An extended debye equivalent circuit modeling method, device, equipment and medium
By measuring and interpreting the spectrum of the extended Debye equivalent circuit using the depolarization current method, the problems of complex iteration process and noise influence are solved, achieving efficient and accurate identification of extended Debye equivalent circuit parameters and improving the reliability and accuracy of the model.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAMEN UNIV OF TECH
- Filing Date
- 2026-01-22
- Publication Date
- 2026-05-29
Smart Images
Figure CN122113375A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of extended Debye equivalent circuit modeling technology, specifically to an extended Debye equivalent circuit modeling method, apparatus, device, and medium. Background Technology
[0002] With the development of power systems, the health status of oil-paper insulated equipment is crucial to the safe and stable operation of power equipment. Time-frequency domain dielectric spectroscopy is an important method for analyzing the aging of the internal insulating medium in oil-paper insulated equipment, and the extended Debye equivalent circuit is often used to characterize the dielectric response characteristics of the time-frequency domain dielectric spectrum. Currently, the main methods for constructing the extended Debye equivalent circuit include traditional intelligent optimization algorithms and novel time-frequency domain dielectric spectrum differential decomposition methods. Traditional intelligent optimization algorithms establish an objective function between the equivalent circuit parameters and the time-frequency domain dielectric spectrum characteristics, and use optimization algorithms such as particle swarm optimization for iterative optimization. However, these methods suffer from problems such as the need to pre-assume the number of polarization branches, complex iterative processes, and susceptibility to local optima, which limits the reliability and accuracy of parameter identification. The novel time-frequency domain dielectric spectrum differential decomposition method decomposes the implicit sub-spectral lines by differentiating the dielectric spectrum, and then solves the circuit parameters based on the sub-spectral line parameters (i.e., it requires complex mathematical transformations and differential processing of the original time-frequency domain dielectric spectrum data). Although this method avoids some of the defects of intelligent algorithms, the differential processing is complex, which not only increases the calculation steps and reduces the identification efficiency, but also amplifies the influence of noise on the original test spectral lines if the original time-frequency domain dielectric spectrum test values are affected by noise or other interference, thus affecting the accuracy of subsequent parameter identification.
[0003] In view of the above, this application is hereby submitted. Summary of the Invention
[0004] The present invention provides an extended Debye equivalent circuit modeling method, apparatus, device and medium, which can at least partially improve the above-mentioned problems.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: An extended Debye equivalent circuit modeling method, comprising: The dielectric response of the transformer oil-paper insulation medium is characterized by the extended Debye equivalent circuit, and the depolarization current method is used to measure the depolarization current of the extended Debye equivalent circuit to generate the total depolarization current. The logarithm of both sides of the overall depolarization current expression is taken to obtain the logarithmic curve of the depolarization current. The multiple sub-spectral lines in the logarithmic curve of the depolarization current are then despectrated to obtain the parameters of each polarization branch. Modeling of the extended Debye equivalent circuit of transformer oil-paper insulation is performed based on the parameters of each polarization branch.
[0006] The present invention also provides an extended Debye equivalent circuit modeling apparatus, comprising: The depolarization current calculation unit is used to characterize the dielectric response of the transformer oil-paper insulation medium using the extended Debye equivalent circuit, and to perform depolarization current measurement processing on the extended Debye equivalent circuit using the depolarization current method to generate the total depolarization current. The spectral decomposition unit is used to take the logarithm of both sides of the total depolarization current expression to obtain the logarithmic curve of the depolarization current, and to perform spectral decomposition on multiple sub-spectral lines within the logarithmic curve of the depolarization current to obtain the parameters of each polarization branch. The modeling unit is used to model the extended Debye equivalent circuit of the transformer oil-paper insulation based on the parameters of each polarization branch.
[0007] The present invention also provides an extended Debye equivalent circuit modeling apparatus, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the extended Debye equivalent circuit modeling method as described above.
[0008] The present invention also provides a readable storage medium storing a computer program that can be executed by a processor of the device in which the storage medium is located, to implement the extended Debye equivalent circuit modeling method as described in any of the above claims.
[0009] In summary, the core of this method lies in transforming the measured depolarization current curve into a logarithmic curve composed of multiple linear sub-spectral lines by performing a natural logarithmic transformation. Then, starting from the end of the curve, the resistance and capacitance parameters of the corresponding polarization branch are directly calculated by separating each linear sub-spectral line and extracting its slope and intercept. The entire process does not rely on traditional intelligent optimization algorithms for iterative optimization, nor does it require complex differential preprocessing of the original data. This method can simultaneously and accurately determine the number of polarization branches and the parameters of each branch in the extended Debye model, effectively overcoming the problems of inaccurate modeling and low efficiency caused by pre-setting the number of branches, complex iterative processes, or noise amplification in existing technologies.
[0010] In short, the proposed depolarization current method linear spectrum analysis can quickly identify the polarization resistance and polarization capacitance of corresponding branches using the slope and intercept of each sub-spectral line. This eliminates the need for complex intelligent optimization algorithms, avoiding the iterative optimization process and the tendency for parameter identification to find local optima. Furthermore, it can determine the number of polarization branches in the extended Debye equivalent circuit by calculating the total number of sub-spectral lines during the spectrum analysis process, without requiring traditional intelligent optimization algorithms to pre-assume the number of polarization branches, thus avoiding a lack of scientific basis. All of these factors effectively improve the reliability and accuracy of parameter identification in the extended Debye equivalent circuit. Simultaneously, the simplified identification steps enhance identification efficiency. Attached Figure Description
[0011] Figure 1 This is a flowchart illustrating the extended Debye equivalent circuit modeling method provided in the first embodiment of the present invention.
[0012] Figure 2 This is a schematic diagram of the extended Debye equivalent circuit provided in an embodiment of the present invention.
[0013] Figure 3 This is a schematic diagram of polarization / depolarization current measurement provided in an embodiment of the present invention.
[0014] Figure 4 This is a schematic diagram of the linear spectrum interpretation process provided in an embodiment of the present invention.
[0015] Figure 5 This is a schematic diagram of the module of the extended Debye equivalent circuit modeling device provided in the second embodiment of the present invention. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0017] refer to Figure 1 , Figure 2 As shown, the first embodiment of the present invention discloses an extended Debye equivalent circuit modeling method, which can be executed by an extended Debye equivalent circuit modeling device (hereinafter referred to as the modeling device), specifically, by one or more processors within the modeling device, to implement the following method: S1. The dielectric response of the transformer oil-paper insulation medium is characterized by the extended Debye equivalent circuit, and the depolarization current method is used to measure the depolarization current of the extended Debye equivalent circuit to generate the total depolarization current. Specifically, step S1 further includes: characterizing the dielectric response of the transformer oil-paper insulation medium using an extended Debye equivalent circuit; The extended Debye equivalent circuit was measured using the depolarization current method, in which a DC voltage was applied to the extended Debye equivalent circuit. The polarization process is performed, and the polarization stage is entered. The polarization current is then measured. ; During charging time After completion, the extended Debye equivalent circuit is short-circuited to enter the depolarization stage, and the depolarization current is measured. And based on polarization current and depolarization current The insulation condition is assessed; When charging time When the preset duration is reached, After a short circuit, the discharge currents of each branch of the extended Debye equivalent circuit are superimposed to obtain the total depolarization current. , , , For the number of polarization branches, Let be the initial current amplitude of the i-th polarization branch, the magnitude of which is determined by the test conditions and the branch's own parameters. The time constant of the polarization branch characterizes the polarization relaxation response rate of the corresponding insulating medium. Let be the polarization resistance of the i-th polarization branch. Let be the polarization capacitor of the i-th polarization branch, i=1,2,...,n.
[0018] Please see Figure 2 Preferably, in this embodiment, the extended Debye equivalent circuit includes a geometric equivalent circuit and a polarization equivalent circuit, wherein the geometric equivalent circuit and the polarization equivalent circuit are connected in parallel, and the geometric equivalent circuit is composed of an insulation resistance. and geometric capacitance The polarization equivalent circuit is composed of multiple polarization branches connected in parallel, and each polarization branch is generated by a polarization resistor and a polarization capacitor connected in series.
[0019] In this embodiment, an extended Debye equivalent circuit is used to characterize the dielectric response properties of the transformer oil-paper insulation medium. This model includes a geometric equivalent circuit and a polarization equivalent circuit connected in parallel. The specific circuit is as follows: Figure 2 As shown. The equivalent circuit was measured using the depolarization current method, a time-domain dielectric response technique that assesses the aging state of paper insulation by monitoring its current response under DC voltage. First, a DC voltage is applied to the insulating medium to polarize it; this is the polarization stage, and the polarization current is measured using a Keithley 6517B electrometer. After the charging time, the two ends of the medium are short-circuited to enter the depolarization stage, and the depolarization current is measured using a Keithley 6517B electrometer. This current is the reverse decaying current generated by the release of polarization charges within the medium. The insulation state is assessed by analyzing the polarization current and depolarization current. A typical test curve for this process is shown below. Figure 3 As shown.
[0020] It should be noted that the polarization / depolarization current method is a non-destructive time-domain dielectric spectroscopy method commonly used to assess the aging state of oil-paper insulation equipment. Taking depolarization current as an example, the insulation state is typically evaluated using the depolarization current value obtained through testing in the following ways: First, by directly utilizing the curve values, including the ratio of the initial polarization current to the initial depolarization current, to study aging characteristics such as the aging coefficient, and by studying aging characteristics such as the discharge quantity through the overall curve area; second, by indirectly using the curve data to construct an extended Debye equivalent circuit, and evaluating the aging state through the magnitude of the equivalent circuit parameters. The second method is also the most commonly used. Other methods can also be used to assess the insulation state, and no limitations are made here.
[0021] S2, take the logarithm of both sides of the overall depolarization current expression to obtain the logarithmic curve of the depolarization current, and perform spectral analysis on multiple sub-spectral lines within the logarithmic curve of the depolarization current to obtain the parameters of each polarization branch. Specifically, step S2 further includes: adjusting the total depolarization current. Taking the logarithm of both sides of the expression yields the logarithmic curve of the depolarization current. The mathematical expression for the logarithmic curve is as follows: ; The first sub-spectral line is obtained from the linear region at the end of the logarithmic curve of the depolarization current. slope With intercept And through the formula The parameters of the first polarization branch are obtained by solving. and ; Subtracting the first sub-spectral line from the logarithmic curve of the depolarization current yields the current remaining spectral line. The second sub-spectral line is then obtained from the linear region at the end of the current remaining spectral line. slope With intercept And through the formula The parameters of the second polarization branch are obtained by solving. and ; Repeat the above steps until the parameters of the nth polarization branch are obtained.
[0022] In this embodiment, the goal of this step is to decompose the complex current response of multiple exponential superpositions into easily tractable linear components and directly calculate the circuit parameters of each polarization branch. First, since the overall depolarization current expression is a nonlinear superposition model of a multinomial exponential function, the natural logarithm of both ends of this expression is taken (i.e., a natural logarithmic coordinate transformation on the vertical axis) to obtain the logarithmic curve of the depolarization current. This transformation is key to the invention. By taking the logarithm, the multiple exponential decay terms coupled together in the original time domain are transformed into a superposition of a series of linear sub-spectral lines with different slopes and intercepts in logarithmic coordinates. This processing method is direct and efficient, eliminating the need for complex differential operations on the original data as in differential spectral decomposition methods, thus avoiding the risk of amplifying measurement noise and introducing additional errors during the differential process, and significantly simplifying the data processing flow.
[0023] Since the depolarization current curve in logarithmic coordinates consists of a series of linear sub-spectral lines, and the intercept and slope of each sub-spectral line are related to the parameters of the corresponding polarization branch, the number and parameters of polarization branches in the extended Debye equivalent circuit of transformer oil-paper insulation can be efficiently and accurately identified by decomposing the depolarization current curve in logarithmic coordinates. Specifically, linear spectral decomposition is performed on the aforementioned logarithmic depolarization current curve to separate each implicit sub-spectral line and extract its parameters. The spectral decomposition process follows the order from the slowest decaying branch (corresponding to the largest time constant) to the fastest decaying branch (corresponding to the smallest time constant): First, observe the end of the logarithmic curve (corresponding to the region with a larger time constant), which is mainly dominated by the slowest decaying polarization process and exhibits good linearity. By performing linear fitting on this linear region at the end, the first sub-spectral line is obtained, and its slope and intercept are extracted. Secondly, based on the mathematical relationship between the sub-spectral line parameters and the polarization branch parameters, the time constant and initial current amplitude of the first polarization branch are calculated using formulas; furthermore, by combining the known test voltage and charging time, the polarization resistance and polarization capacitance of the first polarization branch can be accurately solved.
[0024] Subsequently, after identifying and calculating the parameters of the first sub-spectral line, spectral line stripping is performed. The original logarithmic curve of the depolarization current is subtracted from the identified first sub-spectral line to obtain the current remaining spectral line. At this point, the slowest decaying component has been removed. At the end of the new remaining spectral line (now dominated by the second slowest decaying polarization process), the second sub-spectral line is obtained through linear fitting, and its slope and intercept are extracted. The same set of formulas as in the previous steps is used to solve for the parameters of the second polarization branch using the slope and intercept.
[0025] The steps of "fitting and extracting parameters" and "curve stripping" constitute a loop. This loop is repeated: continuously fitting the next sub-spectral line from the linear region at the end of the latest remaining spectral line, taking its slope and intercept, and calculating the parameters of the corresponding polarization branch. This loop continues until the nth sub-spectral line is successfully deciphered and the parameters of the corresponding nth polarization branch are solved. At this point, the deciphering process naturally terminates. The total number of separated sub-spectral lines, n, is the accurate number of polarization branches in the extended Debye equivalent circuit model. This method objectively determines the model complexity through the data itself, completely abandoning the traditional intelligent algorithm's practice of manually assuming the number of branches in advance, thus improving the scientific rigor and reliability of the model.
[0026] S3, model the extended Debye equivalent circuit of the transformer oil-paper insulation based on the parameters of each polarization branch.
[0027] Specifically, in this embodiment, to more intuitively demonstrate the parameter identification process based on the linear depolarization current spectral analysis method, a transformer T1 with known equivalent circuit parameters is subjected to linear depolarization current spectral analysis. The spectral analysis process of each sub-spectral line of the depolarization current of transformer T1 is as follows: Figure 4 As shown in Table 1, the parameters of each sub-spectral line obtained during the spectral interpretation process are as follows.
[0028] Table 1. Parameters of each sub-spectral line
[0029] Depend on Figure 4 As shown in Table 1, the linear spectral analysis method of the depolarization current curve can accurately separate each implicit sub-spectral line within the depolarization current. The parameters of each polarization branch obtained by using the data in Table 1 and combining them with the parameter calculation formula are shown in Table 2.
[0030] Table 2. Polarization Branch Parameter Identification Results
[0031] On the one hand, as shown in Tables 1 and 2, the total number of sub-spectral lines and the number of polarization branches obtained from the final spectrum analysis of the depolarization current curve of transformer T1 are both 6, indicating that the linear spectrum analysis method proposed in this invention can accurately determine the number of polarization branches. On the other hand, as shown in Table 2, the error between the extended Debye polarization branch parameter values identified by the linear spectrum analysis method and the original values is no more than 2%. This verifies that the linear spectrum analysis method for depolarization current can accurately identify the equivalent circuit parameters, thereby achieving accurate modeling of the extended Debye equivalent circuit of the transformer.
[0032] To further verify the universality of the depolarization current linear spectral analysis method involved in this invention for transformers with different aging levels, an extended Debye equivalent circuit modeling study was conducted on three transformers with different aging levels: T2 (0.3% moisture content in paper), T3 (0.9% moisture content in paper), and T4 (4.68% moisture content in paper). The equivalent circuit parameters of the three transformers were identified using both the depolarization current linear spectral analysis method and the particle swarm optimization intelligent algorithm. The identification results of each sub-spectral line parameter of the depolarization current for the three transformers are shown in Table 3, and the identification results of the two methods are shown in Table 4.
[0033] Table 3. Parameters of each sub-spectral line of the three transformers.
[0034] Table 4 Comparison of identification results between the two identification methods
[0035] In this embodiment, the equivalent circuit parameters obtained from the three transformers using different identification methods in Table 4 are used to construct the corresponding depolarization current curves based on the overall depolarization current formula. These curves are then compared and analyzed with the corresponding measured depolarization current curves. To better quantify the fit between the identified and measured values of the depolarization current curves, this method introduces a formula... The goodness-of-fit P is used to judge the fit between the two curves. The goodness-of-fit for the three transformers under various operating conditions is shown in Table 5. This is the field-measured value of the depolarization current. is the calculated value of the depolarization current, and N is the total number of field-measured values of the depolarization current.
[0036] Table 5. Fit of the three transformers under various operating conditions.
[0037] Table 5 clearly shows that the depolarization current curve constructed based on the identification method of this invention has an average fitting degree of 99% with the measured value, while the depolarization current curve constructed using the intelligent optimization algorithm has an average fitting degree of 73% with the measured value. This further verifies that the linear depolarization current spectrum method proposed in this invention has good universality for transformers with different aging levels, and the extended Debye equivalent circuit model constructed by it can more accurately reflect the dielectric spectrum characteristics of the depolarization current, laying an important foundation for the accurate assessment of the oil-paper insulation state of the transformer.
[0038] In summary, this invention provides a method for modeling the extended Debye equivalent circuit of oil-paper insulation equipment based on linear depolarization current spectral analysis. Its core lies in achieving efficient and high-precision decomposition and parameter identification of complex dielectric response signals through an innovative linearization analytical technique. Starting from the physical basis of depolarization current testing, this method first uses the extended Debye equivalent circuit model to characterize the polarization characteristics of the oil-paper insulation medium. Its innovation is mainly reflected in the subsequent signal processing stage: by applying a natural logarithmic transformation to the measured total depolarization current curve, the complex waveform, originally a nonlinear superposition of multiple exponential decay functions, is transformed into a superimposed signal composed of a series of linear sub-spectral lines in logarithmic coordinates. This transformation is a crucial preprocessing step, cleverly transforming the parameter identification problem from complex nonlinear fitting into the stripping and analysis of linear components.
[0039] Based on this, this invention proposes a systematic linear spectral decomposition process. Starting from the end of the logarithmic curve (corresponding to the longest time constant), the process sequentially executes two core steps: "linear fitting to extract parameters" and "curve stripping," gradually separating each linear sub-spectral line. Each fitting operation directly obtains the slope and intercept of the sub-spectral line; each stripping operation clears obstacles for identifying the next faster-decreasing polarization process. This iterative process continues until all significant linear components are completely separated. This method does not require a pre-defined model order (i.e., the number of polarization branches); the total number of sub-spectral lines ultimately separated is the optimal number of polarization branches for the model, thus scientifically determining the model's complexity. More importantly, this invention establishes a direct and explicit mathematical mapping relationship between the linear sub-spectral line parameters obtained from the spectral decomposition and the physical parameters of the extended Debye equivalent circuit. Using the slope and intercept of each sub-spectral line, combined with known test conditions, the polarization resistance and polarization capacitance of the corresponding polarization branch can be directly calculated using a derived, concise formula. This process completely avoids the time-consuming iterative optimization and the risk of getting trapped in local optima that are necessary for traditional intelligent optimization algorithms. It also avoids the complex differential operations in frequency domain differential spectral decomposition and their amplification effect on measurement noise.
[0040] Compared with existing technologies, this invention has the following advantages: 1. The proposed depolarization current method linear spectrum decomposition method determines the number of polarization branches in the extended Debye equivalent circuit by the total number of sub-spectral lines in the spectrum decomposition process. The total number of sub-spectral lines increases with the aging of the transformer oil paper insulation, avoiding the drawback of traditional intelligent algorithms that require prior assumption of the number of polarization branches. 2. The proposed depolarization current method linear spectrum decomposition method can quickly identify the polarization resistance and polarization capacitance of the corresponding branch by utilizing the slope and intercept of each sub-spectral line, without the need for complex intelligent optimization algorithms. This avoids the problems of iterative optimization processes and local optima in parameter identification required by intelligent optimization algorithms, effectively improving the accuracy of parameter identification in the extended Debye equivalent circuit. 3. Although the novel time-frequency domain dielectric spectrum differential decomposition method can also solve the problems of traditional intelligent optimization algorithms' difficulty in accurately determining the number of polarization branches and poor parameter identification accuracy, it requires a complex differential processing step beforehand, which increases the identification process and easily amplifies the test error of the time-frequency domain dielectric spectrum, which has a certain impact on the subsequent identification accuracy. The linear spectrum interpretation method proposed in this invention can achieve effective and accurate spectrum interpretation of each sub-spectral line within the depolarization current by simply performing a mathematical logarithmic transformation on the depolarization current curve. It does not require complex differential processing and other steps, which simplifies the identification process, improves identification efficiency, and enhances identification accuracy, thus facilitating the promotion and application of transformer field aging diagnosis.
[0041] Please see Figure 5 A second embodiment of the present invention provides an extended Debye equivalent circuit modeling apparatus, comprising: The depolarization current calculation unit 101 is used to characterize the dielectric response of the transformer oil-paper insulation medium using the extended Debye equivalent circuit, and to perform depolarization current measurement processing on the extended Debye equivalent circuit using the depolarization current method to generate the total depolarization current. The spectrum decomposition unit 102 is used to take the logarithm of both sides of the total depolarization current expression to obtain the logarithmic curve of the depolarization current, and to perform spectrum decomposition on multiple sub-spectral lines within the logarithmic curve of the depolarization current to obtain the parameters of each polarization branch. Modeling unit 103 is used to model the extended Debye equivalent circuit of transformer oil-paper insulation based on the parameters of each polarization branch.
[0042] The depolarization current calculation unit 101 is specifically used to: characterize the dielectric response of the transformer oil-paper insulation medium using the extended Debye equivalent circuit; The extended Debye equivalent circuit was measured using the depolarization current method, in which a DC voltage was applied to the extended Debye equivalent circuit. The polarization process is performed, and the polarization stage is entered. The polarization current is then measured. ; During charging time After completion, the extended Debye equivalent circuit is short-circuited to enter the depolarization stage, and the depolarization current is measured. And based on polarization current and depolarization current The insulation condition is assessed; When charging time When the preset duration is reached, After a short circuit, the discharge currents of each branch of the extended Debye equivalent circuit are superimposed to obtain the total depolarization current. , , , For the number of polarization branches, Let be the initial current amplitude of the i-th polarization branch. The time constant of the polarization branch, Let be the polarization resistance of the i-th polarization branch. Let be the polarization capacitor of the i-th polarization branch.
[0043] The spectral decomposition unit 102 is specifically used for: determining the total depolarization current. Taking the logarithm of both sides of the expression yields the logarithmic curve of the depolarization current. The mathematical expression for the logarithmic curve is as follows: ; The first sub-spectral line is obtained from the linear region at the end of the logarithmic curve of the depolarization current. slope With intercept And through the formula The parameters of the first polarization branch are obtained by solving. and ; Subtracting the first sub-spectral line from the logarithmic curve of the depolarization current yields the current remaining spectral line. The second sub-spectral line is then obtained from the linear region at the end of the current remaining spectral line. slope With intercept And through the formula The parameters of the second polarization branch are obtained by solving. and ; Repeat the above steps until the parameters of the nth polarization branch are obtained.
[0044] A third embodiment of the present invention provides an extended Debye equivalent circuit modeling apparatus, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the extended Debye equivalent circuit modeling method as described in any of the above embodiments.
[0045] A fourth embodiment of the present invention provides a readable storage medium storing a computer program that can be executed by a processor of the device in which the storage medium is located, to implement the extended Debye equivalent circuit modeling method as described in any of the above claims.
[0046] For example, the various devices and process steps described above can be implemented by a computer program, which can be divided into one or more units, which are stored in the memory and executed by the processor to complete the present invention.
[0047] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.
[0048] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the present invention by running or executing the computer programs and / or modules stored in the memory and by calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.
[0049] If the unit integrated into the electronic device or printer is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and inventive practice in the jurisdiction. For example, in some jurisdictions, according to legislation and inventive practice, computer-readable media do not include electrical carrier signals and telecommunication signals.
[0050] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.
[0051] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.
Claims
1. A method for modeling extended Debye equivalent circuits, characterized in that, include: The dielectric response of the transformer oil-paper insulation medium is characterized by the extended Debye equivalent circuit, and the depolarization current method is used to measure the depolarization current of the extended Debye equivalent circuit to generate the total depolarization current. The logarithm of both sides of the overall depolarization current expression is taken to obtain the logarithmic curve of the depolarization current. The multiple sub-spectral lines in the logarithmic curve of the depolarization current are then despectrated to obtain the parameters of each polarization branch. Modeling of the extended Debye equivalent circuit of transformer oil-paper insulation is performed based on the parameters of each polarization branch.
2. The extended Debye equivalent circuit modeling method according to claim 1, characterized in that, The extended Debye equivalent circuit includes a geometric equivalent circuit and a polarization equivalent circuit, wherein the geometric equivalent circuit and the polarization equivalent circuit are connected in parallel, and the geometric equivalent circuit consists of an insulation resistance. and geometric capacitance The polarization equivalent circuit is composed of multiple polarization branches connected in parallel, and each polarization branch is generated by a polarization resistor and a polarization capacitor connected in series.
3. The extended Debye equivalent circuit modeling method according to claim 1, characterized in that, The dielectric response of the transformer oil-paper insulation medium is characterized using the extended Debye equivalent circuit. The depolarization current method is then used to measure and process the depolarization current of the extended Debye equivalent circuit, generating the total depolarization current, specifically: The dielectric response of the transformer oil-paper insulation medium was characterized using the extended Debye equivalent circuit. The extended Debye equivalent circuit was measured using the depolarization current method, in which a DC voltage was applied to the extended Debye equivalent circuit. The polarization process is performed, and the polarization stage is entered. The polarization current is then measured. ; During charging time After completion, the extended Debye equivalent circuit is short-circuited to enter the depolarization stage, and the depolarization current is measured. And based on polarization current and depolarization current The insulation condition is assessed; When charging time When the preset duration is reached, After a short circuit, the discharge currents of each branch of the extended Debye equivalent circuit are superimposed to obtain the total depolarization current. , , , For the number of polarization branches, Let be the initial current amplitude of the i-th polarization branch. The time constant of the polarization branch, Let be the polarization resistance of the i-th polarization branch. Let be the polarization capacitor of the i-th polarization branch.
4. The extended Debye equivalent circuit modeling method according to claim 3, characterized in that, Taking the logarithm of both sides of the overall depolarization current expression yields the logarithmic curve of the depolarization current. Then, the parameters of each polarization branch are obtained by interpreting the multiple sub-spectral lines within the logarithmic curve. Specifically: For the total depolarization current Taking the logarithm of both sides of the expression yields the logarithmic curve of the depolarization current. The mathematical expression for the logarithmic curve is as follows: ; The first sub-spectral line is obtained from the linear region at the end of the logarithmic curve of the depolarization current. slope With intercept And through the formula The parameters of the first polarization branch are obtained by solving. and ; Subtracting the first sub-spectral line from the logarithmic curve of the depolarization current yields the current remaining spectral line. The second sub-spectral line is then obtained from the linear region at the end of the current remaining spectral line. slope With intercept And through the formula The parameters of the second polarization branch are obtained by solving. and ; Repeat the above steps until the parameters of the nth polarization branch are obtained.
5. An extended Debye equivalent circuit modeling apparatus, characterized in that, include: The depolarization current calculation unit is used to characterize the dielectric response of the transformer oil-paper insulation medium using the extended Debye equivalent circuit, and to perform depolarization current measurement processing on the extended Debye equivalent circuit using the depolarization current method to generate the total depolarization current. The spectral decomposition unit is used to take the logarithm of both sides of the total depolarization current expression to obtain the logarithmic curve of the depolarization current, and to perform spectral decomposition on multiple sub-spectral lines within the logarithmic curve of the depolarization current to obtain the parameters of each polarization branch. The modeling unit is used to model the extended Debye equivalent circuit of the transformer oil-paper insulation based on the parameters of each polarization branch.
6. The extended Debye equivalent circuit modeling apparatus according to claim 1, characterized in that, The depolarization current calculation unit is specifically used for: The dielectric response of the transformer oil-paper insulation medium was characterized using the extended Debye equivalent circuit. The extended Debye equivalent circuit was measured using the depolarization current method, in which a DC voltage was applied to the extended Debye equivalent circuit. The polarization process is performed, and the polarization stage is entered. The polarization current is then measured. ; During charging time After completion, the extended Debye equivalent circuit is short-circuited to enter the depolarization stage, and the depolarization current is measured. And based on polarization current and depolarization current The insulation condition is assessed; When charging time When the preset duration is reached, After a short circuit, the discharge currents of each branch of the extended Debye equivalent circuit are superimposed to obtain the total depolarization current. , , , For the number of polarization branches, Let be the initial current amplitude of the i-th polarization branch. The time constant of the polarization branch, Let be the polarization resistance of the i-th polarization branch. Let be the polarization capacitor of the i-th polarization branch.
7. The extended Debye equivalent circuit modeling method according to claim 1, characterized in that, The spectrum interpretation unit is specifically used for: For the total depolarization current Taking the logarithm of both sides of the expression yields the logarithmic curve of the depolarization current. The mathematical expression for the logarithmic curve is as follows: ; The first sub-spectral line is obtained from the linear region at the end of the logarithmic curve of the depolarization current. slope With intercept And through the formula The parameters of the first polarization branch are obtained by solving. and ; Subtracting the first sub-spectral line from the logarithmic curve of the depolarization current yields the current remaining spectral line. The second sub-spectral line is then obtained from the linear region at the end of the current remaining spectral line. slope With intercept And through the formula The parameters of the second polarization branch are obtained by solving. and ; Repeat the above steps until the parameters of the nth polarization branch are obtained.
8. An extended Debye equivalent circuit modeling apparatus, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the extended Debye equivalent circuit modeling method as described in any one of claims 1 to 4.
9. A readable storage medium, characterized in that, The storage medium contains a computer program that can be executed by a processor of the device in which the storage medium resides, to implement the extended Debye equivalent circuit modeling method as described in any one of claims 1 to 4.