Method for predicting service life of high-voltage power capacitor and related device

Abstract

The invention provides a high-voltage power capacitor life prediction method and a related device, and belongs to the field of power equipment monitoring. The method is realized based on a pre-constructed material characteristic database, the material characteristic database comprises the aging degree of each area in the capacitor under the action of different temperatures and voltages, and the method comprises the following steps: acquiring the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted; according to the internal temperature distribution and the real-time voltage waveform characteristics, utilizing a material characteristic database to determine the aging degree of each region in the to-be-predicted capacitor; and obtaining the service life of the to-be-predicted capacitor according to the aging degree of each region in the to-be-predicted capacitor. By acquiring the internal temperature distribution and the real-time voltage waveform characteristics, the service life can be predicted by comprehensively combining the actual operation condition. Meanwhile, the service life is determined based on a material characteristic database containing the aging degree of each region under the action of different temperatures and voltages, and the service life of the high-voltage power capacitor can be predicted more accurately.

Description

Technical Field

[0001] The present invention belongs to the technical field of power equipment monitoring, and in particular relates to a life prediction method for a high-voltage power capacitor and a related device. Background Art

[0002] In power systems, high-voltage power capacitors, due to their high reliability, long lifespan, and mature technology, are widely used in numerous critical applications, including DC transmission, reactive power compensation, and AC / DC filtering. However, over long-term operation, high-voltage power capacitors are subject to the effects of various factors, including high-voltage DC, AC, and harmonics. This can cause the capacitor's performance to gradually degrade, shortening its service life. Capacitor failure can have a serious impact on the stable operation of the entire power system, making it particularly important to predict the remaining life of high-voltage power capacitors over long-term operation.

[0003] During long-term operation, capacitors experience internal temperature rises due to various factors. This, combined with the effects of high-voltage electric fields, further shortens the lifespan of capacitors. Furthermore, capacitor lifespan is dependent on numerous factors, including material properties, the voltage and current it withstands, and the temperature it encounters. Therefore, developing a lifespan prediction method for high-voltage power capacitors that comprehensively considers these factors is a pressing issue.

[0004] Currently, existing technologies are insufficient in predicting the lifespan of high-voltage power capacitors. A common practice is to conduct accelerated aging tests on capacitors in the laboratory and obtain an equivalent lifespan through data fitting. However, this approach does not take into account changes in operating conditions during operation. Other methods only measure the voltage and current on the capacitor in real time, or only measure the temperature rise of the capacitor shell in real time, to predict the remaining lifespan. For example, one method predicts the lifespan by calculating the aging factor by measuring the voltage waveform the capacitor is subjected to, but the internal temperature is obtained through calculation, and the accuracy of the temperature calculation cannot be guaranteed under actual operating conditions. Another method establishes a relationship between the temperature rise of the capacitor shell and the capacitance in the laboratory, and then measures the shell temperature in practice to obtain the capacitance, i.e., the remaining lifespan. This method is overly simple and cannot accurately reflect the actual lifespan of the capacitor. Summary of the Invention

[0005] In view of this, the present invention provides a high-voltage power capacitor life prediction method and related devices, aiming to more accurately predict the life of high-voltage power capacitors by comprehensively considering factors such as material properties and actual operating conditions.

[0006] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for predicting the life of a high-voltage power capacitor, which is implemented based on a pre-built material property database. The material property database contains the aging degree of various regions inside the capacitor under different temperatures and voltages, and includes the following steps:

[0008] Obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted;

[0009] Based on the internal temperature distribution and real-time voltage waveform characteristics, the material property database is used to determine the aging degree of each area inside the capacitor to be predicted;

[0010] The life of the capacitor to be predicted is obtained according to the aging degree of each area inside the capacitor to be predicted.

[0011] Furthermore, the process of building the material property database includes:

[0012] Apply voltages of different magnitudes and forms to the polypropylene film material, and simultaneously apply different temperatures;

[0013] Measure the electrical performance parameters of polypropylene film after applying voltage and temperature treatment;

[0014] Combining the applied voltage and temperature with the measured electrical performance parameters, the degree of aging is calculated and a material property database is established.

[0015] Furthermore, for voltage and temperature, the corresponding aging degrees are calculated according to the following formulas:

[0016] Aging degree at different voltages:

[0017]

[0018] Where, is the actual service life, For the design service life, is the rated voltage, is the actual operating voltage;

[0019] Aging degree at different temperatures:

[0020]

[0021] Where, The film is in the aging state. is the apparent activation energy, is the gas constant, is the aging temperature, is the parameter factor, To reach the aging state The time required.

[0022] Furthermore, obtaining the internal temperature distribution of the capacitor to be predicted includes:

[0023] The interior of the capacitor to be predicted is divided into several small areas; adjacent small areas are connected by thermal resistance, and the heat flow between different small areas satisfies the law of heat conduction;

[0024] Obtaining the case temperature and inherent thermal resistance parameters of the capacitor to be predicted;

[0025] Based on the shell temperature and inherent thermal resistance parameters, the temperature of each small area inside the capacitor is calculated according to the law of heat conduction, thereby obtaining the internal temperature distribution.

[0026] Furthermore, the real-time voltage waveform characteristics of the capacitor to be predicted are obtained, including:

[0027] In the circuit loop of the capacitor to be predicted, the voltage signal across the capacitor is collected in real time;

[0028] The collected voltage signal is processed using the Fourier decomposition algorithm to obtain the real-time voltage waveform characteristics containing different frequency components.

[0029] Furthermore, when the collected voltage signal is processed using the Fourier decomposition algorithm, the real-time voltage waveform characteristics are obtained according to the following formula:

[0030]

[0031] Where, is the actual waveform, that is, the real-time voltage waveform characteristics, is the DC component, is the frequency of a component, is the amplitude of the corresponding frequency component, is the phase of the corresponding frequency component.

[0032] Furthermore, the life of the capacitor to be predicted is determined according to the following formula:

[0033]

[0034] Where, is the life of the capacitor under voltage U and temperature T, is the total number of small areas divided inside the capacitor, For the region The life of the polypropylene film inside.

[0035] In a second aspect, the present invention provides a life prediction device for high-voltage power capacitors, which is implemented based on a pre-built material property database. The material property database contains the aging degree of various regions inside the capacitor under different temperatures and voltages, including:

[0036] A data acquisition module is used to obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted;

[0037] A small area aging determination module is used to determine the aging degree of each area inside the capacitor to be predicted based on the internal temperature distribution and real-time voltage waveform characteristics using the material property database;

[0038] The capacitor life prediction module is used to obtain the life of the capacitor to be predicted based on the aging degree of each area inside the capacitor to be predicted.

[0039] In a third aspect, the present invention provides a computer device, comprising a processor and a memory:

[0040] The memory is used to store computer programs and send instructions of the computer programs to the processor;

[0041] The processor executes the high-voltage power capacitor life prediction method of the first aspect according to the instructions of the computer program.

[0042] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, a high-voltage power capacitor life prediction method according to the first aspect is implemented.

[0043] In summary, the present invention provides a method for predicting the life of a high-voltage power capacitor, which is implemented based on a pre-built material property database. The material property database contains the aging degree of each region inside the capacitor under different temperatures and voltages, including obtaining the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted; using the material property database to determine the aging degree of each region inside the capacitor to be predicted based on the internal temperature distribution and real-time voltage waveform characteristics; and obtaining the life of the capacitor to be predicted based on the aging degree of each region inside the capacitor to be predicted. By obtaining the internal temperature distribution and real-time voltage waveform characteristics, the present invention can comprehensively combine the actual operating conditions to predict the life. At the same time, by determining the life based on the material property database containing the aging degree of each region under different temperatures and voltages, the life of the high-voltage power capacitor can be predicted more accurately.

[0044] The present invention also provides a high-voltage power capacitor life prediction device, computer equipment and computer-readable storage medium, which have similar effects to the above method when implemented and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 A flowchart of a method for predicting the life of a high-voltage power capacitor provided by an embodiment of the present invention;

[0047] Figure 2 A diagram illustrating the implementation process of a high-voltage power capacitor life prediction method provided by an embodiment of the present invention;

[0048] Figure 3 A block diagram of a high-voltage power capacitor life prediction device provided by an embodiment of the present invention;

[0049] Figure 4 A block diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purposes, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] Hereinafter, the prior art terms involved in the present invention will be first introduced.

[0052] (1) High-voltage power capacitor: An electrical device used in power systems to operate in high-voltage environments and store and release electrical energy. It is usually composed of electrodes, dielectrics, and other components. It has a high rated voltage and can be used in power system applications such as DC transmission, reactive power compensation, and AC / DC filtering. During operation, its performance will gradually change due to factors such as electric fields and temperature.

[0053] (2) Accelerated aging test: A test method that simulates the aging process of a product under normal operating conditions for a long time in a relatively short period of time by strengthening stress conditions (such as increasing temperature, voltage, humidity, etc.). The purpose is to quickly evaluate the aging characteristics and life of the product. In the field of capacitors, the aging process is often accelerated by applying stress such as voltage and temperature higher than normal operating conditions to the capacitor in the laboratory, so as to obtain aging-related data more quickly.

[0054] (3) Operating conditions: refers to the working status and conditions of the equipment during actual operation. For high-voltage power capacitors, operating conditions include factors such as the voltage and current it withstands, the magnitude and waveform of the current (such as whether it is a standard sine wave, whether it contains harmonics, etc.), the operating environment temperature, and load changes. These factors have a significant impact on the performance and life of the capacitor, but some prediction methods in existing technologies do not fully consider the changes in these operating conditions.

[0055] See also Figure 1 The embodiment of the present invention provides a method for predicting the life of a high-voltage power capacitor, which is implemented based on a pre-built material property database. The material property database contains the aging degree of each region inside the capacitor under different temperatures and voltages, and includes the following steps:

[0056] S1: Obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted.

[0057] It should be noted that internal temperature distribution refers to the temperature conditions at different locations within a high-voltage power capacitor. Due to differences in heating and cooling conditions across various internal regions during capacitor operation, this results in uneven temperature distribution. Understanding this distribution is crucial for accurately assessing its aging condition. Real-time voltage waveform characteristics refer to the time-varying waveform characteristics of the voltage across the capacitor during actual operation, such as waveform shape, frequency content, and amplitude. These characteristics reflect the electrical stress experienced by the capacitor, and different voltage waveforms will have different effects on capacitor aging.

[0058] In this step, temperature sensors (such as thermocouples and thermistors) can be placed inside the capacitor or a thermal simulation model (based on finite element analysis) can be used to collect or calculate temperature data in each area in real time to obtain the internal temperature distribution. At the same time, voltage sensors and data acquisition systems can be used to sample the voltage in real time, and characteristic parameters in the waveform (such as fundamental wave amplitude, harmonic content, voltage fluctuation amplitude, etc.) can be extracted through methods such as Fourier transform and wavelet analysis.

[0059] S2: Based on the internal temperature distribution and real-time voltage waveform characteristics, the material property database is used to determine the aging degree of each area inside the capacitor to be predicted.

[0060] It should be noted that the material properties database is a pre-built database that stores data related to the aging degree of various regions within the capacitor (such as the area containing the polypropylene film material) under different temperatures and voltages. This data was obtained through a large number of laboratory tests on capacitor materials under different conditions and provides a reference for determining the degree of aging.

[0061] In this step, the corresponding aging data is searched in the material properties database based on the acquired internal temperature distribution and real-time voltage waveform characteristics. Because the database already establishes the relationship between temperature, voltage, and aging, it can accurately determine the aging degree of each internal region under the current operating temperature and voltage conditions of the capacitor, thereby quantifying the aging status of each region of the capacitor.

[0062] S3: Obtain the life of the capacitor to be predicted according to the aging degree of each region inside the capacitor to be predicted.

[0063] It's important to note that capacitor lifespan refers to the time it takes for a high-voltage power capacitor to degrade from its initial use to the point where it no longer meets normal operating requirements. Accurately predicting capacitor lifespan helps plan maintenance and replacement tasks in advance, ensuring stable power system operation.

[0064] In this step, based on the correlation between the degree of aging of each region within the capacitor and the overall lifespan, the degree of aging of each region is comprehensively calculated through methods such as weighted averaging and specific models that comprehensively consider the impact of aging in each region on overall performance, thereby deriving a predicted lifespan value for the entire capacitor to be predicted.

[0065] This embodiment provides a method for predicting the life of a high-voltage power capacitor. The method first obtains two key operating parameters, namely the internal temperature distribution and real-time voltage waveform characteristics of the high-voltage power capacitor during operation, through specific means. These two parameters reflect the thermal stress and electrical stress conditions of the capacitor during actual operation. Then, with the help of a pre-built material property database, the aging degree of each area inside the capacitor is determined based on the operating parameters. This database is a set of corresponding relationships between temperature, voltage and aging degree established based on a large number of experiments. Finally, based on the intrinsic relationship between the aging degree of each area and the overall life, the life of the capacitor is obtained by comprehensive calculation through a suitable algorithm. The entire process revolves around the actual operating state parameters of the capacitor and relies on experimental data to achieve the prediction of the capacitor's life.

[0066] Compared with existing technologies, the innovation of this method lies in its comprehensive consideration of multiple practical factors in the operation of high-voltage power capacitors. Existing technologies often use a single factor (such as laboratory accelerated aging only, measuring only voltage and current, or shell temperature rise) to predict lifespan, without fully considering the complexity of actual operating conditions. This method, on the other hand, obtains internal temperature distribution and real-time voltage waveform characteristics, comprehensively considers the effects of thermal and electrical stress on capacitor aging, and utilizes a pre-built material property database to more accurately determine the degree of aging in each area, thereby deriving the overall lifespan. This multi-factor comprehensive analysis and the construction of a database based on experimental data have greatly improved the accuracy and reliability of high-voltage power capacitor lifespan predictions, providing stronger support for power system operation and maintenance management.

[0067] See also Figure 2 , Figure 2 The implementation process of a high-voltage power capacitor life prediction method is shown, and the implementation process is introduced below in conjunction with some embodiments of the present invention.

[0068] In one embodiment of the present invention, the process of constructing a material property database includes:

[0069] Step 1: Apply voltages of different sizes and forms to the polypropylene film material, and simultaneously apply different temperatures.

[0070] Step 2: Measure the electrical performance parameters of the polypropylene film after applying voltage and temperature treatment;

[0071] Step 3: Combine the applied voltage and temperature with the measured electrical performance parameters to calculate the aging degree and establish a material property database.

[0072] In this embodiment, the construction of the material property database comprehensively considers various actual factors such as thermal stress (internal temperature distribution) and electrical stress (real-time voltage waveform characteristics) during the operation of high-voltage power capacitors. Compared with the existing technology that mostly uses a single factor to predict life, the use of a pre-constructed material property database based on a large amount of experimental data comprehensively considers the impact of multiple factors on capacitor aging, greatly improving the accuracy and reliability of high-voltage power capacitor life prediction, providing strong support for power system operation and maintenance management.

[0073] In one embodiment of the present invention, the corresponding aging degrees are calculated according to the following formulas for voltage and temperature:

[0074] Aging degree at different voltages:

[0075]

[0076] Where, is the actual service life, For the design service life, is the rated voltage, is the actual operating voltage;

[0077] Aging degree at different temperatures:

[0078]

[0079] Where, The film is in the aging state. is the apparent activation energy, is the gas constant, is the aging temperature, is the parameter factor, To reach the aging state The time required.

[0080] This embodiment provides a method for calculating the degree of aging at different voltages and temperatures. This method, combined with the product method and weighted summation method, can determine the degree of capacitor aging. The product method, based on the assumption that temperature and voltage have independent and cumulative effects on aging, multiplies the degree of aging at different temperatures by the degree of aging at different voltages. The weighted summation method, taking into account the potentially different weights of temperature and voltage on aging, uses different weighting systems to comprehensively calculate the degree of aging.

[0081] In one embodiment of the present invention, obtaining the internal temperature distribution of the capacitor to be predicted includes:

[0082] Step 1: Divide the interior of the capacitor to be predicted into several small areas; adjacent small areas are connected by thermal resistance, and the heat flow between different small areas satisfies the law of heat conduction;

[0083] Step 2: Obtain the case temperature and inherent thermal resistance parameters of the capacitor to be predicted;

[0084] Step 3: Based on the case temperature and inherent thermal resistance parameters, calculate the temperature of each small area inside the capacitor according to the law of heat conduction to obtain the internal temperature distribution.

[0085] In this embodiment, the principle of obtaining the internal temperature distribution of the capacitor to be predicted is to first divide the interior of the capacitor to be predicted into several small areas. Since the capacitor can be equivalent to a three-dimensional thermal network, the internal thermal resistance network of each capacitor is determined after the design and manufacturing is completed, so the adjacent small areas are connected by thermal resistance. connected, and the heat flow between different small areas satisfies the law of heat conduction . Then, the shell temperature and inherent thermal resistance parameters of the capacitor to be predicted are obtained. The inherent thermal resistance parameters can be determined by combining measurement and calculation when the capacitor leaves the factory using its inherent thermal resistance network model. Finally, based on the obtained shell temperature and inherent thermal resistance parameters, in accordance with the law of heat conduction, using the determined thermal resistance network, by measuring the temperature value on the boundary of the capacitor shell, the temperature of each small area inside the capacitor is inferred, and then the internal temperature distribution is obtained. This process is based on the principle of treating the capacitor as an equivalent thermal network. Through area division, parameter acquisition and calculation based on the law of heat conduction, the internal temperature distribution of the capacitor is obtained.

[0086] In one embodiment of the present invention, obtaining the real-time voltage waveform characteristics of the capacitor to be predicted includes:

[0087] Step 1: In the circuit loop of the capacitor to be predicted, collect the voltage signal across the capacitor in real time;

[0088] Step 2: Use the Fourier decomposition algorithm to process the collected voltage signal to obtain the real-time voltage waveform characteristics containing different frequency components.

[0089] In this embodiment, the principle for obtaining the real-time voltage waveform characteristics of the capacitor to be predicted is that during actual operation, the voltage waveform actually experienced by the capacitor is not a standard sine wave, but rather contains multiple components. Therefore, the voltage signal across the capacitor in the circuit loop of the capacitor to be predicted is first collected in real time to obtain data reflecting the actual voltage condition of the capacitor. The collected voltage signal is then processed using a Fourier decomposition algorithm to decompose the complex voltage waveform, thereby obtaining real-time voltage waveform characteristics containing different frequency components. These characteristics clearly demonstrate the specific characteristics of the actual voltage waveform.

[0090] In a further embodiment of the present invention, when processing the collected voltage signal using the Fourier decomposition algorithm, the real-time voltage waveform characteristics are obtained according to the following formula:

[0091]

[0092] Where, is the actual waveform, that is, the real-time voltage waveform characteristics, is the DC component, is the frequency of a component, is the amplitude of the corresponding frequency component, is the phase of the corresponding frequency component.

[0093] Based on the above embodiment, the process of obtaining the aging degree of materials in different regions and determining the life of the capacitor to be predicted is as follows: First, the previous embodiment has divided the interior of the capacitor into several small regions and established a relevant database. Based on this, combined with the temperature information of different regions inside the capacitor obtained in the above embodiment and the voltage information reflected by the obtained real-time voltage waveform characteristics, according to the material property database, the aging characteristics of the material in each small region can be obtained. Since the capacitor is composed of all these small regions, in one embodiment of the present invention, the life of the entire capacitor is determined by the following formula:

[0094]

[0095] Where, is the life of the capacitor under voltage U and temperature T, is the total number of small areas divided inside the capacitor, For the region The life of the polypropylene film inside.

[0096] Based on the same inventive concept, the present application also provides a high-voltage power capacitor life prediction device for implementing the above-mentioned high-voltage power capacitor life prediction method. The solution provided by this device is similar to the solution described in the above-mentioned method. Therefore, the specific limitations in the embodiment of the high-voltage power capacitor life prediction device provided below can be found in the above-mentioned limitations on the high-voltage power capacitor life prediction method and will not be repeated here.

[0097] See also Figure 3 The embodiment of the present invention provides a life prediction device for high-voltage power capacitors, which is implemented based on a pre-built material property database. The material property database contains the aging degree of various regions inside the capacitor under different temperatures and voltages, including:

[0098] A data acquisition module is used to obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted;

[0099] A small area aging determination module is used to determine the aging degree of each area inside the capacitor to be predicted based on the internal temperature distribution and real-time voltage waveform characteristics using the material property database;

[0100] The capacitor life prediction module is used to obtain the life of the capacitor to be predicted based on the aging degree of each area inside the capacitor to be predicted.

[0101] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0102] Reference Figure 4 An embodiment of the present invention further provides a computer device, comprising: a memory and a processor and a computer program stored in the memory. When the computer program is executed on the processor, the high-voltage power capacitor life prediction method as described in any one of the above methods is implemented.

[0103] The computer device may be a desktop computer, notebook computer, PDA, cloud server or other computing device. The computer device may include, but is not limited to, a processor and a memory. It will be understood by those skilled in the art that Figure 4 The computer device is merely an example and does not constitute a limitation on the computer device. The computer device may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, etc.

[0104] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0105] In some embodiments, the memory may be an internal storage unit of the computer device, such as a hard drive or memory of the computer device. In other embodiments, the memory may also be an external storage device of the computer device, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped with the computer device. Furthermore, the memory may include both an internal storage unit of the computer device and an external storage device. The memory is used to store an operating system, application programs, a boot loader, data, and other programs, such as the program code of the computer program. The memory may also be used to temporarily store data that has been output or is about to be output.

[0106] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for predicting the life of a high-voltage power capacitor as described in any one of the above methods is implemented.

[0107] In this embodiment, if the integrated unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the process steps in the above-mentioned method embodiments by using a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a camera / terminal device, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunication signals, and software distribution media. Examples include USB flash drives, removable hard drives, magnetic disks, or optical disks. In some jurisdictions, based on legislation and patent practice, computer-readable media cannot be electric carrier signals or telecommunication signals.

[0108] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0109] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0110] In the embodiments disclosed in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0111] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for predicting the life of a high-voltage power capacitor, characterized in that: This is based on a pre-built material property database that contains the aging degree of various regions within the capacitor under different temperatures and voltages, and includes the following steps: Obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted; Determining the aging degree of each region inside the capacitor to be predicted using the material property database according to the internal temperature distribution and the real-time voltage waveform characteristics; The life of the capacitor to be predicted is obtained according to the aging degree of each area inside the capacitor to be predicted.

2. The high-voltage power capacitor life prediction method according to claim 1, characterized in that: The process of constructing the material property database includes: Apply voltages of different magnitudes and forms to the polypropylene film material, and simultaneously apply different temperatures; Measure the electrical performance parameters of polypropylene film after applying voltage and temperature treatment; The applied voltage and temperature, as well as the measured electrical performance parameters, are combined to calculate the aging degree and establish the material property database.

3. The high-voltage power capacitor life prediction method according to claim 1, characterized in that: For voltage and temperature, the corresponding aging degree is calculated according to the following formula: Aging degree at different voltages: Where, is the actual service life, For the design service life, is the rated voltage, is the actual operating voltage; Aging degree at different temperatures: Where, The film is in the aging state. is the apparent activation energy, is the gas constant, is the aging temperature, is the parameter factor, To reach the aging state The time required.

4. The high-voltage power capacitor life prediction method according to claim 1, characterized in that: Obtain the internal temperature distribution of the capacitor to be predicted, including: The interior of the capacitor to be predicted is divided into several small areas; adjacent small areas are connected by thermal resistance, and the heat flow between different small areas satisfies the law of heat conduction; Obtaining the shell temperature and inherent thermal resistance parameters of the capacitor to be predicted; Based on the shell temperature and the inherent thermal resistance parameter, the temperature of each small area inside the capacitor is calculated according to the heat conduction law, thereby obtaining the internal temperature distribution.

5. The high-voltage power capacitor life prediction method according to claim 1, characterized in that: Acquiring the real-time voltage waveform characteristics of the capacitor to be predicted, including: In the circuit loop of the capacitor to be predicted, the voltage signal across the capacitor is collected in real time; The collected voltage signal is processed using a Fourier decomposition algorithm to obtain the real-time voltage waveform characteristics containing different frequency components.

6. The high-voltage power capacitor life prediction method according to claim 5, characterized in that: When the collected voltage signal is processed using the Fourier decomposition algorithm, the real-time voltage waveform characteristics are obtained according to the following formula: Where, is the actual waveform, i.e. the real-time voltage waveform feature, is the DC component, is the frequency of a component, is the amplitude of the corresponding frequency component, is the phase of the corresponding frequency component.

7. The high-voltage power capacitor life prediction method according to claim 1, characterized in that: The life of the capacitor to be predicted is determined according to the following formula: Where, is the life of the capacitor under voltage U and temperature T, is the total number of small areas divided inside the capacitor, For the region The life of the polypropylene film inside.

8. A high-voltage power capacitor life prediction device, characterized in that: This is achieved based on a pre-built material properties database that contains the aging degree of various regions within the capacitor under different temperatures and voltages, including: A data acquisition module is used to obtain the internal temperature distribution and real-time voltage waveform characteristics of the capacitor to be predicted; A small area aging determination module is used to determine the aging degree of each area inside the capacitor to be predicted based on the internal temperature distribution and the real-time voltage waveform characteristics using the material property database; The capacitor life prediction module is used to obtain the life of the capacitor to be predicted according to the aging degree of each area inside the capacitor to be predicted.

9. A computer device, characterized in that: The device includes a processor and a memory: The memory is used to store the computer program and send instructions of the computer program to the processor; The processor executes a high-voltage power capacitor life prediction method according to any one of claims 1 to 7 according to instructions of the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for predicting the life of a high-voltage power capacitor according to any one of claims 1 to 7 is implemented.

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