wire are obtained as follows:

[0020] Obtain the user's minimum required corona resistance time T. 客户 ;

[0021] Obtain the fitted equation model and establish the comparison relationship:

[0022]

[0023] By adjusting the paint ratio and paint film thickness, a combination of paint ratio and paint film thickness values ​​that can satisfy the above comparison formula is obtained, and the combination of paint ratio values ​​corresponding to the minimum paint film thickness or the most cost-effective paint film thickness is obtained to meet user needs.

[0024] Furthermore, the fitting analysis software is Minitab or Origin.

[0025] Furthermore, obtaining the corona resistance time, coating thickness, and surface coating ratio of multiple sets of enameled wires includes:

[0026] Enamelled wire samples with different coating thicknesses H and different coating ratios were selected;

[0027] The corona resistance time of each sample was tested multiple times under the same conditions using a corona resistance tester.

[0028] The corona resistance times of each sample are arranged in order of magnitude and the median value is taken as the corona resistance time T of the corresponding sample, thus obtaining n sets of data groups {Hn, Pn, Tn} of the coating thickness and corona resistance time of the enameled wire.

[0029] The enameled wire parameter determination device of the present invention includes a memory and a processor. The processor executes the enameled wire parameter determination method as described above by calling a control program stored in the memory.

[0030] The present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed on a computer, causes the computer to perform the method for determining the parameters of the enameled wire as described in the above technical solution.

[0031] This invention constructs a quantitative fitting model between corona resistance time, coating thickness, and surface coating ratio, achieving a functional description of their relationship. This allows for precise design of coating thickness and surface coating ratio while meeting customer corona resistance time requirements. Furthermore, this invention uses logarithmic transformation to convert the exponential relationship into a linear form and combines multiple linear regression analysis to solve the model parameters. The calculation process is simple, convenient, and has high fitting accuracy, making it applicable to corona-resistant enameled wires of different specifications and varieties. Based on the fitted curve model, this invention directly obtains the minimum coating thickness or minimum surface coating ratio that meets the corona resistance time requirements by solving inequalities related to coating thickness or surface coating ratio. This helps reduce material usage and production costs while ensuring performance, thereby improving the product's market competitiveness. Attached Figure Description

[0032] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0033] Figure 1 This is a main flowchart of an embodiment of the present invention.

[0034] Figure 2 This is a flowchart of a fitting method according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the corona resistance time of multiple groups of paint film thicknesses under different paint ratios according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic representation of the relationship between the fitted value of the corona resistance time and the actual test value according to an embodiment of the present invention.

[0037] Figure 5 This is a flowchart of a design method according to an embodiment of the present invention. Detailed Implementation

[0038] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0040] like Figure 1 As shown, in one embodiment, the method for determining the parameters of the enameled wire of the present invention includes the following steps.

[0041] Obtain the corona resistance time, coating thickness, and surface coating ratio of multiple sets of enameled wires;

[0042] A fitting equation model was constructed to fit the relationship curve between the logarithm of corona resistance time, film thickness, and surface paint ratio.

[0043] The constant values ​​of the fitting equation model were determined by fitting the logarithmic values ​​of the corona resistance time of each group with the coating thickness and the topcoat ratio.

[0044] When it is necessary to determine the parameters of the enameled wire, the parameters of the corresponding enameled wire are obtained based on the user's corona resistance time requirements and the fitted equation model.

[0045] This invention establishes an explicit mathematical relationship between corona resistance time, film thickness, and topcoat ratio by curve fitting to historical test data. This transforms the design process, which previously relied on experience-based judgment, into a calculable quantitative design process. Technicians only need to input the target corona resistance time to directly calculate the corresponding parameter range through the fitted equation, avoiding the uncertainty of "relying on experience" and significantly improving the accuracy and repeatability of the design results.

[0046] In traditional solutions, to meet the corona resistance time requirements of different customers, it is often necessary to repeatedly adjust the paint film thickness and topcoat ratio and conduct multiple rounds of corona resistance tests. This results in a large number of prototype samples, long testing cycles, and high costs. This invention, by pre-providing the required parameter combinations through a fitting equation, significantly reduces blind and repeated testing. Only a few key parameter points need to be verified to complete the product finalization, thereby significantly shortening the new product development cycle and reducing experimental costs.

[0047] In a further embodiment, the fitting equation model of the present invention is:

[0048]

[0049] Where A, B, and D are constants, T is the corona resistance time, H is the paint film thickness, P is the paint ratio, and e is the base of the natural logarithm or any positive integer.

[0050] The fitting equation model of this invention adopts an exponential equation. The exponential equation yields a positive corona resistance time T for any film thickness H and surface paint ratio P, avoiding physically unreasonable results such as negative corona resistance time during extrapolation from linear or polynomial models. This makes the fitting model more reliable in engineering applications. By using logarithmic transformation, the exponential relationship is converted into a linear expression for film thickness H and surface paint ratio P. The parameters A, B, and D can be directly solved using mature multiple linear regression methods, eliminating the need for iterative solutions to complex nonlinear equations. This approach offers advantages such as simple implementation, low computational cost, and good numerical stability, making it easy to implement in conventional statistical software or embedded systems.

[0051] In one embodiment, the present invention performs a fitting analysis on the logarithmic values ​​of each group of corona resistance times with the paint film thickness and the topcoat ratio to determine the constant values ​​of the fitting equation model, including:

[0052] Importing the n sets of data {Hn, Pn, Tn} into the fitted equation model, and taking the logarithm to the base e of both sides of the equation, we get:

[0053]

[0054] Multiple sets of data were calculated: {Hn, Pn, Tn, \ln(Tn)}, where Hn is the paint film thickness of the nth set, Pn is the topcoat ratio of the nth set, and Tn is the corona resistance time of the nth set.

[0055] The data set {Hn, Pn, Tn, \ln(Tn)} was fitted using fitting analysis software to determine the constant values ​​A, B, and D.

[0056] This embodiment transforms the originally exponentially related nonlinear fitting problem between T and H, P by taking the logarithm of the corona resistance time into ln(T) / H. n ) and H n P nThe linear relationship between the parameters allows for the direct application of mature multiple linear regression methods to solve for the constants A, B, and D. This eliminates the need for complex nonlinear optimization algorithms and avoids the problems of getting trapped in local optima or failing to converge in iterative solutions, making the parameter solution process simpler, more stable, and more reliable. By taking the logarithm to compress the numerical range of the corona resistance time, the influence of maxima and minima on the overall regression results is effectively reduced, resulting in a more balanced regression residual. This improves the robustness and overall accuracy of the fitting results, thus providing a more reliable mathematical model for subsequent parameter design.

[0057] In a further embodiment, based on user requirements and the fitted equation model, the parameters of the corresponding enameled wire are obtained as follows:

[0058] Obtain the user's minimum required corona resistance time T. 客户 ;

[0059] Obtain the fitted equation model and establish the comparison relationship:

[0060]

[0061] By adjusting the paint ratio and paint film thickness, a combination of paint ratio and paint film thickness values ​​that can satisfy the above comparison formula is obtained, and the combination of paint ratio values ​​corresponding to the minimum paint film thickness or the most cost-effective paint film thickness is obtained to meet user needs.

[0062] After obtaining the relationship between corona resistance time T, film thickness H, and topcoat ratio P, multiple sets of corona resistance time data that meet user needs can be obtained by establishing a preliminary comparison formula. From these data, the minimum film thickness or the most cost-effective topcoat ratio combination can be selected, which satisfies customer needs while saving costs.

[0063] The fitting analysis software in the above technical solutions includes, but is not limited to, Minitab or Origin software.

[0064] Minitab and Origin are both widely used software for fitting analysis, but they have some differences in focus. Minitab is a professional statistical analysis software, while Origin is a scientific and engineering graphing and data analysis software. Technicians in this field can choose the appropriate fitting analysis software according to their needs.

[0065] In one embodiment, obtaining the corona resistance time, coating thickness, and surface coating ratio of multiple sets of enameled wires includes:

[0066] Enamelled wire samples with different coating thicknesses H and different coating ratios were selected;

[0067] The corona resistance time of each sample was tested multiple times under the same conditions using a corona resistance tester.

[0068] The corona resistance times of each sample are arranged in order of magnitude and the median value is taken as the corona resistance time T of the corresponding sample, thus obtaining n sets of data groups {Hn, Pn, Tn} of the coating thickness and corona resistance time of the enameled wire.

[0069] In this embodiment, all samples were tested under the same corona resistance test conditions (such as voltage, frequency, temperature, voltage rise time, etc.), avoiding the interference of test condition variations on corona resistance time. This ensures that the differences in corona resistance time between different coating thicknesses and topcoat ratios mainly stem from the structural differences of the samples themselves, thus guaranteeing good comparability and consistency among the data and laying a reliable foundation for subsequent fitting analysis. This embodiment improves the representativeness and anomaly resistance of single-set data by conducting multiple tests and taking the median value. Multiple corona resistance time tests were performed on each group of enameled wire samples, and the median value was taken as the representative corona resistance time T for that sample after sorting the multiple test values. Compared to using only a single test result, this effectively reduces the impact of random fluctuations, test errors, or individual outliers on the results, making each group of corona resistance times T more stable and statistically representative, thus improving data quality.

[0070] The concept of this invention will be illustrated below with a specific example.

[0071] like Figure 2 As shown, this invention first obtains the corona resistance time and enamel film thickness of multiple sets of enameled wires. Enameled wire samples with different enamel film thicknesses H are selected, including 74±1μm, 80±1μm, 93±1μm, 94±1μm, and 98±1μm. Using a corona resistance tester under conditions of a load voltage of 3.5 kV, a frequency of 20 kHz, a temperature of 155℃, and a rise time of 100ns, the corona resistance time of the enameled wire samples with different enamel ratios and multiple enamel film thicknesses is tested. The results are as follows: Figure 3 The data shown.

[0072] Figure 3 In this context, H represents the coating thickness, P represents the coating ratio, and T' represents the average corona resistance time calculated from five repeated tests of each group of enameled wire samples under the same conditions.

[0073] A fitting equation model was constructed to fit the relationship between corona resistance time, film thickness, and topcoat ratio curves. The results were obtained through multiple linear regression (including interactive calculations).

[0074] Ln(T')=-9.61+0.105H+2.34P

[0075] R-degree of excellence 2 ≈0.99.

[0076] The specific fitting equation described above uses film thickness H and topcoat ratio P as independent variables, and the logarithm of corona resistance time ln(T') as the dependent variable. The model structure is simple, containing only one constant term and two linear coefficients. Furthermore, the meaning of each parameter is clear: coefficient 0.105 represents the influence of film thickness variation on the logarithm of corona resistance time, and coefficient 2.34 represents the influence of topcoat ratio variation on the logarithm of corona resistance time. This facilitates process engineers' intuitive understanding of the contribution of different process parameters to corona resistance performance and is beneficial for subsequent sensitivity analysis and process optimization.

[0077] Through multiple linear regression (including a modeling process with interaction factors), and considering the combined effects of film thickness and surface paint ratio, the simplified model described above was finally obtained. The goodness of fit (R²) ≈ 0.99 indicates that the model can explain approximately 99% of the sample data variation, with minimal residuals. In other words, given the film thickness H and surface paint ratio P, this equation has a small prediction error for corona resistance time, significantly outperforming simple empirical formulas or qualitative judgments, and can serve as a reliable mathematical basis for enameled wire design and process adjustments.

[0078] The fitted equation model can be further validated.

[0079] Multiple data sets with a paint ratio of 0.90 {0.90, H} were used. n ,T n The paint film thickness H n Substituting this into the fitted curve model, Ln(T') = -9.61 + 0.105 H + 2.34 P Calculate and obtain the corona resistance time fitting value Ln(T) corresponding to each group of data. n ), can yield results such as Figure 4 The data.

[0080] pass Figure 4 It can be seen that the absolute difference between the actual measured value of corona resistance time and the fitted value of corona resistance time is not much different from the measured corona resistance time of the corresponding coating thickness. That is, the two are not much different, which effectively confirms that the fitted curve model Ln(T') = -9.61 + 0.105 H + 2.34 P has good accuracy.

[0081] Other implementation methods of this example are not limited to logarithms with the natural base e. The logarithm with the base e is used here only for the convenience of calculation and demonstration.

[0082] like Figure 5As shown, when designing enameled wire, the corona resistance test conditions for this batch of enameled wire to be produced are determined. For example, the corona resistance test conditions are a load voltage of 3.5 kV, a frequency of 20 kHz, a temperature of 155℃, and a rise time of 100 ns. Under these test conditions, the minimum required value of the corona resistance time T is obtained. 客户 When the customer requires a coating thickness H of 100-120μm for the enameled wire and a corona resistance time of 30h or more, the following must be met:

[0083] Corona resistance time T > T 客户 =30, 100-120).

[0084] Based on the previously obtained fitting equation model Ln(T)=Ln(A') + B'×H + D'×P, and establishing the corona resistance time comparison relationship... .

[0085] Ln(30) = 3.401 was calculated using the determined constant values ​​ln(A') = -9.61, B' = 0.105, and D' = 2.34, and then converted to obtain:

[0086] .

[0087] Solve the above relationship:

[0088] When P=1, design the paint film thickness H min >102 ensures that the corona resistance requirements are met;

[0089] Take H max When the temperature is 120°C, the design paint ratio P > 0.65, which can ensure that the corona resistance requirements are met.

[0090] Therefore, the minimum film thickness can be determined to ensure that the corona resistance time meets the customer's minimum requirements, or the most cost-effective topcoat ratio can be selected.

[0091] The present invention also protects an enameled wire parameter determination device, including a memory and a processor, which executes the method for determining the parameters of the enameled wire according to any of the above technical solutions by calling a control program stored in the memory.

[0092] The present invention also protects a computer-readable storage medium storing a computer program that, when executed on a computer, causes the computer to perform the method for determining the parameters of the enameled wire described above.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for determining the parameters of enameled wire, characterized in that, include: Obtain the corona resistance time, coating thickness, and surface coating ratio of multiple sets of enameled wires; A fitting equation model was constructed to fit the relationship curve between the logarithm of corona resistance time, film thickness, and surface paint ratio. The constant values ​​of the fitting equation model were determined by fitting the logarithmic values ​​of the corona resistance time of each group with the coating thickness and the topcoat ratio. When it is necessary to determine the parameters of the enameled wire, the parameters of the corresponding enameled wire are obtained based on the user's corona resistance time requirements and the fitted equation model.

2. The method for determining the parameters of enameled wire as described in claim 1, characterized in that, The fitting equation model is as follows: ； Where A, B, and D are constants, T is the corona resistance time, H is the paint film thickness, P is the paint ratio, and e is the base of the natural logarithm or any positive integer.

3. The method for determining the parameters of enameled wire as described in claim 2, characterized in that, The constant values ​​of the fitting equation model, determined by fitting the logarithmic values ​​of each group of corona resistance times with the film thickness and the topcoat ratio, include: Importing the n sets of data {Hn, Pn, Tn} into the fitted equation model, and taking the logarithm to the base e of both sides of the equation, we get: ； Multiple sets of data were calculated: {Hn, Pn, Tn, \ln(Tn)}, where Hn is the paint film thickness of the nth set, Pn is the topcoat ratio of the nth set, and Tn is the corona resistance time of the nth set. The data set {Hn, Pn, Tn, \ln(Tn)} was fitted using fitting analysis software to determine the constant values ​​A, B, and D.

4. The method for determining the parameters of enameled wire as described in claim 3, characterized in that, Based on the user's corona resistance time requirements and the fitted equation model, the parameters of the corresponding enameled wire are obtained as follows: Obtain the user's minimum required corona resistance time T. 客户 ; Obtain the fitted equation model and establish the comparison relationship: ； By adjusting the paint ratio and paint film thickness, a combination of paint ratio and paint film thickness values ​​that can satisfy the above comparison formula is obtained, and the combination of paint ratio values ​​corresponding to the minimum paint film thickness or the most cost-effective paint film thickness is obtained to meet user needs.

5. The method for determining the parameters of enameled wire as described in claim 3, characterized in that, The fitting analysis software used is Minitab or Origin.

6. The method for determining the parameters of enameled wire as described in claim 1, characterized in that, The process of obtaining the corona resistance time, enamel film thickness, and surface enamel ratio of multiple sets of enameled wires includes: Enamelled wire samples with different coating thicknesses H and different coating ratios were selected; The corona resistance time of each sample was tested multiple times under the same conditions using a corona resistance tester. The corona resistance times of each sample are arranged in order of magnitude and the median value is taken as the corona resistance time T of the corresponding sample, thus obtaining n sets of data groups {Hn, Pn, Tn} of the coating thickness and corona resistance time of the enameled wire.

7. A device for determining enameled wire parameters, comprising a memory and a processor, characterized in that: The processor executes the method for determining the parameters of the enameled wire as described in any one of claims 1-6 by calling the control program stored in the memory.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed on a computer, it causes the computer to perform the method for determining the parameters of the enameled wire as described in any one of claims 1-6.

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