Transient high current impulse test method for aluminum electrolytic capacitors and related apparatus

Abstract

The application discloses a kind of transient large current impact test method and related device of aluminum electrolytic capacitor, for screening aluminum electrolytic capacitor for defect.The application includes: according to the aluminum electrolytic capacitor to be measured determines transient impact energy range;The aluminum electrolytic capacitor to be measured is connected to test loop, and it is in preset polarity state;Pre-excitation electrical signal is applied to the aluminum electrolytic capacitor to be measured, so that potential defect area in the aluminum electrolytic capacitor to be measured generates local current concentration, and forms local response area;Based on transient impact energy range, transient large current impact signal is applied to the aluminum electrolytic capacitor to be measured, so that local response area generates nonlinear current response, and induces local gas generation reaction and / or flash reaction;Abnormal response information of the aluminum electrolytic capacitor to be measured is collected, and corresponding transient response characteristic is obtained;According to transient response characteristic and preset normal response characteristic, determine whether the aluminum electrolytic capacitor to be measured exists hidden defect.

Description

Technical Field

[0001] This application relates to the field of electrolytic capacitor testing, and in particular to a transient high-current impact testing method and related apparatus for aluminum electrolytic capacitors. Background Technology

[0002] Aluminum electrolytic capacitors possess large capacitance and high energy storage capacity, making them widely used in power supplies, industrial control, and electronic equipment. An oxide film forms on the surface of the anode foil of an aluminum electrolytic capacitor. This oxide film serves as the capacitor's dielectric layer, and its integrity and insulation performance significantly impact the capacitor's reliability. During actual production, factors such as raw materials, corrosion treatment, formation processes, and subsequent processing can cause varying degrees of minor defects in the anode foil oxide film. Some of these defects may not show obvious abnormalities under normal testing conditions, but they can gradually develop and lead to product failure during long-term operation.

[0003] Currently, the production process of aluminum electrolytic capacitors typically involves applying a specific test current or voltage and detecting electrical performance parameters such as capacitance and leakage current to screen products for quality. For capacitors with obvious oxide film defects, abnormal currents, explosion-proof valve activation, or flash explosions may occur during testing, making them identifiable. However, some more subtle oxide film defects produce weaker abnormal responses under standard testing conditions, potentially failing to manifest as obvious external defects. This results in these defective products not being effectively screened out, thus posing a risk of failure during subsequent use. Summary of the Invention

[0004] This application discloses a transient high-current impact test method and related apparatus for aluminum electrolytic capacitors, used for defect screening of aluminum electrolytic capacitors.

[0005] In a first aspect, this application discloses a method for transient high-current impact testing of aluminum electrolytic capacitors, including: The transient impact energy range is determined based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. Connect the aluminum electrolytic capacitor under test to the test circuit and place the aluminum electrolytic capacitor under test in a preset polarity state. A pre-excitation electrical signal with a preset voltage amplitude is applied to the aluminum electrolytic capacitor under test, and the leakage current change information of the aluminum electrolytic capacitor under test is collected. Based on the leakage current change information, an abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test is identified, which has a higher conductivity response than the surrounding area, and the current response characteristics corresponding to the abnormal conductive region are determined. The pre-excitation electrical signal is continuously applied to increase the current density in the abnormal conductive region; When the increase in current density satisfies the preset local current concentration condition, the corresponding abnormal response region is determined as the local current concentration region, and a local response region is formed based on the conductivity response characteristics of the local current concentration region. Based on the transient impact energy range, a transient high-current impact signal is applied to the aluminum electrolytic capacitor under test, causing a nonlinear current response in the local response region and inducing a local gas generation reaction and / or flashover reaction. The abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process is collected, and the corresponding transient response characteristics are obtained. Based on the difference between the transient response characteristics and the preset normal response characteristics, it is determined whether the aluminum electrolytic capacitor under test has hidden defects.

[0006] Optionally, the amplitude of the impact current is 100 amperes to 200 amperes, and the duration is 0.1 seconds to 0.5 seconds.

[0007] Optionally, the amplitude of the impact current is 150 amperes, and the duration is 0.2 seconds.

[0008] Optionally, the step of applying a transient high-current impulse signal to the aluminum electrolytic capacitor under test based on the transient impulse energy range, causing a nonlinear current response in the local response region, and inducing a local gas generation reaction and / or flashover reaction, includes: Based on the conductivity response characteristics of the local response region, the impulse current amplitude and impulse duration that match the aluminum electrolytic capacitor under test are determined within the transient impulse energy range, and the transient high current impulse signal is generated according to the impulse current amplitude and the impulse duration. The transient high-current impulse signal is applied to the aluminum electrolytic capacitor under test, and transient current change information corresponding to the local response region is collected during the application of the transient high-current impulse signal. Based on the transient current change information, determine whether the current response of the local response region undergoes a sudden change, and identify the local response region where a sudden change occurs as a nonlinear response region; Identify the local gas generation reaction and / or flash fire reaction generated in the nonlinear response region, and collect the abnormal response information corresponding to the local gas generation reaction and / or flash fire reaction.

[0009] Optionally, after determining whether the aluminum electrolytic capacitor under test has hidden defects based on the difference between the transient response characteristics and the preset normal response characteristics, the transient high-current impulse test method further includes: After determining that the aluminum electrolytic capacitor under test has a hidden defect, a transient high current impulse signal is applied to the aluminum electrolytic capacitor under test again, and the second transient response characteristics are obtained. The defect level of the hidden defects in the oxide film is determined by comparing the second transient response feature with the transient response feature of the first impact.

[0010] Optionally, the transient response characteristics include at least one of the following: current anomaly information, voltage anomaly information, explosion-proof valve status information, flash explosion status information, temperature change information, pressure change information, acoustic response information, and optical response information.

[0011] Secondly, this application provides a transient high-current impact testing device for aluminum electrolytic capacitors, comprising: The initialization unit is used to determine the transient impact energy range based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. The processing unit is used to connect the aluminum electrolytic capacitor under test to the test circuit and to put the aluminum electrolytic capacitor under test into a preset polarity state. The pre-excitation unit is used to apply a pre-excitation electrical signal with a preset voltage amplitude to the aluminum electrolytic capacitor under test, and to collect information on the leakage current change of the aluminum electrolytic capacitor under test. The identification unit is used to identify, based on the leakage current change information, an abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test whose conductivity response is higher than that of the surrounding area, and to determine the current response characteristics corresponding to the abnormal conductive region. An application unit is used to continuously apply the pre-excitation electrical signal to increase the current density in the abnormal conductive region; The determining unit is used to determine the corresponding abnormal response region as a local current concentration region when the increase in current density meets the preset local current concentration condition, and to form a local response region based on the conductivity response characteristics of the local current concentration region. The transient impact unit is used to apply a transient large current impact signal to the aluminum electrolytic capacitor under test based on the transient impact energy range, so as to generate a nonlinear current response in the local response region and induce local gas generation reaction and / or flashover reaction. The acquisition unit is used to acquire abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process and obtain the corresponding transient response characteristics. The detection unit is used to determine whether the aluminum electrolytic capacitor under test has hidden defects based on the difference between the transient response characteristics and the preset normal response characteristics.

[0012] Specifically, the transient high-current impact testing device also includes: The secondary impact unit is used to apply a transient high-current impact signal to the aluminum electrolytic capacitor under test again after determining that there is a hidden defect in the aluminum electrolytic capacitor under test, and to obtain the second transient response characteristics. The determination unit is used to compare the second transient response characteristics with the transient response characteristics of the first impact to determine the defect level of the hidden defects in the oxide film.

[0013] Thirdly, this application also provides a transient high-current impulse testing device for aluminum electrolytic capacitors, comprising: Processor, memory, input / output units, and bus; The processor is connected to memory, input / output units, and a bus; The memory holds a program, which the processor calls to execute, as in the first aspect and any optional method of the first aspect.

[0014] The fourth aspect of this application provides a computer-readable storage medium on which a program is stored, which, when executed on a computer, performs the methods of the first aspect and any optional methods of the first aspect.

[0015] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: The transient impact energy range is determined based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test, providing a basis for subsequent pre-excitation and transient high-current impact testing. The aluminum electrolytic capacitor under test is connected to the test circuit with a preset polarity, allowing it to enter the subsequent testing process under that preset polarity.

[0016] By applying a pre-excitation electrical signal to the aluminum electrolytic capacitor under test, the potential defect region in the oxide film of the anode foil exhibits corresponding electrical response characteristics under the pre-excitation state, and a local response region is formed based on the abnormal electrical response that continuously meets the preset response conditions. After the formation of the local response region, the local response region has an abnormal conductive response state that is different from the normal oxide film region. The local response region serves as the basis for the response to subsequent transient high current impacts.

[0017] By applying a transient high-current impact signal based on the transient impact energy range and the corresponding current response characteristics of the local response region, a nonlinear current response is generated in the local response region under the action of the transient high current, further producing local gas generation and / or flashover reactions. This allows the abnormal state corresponding to the potential defect to be further characterized during the transient impact process. Abnormal response information is simultaneously acquired, and the corresponding transient response characteristics are obtained, providing data for subsequent defect determination.

[0018] By comparing the obtained transient response characteristics with the preset normal response characteristics, and determining whether there are hidden defects in the oxide film of the anode foil based on the difference between the two, hidden defects in the oxide film that are not easily manifested under traditional test conditions can be identified through the abnormal response during the transient impact process, and defects can be screened for aluminum electrolytic capacitors under test accordingly. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating an embodiment of the transient high-current impact test method for aluminum electrolytic capacitors provided in this application; Figure 2 A flowchart illustrating an embodiment of the nonlinear current response and the induction of local gas generation and / or flashover reaction provided in this application; Figure 3 A flowchart illustrating an embodiment for determining the defect level provided in this application; Figure 4 A schematic diagram of the transient high-current impact testing device for aluminum electrolytic capacitors provided in this application; Figure 5 Another schematic diagram of the transient high current impact test device for aluminum electrolytic capacitors provided in this application. Detailed Implementation

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0022] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0023] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0025] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not an embodiment," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0027] Based on this, this application discloses a transient high-current impact test method and related apparatus for aluminum electrolytic capacitors, which is used to screen for defects in aluminum electrolytic capacitors.

[0028] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0029] The method of this application can be applied to servers, devices, terminals, or other devices with logical processing capabilities; therefore, this application does not limit its application. For ease of description, the following description uses a system as the executing entity.

[0030] Please see Figure 1This application provides an embodiment of a transient high-current impact test method for aluminum electrolytic capacitors, comprising: 101. Determine the transient impact energy range based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. Obtain the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The rated operating parameters may include rated voltage, rated capacitance, rated operating temperature and rated ripple current, etc., while the electrical performance parameters may include capacitance, leakage current, loss tangent and equivalent series resistance, etc.

[0031] The test parameter range for the aluminum electrolytic capacitor under test is established based on its rated operating parameters and electrical performance parameters. The transient impact energy range is then determined based on this range, including the amplitude and duration of the transient high-current impact signal. Specifically, the transient impact energy range can be pre-calibrated using aluminum electrolytic capacitors of the same model or with the same rated operating parameters, and then selected accordingly based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. For example, for two aluminum electrolytic capacitors under test with the same rated voltage and rated capacitance but different capacitance and leakage current, their corresponding transient impact energy ranges can be obtained separately, and the corresponding impact current amplitude and duration can be determined based on their respective transient impact energy ranges.

[0032] 102. Connect the aluminum electrolytic capacitor to be tested to the test circuit and ensure that the aluminum electrolytic capacitor to be tested is in the preset polarity state. Connect the anode terminal of the aluminum electrolytic capacitor under test to the positive terminal in the test circuit, and connect the cathode terminal to the negative terminal in the test circuit to place the aluminum electrolytic capacitor under test in the preset polarity state. For example, when the aluminum electrolytic capacitor under test has a lead marked as positive and a lead marked as negative, connect them in the manner that the positive terminal corresponds to the positive terminal and the negative terminal corresponds to the negative terminal.

[0033] After the connection is completed, the connection status of the test circuit is detected, and the initial voltage and initial current information across the aluminum electrolytic capacitor under test are obtained. Based on the detection results, the polarity of the aluminum electrolytic capacitor under test and the conduction status of the test circuit are confirmed. After the test circuit is in the preset connection state, the pre-excitation process begins.

[0034] 103. Apply a pre-excitation electrical signal with a preset voltage amplitude to the aluminum electrolytic capacitor under test, and collect information on the leakage current change of the aluminum electrolytic capacitor under test; After the aluminum electrolytic capacitor under test has completed polarity connection and the test circuit has been confirmed to be in normal conduction state, a pre-excitation electrical signal with a preset voltage amplitude is applied to the aluminum electrolytic capacitor under test, so that a preset electric field is formed between the anode foil and the cathode foil of the aluminum electrolytic capacitor under test. The pre-excitation electrical signal can be a DC voltage signal, or other electrical excitation methods that can induce leakage current response in the aluminum electrolytic capacitor under test.

[0035] After the pre-excitation begins, the leakage current of the aluminum electrolytic capacitor under test may first show a certain degree of change, and then gradually tend to stabilize; for the product under test with potential defects in the oxide film of the anode foil, its leakage current change process may show abnormal changes that are different from those of normal products.

[0036] During the application of the pre-excitation electrical signal, the leakage current of the aluminum electrolytic capacitor under test is continuously or intermittently collected to obtain leakage current variation information as the pre-excitation application time and voltage state change. The leakage current variation information can include the instantaneous change state of the leakage current, the trend of change, and the degree of deviation from the preset normal state.

[0037] 104. Based on the leakage current change information, identify the abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test, where the conductivity response is higher than that of the surrounding area, and determine the current response characteristics corresponding to the abnormal conductive region. Response state analysis is performed on leakage current changes to identify abnormal electrical responses corresponding to potential defects in the anode foil oxide film. Since regions with varying degrees of oxide film integrity exhibit different conductivity responses under pre-excitation electrical signals, the current response in a region with minor defects, reduced local insulation performance, or abnormal local structures may deviate from that of a normal oxide film region. Therefore, abnormal conductivity responses in the tested aluminum electrolytic capacitor can be identified based on abnormal changes in leakage current information.

[0038] After identifying the abnormal conductive region, further determine its corresponding current response characteristics, such as the leakage current variation amplitude, variation trend, response duration, or the time when the abnormal response occurs.

[0039] It should be noted that since the anode foil oxide film is located inside the aluminum electrolytic capacitor, the "abnormal conductivity region" does not require directly obtaining a spatial image of the interior of the oxide film or directly measuring the current at a certain physical location. Instead, it refers to characterizing the abnormal conductivity state corresponding to potential defects in the oxide film based on the detectable current response on the outside of the aluminum electrolytic capacitor under test.

[0040] 105. Continuously apply a pre-excitation electrical signal to increase the current density in the abnormal conductive region; After identifying the abnormally conductive region corresponding to the potential defect in the oxide film, the pre-excitation signal is maintained in a preset state and continuously applied, ensuring that the abnormally conductive region remains under the influence of the electric field. During continuous pre-excitation, the current is more likely to concentrate in areas with relatively weak electrical properties, thereby further increasing the difference in current response between the abnormally conductive region and the normal region. Thus, through continuous pre-excitation, the abnormal response corresponding to the potential defect gradually develops from an initial slight difference into a more pronounced local response.

[0041] Here, "increased current density" is used to characterize the enhanced local current effect on the abnormally conductive area. It does not require direct measurement of the actual spatial current density inside the oxide film, but can be indirectly characterized based on leakage current change information collected from the outside.

[0042] During continuous pre-excitation, the change in leakage current is monitored synchronously. When the response corresponding to the abnormal conductive area continues to increase or the difference between the response and the normal response further widens, it indicates that the area has a relatively obvious local current concentration trend.

[0043] 106. When the increase in current density meets the preset local current concentration condition, the corresponding abnormal response region is determined as the local current concentration region, and a local response region is formed based on the conductivity response characteristics of the local current concentration region.

[0044] During the continuous application of the pre-excitation electrical signal, the response changes in the abnormal conductivity region are continuously monitored, and the difference between the abnormal conductivity region and the normal response state is used to determine whether a local current concentration state has formed. The preset local current concentration conditions can be determined in advance based on the specifications of the aluminum electrolytic capacitor under test, its initial electrical performance state, and the response state of normal products under the same pre-excitation conditions.

[0045] When the change in current response corresponding to an abnormally conductive region reaches a preset local current concentration condition, it is identified as a local current concentration region. Furthermore, a local response region is formed based on the conductivity response characteristics corresponding to the local current concentration region.

[0046] It should be noted that the local response region does not necessarily correspond to the physical location of the oxide film that can be directly observed, but is a defect response characterization region established based on the current response characteristics obtained in the pre-excitation stage.

[0047] 107. Based on the transient impact energy range, a transient large current impact signal is applied to the aluminum electrolytic capacitor under test, causing a nonlinear current response in the local response region and inducing a local gas generation reaction and / or flashover reaction. A transient high-current impulse signal is applied to the aluminum electrolytic capacitor under test according to the transient impulse energy range determined in step 101. The transient high-current impulse signal has a large instantaneous current amplitude and is applied to the aluminum electrolytic capacitor under test within a short duration.

[0048] During the application of a transient high-current impact signal, the local response region formed by the aforementioned pre-excitation exhibits a more pronounced electrical response compared to other regions of the oxide film, and this local response region may be subjected to a higher local current. Under this influence, the current response of the local response region may exhibit abrupt changes, rapid variations, or other nonlinear responses.

[0049] For aluminum electrolytic capacitors under test with relatively hidden oxide film defects, localized electrochemical reactions may further occur in the defective areas under transient high current, intensifying related reactions in the electrolyte and generating gas. When the local current reaches a certain level, localized flashover may also occur. These gas-generating and / or flashover reactions alter the detectable state of the aluminum electrolytic capacitor both internally and externally, making previously difficult-to-identify hidden defects exhibit more obvious abnormalities.

[0050] 108. Collect abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process, and obtain the corresponding transient response characteristics; During the application of a transient high-current impact signal, the response information of the aluminum electrolytic capacitor under test is collected in real time or in stages. Abnormal response information may include the current response of the aluminum electrolytic capacitor under test, the voltage response across its terminals, and information on external abnormal conditions. Specifically, the current response information reflects changes in current, and the voltage response information reflects changes in the voltage across its terminals.

[0051] When a potential defect causes an abnormal current change, the acquisition system can record the corresponding abnormal response process and determine the time, location, and changes of the abnormal response.

[0052] Based on this, the corresponding transient response characteristics are obtained according to the abnormal response information. The transient response characteristics are used to describe the dynamic response state of the aluminum electrolytic capacitor under test during a transient high current impact.

[0053] 109. Based on the difference between the transient response characteristics and the preset normal response characteristics, determine whether the aluminum electrolytic capacitor under test has hidden defects.

[0054] In practical applications, normal aluminum electrolytic capacitors are subjected to corresponding transient impact tests in advance, and normal response characteristics are formed based on the response information obtained during the test, which are used as the judgment criteria for the aluminum electrolytic capacitor under test. The preset normal response characteristics are used to characterize the normal transient response state exhibited by aluminum electrolytic capacitors without hidden defects in the anode foil oxide film under the same or similar test conditions.

[0055] After obtaining the transient response characteristics of the aluminum electrolytic capacitor under test, the transient response characteristics are compared with the normal response characteristics. When the transient response characteristics are within the normal response range corresponding to the normal response characteristics, it is determined that no obvious oxide film hidden defects are detected in the aluminum electrolytic capacitor under test. When there is a significant difference between the transient response characteristics and the normal response characteristics, it is determined that the aluminum electrolytic capacitor under test has an abnormal response related to the anode foil oxide film, and it is further determined that there is an oxide film hidden defect.

[0056] In this embodiment, the transient impact energy range is determined based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test, providing a basis for subsequent pre-excitation and transient high-current impact testing. The aluminum electrolytic capacitor under test is connected to the test circuit according to a preset polarity state, allowing it to enter the subsequent testing process under that preset polarity state.

[0057] By applying a pre-excitation electrical signal to the aluminum electrolytic capacitor under test, the potential defect region in the oxide film of the anode foil exhibits corresponding electrical response characteristics under the pre-excitation state, and a local response region is formed based on the abnormal electrical response that continuously meets the preset response conditions. After the formation of the local response region, the local response region has an abnormal conductive response state that is different from the normal oxide film region. The local response region serves as the basis for the response to subsequent transient high current impacts.

[0058] By applying a transient high-current impact signal based on the transient impact energy range and the corresponding current response characteristics of the local response region, a nonlinear current response is generated in the local response region under the action of the transient high current, further producing local gas generation and / or flashover reactions. This allows the abnormal state corresponding to the potential defect to be further characterized during the transient impact process. Abnormal response information is simultaneously acquired, and the corresponding transient response characteristics are obtained, providing data for subsequent defect determination.

[0059] By comparing the obtained transient response characteristics with the preset normal response characteristics, and determining whether there are hidden defects in the oxide film of the anode foil based on the difference between the two, hidden defects in the oxide film that are not easily manifested under traditional test conditions can be identified through the abnormal response during the transient impact process, and defects can be screened for aluminum electrolytic capacitors under test accordingly.

[0060] In the above embodiment, the impulse current amplitude is 100 amperes to 200 amperes, and the duration is 0.1 seconds to 0.5 seconds.

[0061] Specifically, the surge current amplitude is 150 amperes and the duration is 0.2 seconds.

[0062] The amplitude of the transient high-current impulse signal can be set to 100 amperes to 200 amperes, and the duration can be set to 0.1 seconds to 0.5 seconds. Within this parameter range, the transient high-current impulse signal can apply a large instantaneous current to the aluminum electrolytic capacitor under test in a short period of time, further subjecting the local response area, which has already formed an abnormal electrical response after pre-excitation, to a large current impact, thereby enhancing the response difference between the local response area and the normal oxide film area. Compared with the smaller test current used in conventional testing, the above-mentioned transient high-current impulse conditions can subject the potential defect area of ​​the oxide film to a stronger current in a short period of time, making the small defects that are not easily manifested in conventional testing produce a more obvious transient response.

[0063] In actual testing, the amplitude and duration of the impulse current can be selected within the above range based on the rated operating parameters, electrical performance parameters, and response state obtained during the pre-excitation stage of the aluminum electrolytic capacitor under test.

[0064] Specifically, in one embodiment of this example, the amplitude of the transient high-current impulse signal is set to 150 amperes, and the duration is set to 0.2 seconds.

[0065] During testing, a transient high-current surge of 150 amps was applied to the aluminum electrolytic capacitor under test for 0.2 seconds. During this transient surge, the current response in the localized response region showed a more pronounced change compared to the normal region. When the oxide film corresponding to the localized response region has hidden defects, this defective region is more likely to experience rapid changes in localized current, further inducing localized gas generation and / or flashover reactions.

[0066] In this embodiment, 150 amperes and 0.2 seconds are preferred transient high-current impact conditions, used to illustrate a specific implementation of the test method of this application, and should not be construed as limiting the transient high-current impact parameters of this application. As long as the selected transient impact conditions can cause the oxide film hidden defects to produce a transient response that is different from that of normal products, they can be used for subsequent hidden defect determination.

[0067] Please see Figure 2 This application provides an embodiment for generating a nonlinear current response and inducing a local gas generation reaction and / or a flashover reaction, comprising: 201. Based on the conductivity response characteristics of the local response region, determine the impulse current amplitude and impulse duration that match the aluminum electrolytic capacitor under test within the transient impulse energy range, and generate a transient high-current impulse signal according to the impulse current amplitude and impulse duration. Based on the conductivity response characteristics, within a predetermined transient impact energy range, impact conditions matching the aluminum electrolytic capacitor under test are selected so that the transient high-current impact can sufficiently excite potential defects.

[0068] After determining the impulse current amplitude and impulse duration, the test circuit is controlled to generate a transient high-current impulse signal according to the corresponding impulse parameters, and the transient high-current impulse signal has a preset rise process, impulse current amplitude and duration.

[0069] For aluminum electrolytic capacitors under test that exhibit obvious abnormal conductivity response during the pre-excitation stage, a relatively low impact strength can be used for subsequent testing; for aluminum electrolytic capacitors under test with relatively weak abnormal conductivity response, a relatively high impact strength can be used for testing. This allows products under test with different response states to obtain effective defect excitation within the preset impact range.

[0070] 202. Apply a transient high-current impulse signal to the aluminum electrolytic capacitor under test, and collect transient current change information corresponding to the local response area during the application of the transient high-current impulse signal; After generating a transient high-current impulse signal, the signal is applied to the aluminum electrolytic capacitor under test (AIC) via a test circuit, causing the AIC to withstand a large instantaneous current for a short period. Before applying the transient high-current impulse signal, the initial response state of the AIC during the pre-excitation phase can be recorded as a reference for subsequent analysis of transient current changes.

[0071] During the application of a transient high-current impact signal, the current response of the aluminum electrolytic capacitor under test is continuously acquired or acquired according to a preset sampling sequence to obtain transient current change information from the start to the end of the transient impact. The transient current change information is used to characterize the dynamic response state of the local response region under the action of high current, and can include the current response at the beginning of the impact, the current change process during the impact, and the current recovery state at the end of the impact.

[0072] 203. Determine whether the current response in the local response region changes abruptly based on transient current change information, and identify the local response region where the change occurs as the nonlinear response region; A time-series analysis is performed on transient current changes to determine whether a sudden change in the current response occurs in the corresponding local response region. In the actual judgment process, the current response before or at the initial stage of the transient impact is used as a reference state, and the current changes during the impact process are compared with this reference state. When the current change corresponding to the local response region exceeds the preset normal range, or its trend significantly deviates from the normal current response pattern of the product, a sudden change in current is considered to have occurred in the local response region.

[0073] Furthermore, the abnormal response is confirmed by combining the time, duration, and degree of change of the current surge. Once a current surge meeting preset conditions is determined to occur in a local response region, the corresponding local response region is defined as the nonlinear response region.

[0074] 204. Identify the local gas generation reaction and / or flash fire reaction generated in the nonlinear response region, and collect the abnormal response information corresponding to the local gas generation reaction and / or flash fire reaction.

[0075] The system identifies localized gas generation and / or flashover reactions corresponding to the nonlinear response region of the aluminum electrolytic capacitor under test. For gas generation reactions, it identifies potential pressure changes or other externally detectable abnormalities within the capacitor. For flashover reactions, it identifies transient optical changes, acoustic changes, sudden current changes, or other abnormal responses.

[0076] Collect abnormal response information corresponding to gas generation reactions and / or flashover reactions, and correlate them with transient current change information according to the occurrence time to determine the correlation between abnormal states and nonlinear current responses.

[0077] In this embodiment, by first determining the amplitude and duration of a matching transient impact current based on the conductivity response characteristics of the local response region, and then applying a transient high-current impact signal, the local response region formed during the pre-excitation stage is further enhanced, thereby improving the response degree of the potential oxide film defect region. By collecting transient current change information and identifying current abrupt changes, the abnormal response region is identified as a nonlinear response region. Furthermore, by combining the abnormal response information corresponding to gas generation reaction and / or flashover reaction, a multi-dimensional characterization of the defect response process is achieved. This transforms the hidden oxide film defects that are not easily revealed under traditional low-current testing conditions into abnormal states with obvious transient response characteristics, improving the identification and screening capabilities of hidden defects in the oxide film of the anode foil of aluminum electrolytic capacitors.

[0078] In the above embodiments, by applying a pre-excitation electrical signal and a transient high-current impact signal to the aluminum electrolytic capacitor under test, some hidden defects in the oxide film that are not easily apparent under conventional testing conditions can be transformed into detectable transient abnormal responses, thereby determining whether the aluminum electrolytic capacitor under test has hidden defects. However, for aluminum electrolytic capacitors under test that have been determined to have hidden defects, the degree of defect may vary between different products, and it is difficult to further reflect the differences between different defect states based solely on whether an abnormal response is generated. To further improve the characterization ability of the test results for the degree of hidden defects in the oxide film, please refer to [link to relevant documentation]. Figure 3 This application provides an embodiment for determining a defect level, including: 301. After determining that the aluminum electrolytic capacitor under test has a hidden defect, a transient high current impulse signal is applied to the aluminum electrolytic capacitor under test again, and the second transient response characteristics are obtained. The same aluminum electrolytic capacitor under test is subjected to a transient high-current impulse test again. The transient high-current impulse signal applied again can be subjected to the same test conditions as the first impulse, or the impulse conditions within the preset range can be used according to the transient response state obtained from the first impulse.

[0079] During the second impact, the current response of the aluminum electrolytic capacitor under test and the abnormal state caused by the impact process were collected, and the second transient response characteristics were obtained based on the collected results. The second transient response characteristics are used to reflect the response state of the oxide film hidden defects after being subjected to a transient large current again.

[0080] 302. Compare the second transient response characteristics with the transient response characteristics of the first impact to determine the defect level of the hidden defects in the oxide film.

[0081] In the aforementioned embodiments, transient response characteristics were collected and stored during the first transient high-current impact.

[0082] After obtaining the second transient response characteristic, it is compared with the transient response characteristic to analyze the degree of response change of the aluminum electrolytic capacitor under test under two impacts. During the comparison, similar response characteristics can be compared, such as the degree of current anomaly, the time of occurrence of the abnormal response, the duration of the abnormal response, or other transient response states during the two impacts. This allows determination of whether the defect response of the aluminum electrolytic capacitor under test has been enhanced, weakened, or remained relatively stable.

[0083] If the response is weak after the first impact but significantly stronger after the second impact, the corresponding hidden defects in the oxide film are considered to have strong impact response characteristics; if the defects show strong abnormal responses in both impacts, the corresponding defects are considered to have a high degree of abnormality.

[0084] Based on the above comparison results, and according to the preset defect level classification conditions, the hidden defects of the oxide film are determined as corresponding defect levels. Defect levels can be used to distinguish between different degrees of hidden defects in the oxide film, for example, by classifying them into different levels according to the degree of defect response, without limiting the specific number of levels or the classification method.

[0085] Furthermore, the aluminum electrolytic capacitors under test can be classified according to the determined defect level, so that products with different defect levels can be processed separately. For example, if the defect is minor, it can be repaired by a momentary current surge; if the defect is severe, it is identified as a defective product and screened out.

[0086] In this embodiment, based on the initial transient high-current impact test, a second transient impact test is performed on the aluminum electrolytic capacitor under test that has been identified as having hidden defects. By comparing the transient response characteristics obtained during the two impacts, the defect level corresponding to the hidden defects in the oxide film is determined, thereby providing a basis for subsequent defect classification and quality control.

[0087] In any of the above embodiments, the transient response characteristics include at least one of the following: current anomaly information, voltage anomaly information, explosion-proof valve status information, flash explosion status information, temperature change information, pressure change information, acoustic response information, and optical response information.

[0088] Transient response characteristics include one or more abnormal response information to characterize the response state of the anodic foil oxide film after being subjected to transient impact from different dimensions.

[0089] Specifically, current anomaly information can be used to characterize the current amplitude, trend of change, or local sudden change state during the impact process; voltage anomaly information can be used to characterize the abnormal changes in the voltage across the aluminum electrolytic capacitor under test during the impact process; explosion-proof valve status information can be used to characterize whether the explosion-proof valve has been activated or its status has changed; flash explosion status information can be used to characterize whether abnormal phenomena such as flash fire or flash explosion occur during the impact process; temperature change information can be used to characterize the degree of temperature change of the aluminum electrolytic capacitor under test before and after the impact or during the impact process; pressure change information can be used to characterize the pressure change caused by the gas generated inside the capacitor due to local reaction; acoustic response information can be used to characterize the abnormal sounds generated during the impact process and their changing states; and optical response information can be used to characterize the instantaneous brightness or other optical changes generated during the impact process.

[0090] In actual testing, one or more of the above-mentioned response information can be collected synchronously or according to a preset time sequence, and corresponding transient response characteristics can be formed based on the occurrence time, degree of change, duration, and trend of each response information. For example, when the aluminum electrolytic capacitor under test simultaneously exhibits a sudden current change and an abnormal optical response during a transient impact, the two are correlated in time to enhance the ability to identify local flashover reactions; when an abnormal current occurs accompanied by changes in pressure or acoustic response, it helps to determine local gas generation reactions. By combining and characterizing multiple abnormal response information, the reliability of identifying hidden defects in the oxide film is improved.

[0091] Please see Figure 4 This application provides an embodiment of a transient high-current impact testing device for aluminum electrolytic capacitors, comprising: Initialization unit 401 is used to determine the transient impact energy range based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. Processing unit 402 is used to connect the aluminum electrolytic capacitor under test to the test circuit and to put the aluminum electrolytic capacitor under test into a preset polarity state. The pre-excitation unit 403 is used to apply a pre-excitation electrical signal with a preset voltage amplitude to the aluminum electrolytic capacitor under test, and to collect information on the leakage current change of the aluminum electrolytic capacitor under test. The identification unit 404 is used to identify, based on the leakage current change information, an abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test whose conductivity response is higher than that of the surrounding area, and to determine the current response characteristics corresponding to the abnormal conductive region. The application unit 405 is used to continuously apply the pre-excitation electrical signal to increase the current density in the abnormal conductive region; The determining unit 406 is used to determine the corresponding abnormal response region as a local current concentration region when the increase in current density meets the preset local current concentration condition, and to form the local response region based on the conductivity response characteristics of the local current concentration region. The transient impact unit 407 is used to apply a transient large current impact signal to the aluminum electrolytic capacitor under test based on the transient impact energy range, so as to generate a nonlinear current response in the local response region and induce a local gas generation reaction and / or flashover reaction. The acquisition unit 408 is used to acquire abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process and obtain the corresponding transient response characteristics. The detection unit 409 is used to determine whether there are hidden defects in the aluminum electrolytic capacitor under test based on the difference between the transient response characteristics and the preset normal response characteristics.

[0092] Specifically, the transient high-current impact testing device also includes: The secondary impact unit 410 is used to apply a transient high-current impact signal to the aluminum electrolytic capacitor under test again after determining that there is a hidden defect in the aluminum electrolytic capacitor under test, and obtain the second transient response characteristics. The determination unit 411 is used to compare the second transient response characteristics with the transient response characteristics of the first impact to determine the defect level of the hidden defects in the oxide film.

[0093] For detailed implementation methods, please refer to... Figures 1 to 3 Examples are not detailed here.

[0094] Please see Figure 5 This application provides a transient high-current impulse test for aluminum electrolytic capacitors, including: Processor 501, memory 502, input / output unit 503, and bus 504.

[0095] The processor 501 is connected to the memory 502, the input / output unit 503, and the bus 504.

[0096] The memory 502 stores a program, and the processor 501 calls the program to execute it, such as... Figures 1 to 3 The method in the middle.

[0097] This application provides a computer-readable storage medium on which a program is stored, and when the program is executed on a computer, it performs the following... Figures 1 to 3 The method in the middle.

[0098] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0100] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0101] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0102] If the integrated unit 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, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for transient high-current impulse testing of aluminum electrolytic capacitors, characterized in that, include: The transient impact energy range is determined based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. Connect the aluminum electrolytic capacitor under test to the test circuit and place the aluminum electrolytic capacitor under test in a preset polarity state. A pre-excitation electrical signal with a preset voltage amplitude is applied to the aluminum electrolytic capacitor under test, and the leakage current change information of the aluminum electrolytic capacitor under test is collected. Based on the leakage current change information, an abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test is identified, which has a higher conductivity response than the surrounding area, and the current response characteristics corresponding to the abnormal conductive region are determined. The pre-excitation electrical signal is continuously applied to increase the current density in the abnormal conductive region; When the increase in current density satisfies the preset local current concentration condition, the corresponding abnormal response region is determined as the local current concentration region, and a local response region is formed based on the conductivity response characteristics of the local current concentration region. Based on the transient impact energy range, a transient high-current impact signal is applied to the aluminum electrolytic capacitor under test, causing a nonlinear current response in the local response region and inducing a local gas generation reaction and / or flashover reaction. The abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process is collected, and the corresponding transient response characteristics are obtained. Based on the difference between the transient response characteristics and the preset normal response characteristics, it is determined whether the aluminum electrolytic capacitor under test has hidden defects.

2. The transient high-current impulse test method for aluminum electrolytic capacitors according to claim 1, characterized in that, The magnitude of the impact current is 100 amperes to 200 amperes, and the duration is 0.1 seconds to 0.5 seconds.

3. The transient high-current impulse test method for aluminum electrolytic capacitors according to claim 2, characterized in that, The magnitude of the impact current is 150 amperes, and the duration is 0.2 seconds.

4. The transient high-current impact test method according to claim 1, characterized in that, The process of applying a transient high-current impulse signal to the aluminum electrolytic capacitor under test based on the transient impulse energy range, causing a nonlinear current response in the local response region, and inducing a local gas generation reaction and / or flashover reaction, includes: Based on the conductivity response characteristics of the local response region, the impulse current amplitude and impulse duration that match the aluminum electrolytic capacitor under test are determined within the transient impulse energy range, and the transient high current impulse signal is generated according to the impulse current amplitude and the impulse duration. The transient high-current impulse signal is applied to the aluminum electrolytic capacitor under test, and transient current change information corresponding to the local response region is collected during the application of the transient high-current impulse signal. Based on the transient current change information, determine whether the current response of the local response region undergoes a sudden change, and identify the local response region where a sudden change occurs as a nonlinear response region; Identify the local gas generation reaction and / or flash fire reaction generated in the nonlinear response region, and collect the abnormal response information corresponding to the local gas generation reaction and / or flash fire reaction.

5. The transient high-current impact test method according to claim 1, characterized in that, After determining whether the aluminum electrolytic capacitor under test has hidden defects based on the difference between the transient response characteristics and the preset normal response characteristics, the transient high-current impulse test method further includes: After determining that the aluminum electrolytic capacitor under test has a hidden defect, a transient high current impulse signal is applied to the aluminum electrolytic capacitor under test again, and the second transient response characteristics are obtained. The defect level of the hidden defects in the oxide film is determined by comparing the second transient response feature with the transient response feature of the first impact.

6. The transient high-current impulse test method according to any one of claims 1 to 5, characterized in that, The transient response characteristics include at least one of the following: abnormal current information, abnormal voltage information, explosion-proof valve status information, flash explosion status information, temperature change information, pressure change information, acoustic response information, and optical response information.

7. A transient high-current impulse testing device for aluminum electrolytic capacitors, characterized in that, include: An initialization unit is used to determine the transient impact energy range based on the rated operating parameters and electrical performance parameters of the aluminum electrolytic capacitor under test. The transient impact energy range includes the impact current amplitude and duration of the transient high current impact signal. The processing unit is used to connect the aluminum electrolytic capacitor under test to the test circuit and to put the aluminum electrolytic capacitor under test into a preset polarity state. The pre-excitation unit is used to apply a pre-excitation electrical signal with a preset voltage amplitude to the aluminum electrolytic capacitor under test, and to collect information on the leakage current change of the aluminum electrolytic capacitor under test. The identification unit is used to identify, based on the leakage current change information, an abnormal conductive region in the anode foil oxide film of the aluminum electrolytic capacitor under test whose conductivity response is higher than that of the surrounding area, and to determine the current response characteristics corresponding to the abnormal conductive region. An application unit is used to continuously apply the pre-excitation electrical signal to increase the current density in the abnormal conductive region; The determining unit is used to determine the corresponding abnormal response region as a local current concentration region when the increase in current density meets the preset local current concentration condition, and to form a local response region based on the conductivity response characteristics of the local current concentration region. The transient impact unit is used to apply a transient large current impact signal to the aluminum electrolytic capacitor under test based on the transient impact energy range, so as to generate a nonlinear current response in the local response region and induce a local gas generation reaction and / or a flashover reaction. The acquisition unit is used to acquire abnormal response information of the aluminum electrolytic capacitor under test during the transient high current impact process and obtain the corresponding transient response characteristics. The detection unit is used to determine whether the aluminum electrolytic capacitor under test has hidden defects based on the difference between the transient response characteristics and the preset normal response characteristics.

8. A transient high-current impulse testing device for aluminum electrolytic capacitors, characterized in that, include: The processor, memory, input / output unit, and bus are connected to the memory, the input / output unit, and the bus. The memory stores a program, and the processor calls the program to execute the transient high-current impact test method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium contains a program that, when executed on a computer, performs the transient high-current impact test method as described in any one of claims 1 to 6.

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