Simulated working condition test method and device for power electronic film capacitor

Abstract

The invention relates to the field of power electronic thin film capacitor testing, and provides a power electronic thin film capacitor simulation working condition testing method and device. According to the method, after a tested capacitor is fixed through a tool clamp, target test temperature and humidity are set and maintained through a high-temperature damp-heat box, and the actual working environment working condition of the tested capacitor is simulated; applying a fundamental wave voltage matched with an actual working condition to the two electrodes of the tested capacitor through an adjustable power supply; a high-frequency ripple current is superposed on a tested capacitor through a high-frequency ripple power supply, temperature data of multiple point positions of the tested capacitor are collected in real time through a multi-channel temperature rise tester in the testing process, voltage at the two ends of the tested capacitor and parameters of flowing current are monitored in real time through an oscilloscope, and simulation working condition testing is completed. The real scene of multi-stress coexistence in actual work of the power electronic film capacitor is completely reproduced, the aging process of the capacitor in actual application can be accurately reproduced, and the accuracy and sufficiency of product reliability verification are improved.

Description

Technical Field

[0001] This application relates to the field of power electronic thin-film capacitor testing technology, and in particular to a method and equipment for simulating operating conditions testing of power electronic thin-film capacitors. Background Technology

[0002] Film capacitors are passive components, serving functions such as AC blocking DC, high-frequency passing and low-frequency blocking, DC filtering, high-frequency resonance, and peak absorption. They are widely used in various household appliances, lighting, smart homes, industrial control, new energy (photovoltaic power generation, energy storage, electric vehicles, wind power generation), rail transportation, smart grids, AI servers, and other fields.

[0003] Once the specific application parameters of the capacitor are obtained, the capacitor manufacturer needs to conduct simulated operating condition tests on the capacitor product to verify whether the product can meet the actual application conditions, avoid quality risks caused by incorrect product selection, and thus ensure that the product works safely and reliably throughout its life cycle.

[0004] Currently, the industry uses fundamental voltage (1.3Un DC voltage for DC capacitors and 1.25Un AC voltage for AC capacitors) for reliability testing of power electronic film capacitors, but does not conduct reliability verification on the superimposed high-frequency ripple current of the capacitors.

[0005] In practice, power electronic film capacitors operate under conditions where a fundamental voltage (AC or DC) is superimposed with a high-frequency ripple current (generated by various semiconductor switching devices). This high-frequency ripple current, applied to the film capacitor, causes a significant temperature rise, and this temperature rise and hotspot temperature determine the capacitor's lifespan. Currently, the reliability testing methods for power electronic film capacitors differ considerably from their actual application conditions, failing to adequately validate the products. Summary of the Invention

[0006] This application provides a method and equipment for simulating operating conditions testing of power electronic film capacitors, aiming to solve the problem that the current reliability testing methods for power electronic film capacitor products differ significantly from the actual application conditions of the products, thus failing to fully verify the products.

[0007] In a first aspect, embodiments of this application provide a method for simulating operating conditions of power electronic thin-film capacitors, the method comprising: After the capacitor under test is fixed by the tooling fixture, it is placed in a high temperature and humidity chamber with adjustable temperature and humidity; the target test temperature and humidity are set and maintained by the high temperature and humidity chamber to simulate the actual working environment of the capacitor under test. A fundamental voltage matching the actual operating conditions is applied to the two terminals of the capacitor under test by an adjustable power supply. The fundamental voltage is either a power frequency AC voltage or a DC voltage. A high-frequency ripple current matching the actual operating conditions is superimposed on the capacitor under test by a high-frequency ripple power supply to reproduce the operating conditions of the capacitor under test under actual operation, which is the fundamental voltage plus ripple current. During the test, the temperature data of multiple points of the capacitor under test are collected in real time by a multi-channel temperature rise tester, and the voltage and current parameters across the capacitor under test are detected in real time by an oscilloscope. After the preset total test time is reached, each power supply and test equipment is turned off in sequence, and the test data is exported to complete the simulated working condition test.

[0008] In some embodiments, the step of fixing the capacitor under test using a fixture and placing it in a high-temperature and humidity-controlled chamber with adjustable temperature and humidity includes: welding the capacitor under test onto a printed circuit board fixture using a double-sided copper foil all-glass fiberboard as a carrier; welding one end of multiple strands of high-temperature resistant copper wire onto the pads of the printed circuit board; and fixing the other end of the multiple strands of high-temperature resistant copper wire to a conductive adapter; placing the fixture with the capacitor under test fixed inside the high-temperature and humidity chamber and fixing it to an insulating support plate; and locking each conductive adapter to the output terminals of the adjustable power supply and the high-frequency ripple power supply, respectively, to complete the clamping and electrical connection of the capacitor under test.

[0009] In some embodiments, the step of setting and maintaining the target test temperature and humidity in a high-temperature humidity chamber to simulate the actual working environment of the capacitor under test includes: closing and locking the door of the high-temperature humidity chamber; setting the target test temperature, target test humidity, and total test duration in the high-temperature humidity chamber according to the actual application conditions of the capacitor under test; starting the high-temperature humidity chamber; monitoring the ambient temperature and humidity inside the chamber in real time; and maintaining the stable environmental parameters inside the chamber after the temperature and humidity inside the chamber have stabilized to the target test temperature and target test humidity, thereby completing the simulation of the working environment of the capacitor under test.

[0010] In some embodiments, applying a fundamental voltage matching the actual operating conditions to the two terminals of the capacitor under test via an adjustable power supply includes: selecting a corresponding high-power AC power supply or high-power DC power supply as the selected adjustable power supply according to the actual operating conditions of the capacitor under test; setting a fundamental voltage output parameter matching the actual operating conditions in the selected adjustable power supply; starting the selected adjustable power supply and outputting a stable fundamental voltage to the two terminals of the capacitor under test; detecting the fundamental voltage applied to the two terminals of the capacitor under test in real time using an oscilloscope; if the deviation between the detected fundamental voltage and the preset first target parameter is not within a first preset range, adjusting the fundamental voltage output parameter of the adjustable power supply in real time so that the deviation between the detected fundamental voltage and the preset first target parameter is within a first preset range.

[0011] In some embodiments, the step of superimposing a high-frequency ripple current with adjustable frequency and value matching the actual operating conditions onto the capacitor under test using a high-frequency ripple power supply to reproduce the ripple current actually experienced by the capacitor under test includes: setting frequency and current parameters of the high-frequency ripple current matching the actual operating conditions in the high-frequency ripple power supply according to the actual application conditions of the capacitor under test; starting the high-frequency ripple power supply and superimposing a stable high-frequency ripple current onto the two poles of the capacitor under test; detecting the frequency and current values ​​of the high-frequency ripple current flowing through the capacitor under test in real time using an oscilloscope; if the deviation between the preset second target parameter and the detected frequency value is not within a second preset range, and the deviation between the preset third target parameter and the detected current value is not within a third preset range, adjusting the output parameters of the frequency and current values ​​of the high-frequency ripple power supply in real time so that the deviation between the second target parameter and the detected frequency value is within the second preset range, and the deviation between the third target parameter and the detected current value is within the third preset range.

[0012] In some embodiments, during the test, the temperature data of multiple points of the capacitor under test is collected in real time by a multi-channel temperature rise tester, including: fixing temperature acquisition sensors at multiple target test points of the capacitor under test, connecting the signal output terminals of all temperature acquisition sensors to the corresponding input ports of the multi-channel temperature rise tester; throughout the test, the temperature data of each target test point of the capacitor under test is collected and recorded in real time by the multi-channel temperature rise tester at a preset acquisition frequency, and the ambient temperature data inside the high-temperature humidity chamber is collected simultaneously.

[0013] In some embodiments, the real-time detection of the voltage and current parameters across the capacitor under test using an oscilloscope includes: connecting the voltage acquisition probe of the oscilloscope to the first signal channel of the oscilloscope, and connecting the test terminals of the voltage acquisition probe to the two electrodes of the capacitor under test respectively; connecting the current acquisition probe of the oscilloscope to the second signal channel of the oscilloscope, and placing the sensing terminal of the current acquisition probe onto the current loop of the capacitor under test; throughout the entire test process, the oscilloscope detects and displays in real time the voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor under test.

[0014] In some embodiments, after reaching the preset total test duration, sequentially shutting down each power supply and test equipment, and exporting test data to complete the simulated operating condition test, includes: after reaching the preset total test duration, first shutting down the high-frequency ripple power supply and stopping the output of high-frequency ripple current to the capacitor under test; shutting down the power supply providing the fundamental voltage and stopping the output of the fundamental voltage to the capacitor under test; after the capacitor under test is fully discharged, shutting down the high-temperature humidity chamber, and sequentially shutting down the oscilloscope and the multi-channel temperature rise tester; wherein, by monitoring the remaining voltage across the two terminals of the capacitor under test, if the remaining voltage obtained in the preset number of samplings is lower than the preset safety voltage, it is determined that the capacitor under test is fully discharged; exporting and storing the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data recorded by the oscilloscope to complete this simulated operating condition test.

[0015] In some embodiments, the method further includes: during the test, acquiring temperature data at various points of the capacitor under test collected by a multi-channel temperature rise tester, and voltage and current data collected by an oscilloscope in real time; processing the acquired multiple sets of data in real time using a preset intelligent analysis algorithm; identifying the temperature rise trend and electrical parameter fluctuation characteristics of the capacitor under test using the intelligent analysis algorithm; if the temperature rise rate of the capacitor under test exceeds a preset threshold, or the electrical parameter fluctuation exceeds a preset safety range, automatically adjusting the output current value of the high-frequency ripple power supply and the output voltage value of the fundamental voltage, and simultaneously adjusting the environmental parameters of the high-temperature humidity chamber until the operating parameters of the capacitor under test return to the safe range; after the test, comprehensively analyzing all the test data collected throughout the process using the intelligent analysis algorithm, and outputting the reliability assessment results and service life prediction results of the capacitor under test under the corresponding operating conditions.

[0016] In a second aspect, this application provides a computer device, including a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program and, when executing the computer program, implement the method provided in any embodiment of this application.

[0017] This application simultaneously applies a fundamental voltage and a high-frequency ripple current matching the actual operating conditions to the capacitor under test, and superimposes a simulated target temperature and humidity environment, thus fully reproducing the real scenario of multiple stresses coexisting in the actual operation of power electronic film capacitors. It can accurately reproduce the aging process of capacitors in actual applications, and greatly improve the accuracy and sufficiency of product reliability verification.

[0018] During the testing process, this invention simultaneously collects temperature rise data, applied voltage parameters at both ends, and current parameters flowing through the circuit at multiple points on the capacitor in real time. This allows for precise control of the actual operating parameters that the capacitor is subjected to throughout the entire process, ensuring a high degree of matching between the test parameters and the target application conditions. This effectively improves the consistency and repeatability of the test results, providing accurate and complete quantitative data support for product performance optimization and selection design.

[0019] This invention can complete the full-dimensional performance and reliability verification of capacitors under target actual working conditions through a single test, replacing the verification mode of multiple rounds of single stress testing in the existing technology, which greatly shortens the verification cycle in the new product development stage. At the same time, through sufficient working condition simulation, it can identify the performance shortcomings of the product in advance, effectively avoid product selection errors and field application failures caused by insufficient verification, and ensure the safe and reliable operation of the product throughout its entire life cycle.

[0020] This invention can be flexibly adapted to different types of power electronic film capacitors, such as AC and DC. The type and value of the fundamental voltage, the frequency and current value of the high-frequency ripple current, and the environmental parameters of temperature and humidity can all be flexibly adjusted according to the actual application conditions. It can cover the testing needs of power electronic film capacitors in all scenarios such as new energy power generation, energy storage, electric vehicles, rail transit, and smart grids, and has a wide range of applications.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic flowchart illustrating the steps of a simulated operating condition test method for a power electronic thin-film capacitor provided in an embodiment of this application; Figure 2 This is a schematic diagram of a scenario for a simulated operating condition test method for a power electronic thin-film capacitor provided in an embodiment of this application; Figure 3 This is a schematic block diagram of a power electronic thin-film capacitor simulation test system provided in one embodiment of this application; Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0027] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0028] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] 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.

[0030] Please refer to Figure 1 This application provides a method for simulating operating conditions of power electronic thin-film capacitors, using computer-aided calculations. The computer equipment can be deployed on a single server or a server cluster. It can also be deployed on handheld terminals, laptops, wearable devices, or robots, etc.

[0031] The provided test method for simulated operating conditions of power electronic thin-film capacitors includes steps S101 to S103. Details are as follows: Step S101. After fixing the capacitor under test with the tooling fixture, place it in a high temperature and humidity chamber with adjustable temperature and humidity; set and maintain the target test temperature and humidity through the high temperature and humidity chamber to simulate the actual working environment of the capacitor under test.

[0032] Specifically, this step is the foundation of the entire test, addressing two core technical challenges: first, achieving low-loss, high-reliability clamping and electrical connection of the capacitor under test using specialized fixtures, avoiding issues like loose connections causing overheating and insufficient overcurrent capacity under high-current conditions; second, accurately replicating the actual temperature and humidity environment of the capacitor under test using a high-temperature and humidity chamber, achieving a superposition and matching of environmental stress and subsequent electrical stress, providing a stable and realistic foundational environment for the test. The core technical logic of this step is to first complete reliable physical clamping and electrical circuit construction, and then achieve stable simulation of controllable temperature and humidity conditions in a closed environment, ensuring the consistency and reliability of the test's foundational conditions.

[0033] The fixture and the capacitor under test are clamped together. A matching special fixture is prepared according to the package type, pin spacing, rated current parameters, etc. of the capacitor under test. The conductive circuit design of the fixture must meet the maximum overcurrent requirement of the test, and at the same time, pads matching the leads of the capacitor under test and large-size wiring pads for connection to external power supply are reserved. The rated parameters of the capacitor under test are checked, the capacitor electrodes and the pads of the fixture are cleaned, and the oxide layer and stains are removed to ensure the reliability of subsequent soldering.

[0034] The capacitor under test is fixed and connected to the electrical circuit by aligning the electrodes of the capacitor under test with the corresponding pads of the fixture. The capacitor leads are reliably soldered to the conductive circuit of the fixture using a soldering process. After soldering, the solder joint quality is checked to ensure there are no defects such as cold solder joints, false solder joints, or short circuits. High-current capacity multi-strand high-temperature resistant wires are selected. One end of the wire is soldered to the power supply terminal pad of the fixture, and the other end is used to fix the conductive adapter. The conductive adapter is then locked and fixed to the output terminal of the external power supply to ensure that the entire electrical circuit connection is stable and free from the risk of poor contact.

[0035] The test environment setup involves placing the fixture with the capacitor under test inside the high-temperature humidity chamber and locking it in place using an insulating support plate. This ensures complete insulation between the fixture and the metal casing of the high-temperature humidity chamber, preventing short circuits and leakage risks during testing. After setup, the sealed door of the high-temperature humidity chamber is closed and locked to ensure the sealing strip is fully in place, creating a sealed test environment space and preventing temperature and humidity leakage that could lead to parameter deviations.

[0036] Environmental condition setting and stability maintenance: Based on the actual application scenario of the capacitor under test, determine the ambient temperature and humidity parameters for its long-term operation. Input the target temperature, target humidity and total test duration into the control system of the high temperature and humidity chamber, and set the temperature and humidity control accuracy. Start the high temperature and humidity chamber and monitor the temperature and humidity values ​​inside the chamber in real time through the internal sensors. After the temperature and humidity stabilize to the set target values ​​and the fluctuation range meets the control accuracy requirements, maintain the environmental parameters to stabilize and complete the simulation of the actual working environment of the capacitor under test.

[0037] Step S102. Apply a fundamental voltage matching the actual operating conditions to the two poles of the capacitor under test through an adjustable power supply. The fundamental voltage is an AC voltage or DC voltage at power frequency. Superimpose a high-frequency ripple current matching the actual operating conditions onto the capacitor under test through a high-frequency ripple power supply to reproduce the ripple current that the capacitor under test actually withstands during operation.

[0038] Specifically, this step is the core invention of the entire testing method. Addressing the critical deficiency of existing technologies that can only apply a single fundamental voltage, resulting in a severe disconnect from actual operating conditions, this step achieves the synchronous and precise application of a superimposed fundamental voltage and high-frequency ripple current. This fully replicates the real-world operating conditions of power electronic film capacitors, where the fundamental voltage is superimposed on the high-frequency ripple current generated by semiconductor switching devices. It accurately simulates the heating and aging processes of capacitors during actual operation, fundamentally solving the problem that existing testing technologies cannot reproduce the core failure causes. The core technical logic of this step is to first determine the electrical stress parameters by matching them to actual operating conditions, then separately achieve the stable application of the fundamental voltage and the precise superposition of the high-frequency ripple current, and finally, implement closed-loop control through real-time detection to ensure a high degree of matching between the test conditions and parameters and actual operating conditions.

[0039] The target test conditions and parameters are determined based on the actual application circuit conditions of the capacitor under test. The type (AC / DC) and value of the fundamental voltage that the capacitor has been subjected to for a long time are extracted, as well as the frequency and current parameters of the high-frequency ripple current generated by the semiconductor switching device. The target test conditions and parameters are then determined to ensure that the test conditions and parameters are fully matched with the actual application conditions.

[0040] Based on the determined fundamental voltage type, select a matching high-power adjustable AC or DC power supply. After confirming that the power supply output capacity covers the test requirements, reliably connect the power supply output terminal to the conductive circuit of the tooling fixture. Set the target fundamental voltage parameters in the power control system, and set overvoltage and overcurrent protection thresholds. After confirming that there is no risk of short circuit in the circuit, start the power supply output and apply a stable fundamental voltage to the two poles of the capacitor under test.

[0041] By connecting the output of the high-frequency ripple power supply in parallel with the electrical circuit of the capacitor under test, the high-frequency ripple current frequency and current parameters that match the actual working conditions are set in the high-frequency ripple power supply control system, and an overcurrent protection threshold is set at the same time. After the fundamental voltage is output stably, the high-frequency ripple power supply is started, and a stable high-frequency ripple current is superimposed on the two poles of the capacitor under test to form a composite electrical stress with the fundamental voltage, thus completely reproducing the electrical stress conditions of the capacitor in actual operation.

[0042] The closed-loop detection and adjustment of electrical stress parameters involves real-time acquisition of the actual fundamental voltage across the capacitor under test and the actual high-frequency ripple current flowing through it during power supply operation. The consistency between the measured values ​​and the set target parameters is then checked. If a deviation exists, the output parameters of the corresponding power supply are adjusted in real time until the deviation between the measured parameters and the target parameters meets the accuracy requirements, thus completing the precise closed-loop control of composite electrical stress.

[0043] Step S103. During the test, the temperature data of multiple points of the capacitor under test are collected in real time by a multi-channel temperature rise tester, and the voltage and current parameters across the capacitor under test are detected in real time by an oscilloscope. After the preset total test time is reached, the power supply and test equipment are turned off in sequence, and the test data is exported to complete the simulated working condition test.

[0044] Specifically, this step is the core link in ensuring the integrity of test data and the safety of test operations. It achieves two main functions: First, during the test, it synchronously and in real-time collects multi-point temperature rise data and actual electrical parameter data of the capacitor under test, controlling the stability of the test conditions throughout and capturing the performance changes and temperature rise characteristics of the capacitor. Second, after the test, it shuts down the equipment according to safety regulations to avoid safety risks caused by residual voltage in the capacitor, and simultaneously exports and archives all test data, completing the closed loop of the entire test process. The core technical logic of this step is to first build a multi-dimensional synchronous monitoring system to achieve data traceability throughout the entire test process, and then ensure the safety of the test operation and the integrity of the test data through standardized safety shutdown and data export procedures.

[0045] Before the multi-dimensional monitoring system was started, temperature acquisition sensors were installed at multiple key points of the capacitor under test. The temperature acquisition sensors were then connected to a multi-channel temperature rise tester to establish a temperature monitoring system. At the same time, the voltage and current acquisition probes of the oscilloscope were connected to the electrodes and current loops of the capacitor under test to establish an electrical parameter monitoring system. After the connection was completed, the monitoring equipment was calibrated to ensure that the measurement accuracy met the requirements.

[0046] The entire testing process is monitored synchronously. During the entire testing process, a multi-channel temperature rise tester collects and records the temperature data of each key point of the capacitor under test in real time according to the preset acquisition frequency. The temperature data of the test environment is collected synchronously, and the temperature rise change curve is displayed in real time. The voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor, are detected and displayed in real time by an oscilloscope. The stability of the test conditions is controlled throughout the process, and the waveform data of key nodes are automatically stored.

[0047] The total test duration control and termination triggering are achieved by pre-setting the total test duration. The timing starts after the composite electrical stress is stably applied and the environmental parameters are stable. When the total test duration reaches the preset total test duration, the test termination process is automatically triggered to first confirm that the monitoring equipment has completed the recording and storage of all process data.

[0048] The equipment safety shutdown procedure involves shutting down the equipment in a preset safety sequence. First, the high-frequency ripple power supply is shut down to stop the high-frequency ripple current output. Then, the power supply providing the fundamental voltage is shut down to stop the fundamental voltage output. After the capacitor under test has been fully discharged and it is confirmed that there is no residual voltage in the circuit, the high-temperature humidity chamber is shut down. Finally, the oscilloscope and multi-channel temperature rise tester are shut down in sequence, thus avoiding the risk of electric shock and equipment damage throughout the process.

[0049] The test data export and archiving process involves exporting the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveforms and numerical data recorded by the oscilloscope through the storage medium. After verifying the integrity of the data files, the data is archived and stored to form a complete test data archive, thus completing the entire process of this power electronic thin film capacitor simulated operating condition test.

[0050] In some embodiments, the step of fixing the capacitor under test using a fixture and placing it in a high-temperature and humidity-controlled chamber with adjustable temperature and humidity includes: welding the capacitor under test onto a printed circuit board fixture using a double-sided copper foil all-glass fiberboard as a carrier; welding one end of multiple strands of high-temperature resistant copper wire onto the pads of the printed circuit board; and fixing the other end of the multiple strands of high-temperature resistant copper wire to a conductive adapter; placing the fixture with the capacitor under test fixed inside the high-temperature and humidity chamber and fixing it to an insulating support plate; and locking each conductive adapter to the output terminals of the adjustable power supply and the high-frequency ripple power supply, respectively, to complete the clamping and electrical connection of the capacitor under test.

[0051] This embodiment provides a standardized clamping solution for the clamping and electrical connection of the capacitor under test in step S101, characterized by low loss, high current carrying capacity, and high reliability. The core utilizes a printed circuit board with double-sided copper foil and full glass fiber substrate as the main body of the fixture, combined with high-current-carrying, high-temperature-resistant wires and conductive adapters, to complete the fixing, electrical connection, and internal layout of the capacitor under test. This solves the problems of insufficient current carrying capacity, loose connections leading to overheating, and low assembly efficiency in existing fixtures, ensuring the stability, low loss, and safety of the electrical circuit under high current testing conditions up to 200A.

[0052] The standardized preparation of the tooling fixture uses a double-sided copper foil all-glass fiber printed circuit board with a copper thickness of 2 ounces as the tooling fixture carrier. The conductive lines and pads are designed according to the pin spacing, external dimensions, and maximum test current parameters of the capacitor under test. The pad size is completely matched with the pin / electrode size of the capacitor under test. The width of the conductive line is designed according to the maximum test current of 200A. At the same time, two large-size power connection pads are reserved to ensure overcurrent capacity and connection reliability.

[0053] The capacitor under test is fixed by aligning its leads with the corresponding pads on the fixture. A constant-temperature soldering iron is used to reliably solder the leads to the pads using a lead-free soldering process. After soldering, the solder joint quality is inspected with a magnifying glass to ensure there are no defects such as cold solder joints, false solder joints, solder spikes, bridging, or short circuits, thus ensuring low loss and high strength of the electrical connection.

[0054] For high-current wiring preparation, multi-strand high-temperature resistant silicone copper wire with a cross-sectional area of ​​6 square millimeters is selected as the power connection conductor. After stripping 8mm of the insulation layer from one end of the conductor, it is soldered to the large-sized power connection pad reserved in the tooling fixture. After soldering, the conductor is manually pulled to confirm that the solder joint is not loose. After stripping 15mm of the insulation layer from the other end of the conductor, a copper conductive adapter (copper lug) is crimped and fixed using hydraulic pliers to ensure that the conductor and the adapter are tightly crimped and there is no poor contact.

[0055] The internal insulation fixation involves placing the fixture, with the welded capacitor and wiring wires attached, into the internal cavity of the high-temperature humidity chamber. A 5mm thick insulating bakelite board is used as the support base, and the fixture is locked and fixed to the bakelite board with nylon screws and nylon posts. This ensures that the fixture is completely insulated from the metal body of the high-temperature humidity chamber, with a suspension height of not less than 5cm, to avoid the risk of short circuits and leakage during testing.

[0056] Reliable connection to the power supply is achieved by attaching the conductive adapter at the other end of the high-temperature resistant copper wire to the copper terminals of the adjustable power supply and high-frequency ripple power supply outputs, and then locking the adapter to the terminals with stainless steel hexagonal screws to ensure complete contact without any looseness, thus completing the entire clamping and electrical connection process for the capacitor under test.

[0057] In some embodiments, the step of setting and maintaining the target test temperature and humidity in a high-temperature humidity chamber to simulate the actual working environment of the capacitor under test includes: closing and locking the door of the high-temperature humidity chamber; setting the target test temperature, target test humidity, and total test duration in the high-temperature humidity chamber according to the actual application conditions of the capacitor under test; starting the high-temperature humidity chamber; monitoring the ambient temperature and humidity inside the chamber in real time; and maintaining the stable environmental parameters inside the chamber after the temperature and humidity inside the chamber have stabilized to the target test temperature and target test humidity, thereby completing the simulation of the working environment of the capacitor under test.

[0058] This embodiment provides a precise and stable temperature and humidity environment simulation implementation scheme for the environmental condition simulation stage in step S101. The core of this scheme is to accurately reproduce the actual temperature and humidity environment of the capacitor under test through standardized parameter settings, environmental stability verification, and closed-loop parameter maintenance throughout the entire process. This solves the problems of large parameter deviations, insufficient stability, and disconnection from actual operating conditions in existing environmental simulation technologies, ensuring the consistency between environmental stress and actual operating conditions during testing and providing a stable environmental foundation for multi-stress superposition testing.

[0059] After the capacitor under test is clamped and the temperature sensor is installed, the sealed door of the high temperature and humidity chamber is closed and the two locking buckles around the door are fastened in sequence to ensure that the silicone rubber sealing strip between the door and the chamber is completely in contact, and the chamber is in a completely sealed state to avoid parameter deviations caused by temperature and humidity leakage.

[0060] The environmental parameter standardization setting is achieved by retrieving the ambient temperature and humidity parameters of the capacitor under test during its long-term operation, as well as the standard duration of the product durability test, based on the actual application scenario of the capacitor under test. In the touch control system of the high temperature and humidity chamber, the target test temperature (common operating temperatures such as 60℃, 70℃, and 85℃ can be selected), the target test humidity (common operating humidity such as 85%RH, 93%RH, and 95%RH can be selected), and the total test duration are input. At the same time, the temperature and humidity control accuracy is set to ±2℃ / ±3%RH, and the real-time temperature and humidity recording function is enabled to ensure parameter control accuracy and traceability.

[0061] Environmental condition start-up and real-time monitoring: By starting the high temperature and humidity chamber's operating program, the equipment automatically starts the heating, humidification, and air circulation systems. Through two distributed temperature and humidity sensors inside the chamber, the temperature and humidity values ​​inside the chamber are collected in real time and displayed on the control system's display screen, monitoring the changes in environmental parameters inside the chamber throughout the process.

[0062] Environmental parameter stability verification involves continuously monitoring the temperature and humidity values ​​inside the chamber. When the temperature and humidity inside the chamber reach the set target values ​​and the parameter fluctuation range does not exceed the set control accuracy within 10 consecutive minutes, the environmental parameters are determined to have reached a stable state, thus avoiding operating condition deviations caused by starting the test before the environmental parameters are stable.

[0063] Once the environmental parameters are stabilized, the high-temperature humidity chamber automatically enters the constant temperature and humidity maintenance mode. Throughout the process, the heating and humidification power is automatically adjusted through the PID control algorithm to maintain the temperature and humidity inside the chamber within the set target range until the test ends, thus completing the full-process simulation of the actual working environment of the capacitor under test.

[0064] In some embodiments, applying a fundamental voltage matching the actual operating conditions to the two terminals of the capacitor under test via an adjustable power supply includes: selecting a corresponding high-power AC power supply or high-power DC power supply as the selected adjustable power supply according to the actual operating conditions of the capacitor under test; setting a fundamental voltage output parameter matching the actual operating conditions in the selected adjustable power supply; starting the selected adjustable power supply and outputting a stable fundamental voltage to the two terminals of the capacitor under test; detecting the fundamental voltage applied to the two terminals of the capacitor under test in real time using an oscilloscope; if the deviation between the detected fundamental voltage and the preset first target parameter is not within a first preset range, adjusting the fundamental voltage output parameter of the adjustable power supply in real time so that the deviation between the detected fundamental voltage and the preset first target parameter is within a first preset range.

[0065] This embodiment provides a precise fundamental voltage application scheme for the fundamental voltage application stage in step S102, which can flexibly adapt to AC / DC operating conditions and features real-time closed-loop detection. The core principle is to match the corresponding power supply according to the actual operating conditions of the capacitor under test. Through standardized parameter settings, stable output, real-time detection, and dynamic adjustment, it ensures that the fundamental voltage applied across the capacitor perfectly matches the actual operating conditions. This solves the problems of existing technologies, such as a single fundamental voltage application type, large parameter deviations, and lack of closed-loop control, providing a stable fundamental voltage foundation for composite electrical stress testing.

[0066] The power supply type selection should be based on the actual application conditions of the capacitor under test to determine its fundamental voltage type. If it is an AC filtering condition, a high-power adjustable AC power supply should be selected; if it is a DC filtering condition, a high-power adjustable DC power supply should be selected. After selecting the power supply, check the output voltage range and output power of the power supply to ensure that it fully covers the rated voltage of the capacitor under test and the test requirements. At the same time, check that the grounding protection function of the power supply is normal.

[0067] The fundamental voltage parameter standardization setting involves inputting fundamental voltage output parameters that match the actual operating conditions into the control system of the selected high-power power supply: for AC power supplies, set the effective value of the output voltage, the output frequency to the power frequency of 50Hz, and the output waveform to a pure sine wave, while setting the total harmonic distortion to no more than 2%; for DC power supplies, set the output DC voltage value, and the output ripple voltage to no more than 1%; at the same time, set the overvoltage protection threshold of the power supply to 1.1 times the set voltage and the overcurrent protection threshold to 1.3 times the maximum test current to avoid damage to the capacitor and equipment under test in case of abnormal testing.

[0068] The fundamental voltage output startup is initiated by confirming that the electrical circuit connection between the power supply and the capacitor under test is reliable and there is no risk of short circuit. After the monitoring equipment is connected normally, the standby switch of the power supply is turned on first. After the equipment completes its self-test, the output function of the power supply is started. The power supply outputs a stable fundamental voltage to the two poles of the capacitor under test. The power supply's display screen shows the current output voltage and current values ​​in real time.

[0069] Real-time fundamental voltage detection uses a pre-connected oscilloscope to detect the voltage waveform and value between the two terminals of the capacitor under test in real time. It detects whether the actual fundamental voltage applied to the two ends of the capacitor is consistent with the set target parameters, and at the same time verifies the purity of the voltage waveform to ensure that there is no abnormal distortion.

[0070] The output parameter dynamic closed-loop adjustment is achieved by adjusting the actual fundamental voltage value detected by the oscilloscope. If the deviation from the first target parameter exceeds the first preset range, such as ±1%, the output parameter is finely adjusted in real time in the power supply control system until the deviation of the actual fundamental voltage value detected by the oscilloscope from the set target parameter does not exceed ±1%, thus completing the precise application and closed-loop control of the fundamental voltage.

[0071] In some embodiments, the step of superimposing a high-frequency ripple current with adjustable frequency and value matching the actual operating conditions onto the capacitor under test using a high-frequency ripple power supply to reproduce the ripple current actually experienced by the capacitor under test includes: setting frequency and current parameters of the high-frequency ripple current matching the actual operating conditions in the high-frequency ripple power supply according to the actual application conditions of the capacitor under test; starting the high-frequency ripple power supply and superimposing a stable high-frequency ripple current onto the two poles of the capacitor under test; detecting the frequency and current values ​​of the high-frequency ripple current flowing through the capacitor under test in real time using an oscilloscope; if the deviation between the preset second target parameter and the detected frequency value is not within a second preset range, and the deviation between the preset third target parameter and the detected current value is not within a third preset range, adjusting the output parameters of the frequency and current values ​​of the high-frequency ripple power supply in real time so that the deviation between the second target parameter and the detected frequency value is within the second preset range, and the deviation between the third target parameter and the detected current value is within the third preset range.

[0072] This embodiment provides a high-frequency ripple current superposition scheme with adjustable frequency and value over a wide range and real-time closed-loop detection for the high-frequency ripple current superposition stage in step S102. The core technology uses a high-frequency ripple power supply to superimpose a high-frequency ripple current matching the actual operating conditions onto the capacitor under test. Combined with real-time detection and dynamic adjustment, it accurately reproduces the high-frequency ripple current generated by semiconductor switching devices. This solves the core defects of existing technologies, such as the inability to superimpose high-frequency ripple current and the inability to reproduce the actual heating and aging conditions of capacitors. It is a key step in achieving high-fidelity simulation of operating conditions.

[0073] The high-frequency ripple parameter standardization setting is achieved by setting high-frequency ripple current output parameters that match the actual operating conditions of the capacitor under test, based on the switching frequency of the semiconductor switching devices and the effective value of the ripple current generated by the circuit. These parameters include frequency parameters (selectable within the range of 10KHz-100KHz, adaptable to commonly used switching frequencies such as 10KHz, 20KHz, 32KHz, 50KHz, and 100KHz) and effective current parameters (adjustable within the range of 5A-200A). At the same time, the overcurrent protection threshold of the power supply is set to 1.3 times the set current to ensure the safety of the equipment and the capacitor sample under test.

[0074] The high-frequency ripple current output startup is achieved by confirming that the electrical circuit between the high-frequency ripple power supply and the capacitor under test is reliably connected in parallel, with no risk of short circuit, and that the fundamental voltage has been stably applied. Then, the standby switch of the high-frequency ripple power supply is turned on first. After the equipment completes its self-test, the output function of the power supply is activated. The power supply outputs a stable high-frequency ripple current to the two poles of the capacitor under test, forming a composite electrical stress with the fundamental voltage, thus fully replicating the electrical stress conditions of the capacitor in actual operation.

[0075] The high-frequency ripple parameter real-time detection uses a pre-connected oscilloscope to detect the current waveform, current value and frequency value of the capacitor circuit under test in real time. It detects whether the frequency value and current value of the high-frequency ripple current flowing through the capacitor under test are consistent with the set second target parameter and third target parameter, respectively, and verifies that there is no abnormal distortion of the current waveform.

[0076] The output parameters are dynamically adjusted in a closed loop. If the frequency value of the actual high-frequency ripple current detected by the oscilloscope deviates from the second target parameter by more than the second preset range (e.g., ±2%), and the current value deviates from the third target parameter by more than the third preset range (e.g., ±1.5%), the output parameters are finely adjusted in real time in the control system of the high-frequency ripple power supply until the actual high-frequency ripple current parameter detected by the oscilloscope deviates from the second target parameter by no more than ±2% and from the third target parameter by no more than ±1.5%, thus completing the precise superposition and closed-loop control of the high-frequency ripple current.

[0077] In some embodiments, during the test, the temperature data of multiple points of the capacitor under test is collected in real time by a multi-channel temperature rise tester, including: fixing temperature acquisition sensors at multiple target test points of the capacitor under test, connecting the signal output terminals of all temperature acquisition sensors to the corresponding input ports of the multi-channel temperature rise tester; throughout the test, the temperature data of each target test point of the capacitor under test is collected and recorded in real time by the multi-channel temperature rise tester at a preset acquisition frequency, and the ambient temperature data inside the high-temperature humidity chamber is collected simultaneously.

[0078] This embodiment provides a multi-point, high-frequency, synchronous temperature detection implementation scheme for the temperature data acquisition stage of the capacitor under test in step S103. The core utilizes a K-type thermocouple temperature sensor in conjunction with a multi-channel temperature rise tester to collect real-time temperature data from key points of the capacitor under test and ambient temperature data. This accurately captures the temperature rise changes and hot spot temperatures of the capacitor during the testing process. Temperature rise and hot spot temperatures are core indicators determining the lifespan of the capacitor. This solution addresses the problems of existing technologies that cannot monitor capacitor hot spot temperatures and suffer from untimely and incomplete data acquisition, providing crucial data support for product reliability assessment.

[0079] Temperature acquisition points are determined based on the structure of the capacitor under test. Core temperature acquisition points are determined, including the two gold-plated electrode leads of the capacitor, the printed surface of the outer shell, and the hottest point corresponding to the internal core, for a total of 4 capacitor body monitoring points. At the same time, one ambient temperature monitoring point is set up inside the high-temperature humidity chamber to ensure coverage of the capacitor's hot spot area and environmental monitoring.

[0080] Temperature sensor installation and fixation: K-type thermocouples with accuracy class I are selected as temperature acquisition sensors. Special adhesive for temperature rise and curing catalyst are used to tightly attach the temperature measuring ends of the thermocouples to each target test point of the capacitor under test. After attachment, let stand for 1 minute to cure, ensuring that the temperature measuring ends of the thermocouples are completely in contact with the capacitor shell without gaps, avoiding temperature measurement deviations caused by air layers. At the same time, the temperature measuring end of one thermocouple is fixed to the bakelite board next to the tooling fixture, at the same level as the capacitor, for collecting the ambient temperature of the test environment.

[0081] The data acquisition equipment connection and parameter settings are achieved by connecting the signal output terminals of all thermocouple sensors to the input terminal blocks of the multi-channel temperature rise tester according to the positive and negative polarity correspondence, and tightening the fixing screws to ensure reliable signal connection. In the control system of the multi-channel temperature rise tester, a corresponding point name is set for each channel, the temperature data acquisition frequency is set to 10 times / minute, and a temperature over-threshold alarm function is set. The alarm threshold is set according to the maximum allowable operating temperature of the capacitor.

[0082] Real-time temperature data acquisition and recording: By activating the acquisition function of the multi-channel temperature rise tester, the tester acquires the temperature data of each point corresponding to each channel in real time according to the preset acquisition frequency throughout the test process. The data is automatically recorded and stored in the internal memory of the device. At the same time, the temperature values ​​and temperature rise curves of each point are displayed on the screen in real time. The temperature rise of the capacitor under test is monitored throughout the process, and an audible and visual alarm is triggered immediately when the temperature exceeds the threshold.

[0083] Simultaneous acquisition of ambient temperature involves simultaneously acquiring and recording the ambient temperature data inside the high-temperature humidity chamber with a multi-channel temperature rise tester while the capacitor body temperature is being collected. This data is fully aligned with the time axis of the capacitor body temperature data, enabling subsequent analysis of the correlation between ambient temperature and capacitor body temperature rise, and ensuring the integrity and relevance of the test data.

[0084] In some embodiments, the real-time detection of the voltage and current parameters across the capacitor under test using an oscilloscope includes: connecting the voltage acquisition probe of the oscilloscope to the first signal channel of the oscilloscope, and connecting the test terminals of the voltage acquisition probe to the two electrodes of the capacitor under test respectively; connecting the current acquisition probe of the oscilloscope to the second signal channel of the oscilloscope, and placing the sensing terminal of the current acquisition probe onto the current loop of the capacitor under test; throughout the entire test process, the oscilloscope detects and displays in real time the voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor under test.

[0085] This embodiment provides a full-waveform, real-time synchronous electrical parameter monitoring implementation scheme for the capacitor under test in step S103. The core utilizes a high-bandwidth digital oscilloscope paired with a high-voltage differential voltage probe and a high-frequency current probe to simultaneously acquire the full waveform, numerical values, and frequency parameters of the voltage across the capacitor and the loop current. This allows for continuous monitoring of the actual electrical stress experienced by the capacitor, ensuring consistency between the test conditions and actual operating conditions. This solves the problems of existing technologies that cannot monitor the actual electrical parameters experienced by the capacitor in real time and cannot capture abnormal fluctuations in electrical stress.

[0086] The monitoring equipment and probe connection calibration is performed by selecting a digital oscilloscope with an analog bandwidth of not less than 200MHz, connecting the signal output terminal of the high-voltage differential voltage probe to the first signal channel (CH1) of the oscilloscope, and connecting the signal output terminal of the high-frequency current probe with a bandwidth of not less than 10MHz to the second signal channel (CH2) of the oscilloscope; turn on the power of the oscilloscope and probe, and complete the zero-point calibration and gain calibration of the probe to ensure that the measurement accuracy meets the requirements.

[0087] Reliable connection of the voltage test terminal is achieved by clamping the two test clips of the high-voltage differential voltage probe onto the two electrodes of the capacitor under test, ensuring good contact between the metal probes of the clips and the electrodes without loosening. At the same time, it is ensured that the test leads maintain a safe distance from the high-voltage circuit to avoid electromagnetic interference. The test leads are arranged perpendicular to the current circuit to reduce coupling interference.

[0088] The proper setup for current testing involves placing the induction coil of the high-frequency current probe onto the current loop of the capacitor being tested, ensuring that the loop wires completely pass through the center of the induction coil, and closing the induction coil's latch to guarantee a completely closed magnetic circuit. Simultaneously, ensure the probe is positioned far from the power output to avoid strong electromagnetic interference and ensure the accuracy of current measurements.

[0089] Standardized oscilloscope parameter settings are achieved by configuring the voltage range of the first signal channel in the oscilloscope's control system to match the root mean square (RMS) value of the fundamental voltage of the capacitor under test, and the current range of the second signal channel to match the RMS value of the high-frequency ripple current. The oscilloscope's period is also configured to match the frequency of the high-frequency ripple current, ensuring that 3-5 high-frequency waveform cycles can be displayed completely on a single screen. Simultaneously, real-time waveform display, peak detection, and RMS value calculation functions are enabled, and the automatic waveform storage interval is set to once every 10 minutes to ensure the traceability of key waveform data.

[0090] Real-time acquisition and display of electrical parameters: Throughout the test, the oscilloscope uses voltage and current probes to acquire the voltage waveform, RMS voltage, and peak voltage across the capacitor under test, as well as the current waveform, RMS current, peak current, and frequency value flowing through the capacitor under test. All parameters are displayed on the oscilloscope screen in real time. At the same time, waveform data is automatically stored at preset intervals. The actual electrical stress parameters borne by the capacitor are monitored throughout the test. When abnormal fluctuations occur, waveform locking and storage can be manually triggered.

[0091] In some embodiments, after reaching the preset total test time, the power supply and test equipment are shut down sequentially, and the test data is exported to complete the simulated operating condition test. This includes: after reaching the preset total test time, first shutting down the high-frequency ripple power supply and stopping the output of high-frequency ripple current to the capacitor under test; shutting down the power supply providing the fundamental voltage and stopping the output of the fundamental voltage to the capacitor under test; after the capacitor under test is fully discharged, shutting down the high-temperature humidity chamber; wherein, by monitoring the remaining voltage across the capacitor under test, if the remaining voltage obtained in the preset number of samplings is lower than the preset safety voltage, it is determined that the capacitor under test is fully discharged; finally, the oscilloscope and the multi-channel temperature rise tester are shut down sequentially; the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data recorded by the oscilloscope are exported and stored to complete this simulated operating condition test.

[0092] This embodiment provides a safe and standardized implementation plan for equipment shutdown and data archiving in step S103, specifically addressing the test completion and data export stage. The core principle is to shut down the equipment in the safe sequence of "first stop the high-frequency wave, then stop the fundamental wave, fully discharge the capacitor, and finally stop the auxiliary equipment," completely avoiding the risk of electric shock caused by residual capacitor voltage. Simultaneously, it completely exports and archives all test data from the entire process, ensuring the safety of the test operation and the integrity of the test data. This solves the safety hazards and data loss or incompleteness problems caused by improper equipment shutdown sequences in existing technologies.

[0093] The test closing process is triggered after the total test duration is reached. When the total test duration is reached, the test closing process is automatically triggered. First, it is confirmed that the multi-channel temperature rise tester and oscilloscope have completed the recording and storage of the entire process data, and there is no data interruption or loss.

[0094] Safe shutdown of power equipment involves shutting down the power equipment in the order of high frequency first, then fundamental frequency. First, shut down the output function of the high-frequency ripple power supply, stopping the output of high-frequency ripple current to the capacitor under test. After the power output has completely returned to zero, turn off the power switch of the equipment. Then, shut down the output function of the high-power AC or DC power supply that provides the fundamental voltage, stopping the output of the fundamental voltage to the capacitor under test. After the power output has completely returned to zero, turn off the power switch of the equipment to avoid voltage spikes caused by shutdown under load, which could damage the capacitor under test.

[0095] By continuously monitoring the residual voltage across the capacitor under test with an oscilloscope, the capacitor is considered fully discharged when the residual voltage is sampled three times consecutively (with a sampling interval of 10 seconds) and is consistently below the safe voltage of 36V. After the power supply is turned off, wait 10 minutes to allow the capacitor to fully discharge through the discharge path of the circuit. Monitor the residual voltage across the capacitor using the voltage probe of the oscilloscope. Once the residual voltage is confirmed to have dropped below the safe voltage of 36V, proceed with subsequent operations to completely avoid the risk of electric shock.

[0096] After confirming that the capacitor has discharged completely, shut down the operation of the high-temperature humidity chamber and wait for the temperature inside the chamber to drop to room temperature naturally before turning off the power switch of the equipment. Then, turn off the power switches of the oscilloscope and the multi-channel temperature rise tester in sequence to complete the shutdown operation of all equipment.

[0097] Test data export and archiving are performed by inserting a blank FAT32 formatted USB flash drive into the USB port of the multi-channel temperature rise tester, selecting the full-process temperature data file for this test in the device's control system, and exporting it to the USB flash drive; then inserting the same USB flash drive into the oscilloscope's USB port, selecting the voltage and current waveform files and numerical record files stored for this test, and exporting them to the USB flash drive; after exporting, opening the USB flash drive files on the computer, verifying the integrity of the data files and the consistency of the timeline, and after confirming that there are no errors, naming and archiving the data files, and storing them in a dedicated test data archive, thus completing the entire process of this simulated operating condition test.

[0098] In some embodiments, the method further includes: during the test, acquiring temperature data at various points of the capacitor under test collected by a multi-channel temperature rise tester, and voltage and current data collected by an oscilloscope in real time; processing the acquired multiple sets of data in real time using a preset intelligent analysis algorithm; identifying the temperature rise trend and electrical parameter fluctuation characteristics of the capacitor under test using the intelligent analysis algorithm; if the temperature rise rate of the capacitor under test exceeds a preset threshold, or the electrical parameter fluctuation exceeds a preset safety range, automatically adjusting the output current of the high-frequency ripple power supply and the output voltage of the fundamental voltage, and simultaneously adjusting the environmental parameters of the high-temperature humidity chamber until the operating parameters of the capacitor under test return to the safe range; after the test, comprehensively analyzing all the test data collected throughout the process using the intelligent analysis algorithm, and outputting the reliability assessment results and service life prediction results of the capacitor under test under the corresponding operating conditions.

[0099] This embodiment, based on core steps S101-S103, adds adaptive control of the testing process, graded anomaly safety protection, and post-test quantitative reliability assessment and lifespan prediction functions based on a modular intelligent analysis algorithm. The core functionality involves breaking down the intelligent analysis algorithm into five independently executable standardized modules: filtering and noise reduction, feature extraction, adaptive control, aging analysis, and evaluation output. This enables precise processing of test data, quantitative closed-loop adjustment of abnormal operating conditions, and automatic generation of test results, significantly improving the intelligence level, test safety, and data application value of the testing method. It also solves the problems of existing technologies lacking adaptive control during the testing process and being unable to complete quantitative reliability assessments based on test data.

[0100] The signal output terminals of the multi-channel temperature rise tester and oscilloscope are connected to an industrial control computer equipped with a preset modular intelligent analysis algorithm via an RS485 / Ethernet communication interface to achieve millisecond-level real-time synchronous transmission of test data. In the intelligent analysis system of the industrial control computer, the rated parameters of the capacitor under test (rated voltage, rated current, maximum allowable operating temperature), polypropylene film material characteristic parameters (thermal activation energy, breakdown field strength, aging coefficient), thermal aging failure threshold (capacitance decay rate exceeding 5%, equivalent series resistance rise rate exceeding 20%), preset temperature rise rate threshold (not exceeding 2℃ / minute), electrical parameter safety fluctuation range (voltage fluctuation not exceeding ±2%, current fluctuation not exceeding ±3%), operating condition adaptive adjustment ratio coefficient, capacitor Arrhenius thermal aging model and inverse power law electrical aging model parameters, and life calculation benchmark value are pre-entered.

[0101] Throughout the testing process, the industrial control computer acquires temperature data at various points of the capacitor under test from the multi-channel temperature rise tester at a frequency of 1 time per second, as well as raw voltage, current, and frequency data from the oscilloscope. The raw data is preprocessed by the moving average filtering and noise reduction module in the intelligent analysis algorithm: the arithmetic mean of the temperature, voltage, and current data of 10 consecutive sampling points is calculated as the effective data at that moment, and high-frequency electromagnetic interference and random noise are removed. The preprocessed effective data is quantized using a feature extraction module, including: 1. Real-time temperature rise rate calculation: The real-time temperature rise rate at the current moment is obtained by taking the effective temperature difference between the current moment and the previous moment and dividing it by the sampling time interval of 1 second; the average value of the real-time temperature rise rate at 5 consecutive moments is taken to obtain the stable temperature rise rate. 2. Calculation of electrical parameter fluctuation characteristics: By taking all effective voltage and current data within the most recent minute, calculate their standard deviations respectively. The ratio of the standard deviation to the corresponding parameter setting value is the fluctuation range of the parameter. 3. Calculation of electrical parameter distortion characteristics: The voltage and current waveforms are decomposed into fundamental and harmonic waves by Fast Fourier Transform (FFT), and the total harmonic distortion (THD) is calculated. If the total harmonic distortion exceeds 5%, it is judged as waveform distortion.

[0102] The intelligent analysis algorithm compares the identified operating parameters with preset safety thresholds in real time, and uses proportional control (P control) logic to achieve quantitative adaptive adjustment of the operating conditions: if the stable temperature rise rate of the measured capacitor exceeds the preset threshold, or the fluctuation amplitude of the electrical parameters exceeds the preset safety range, the first-level adaptive adjustment program is immediately triggered to calculate the parameter deviation. Deviation = (Measured parameter value - Preset safety threshold) / Preset safety threshold; The high-frequency ripple current reduction amount = set ripple current value × deviation amount × 0.5, and the maximum reduction amount in a single instance shall not exceed 10% of the set value; The fundamental voltage fine-tuning amount = set fundamental voltage value × deviation × 0.2, and the maximum fine-tuning amount in a single operation shall not exceed 5% of the set value; Ambient temperature reduction amount = set ambient temperature value × deviation amount × 0.1, and the maximum reduction amount in a single instance shall not exceed 3°C of the set value; Based on the above calculation results, the system automatically sends corresponding control commands to the high-frequency ripple power supply, fundamental power supply, and high-temperature humidity chamber to linearly adjust the output parameters. After adjustment, the operating parameters are recalculated every 30 seconds until the operating parameters of the capacitor under test return to the safe range. Then, the parameters are gradually restored to the original test parameters according to the same proportional step size. If the temperature at any point of the capacitor under test exceeds its maximum allowable operating temperature, or the total harmonic distortion of the electrical parameters exceeds 15%, the secondary emergency protection program is immediately triggered: an emergency shutdown command is automatically sent to all power supply equipment to cut off all voltage and current outputs. At the same time, the industrial control computer is triggered to issue an audible and visual alarm and record the time and parameter data of the abnormality, thus achieving full-dimensional safety protection during the testing process.

[0103] After the test is completed and all test data is exported, all test data is imported into the intelligent analysis system. The intelligent analysis algorithm then performs thermal aging analysis and electrical aging analysis to quantitatively calculate the degree of aging. Thermal aging analysis: The Arrhenius thermal aging model was used, and the calculation formula is as follows: Thermal aging acceleration factor = exp[Ea / R×(1 / T0-1 / T1)]; Where Ea is the thermal activation energy of the polypropylene film (value is 0.9eV), R is the gas constant (value is 8.314J / (mol·K)), T0 is the reference temperature (value is 298K, i.e. 25℃), and T1 is the average hot spot temperature of the capacitor under test during the test (unit: K). Electrical aging analysis: An inverse power-law electrical aging model was used, and the calculation formula is as follows: Electro-aging acceleration factor = (U1 / U0) n ; Where U0 is the rated voltage of the capacitor, U1 is the average voltage applied during the test, and n is the electrical aging index (7 for polypropylene film). Calculation of comprehensive aging acceleration factor: Comprehensive aging acceleration factor = thermal aging acceleration factor × electrical aging acceleration factor; Capacitance decay rate calculation: Capacitance decay rate = (Initial capacity - Capacitance after test) / Initial capacity × 100%; Calculation of equivalent series resistance change rate: Equivalent series resistance change rate = (Equivalent series resistance after test - Initial equivalent series resistance) / Initial equivalent series resistance × 100%; Performance bottlenecks and failure risk identification are achieved by comparing the values ​​of thermal aging acceleration factor and electrical aging acceleration factor. The one with the larger value is the main factor leading to capacitor aging. If the capacitance decay rate exceeds 3% or the equivalent series resistance change rate exceeds 10%, the capacitor is judged to have an early failure risk.

[0104] Based on the above quantitative calculation results, the intelligent analysis algorithm performs reliability assessment from three dimensions: Operating condition tolerance assessment: Based on the comprehensive aging acceleration factor and test duration, the equivalent aging time of the capacitor under this operating condition is calculated using the following formula: Equivalent aging time (hours) = Comprehensive aging acceleration factor × Actual test duration (hours); The equivalent aging time indicates the degree of aging of the capacitor caused by this test, which is equivalent to the degree of aging caused by working under rated conditions at 25℃ for a corresponding period of time. An equivalent aging time of less than 1000 hours is considered to be excellent under operating conditions, 1000-5000 hours is considered to be good, and more than 5000 hours is considered to be poor. Based on the fluctuation range of electrical parameters and the stability of temperature rise during the test, a performance stability score is calculated using the following formula: Electrical parameter stability score = 100 - (voltage fluctuation amplitude × 100 + current fluctuation amplitude × 100) × 0.6; Temperature rise stability score = 100 - (average temperature rise fluctuation at all test points × 100) × 0.4; Performance stability score = Electrical parameter stability score × 0.6 + Temperature rise stability score × 0.4; Among them, the temperature rise fluctuation range is the ratio of the standard deviation of the temperature at each point to the average temperature during the test; A performance stability score greater than 90 is considered stable, 70-90 is considered basically stable, and less than 70 is considered unstable. Based on the capacitance decay rate and the equivalent series resistance change rate, the failure risk is divided into three levels: low, medium, and high. The classification criteria are as follows: Low risk: Capacitance decay rate ≤2% and equivalent series resistance change rate ≤10%; Medium risk: 2% < capacitance decay rate ≤ 5% or 10% < equivalent series resistance change rate ≤ 20%; High risk: Capacitance decay rate >5% or equivalent series resistance change rate >20%; Based on the above evaluation results, optimization suggestions are automatically generated using rule matching: if thermal aging is the main aging factor, it is recommended to optimize the capacitor's heat dissipation structure or reduce the operating ambient temperature; if electrical aging is the main aging factor, it is recommended to increase the capacitor's rated voltage or reduce the operating ripple current; if there is a risk of early failure, it is recommended to optimize the capacitor's internal core structure; the Arrhenius life formula is used to predict the service life: expected service life = baseline service life / comprehensive aging acceleration factor; where the baseline service life is the nominal service life of the capacitor under rated operating conditions (valued at 100,000 hours); finally, the intelligent analysis system automatically generates a standardized test report, including all test parameters, full-process data curves, quantitative calculation results, reliability assessment conclusions, expected service life, and optimization suggestions, providing quantitative decision-making basis for product performance optimization, selection design, and mass application.

[0105] In some embodiments, please refer to Figure 2 Based on the power electronic thin-film capacitor simulated operating condition testing method of this invention, a complete standardized test system layout scheme and full-process implementation method are provided, fully corresponding to the system three-dimensional combination structure in the accompanying drawings. This embodiment clarifies the spatial layout rules, electrical connection methods, signal transmission paths, and standardized test operation procedures of each core device in the test system. Reasonable device layout reduces electromagnetic interference between high-current loops and signal acquisition loops, and standardized wiring and connection methods ensure low loss and high reliability of the test loops. It fully realizes the simulated operating condition testing of "temperature and humidity environmental stress + fundamental voltage + high-frequency ripple current" superimposed by multiple stresses, while simultaneously achieving multi-dimensional synchronous monitoring of temperature and electrical parameters during the test process. This ensures stable operation of the test system and accurate and traceable test data, providing a directly implementable standardized hardware implementation scheme for the simulated operating condition testing of power electronic thin-film capacitors. The standardized spatial layout of the test system follows... Figure 2 The layout shown completes the spatial arrangement of the test system: a high-power fundamental wave power supply 01, capable of outputting AC or DC voltage, and a high-frequency ripple power supply 07, capable of outputting high-frequency ripple current with adjustable frequency and current, are symmetrically arranged on the left and right sides of the temperature and humidity adjustable high-temperature humidity chamber 06, respectively. The distance between the two types of power supplies and the high-temperature humidity chamber is no less than 80cm to avoid electromagnetic radiation interference to the signal acquisition equipment during power supply operation; a digital oscilloscope 02 and a multi-channel temperature rise tester 03 are fixed in layers on an insulated metal bracket and arranged as a whole in the front left of the high-temperature humidity chamber, with a distance of no less than 50cm from the high-temperature humidity chamber, to facilitate real-time observation and monitoring of data during the test; the door of the high-temperature humidity chamber is in an openable and closable state, and its cavity is used to place the test piece and tooling. The side wall of the chamber has reserved wire holes with sealing rings for passing through the power supply lines and signal acquisition lines to avoid damaging the temperature and humidity sealing of the chamber.

[0106] The test component is clamped and internally arranged by selecting the power electronic film capacitor 04 to be tested and welding it to the special tooling fixture 05. The tooling fixture uses a double-sided copper foil full glass fiber printed circuit board as the carrier to ensure reliable welding and that the current carrying capacity meets the test requirements. The tooling fixture with the capacitor under test fixed is then locked and fixed to the bakelite insulating support plate inside the high temperature and humidity chamber by insulating nylon columns to ensure that the tooling fixture is completely insulated from the metal box of the high temperature and humidity chamber and to avoid the risk of short circuit leakage during the test.

[0107] The connection between electrical and signal circuits is achieved by completing the standardized connection between the power and signal circuits, corresponding to... Figure 2 The wiring layout in the circuit is as follows: The power circuit is connected by using multi-strand high-temperature resistant copper wire with a cross-sectional area of ​​6 square millimeters. One end is welded to the power terminal pad of the tooling fixture, and the other end passes through the sealed wire hole on the side wall of the high-temperature humidity chamber. It is then fixed to the output terminals of the high-power fundamental wave power supply on the left and the high-frequency ripple power supply on the right by copper lugs and screws. The fundamental wave power supply provides the fundamental wave voltage to the capacitor under test, and the high-frequency ripple power supply is connected in parallel with the capacitor under test to superimpose the high-frequency ripple current and form a composite electrical stress circuit. The temperature signal loop connection involves attaching the temperature measuring end of a K-type thermocouple sensor to multiple key points of the capacitor under test. The thermocouple signal cable passes through the sealed wiring hole of the high-temperature humidity chamber, and the other end is connected to the input wiring port of the multi-channel temperature rise tester, enabling real-time acquisition of temperature data at multiple points of the capacitor under test. The electrical parameter signal loop connection involves connecting the test end of the high-voltage differential voltage probe of the digital oscilloscope to the two electrodes of the capacitor under test, placing the induction coil of the oscilloscope's high-frequency current probe on the current loop of the capacitor under test, and passing the probe's signal cable through the sealed wiring hole of the high-temperature humidity chamber, connecting it to the corresponding signal channel of the oscilloscope, enabling real-time monitoring of the voltage across the capacitor and the loop current.

[0108] After completing all connections, close and lock the door of the high-temperature humidity chamber, ensuring the chamber sealing strip is fully in place and the cavity is well-sealed. Perform power-on self-tests and calibrations on all test equipment: calibrate the output voltage accuracy of the high-power fundamental wave power supply, the output current and frequency accuracy of the high-frequency ripple power supply, the temperature acquisition accuracy of the multi-channel temperature rise tester, and the voltage and current measurement accuracy of the digital oscilloscope. Based on the actual application conditions of the capacitor under test, preset the target test parameters in the control system of each device, including the target temperature, humidity, and total test duration of the high-temperature humidity chamber, the fundamental wave voltage type and value of the fundamental wave power supply, and the ripple current frequency and value of the high-frequency ripple power supply. At the same time, set the overvoltage, overcurrent, and overheat protection thresholds for each device to ensure test safety.

[0109] Environmental condition simulation and composite electrical stress application are achieved by starting a high-temperature humidity chamber, where the equipment automatically runs heating and humidification programs, and monitors the temperature and humidity values ​​inside the chamber in real time. Once the temperature and humidity stabilize at the preset target values ​​and remain stable, the actual working environment of the capacitor under test is simulated. Subsequently, a high-power fundamental wave power supply is started to output a stable fundamental wave voltage to the two poles of the capacitor under test. The actual applied voltage parameters are detected in real time using a digital oscilloscope. If there is a deviation, the output parameters of the fundamental wave power supply are adjusted in real time until the voltage meets the preset requirements. After the fundamental wave voltage stabilizes, a high-frequency ripple power supply is started to superimpose a preset high-frequency ripple current onto the capacitor under test. The frequency and value of the current flowing through the capacitor are detected in real time using a digital oscilloscope, thus completing the precise application of composite electrical stress and reproducing the actual electrical stress conditions of the capacitor under test.

[0110] The entire process of multi-dimensional data monitoring involves using a multi-channel temperature rise tester to collect and record temperature data at various points on the capacitor under test and the ambient temperature inside the cavity in real time at a preset sampling frequency throughout the entire testing process. The temperature rise curve is displayed in real time, and an alarm is automatically triggered when the temperature exceeds the threshold. The voltage waveform and voltage value across the capacitor under test, as well as the waveform, value, and frequency value of the loop current, are collected and displayed in real time using a digital oscilloscope. The waveform data is automatically stored at preset intervals, ensuring the stability of the test conditions throughout the process and guaranteeing that the test parameters are highly matched with the preset target conditions.

[0111] After the preset total test duration is reached, the equipment is shut down in the following safe sequence: first, the high-frequency ripple power supply is shut down to stop the high-frequency ripple current output; then, the fundamental power supply is shut down to stop the fundamental voltage output; after the capacitor under test is fully discharged and the remaining voltage in the circuit drops below the safe threshold, the high-temperature humidity chamber is shut down, followed by the digital oscilloscope and the multi-channel temperature rise tester; finally, the full-process temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data stored in the digital oscilloscope are exported, the data integrity is verified, and the data is archived to form a complete test file, thus completing this simulated operating condition test of the power electronic thin-film capacitor.

[0112] Please see Figure 3 As shown, Figure 3 This is a schematic diagram of the power electronic thin-film capacitor simulated operating condition test system 200 provided in this application embodiment. The power electronic thin-film capacitor simulated operating condition test system 200 is used to execute the steps of the power electronic thin-film capacitor simulated operating condition test methods shown in the above embodiments. The power electronic thin-film capacitor simulated operating condition test system 200 can be a single server or a server cluster, or it can be a terminal, such as a handheld terminal, a laptop computer, a wearable device, or a robot.

[0113] like Figure 3 As shown, the power electronic thin-film capacitor simulation test system 200 includes: The fixture fixing unit 201 is used to fix the capacitor under test in the tooling fixture and place it in a high temperature and humidity chamber with adjustable temperature and humidity; the target test temperature and humidity are set and maintained by the high temperature and humidity chamber to simulate the actual working environment of the capacitor under test. The voltage / current application unit 202 is used to apply a fundamental voltage matching the actual working condition to the two poles of the capacitor under test through an adjustable power supply. The fundamental voltage is a power frequency AC voltage or a DC voltage. A high-frequency ripple current with adjustable frequency and current matching the actual working condition is superimposed on the capacitor under test through a high-frequency ripple power supply to reproduce the electrical stress condition of the capacitor under test in actual operation. The test completion unit 203 is used to collect temperature data at multiple points of the capacitor under test in real time through a multi-channel temperature rise tester during the test, and to monitor the voltage and current parameters across the capacitor under test in real time through an oscilloscope; after the preset total test time is reached, the power supply and test equipment are turned off in sequence, and the test data is exported to complete the simulated working condition test.

[0114] In some embodiments, the step of fixing the capacitor under test using a fixture and placing it in a high-temperature and humidity-controlled chamber with adjustable temperature and humidity includes: welding the capacitor under test onto a printed circuit board fixture using a double-sided copper foil all-glass fiberboard as a carrier; welding one end of multiple strands of high-temperature resistant copper wire onto the pads of the printed circuit board; and fixing the other end of the multiple strands of high-temperature resistant copper wire to a conductive adapter; placing the fixture with the capacitor under test fixed inside the high-temperature and humidity chamber and fixing it to an insulating support plate; and locking each conductive adapter to the output terminals of the adjustable power supply and the high-frequency ripple power supply, respectively, to complete the clamping and electrical connection of the capacitor under test.

[0115] In some embodiments, the step of setting and maintaining the target test temperature and humidity in a high-temperature humidity chamber to simulate the actual working environment of the capacitor under test includes: closing and locking the door of the high-temperature humidity chamber; setting the target test temperature, target test humidity, and total test duration in the high-temperature humidity chamber according to the actual application conditions of the capacitor under test; starting the high-temperature humidity chamber; monitoring the ambient temperature and humidity inside the chamber in real time; and maintaining the stable environmental parameters inside the chamber after the temperature and humidity inside the chamber have stabilized to the target test temperature and target test humidity, thereby completing the simulation of the working environment of the capacitor under test.

[0116] In some embodiments, applying a fundamental voltage matching the actual operating conditions to the two terminals of the capacitor under test via an adjustable power supply includes: selecting a corresponding high-power AC power supply or high-power DC power supply as the selected adjustable power supply according to the actual operating conditions of the capacitor under test; setting a fundamental voltage output parameter matching the actual operating conditions in the selected adjustable power supply; starting the selected adjustable power supply and outputting a stable fundamental voltage to the two terminals of the capacitor under test; detecting the fundamental voltage applied to the two terminals of the capacitor under test in real time using an oscilloscope; if the deviation between the detected fundamental voltage and the preset first target parameter is not within a first preset range, adjusting the fundamental voltage output parameter of the adjustable power supply in real time so that the deviation between the detected fundamental voltage and the preset first target parameter is within a first preset range.

[0117] In some embodiments, the step of superimposing a high-frequency ripple current with adjustable frequency and value matching the actual operating conditions onto the capacitor under test using a high-frequency ripple power supply to reproduce the ripple current actually experienced by the capacitor under test includes: setting frequency and current parameters of the high-frequency ripple current matching the actual operating conditions in the high-frequency ripple power supply according to the actual application conditions of the capacitor under test; starting the high-frequency ripple power supply and superimposing a stable high-frequency ripple current onto the two poles of the capacitor under test; detecting the frequency and current values ​​of the high-frequency ripple current flowing through the capacitor under test in real time using an oscilloscope; if the deviation between the preset second target parameter and the detected frequency value is not within a second preset range, and the deviation between the preset third target parameter and the detected current value is not within a third preset range, adjusting the output parameters of the frequency and current values ​​of the high-frequency ripple power supply in real time so that the deviation between the second target parameter and the detected frequency value is within the second preset range, and the deviation between the third target parameter and the detected current value is within the third preset range.

[0118] In some embodiments, during the test, the temperature data of multiple points of the capacitor under test is collected in real time by a multi-channel temperature rise tester, including: fixing temperature acquisition sensors at multiple target test points of the capacitor under test, connecting the signal output terminals of all temperature acquisition sensors to the corresponding input ports of the multi-channel temperature rise tester; throughout the test, the temperature data of each target test point of the capacitor under test is collected and recorded in real time by the multi-channel temperature rise tester at a preset acquisition frequency, and the ambient temperature data inside the high-temperature humidity chamber is collected simultaneously.

[0119] In some embodiments, the real-time detection of the voltage and current parameters across the capacitor under test using an oscilloscope includes: connecting the voltage acquisition probe of the oscilloscope to the first signal channel of the oscilloscope, and connecting the test terminals of the voltage acquisition probe to the two electrodes of the capacitor under test respectively; connecting the current acquisition probe of the oscilloscope to the second signal channel of the oscilloscope, and placing the sensing terminal of the current acquisition probe on the current loop of the capacitor under test; throughout the test process, acquiring and displaying the voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor under test in real time using the oscilloscope.

[0120] In some embodiments, after reaching the preset total test duration, sequentially shutting down each power supply and test equipment, and exporting test data to complete the simulated operating condition test, includes: after reaching the preset total test duration, first shutting down the high-frequency ripple power supply and stopping the output of high-frequency ripple current to the capacitor under test; shutting down the power supply providing the fundamental voltage and stopping the output of the fundamental voltage to the capacitor under test; after the capacitor under test is fully discharged, shutting down the high-temperature humidity chamber; wherein, by monitoring the remaining voltage across the two terminals of the capacitor under test, if the remaining voltage obtained in the preset number of samplings is lower than the preset safety voltage, it is determined that the capacitor under test is fully discharged; then sequentially shutting down the oscilloscope and the multi-channel temperature rise tester; exporting and storing the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data recorded by the oscilloscope to complete this simulated operating condition test.

[0121] In some embodiments, the method further includes: during the test, acquiring temperature data at various points of the capacitor under test collected by a multi-channel temperature rise tester, and voltage and current data collected by an oscilloscope in real time; processing the acquired multiple sets of data in real time using a preset intelligent analysis algorithm; identifying the temperature rise trend and electrical parameter fluctuation characteristics of the capacitor under test using the intelligent analysis algorithm; if the temperature rise rate of the capacitor under test exceeds a preset threshold, or the electrical parameter fluctuation exceeds a preset safety range, automatically adjusting the output current of the high-frequency ripple power supply and the output voltage of the fundamental voltage, and simultaneously adjusting the environmental parameters of the high-temperature humidity chamber until the operating parameters of the capacitor under test return to the safe range; after the test, comprehensively analyzing all the test data collected throughout the process using the intelligent analysis algorithm, and outputting the reliability assessment results and service life prediction results of the capacitor under test under the corresponding operating conditions.

[0122] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the power electronic thin-film capacitor simulation test system and its modules described above can be referred to the corresponding content in the various embodiments of the power electronic thin-film capacitor simulation test method, and will not be repeated here.

[0123] The aforementioned method for simulating operating conditions of power electronic thin-film capacitors can be implemented as a computer program, which can be used in various applications such as... Figure 3 It runs on the device shown.

[0124] Please see Figure 4 , Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application. The computer device includes a processor, a memory, and a network interface connected via a device bus, wherein the memory may include a storage medium and internal memory.

[0125] The storage medium can store operating devices and computer programs. The computer program includes program instructions that, when executed, cause the processor to perform any power electronic thin-film capacitor simulation test method.

[0126] The processor provides computing and control capabilities, supporting the operation of the entire computer device.

[0127] The internal memory provides an environment for the execution of computer programs in non-volatile storage media. When the computer program is executed by the processor, it enables the processor to perform any power electronic thin-film capacitor simulation test method.

[0128] This network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the terminal to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0129] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0130] In one embodiment, the processor is configured to run a computer program stored in memory to perform the following steps: After the capacitor under test is fixed by the tooling fixture, it is placed in a high temperature and humidity chamber with adjustable temperature and humidity; the target test temperature and humidity are set and maintained by the high temperature and humidity chamber to simulate the actual working environment of the capacitor under test. A fundamental voltage matching the actual operating conditions is applied to the two terminals of the capacitor under test by an adjustable power supply. The fundamental voltage is either a power frequency AC voltage or a DC voltage. A high-frequency ripple current matching the actual operating conditions is superimposed on the capacitor under test by a high-frequency ripple power supply to reproduce the fundamental voltage plus ripple current that the capacitor under test actually withstands during operation. During the test, the temperature data of multiple points of the capacitor under test are collected in real time by a multi-channel temperature rise tester, and the voltage and current parameters across the capacitor under test are monitored in real time by an oscilloscope. After the preset total test time is reached, each power supply and test equipment is turned off in sequence, and the test data is exported to complete the simulated working condition test.

[0131] In some embodiments, the step of fixing the capacitor under test using a fixture and placing it in a high-temperature and humidity-controlled chamber with adjustable temperature and humidity includes: welding the capacitor under test onto a printed circuit board fixture using a double-sided copper foil all-glass fiberboard as a carrier; welding one end of multiple strands of high-temperature resistant copper wire onto the pads of the printed circuit board; and fixing the other end of the multiple strands of high-temperature resistant copper wire to a conductive adapter; placing the fixture with the capacitor under test fixed inside the high-temperature and humidity chamber and fixing it to an insulating support plate; and locking each conductive adapter to the output terminals of the adjustable power supply and the high-frequency ripple power supply, respectively, to complete the clamping and electrical connection of the capacitor under test.

[0132] In some embodiments, the step of setting and maintaining the target test temperature and humidity in a high-temperature humidity chamber to simulate the actual working environment of the capacitor under test includes: closing and locking the door of the high-temperature humidity chamber; setting the target test temperature, target test humidity, and total test duration in the high-temperature humidity chamber according to the actual application conditions of the capacitor under test; starting the high-temperature humidity chamber; monitoring the ambient temperature and humidity inside the chamber in real time; and maintaining the stable environmental parameters inside the chamber after the temperature and humidity inside the chamber have stabilized to the target test temperature and target test humidity, thereby completing the simulation of the working environment of the capacitor under test.

[0133] In some embodiments, applying a fundamental voltage matching the actual operating conditions to the two terminals of the capacitor under test via an adjustable power supply includes: selecting a corresponding high-power AC power supply or a high-power DC power supply as the selected adjustable power supply according to the actual operating conditions of the capacitor under test; setting the fundamental voltage output parameters matching the actual operating conditions in the selected adjustable power supply; starting the selected adjustable power supply and outputting a stable fundamental voltage to the two terminals of the capacitor under test; and detecting the fundamental voltage applied to the two terminals of the capacitor under test in real time using an oscilloscope. If the detected value deviates from the set parameters, the output parameters of the power supply are adjusted in real time until the fundamental voltage meets the set requirements.

[0134] In some embodiments, the step of superimposing a high-frequency ripple current with adjustable frequency and value matching the actual operating conditions onto the capacitor under test using a high-frequency ripple power supply to reproduce the ripple current actually experienced by the capacitor under test includes: setting frequency and current parameters of the high-frequency ripple current matching the actual operating conditions in the high-frequency ripple power supply according to the actual application conditions of the capacitor under test; starting the high-frequency ripple power supply and superimposing a stable high-frequency ripple current onto the two poles of the capacitor under test; detecting the frequency and current values ​​of the high-frequency ripple current flowing through the capacitor under test in real time using an oscilloscope; if the deviation between the preset second target parameter and the detected frequency value is not within a second preset range, and the deviation between the preset third target parameter and the detected current value is not within a third preset range, adjusting the output parameters of the frequency and current values ​​of the high-frequency ripple power supply in real time so that the deviation between the second target parameter and the detected frequency value is within the second preset range, and the deviation between the third target parameter and the detected current value is within the third preset range.

[0135] In some embodiments, during the test, the temperature data of multiple points of the capacitor under test is collected in real time by a multi-channel temperature rise tester, including: fixing temperature acquisition sensors at multiple target test points of the capacitor under test, connecting the signal output terminals of all temperature acquisition sensors to the corresponding input ports of the multi-channel temperature rise tester; throughout the test, the temperature data of each target test point of the capacitor under test is collected and recorded in real time by the multi-channel temperature rise tester at a preset acquisition frequency, and the ambient temperature data inside the high-temperature humidity chamber is collected simultaneously.

[0136] In some embodiments, the real-time detection of the voltage and current parameters across the capacitor under test using an oscilloscope includes: connecting the voltage acquisition probe of the oscilloscope to the first signal channel of the oscilloscope, and connecting the test terminals of the voltage acquisition probe to the two electrodes of the capacitor under test respectively; connecting the current acquisition probe of the oscilloscope to the second signal channel of the oscilloscope, and placing the sensing terminal of the current acquisition probe on the current loop of the capacitor under test; throughout the test process, acquiring and displaying the voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor under test in real time using the oscilloscope.

[0137] In some embodiments, after reaching the preset total test duration, sequentially shutting down each power supply and test equipment, and exporting test data to complete the simulated operating condition test, includes: after reaching the preset total test duration, first shutting down the high-frequency ripple power supply and stopping the output of high-frequency ripple current to the capacitor under test; shutting down the power supply providing the fundamental voltage and stopping the output of the fundamental voltage to the capacitor under test; after the capacitor under test is fully discharged, shutting down the high-temperature humidity chamber; wherein, by monitoring the remaining voltage across the two terminals of the capacitor under test, if the remaining voltage obtained in the preset number of samplings is lower than the preset safety voltage, it is determined that the capacitor under test is fully discharged; then sequentially shutting down the oscilloscope and the multi-channel temperature rise tester; exporting and storing the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data recorded by the oscilloscope to complete this simulated operating condition test.

[0138] In some embodiments, the method further includes: during the test, acquiring temperature data at various points of the capacitor under test collected by a multi-channel temperature rise tester, and voltage and current data collected by an oscilloscope in real time; processing the acquired multiple sets of data in real time using a preset intelligent analysis algorithm; identifying the temperature rise trend and electrical parameter fluctuation characteristics of the capacitor under test using the intelligent analysis algorithm; if the temperature rise rate of the capacitor under test exceeds a preset threshold, or the electrical parameter fluctuation exceeds a preset safety range, automatically adjusting the output amplitude of the high-frequency ripple power supply and the output value of the fundamental voltage, and simultaneously adjusting the environmental parameters of the high-temperature humidity chamber until the operating parameters of the capacitor under test return to the safe range; after the test, comprehensively analyzing all the test data collected throughout the process using the intelligent analysis algorithm, and outputting the reliability assessment results and service life prediction results of the capacitor under test under the corresponding operating conditions.

[0139] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the power electronic thin-film capacitor simulated operating condition test method provided in any embodiment of this application.

[0140] The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, SmartMediaCard (SMC), SecureDigital (SD) card, or FlashCard equipped on the computer device.

[0141] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for simulating operating conditions testing of power electronic thin-film capacitors, characterized in that, include: After the capacitor under test is fixed by the tooling fixture, it is placed in a high temperature and humidity chamber with adjustable temperature and humidity. The target test temperature and humidity are set and maintained in a high-temperature and humidity chamber to simulate the actual working environment of the capacitor under test. A fundamental voltage matching the actual operating conditions is applied to the two terminals of the capacitor under test by an adjustable power supply. The fundamental voltage is either a power frequency AC voltage or a DC voltage. A high-frequency ripple current matching the actual operating conditions is superimposed on the capacitor under test by a high-frequency ripple power supply to reproduce the operating conditions of the capacitor under test under actual operation, which is the fundamental voltage plus ripple current. During the test, the temperature data of multiple points of the capacitor under test were collected in real time by a multi-channel temperature rise tester, and the voltage and current parameters across the capacitor under test were monitored in real time by an oscilloscope. After the preset total test time is reached, the power supply and test equipment are shut down in sequence, and the test data is exported to complete the simulated working condition test.

2. The method according to claim 1, characterized in that, The process of fixing the capacitor under test using a fixture and placing it in a high-temperature and humidity-controlled chamber with adjustable temperature and humidity includes: The capacitor under test is welded and fixed on a printed circuit board fixture with double-sided copper foil and full glass fiber board as the carrier. One end of the multi-strand high-temperature resistant copper wire is welded to the pad of the printed circuit board, and the other end of the multi-strand high-temperature resistant copper wire is fixedly connected to the conductive adapter. Place the fixture with the capacitor under test inside the high temperature and humidity chamber and fix it to the insulating support plate. Secure each conductive adapter to the output terminals of the adjustable power supply and the high-frequency ripple power supply to complete the clamping and electrical connection of the capacitor under test.

3. The method according to claim 1, characterized in that, The process of setting and maintaining the target test temperature and humidity in a high-temperature and humidity chamber to simulate the actual working environment of the capacitor under test includes: Close and lock the door of the high temperature and humidity chamber. Based on the actual application conditions of the capacitor under test, set the target test temperature, target test humidity, and total test duration in the high temperature and humidity chamber. Start the high temperature and humidity chamber and monitor the ambient temperature and humidity inside the chamber in real time. After the temperature and humidity inside the chamber stabilize to reach the target test temperature and target test humidity, maintain the environmental parameters inside the chamber to stabilize and complete the simulation of the working environment of the capacitor under test.

4. The method according to claim 1, characterized in that, The step of applying a fundamental voltage matching the actual operating conditions to the two terminals of the capacitor under test via an adjustable power supply includes: Select the appropriate high-power AC power supply or high-power DC power supply as the selected adjustable power supply according to the actual operating conditions of the capacitor under test, and set the fundamental voltage output parameters that match the actual operating conditions in the selected adjustable power supply. Start the selected adjustable power supply to output a stable fundamental voltage to the two terminals of the capacitor under test; The fundamental voltage applied to the two terminals of the capacitor under test is detected in real time using an oscilloscope. If the deviation between the detected fundamental voltage and the preset first target parameter is not within the first preset range, the fundamental voltage output parameter of the adjustable power supply is adjusted in real time so that the deviation between the detected fundamental voltage and the preset first target parameter is within the first preset range.

5. The method according to claim 1, characterized in that, The process of superimposing a high-frequency ripple current, with adjustable frequency and value matching the actual operating conditions, onto the capacitor under test via a high-frequency ripple power supply to reproduce the ripple current experienced by the capacitor under test during actual operation includes: Based on the actual operating conditions of the capacitor under test, set the frequency and current parameters of the high-frequency ripple current in the high-frequency ripple power supply to match the actual operating conditions. Start the high-frequency ripple power supply to output a stable high-frequency ripple current superimposed on the two poles of the capacitor under test; The frequency and current values ​​of the high-frequency ripple current flowing through the capacitor under test are detected in real time using an oscilloscope. If the deviation between the preset second target parameter and the detected frequency value is not within the second preset range, and the deviation between the preset third target parameter and the detected current value is not within the third preset range, the output parameters of the high-frequency ripple power supply are adjusted in real time so that the deviation between the second target parameter and the detected frequency value is within the second preset range, and the deviation between the third target parameter and the detected current value is within the third preset range.

6. The method according to claim 1, characterized in that, During the test, a multi-channel temperature rise tester is used to collect temperature data at multiple points on the capacitor under test in real time, including: Temperature acquisition sensors are fixed at multiple target test points of the capacitor under test, and the signal output terminals of all temperature acquisition sensors are connected to the corresponding input ports of the multi-channel temperature rise tester. Throughout the test, the temperature data of each target test point of the capacitor under test was collected and recorded in real time at a preset acquisition frequency using a multi-channel temperature rise tester, while the ambient temperature data inside the high-temperature humidity chamber was collected simultaneously.

7. The method according to claim 1, characterized in that, The method of real-time detection of the voltage and current parameters across the capacitor under test using an oscilloscope includes: Connect the voltage acquisition probe of the oscilloscope to the first signal channel of the oscilloscope, and connect the test terminals of the voltage acquisition probe to the two electrodes of the capacitor under test respectively. Connect the current acquisition probe of the oscilloscope to the second signal channel of the oscilloscope, and place the sensing end of the current acquisition probe on the current loop of the capacitor under test. Throughout the test, the voltage waveform and voltage value across the capacitor under test, as well as the current waveform, current value, and frequency value flowing through the capacitor under test, are detected and displayed in real time using an oscilloscope.

8. The method according to claim 1, characterized in that, After the preset total test time is reached, all power supplies and test equipment are turned off sequentially, and the test data is exported to complete the simulated operating condition test, including: Once the preset total test duration is reached, first turn off the high-frequency ripple power supply to stop outputting high-frequency ripple current to the capacitor under test. Turn off the power supply providing the fundamental voltage and stop outputting the fundamental voltage to the capacitor under test; After the capacitor under test is fully discharged, the high temperature and humidity chamber is turned off. The remaining voltage across the capacitor under test is monitored. If the remaining voltage obtained in the preset number of samplings is lower than the preset safety voltage, the capacitor under test is determined to be fully discharged. Turn off the oscilloscope and multi-channel temperature rise tester in sequence; Export and store the temperature data recorded by the multi-channel temperature rise tester and the voltage and current waveform data recorded by the oscilloscope to complete this simulated working condition test.

9. The method according to claim 1, characterized in that, The method further includes: During the test, the temperature data of each point of the capacitor under test collected by the multi-channel temperature rise tester and the voltage and current data collected by the oscilloscope are acquired in real time. The acquired data are processed in real time through a preset intelligent analysis algorithm. The intelligent analysis algorithm identifies the temperature rise trend and electrical parameter fluctuation characteristics of the capacitor under test. If the temperature rise rate of the capacitor under test exceeds the preset threshold or the electrical parameter fluctuation exceeds the preset safety range, the output current value and fundamental voltage value of the high frequency ripple power supply are automatically adjusted, and the environmental parameters of the high temperature and humidity chamber are adjusted simultaneously until the operating parameters of the capacitor under test return to the safe range. After the test, all the test data collected throughout the process are comprehensively analyzed by intelligent analysis algorithms, and the reliability assessment results and service life prediction results of the tested capacitor under the corresponding operating conditions are output.

10. A computer device, characterized in that, The computer device includes a memory and a processor; The memory is used to store computer programs; The processor is configured to execute the computer program and, in executing the computer program, implement the method as described in any one of claims 1 to 9.

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