Test working condition management and control method and device for power module

Abstract

This application relates to a method and apparatus for controlling the test conditions of a power module. The method includes: obtaining an edited test condition file during the test condition editing stage of the power module; the test condition file includes multiple test current values ​​and corresponding preset durations; predicting the stable temperature at the crimping point during testing based on the test current value for each current level among the multiple levels; the crimping point is the location where the copper busbar in the test equipment is crimped with the power module; comparing the difference between the initial crimping temperature and the stable temperature corresponding to the test current value to determine the temperature change trend; predicting the end-of-segment temperature based on the temperature change trend and the preset duration; the end-of-segment temperature is the temperature at the crimping point after continuous testing of the test current value for the preset duration; and verifying the rationality of the test condition file based on the end-of-segment temperature. This method can improve the rationality of the test condition file verification.

Description

Technical Field

[0001] This application relates to the field of semiconductor testing technology, and in particular to a method and apparatus for controlling the test conditions of a power module. Background Technology

[0002] In the field of semiconductor testing, the testing of power modules (such as IGBTs, SiC, and other power semiconductor devices) is a crucial step in ensuring their performance and reliability. For mass-production power module testing, to balance testing efficiency and the needs of large-scale production, the connection between the testing equipment and the power module typically does not use traditional methods such as screw fixing (these methods are time-consuming to install and remove and are not suitable for the pace of mass production). Instead, a copper busbar crimping method is used to achieve electrical connection—mechanical pressure is used to make the copper busbar and the power module electrodes make tight contact, which can meet the requirements of high current transmission and improve testing turnaround efficiency.

[0003] However, the copper busbar crimping method has significant drawbacks: the contact resistance at the crimp point is much higher than that of rigid connections such as screw fixing, and it is prone to fluctuations due to factors such as the stability of the crimping force and oxidation of the contact surface. In power module testing, the test current is usually large (hundreds to thousands of amperes). According to Joule's law, a large current passing through the contact resistance at the crimp point will generate a large amount of Joule heat, causing the temperature at the crimp point to rise rapidly. If the accumulated heat cannot be dissipated in time, it may cause local melting of the copper busbar, short circuit in the test circuit, or even damage to the test equipment (such as the drive circuit), which not only increases equipment maintenance costs but also affects mass production schedules due to test interruptions.

[0004] Therefore, to avoid excessively high temperatures at the crimping point during actual testing, the rationality of the test current data needs to be verified when editing the power module's operating condition file. Some solutions incorporate peak current verification and multi-stage time limit verification during the power module's operating condition file editing phase. Peak current verification limits the user-edited test current value from exceeding the system's preset peak current. Multi-stage time limit verification limits the duration set by the user for each test current value from exceeding the preset maximum allowable duration.

[0005] However, the operating condition files edited based on the above verification methods are often unreasonable, leading to problems such as excessively high temperatures at the crimping points or low testing efficiency during actual testing. Therefore, there is an urgent need to propose a method to more accurately verify the rationality of the operating condition files. Summary of the Invention

[0006] Therefore, it is necessary to provide a method, apparatus, electronic device, computer-readable storage medium, and computer program product for controlling the test conditions of power modules that can improve the rationality of the verification of operating condition documents, in order to address the above-mentioned technical problems.

[0007] Firstly, this application provides a method for controlling the test conditions of a power module. The method includes: during the power module's test condition editing stage, obtaining an edited test condition file; the test condition file includes multiple test current values ​​and corresponding preset durations; for each current test current value among the multiple test current values, predicting the stable temperature at the crimping point during testing based on the test current value; the crimping point is the location where the copper busbar in the test equipment is crimped with the power module; comparing the difference between the initial crimping temperature and the stable temperature corresponding to the test current value to determine the temperature change trend; predicting the end-of-segment temperature based on the temperature change trend and the preset duration; the end-of-segment temperature is the temperature at the crimping point after continuous testing with the test current value for the preset duration; and verifying the rationality of the test condition file based on the end-of-segment temperature.

[0008] Secondly, this application provides a test condition control device for a power module, the device comprising:

[0009] The acquisition module is used to acquire the edited operating condition file during the test condition editing phase of the power module; the operating condition file includes test current values ​​for multiple ranges and corresponding preset durations;

[0010] The temperature prediction module is used to predict the stable temperature at the crimping point during testing based on the test current value of each current range among multiple ranges; the crimping point is the crimping position between the copper busbar and the power module in the test equipment.

[0011] The trend prediction module is used to compare the difference between the initial crimping temperature and the stable temperature corresponding to the test current value to determine the temperature change trend.

[0012] The temperature prediction module is also used to predict the end temperature of the segment based on the temperature change trend and the preset duration; the end temperature is the temperature at the crimping point after the test current value has been continuously tested for the preset duration.

[0013] The operating condition verification module is used to verify the rationality of the operating condition file based on the end-of-segment temperature predicted by the temperature prediction module.

[0014] Thirdly, this application also provides an electronic device. The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the embodiments of this application.

[0015] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps in the embodiments of this application.

[0016] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps in the embodiments of this application.

[0017] The aforementioned power module test condition control method, device, electronic equipment, computer-readable storage medium, and computer program product, during the test condition editing stage, predict the stable temperature corresponding to the test current value for each range, and determine the temperature change trend based on the difference between the predicted stable temperature and the initial crimping temperature corresponding to that test current value. Furthermore, based on this temperature change trend and the preset duration corresponding to that range, the end-of-segment temperature at the crimping point under each current value is predicted, which can more effectively avoid excessively high crimping temperatures, thereby more accurately verifying the rationality of the test condition file. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a test condition control method for a power module in one embodiment.

[0019] Figure 2 This is a schematic diagram of the fitting process for the heating formula in one embodiment;

[0020] Figure 3 This is a schematic diagram of the cooling formula fitting process in one embodiment;

[0021] Figure 4 This is a schematic diagram illustrating the principle of data acquisition in one embodiment;

[0022] Figure 5 This is a schematic diagram of the fitting process for the stable temperature calculation formula in one embodiment;

[0023] Figure 6 This is a flowchart illustrating the test condition control method for the power module in another embodiment;

[0024] Figure 7 This is a block diagram of a test condition control device for a power module in one embodiment;

[0025] Figure 8 This is a diagram of the internal structure of an electronic device in one embodiment. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] During the operation condition file editing phase, users can edit test current values ​​for multiple ranges and set the corresponding duration for each range. The electronic equipment will then perform peak current verification and multi-range time limit verification on the edited operation condition file.

[0028] During peak current verification, if the test current value edited by the user exceeds the system's preset peak current (e.g., 500A), the host computer will immediately pop up an alarm and prohibit saving the operating condition file to prevent the excessive peak current from being written into the test process.

[0029] In the multi-level time limit verification, the system presets multiple sets of "test current value - maximum allowable duration" correspondences (e.g., 100A corresponds to 50 seconds, 200A corresponds to 30 seconds, etc.). When the user edits the operating condition, the host computer verifies it in real time. If the duration corresponding to a certain level exceeds the corresponding maximum allowable duration (for example, editing the duration of 200A to 60 seconds exceeds the preset maximum allowable duration of 50 seconds), the operating condition is deemed invalid and saving is prohibited.

[0030] Only after both of the above checks pass can the operating condition file be saved and used for testing. During actual testing, the system only executes the tests according to the edited operating condition file, without any other intervention, until the process set in the operating condition file ends or a hardware failure (such as a fuse) causes a forced shutdown. This approach will lead to the following problems:

[0031] Problem 1: Protection is delayed and cannot cope with dynamic operating conditions.

[0032] The time limit during the editing phase (i.e., the maximum allowable duration) is a fixed value preset based on the "ideal contact resistance." However, in actual testing, the contact resistance at the copper busbar crimping point can dynamically change due to factors such as fluctuations in crimping force, oxidation of the contact surface, and dust adhesion (for example, insufficient crimping force in a certain test may lead to increased contact resistance). In some special cases, even if the edited current value and duration (e.g., 200A corresponds to 50 seconds) meet the limits, the actual heat generation rate may be much higher than the preset scenario. The crimping point may overheat within 50 seconds, but the system will still execute the process set in the operating condition file until hardware failure occurs, at which point it will passively stop, resulting in a complete delay in protection.

[0033] Problem 2: Excessive restrictions lead to inefficiency.

[0034] To cover the "worst-case contact resistance" scenario, the preset "current-time" limit is usually conservative (e.g., 200A for 50 seconds, while in most normal crimping conditions it can safely last for 60 seconds). However, this limit must be strictly followed during the editing stage, resulting in a large number of tests being "prematurely terminated" before the actual overheating risk is reached, significantly reducing the turnaround efficiency of mass production testing and conflicting with the needs of large-scale production.

[0035] Question 3: Setting multiple parameters is difficult.

[0036] Users need to rely on their experience and manually fill in the test current values ​​and corresponding durations for multiple speed ranges based on the "ideal heat generation hypothesis." The more detailed the speed range division, the more parameters need to be manually set. This idealized hypothesis operation is complex, and users need to spend a lot of time debugging the parameters for each speed range. The more speed ranges there are, the greater the debugging difficulty.

[0037] In response to the above problems, such as Figure 1 As shown, in some embodiments, a method for controlling the test conditions of a power module is provided. This method can be implemented through an electronic device, which may be a host computer. The method specifically includes the following steps:

[0038] S11, during the power module's test condition editing phase, obtain the edited condition file; the condition file includes multiple test current values ​​and corresponding preset durations.

[0039] The test current value refers to the current value applied to the power module during the testing phase. The preset duration corresponding to each test current value refers to the duration for which the power module is tested based on that test current value.

[0040] For example, 100A / 50s, 200A / 30s, 300A / 20s...500A / 2s represent different test current values ​​and their corresponding preset durations. Taking 200A / 30s as an example, during the power module testing phase, a current of 200A will be applied to the power module for 30 seconds to determine the relevant test results under this condition.

[0041] S12 predicts the stable temperature at the crimping point during testing based on the test current value for each current gear among multiple gears; the crimping point is the crimping position between the copper busbar and the power module in the testing equipment.

[0042] For each test current value in the operating condition file, steps S12 to S15 will be executed. Each range for which steps S12 to S15 are executed is the current range.

[0043] In some embodiments, the working condition file is preprocessed, for example, split into a one-dimensional array WorkData=[[I1,t 保1 ],[I2,t 保2 ], ... ]. I represents the test current value, I1 or I2 represent the first or second test current value respectively, t 保 Indicates the preset duration or duration of hold, t 保1 or t 保2These represent the preset duration corresponding to the first or second test current value, respectively. Furthermore, the one-dimensional array WorkData can be traversed, and for each element [I,t]... 保 Perform steps S12 to S15.

[0044] For example, in the event of a power outage and restart, the data before the power outage can be automatically loaded, and processing can continue based on the remaining operating conditions (i.e., the remaining test current value to be tested), thus avoiding test interruption.

[0045] Predicting the stable temperature at the crimping point during testing based on the test current value refers to predicting the stable temperature that the crimping point may reach when the power module is tested with the current test current value applied during the actual testing phase, as predicted during the test condition editing stage.

[0046] In some examples, electronic devices can use test current values ​​to predict the stable temperature by substituting them into a pre-trained temperature prediction model. This temperature prediction model is trained using a neural network model with a combination of sample data. The sample data combination includes sample current values ​​and the stable temperature at the crimp point. Through iterative training with this sample data combination, the final temperature prediction model gains the ability to predict the stable temperature.

[0047] In other examples, the electronic device may also substitute the test current value into a pre-fitted formula for calculating the steady-state temperature. See the description below for details.

[0048] S13. Compare the difference between the initial crimping temperature and the stable temperature corresponding to the test current value to determine the temperature change trend.

[0049] The initial crimping temperature refers to the temperature at the crimping point when a test current is applied to the power module.

[0050] When applying test current values ​​to the power module in stages, the initial crimping temperature corresponding to the first test current value can be the ambient temperature. The initial crimping temperature for test current values ​​other than the first one is the end temperature after testing the previous test current value. For example, 200A / 30s → 300A / 20s: if 200A is applied and maintained for 30s, and the temperature is 30℃, then the initial crimping temperature corresponding to the next test current value of 300A will be 30℃.

[0051] When the initial pressing temperature T is less than or equal to the stable temperature T1, the temperature trend is upward. When the initial pressing temperature T is greater than the stable temperature T1, the temperature trend is downward.

[0052] S14, predicts the end temperature of the segment based on the temperature change trend and the preset duration.

[0053] The end-of-segment temperature is the temperature at the crimp point after the test current value has been continuously tested for a preset duration. The initial crimp temperature, stable temperature, and end-of-segment temperature in steps S12 to S14 are all predicted during the test condition editing stage, and are not the temperatures measured after the actual test current value is loaded onto the power module.

[0054] In some embodiments, the end-of-segment temperature is calculated based on a temperature change formula corresponding to the temperature change trend. The temperature change formula is obtained by fitting temperature change data corresponding to multiple experimental current values ​​in the experimental test; wherein, the temperature change data corresponding to each experimental current value includes the temperature value at each time point when the crimping point changes with time from the target initial temperature during the experimental test based on the experimental current value.

[0055] The experimental current value refers to the current applied during the testing of the power module in the experimental phase. Experimental testing refers to the process of testing the power module during the experimental phase.

[0056] In this embodiment, "current-time-temperature" data is first collected during the experimental phase, and a corresponding formula with predictive capabilities is fitted, such as at least one formula for temperature change or stable temperature calculation. Then, during the test condition editing phase, the pre-fitted formula is used to predict the end-of-segment temperature, and the edited test condition file is validated for reasonableness based on the predicted end-of-segment temperature. After successful validation, the test condition file is used to perform substantive testing on the power module.

[0057] Specifically, during the experimental phase, multiple experimental current values ​​are set. Before conducting experiments based on these current values, the temperature at the crimping point is controlled to the target initial temperature. Then, starting from the target initial temperature, experiments are conducted based on each experimental current value, and the temperature at the crimping point is recorded at each time point as the temperature changes over time from the target initial temperature, obtaining the temperature change data corresponding to each experimental current value. Furthermore, a temperature change formula is obtained by fitting the temperature change data corresponding to each of the multiple experimental current values. For example, a univariate temperature change formula is fitted based on the temperature change data corresponding to each experimental current value; a bivariate temperature change formula is obtained by performing multivariate regression fitting based on the univariate temperature change formulas corresponding to multiple experimental current values.

[0058] For example, Figure 2 As shown, the experimental current values ​​are divided into multiple ranges from 0A to the peak current, according to a preset step size, such as 0A, 50A, 100A…500A. Among them, the peak current (I… peakThe maximum allowable test current is 50A, used to limit the upper limit of the current and prevent damage to the equipment due to exceeding the range. The preset step size is the current gradient interval (e.g., 50A) used to divide the experimental current values ​​into experimental phases (equivalent to dividing the test conditions into experimental phases). The smaller the preset step size, the higher the accuracy of the formula.

[0059] In some examples, the temperature change formula corresponding to the upward trend of temperature is the heating formula y=F(x,t), where x is the current value, t is the time, y is the temperature at the crimping point, and F() is the heating function.

[0060] The target initial temperature corresponding to the experimental current value for each setting is the ambient temperature. The purpose of fitting the temperature rise formula is to reflect the temperature rise of the crimping point over time when a certain experimental current value is applied to the power module, starting from the ambient temperature. Temperature rise tests can be performed by iterating through the experimental current values ​​for each setting; each experimental current value used in the current temperature rise test is the experimental current value for that setting.

[0061] like Figure 2 As shown, before performing a temperature rise test on the current setting, the temperature of the crimping point is controlled to be at ambient temperature, for example, through natural cooling. This ensures that the target starting temperature for each experimental current value is equal to the stable temperature (i.e., ambient temperature) corresponding to 0A.

[0062] Furthermore, the experimental current value for the current setting is loaded for a temperature rise test, and the time t and temperature y are recorded in real time. That is, "time-temperature" data or temperature change data is recorded. During the temperature rise test, it can be determined whether the temperature is stable (e.g., temperature fluctuation at the crimping point ≤1℃ for 30 consecutive seconds). If so, all time-temperature data corresponding to the experimental current value is saved, and the temperature rise test corresponding to that experimental current value is stopped. If not, it is determined whether the protection temperature has been exceeded. If the protection temperature (T) is exceeded... protect If the temperature exceeds the protection temperature, the time point can be recorded. If the protection temperature is not exceeded, the time t and temperature y can be recorded in real time, and the test can continue. In other words, the test corresponding to the experimental current value will stop when the temperature stabilizes or exceeds the protection temperature. The protection temperature is a pre-set safe temperature threshold for the crimping joint. The protection temperature can be set based on the copper busbar material of the crimping joint (melting point 1083℃), heat dissipation conditions, and the equipment's tolerance limit (e.g., 50%-80% of the melting point).

[0063] Continue reading Figure 2After stopping the temperature rise test of the current value of the current gear, it can be determined whether the test of the current values ​​of all gears has been completed. If not, the test current value of the next gear is used as the test current value of the current gear, and the process returns to before executing the temperature rise test of the current value of the current gear. The temperature of the crimping point is controlled at the ambient temperature and subsequent steps are performed until the test of the current values ​​of all gears is completed.

[0064] Furthermore, a heating formula can be obtained by fitting the temperature change data (i.e., time-temperature data) corresponding to the experimental current values ​​at multiple levels.

[0065] like Figure 2 As shown, if the test of the experimental current values ​​for all gears is completed, the temperature rise formula can be obtained by sequentially performing first-order and second-order fitting based on the temperature change data corresponding to the experimental current values ​​for multiple gears. Then, this temperature rise formula is saved.

[0066] Specifically, the heating formula can be fitted using the following steps:

[0067] (1-1) Perform first-order fitting: For each experimental current value, a univariate heating formula (i.e., a single-current univariate formula) can be fitted based on its corresponding temperature change data (i.e., "time-temperature" data), such as y=a*(1-e -t / b )+c, where a, b, and c are the fitting coefficients for the experimental current value, and y is the temperature at the pressing point. It should be understood that t is a variable in the univariate heating formula.

[0068] (1-2) Second-order fitting: Integrate the univariate heating formulas corresponding to all experimental current values, and quasi-bivariate heating formulas (i.e., total current bivariate formulas) through multivariate regression, such as y=25+0.001x 2 t(1- e -t / 20 ), where 25℃ is the ambient temperature, x is the current value, and t is the time. In the binary heating formula, both x and t are variables.

[0069] In other examples, the temperature change formula corresponding to the temperature decrease trend is the cooling formula y=H(x, t), where x is the current value, t is time, y is the temperature at the crimp point, and H() is the cooling function. The target initial temperature corresponding to each experimental current value is the protection temperature. The purpose of fitting the cooling formula is to reflect the temperature decrease of the crimp point over time when a certain experimental current value is applied to the power module, starting from the protection temperature. Cooling experiments can be performed by iterating through the experimental current values ​​at various levels; each experimental current value used in the current cooling experiment is the experimental current value for that level.

[0070] like Figure 3As shown, before performing a cooling test on the current setting, the crimping point is preheated to the protection temperature (i.e., the target initial temperature corresponding to the current setting is the protection temperature). For example, the tester can be controlled to continuously output peak current to the power module until the temperature of the crimping point is preheated to the protection temperature and stabilizes (e.g., the temperature fluctuation at the crimping point is ≤1℃ for 30 seconds). Then, the current setting's current value is loaded for the cooling test, and the time t and temperature y (i.e., temperature change data) are recorded in real time. During the cooling test, it can be determined whether the temperature is stable. If so, all time-temperature data corresponding to the current setting is saved, and the cooling test corresponding to that current setting is stopped. If not, it is determined whether the protection temperature is exceeded. If the protection temperature is exceeded, it means that this part of the time and temperature data is unusable, and an anomaly mark can be added for subsequent anomaly checks. If the protection temperature is not exceeded, the time t and temperature y are recorded in real time, and the test continues. In other words, the cooling test corresponding to that current setting is stopped until the temperature stabilizes or exceeds the protection temperature.

[0071] It should be noted that, Figure 3 The document describes the steps for obtaining multiple experimental current values ​​from 0A to the peak current by dividing the current into preset steps. This is intended to make the entire process of fitting the cooling formula look more complete. However, it does not mean that the cooling formula fitting and heating formula fitting need to repeat this step. In fact, only one division is needed. The cooling formula fitting and heating formula fitting processes can share the experimental current values ​​of the multiple divisions.

[0072] Please continue reading. Figure 3 After stopping the cooling test corresponding to the current current value, it can be determined whether the test of all current values ​​has been completed. If not, the test current value of the next current value is used as the test current value of the current current value, and the process returns to preheating the crimping joint to the protection temperature and subsequent steps before performing the cooling test on the current current value, until the test of all current values ​​is completed. If yes, a cooling formula can be obtained by performing first-order and second-order fitting on the temperature change data corresponding to the test current values ​​of multiple current values, and this cooling formula is saved. That is, the cooling formula is obtained by fitting the formula based on the temperature change data corresponding to the test current values ​​of multiple current values ​​in the cooling test.

[0073] Specifically, the cooling formula can be fitted using the following steps:

[0074] (2-1) Perform first-order fitting: For each experimental current value, a univariate cooling formula can be fitted based on its corresponding temperature change data (i.e., "time-temperature" data), such as y = T protect * e-t / d +g, where d and g are fitting coefficients, and y is the temperature at the compression point. For example, g is obtained with e as the base and the experimental current value as the exponent. It should be understood that t is a variable in the univariate cooling formula.

[0075] (2-2) Second-order fitting: Integrate the univariate cooling formulas corresponding to all experimental current values, and quasi-bivariate cooling formulas through multivariate regression, such as y=200 e -t / (5x) +25(1-e -t / (5x) In the binary cooling formula, x is the current value and t is the time. Both x and t are variables.

[0076] As mentioned above, temperature and current data are required in heating and cooling experiments. This data is obtained from the corresponding temperature and current sensors. For example, if a sensor malfunctions, such as a temperature / current data fluctuation exceeding a preset range (e.g., ±50%), the system can automatically switch to a "conservative mode" (current current drops to 80%) and trigger an alarm to avoid misjudgment.

[0077] like Figure 4 As shown, the host computer can send control signals to the lower-level control module of the electric drive. The lower-level control module of the electric drive can respond to the control signals to control the drive, so that the current drive module drives current to the test equipment, thus creating a current loop. A current sensor is connected in series in the test loop, thus collecting current data. Furthermore, the current sensor can directly feed back current data to the host computer, or it can indirectly feed back current data to the host computer through the lower-level control module of the electric drive. The test equipment includes a copper busbar crimping structure, and there is a copper busbar crimping point (also referred to as the crimping point) between it and the power module. A temperature sensor mounted on the copper busbar crimping point collects the temperature data of the crimping point and feeds the temperature data back to the host computer.

[0078] S15, perform a rationality check on the operating condition file based on the end-of-section temperature.

[0079] Specifically, the end temperature of the section is compared with the preset protection temperature, and at the end temperature T... 末 > If the reasonableness check of the operating condition document fails when the temperature is protected, saving or editing the operating condition document is prohibited. In addition, a pop-up alarm can be displayed saying "There is a risk of over-temperature in the operating condition".

[0080] At the end of the section temperature T 末 If the temperature is ≤ the protection temperature, the end temperature of this segment can be updated to the starting crimping temperature T corresponding to the test current value of the next range (i.e., update T=T). 末 Then, the next gear is used as the new current gear for processing. That is, steps S12 to S14 are continued.

[0081] In some examples, if the reasonableness check passes after testing the test current value for each range, it is permissible to save the operating condition file.

[0082] In other examples, after testing the current value for each range (e.g., after iterating through the WorkData array), a temperature trend graph is plotted with time on the X-axis and temperature on the Y-axis. The temperature trend graph can show the temperature change trend, for example, showing the temperature rising from 25℃ to 105℃ in the 0s-40s period, and rising to 200℃ in the 40s-75s period. If the temperature trend graph confirms that there are no overheating periods (i.e., no time periods where the temperature at the crimping point exceeds the protection temperature), the operating condition file can be saved.

[0083] In the above method, during the operating condition editing stage, the stable temperature corresponding to the test current value of each gear is predicted, and the temperature change trend is determined based on the difference between the predicted stable temperature and the initial crimping temperature corresponding to the test current value. Furthermore, based on this temperature change trend and the preset duration corresponding to that gear, the end-of-segment temperature at the crimping point under each current value is predicted, which can more effectively avoid excessively high crimping temperatures, thereby more accurately verifying the rationality of the operating condition file.

[0084] In this way, operating condition data that could lead to excessively high temperatures at the crimping point can be removed during the operating condition editing stage, avoiding the need to stop testing only after hardware damage has occurred in actual testing, thus mitigating or reducing protection lag to some extent. Furthermore, traditional methods rely on "current-time" limits for operating condition verification, which is a static control approach detached from the core risk indicator—crimping point temperature—and prone to over-limitation and inefficiency. The proposed solution, through dynamic temperature prediction, verifies the operating condition file based on the core risk indicator of crimping point temperature, making the protection logic strongly correlated with actual risk points. This enables precise control of the test current, ensuring that the copper busbar crimping point temperature does not exceed the safety threshold, and mitigating the problem of over-limitation to some extent, thus improving testing efficiency. Moreover, the pre-predicted temperature provides users with a valuable reference for editing, allowing for more efficient and convenient debugging of the set operating condition data.

[0085] In some embodiments, step S14, which predicts the end temperature of the segment based on the temperature change trend and the preset duration, includes: calculating the compensation duration based on the temperature change formula corresponding to the temperature change trend; the compensation duration is the time required for the crimping point to change from the target initial temperature to the starting crimping temperature; determining the target duration based on the compensation duration and the preset duration; and substituting the target duration into the temperature change formula to calculate the end temperature of the segment.

[0086] In this embodiment, the temperature change data of each experimental current value used to fit the temperature change formula (heating formula / cooling formula) is collected starting from a unified target initial temperature (ambient temperature / protection temperature). Therefore, the temperature change formula is suitable for predicting the temperature after a certain period of time, starting from the target initial temperature. However, in actual testing, the initial pressing temperature (i.e., the current temperature at the pressing point) of each test setting is not necessarily the target initial temperature. For example, after testing at one setting, the pressing point has already heated up, and the current temperature (i.e., the initial pressing temperature) at the next setting is no longer the ambient temperature. In this case, if the preset duration corresponding to the test current value of a certain setting is directly input into the temperature change formula for prediction, the predicted temperature will not be accurate enough.

[0087] Therefore, based on the temperature change formula corresponding to the temperature change trend, the time required for the crimping point to change from the target initial temperature to the initial crimping temperature corresponding to the test current value of the current setting is calculated and recorded as the compensation time. Then, the target time is obtained by summing the compensation time and the preset duration corresponding to the current setting. Substituting the target time into the temperature change formula allows for a more accurate prediction of the end-of-segment temperature corresponding to the test current value of the current setting.

[0088] In some embodiments, when the temperature change trend is an upward trend, the temperature change formula is a heating formula, and the target initial temperature is the ambient temperature. The first compensation duration Δt1=F can be calculated using the heating formula. -1 (I, T 环 ,T), where I is the test current value of the current range, and T 环 It is the ambient temperature, T is the starting crimp temperature corresponding to the test current value of the current range; the first compensation duration Δt1 starts from the ambient temperature T. 环 The time required to raise the test current value I to the starting crimp temperature T corresponding to the current gear level.

[0089] Therefore, the target duration t1 = t can be calculated. 保 +Δt1, where t 保 This is the preset duration corresponding to the test current value I at the current gear level. Further, substituting the target duration t1 into the temperature rise formula, the final temperature T is calculated. 末 =F(I,t1).

[0090] In other embodiments, when the temperature change trend is a decreasing trend, the temperature change formula is a cooling formula, and the target initial temperature is a preset protection temperature. The second compensation duration Δt2=H can be calculated using the cooling formula. -1 (I, T protect ,T), where I is the test current value of the current range, and Tprotect This is the protection temperature, where T is the initial crimping temperature corresponding to the test current value of the current range. The second compensation duration Δt2 is from the protection temperature T. protect The time required to reduce the test current value I to the starting crimp temperature T corresponding to the current gear level.

[0091] Therefore, the target duration t2 = t can be calculated. 保 +Δt2, where t 保 This is the preset duration corresponding to the test current value I at the current gear level. Further, substituting the target duration t2 into the cooling formula, the final temperature T is calculated. 末 =H(I,t2).

[0092] In some embodiments, the stable temperature in step S12 is calculated by substituting the test current value into a pre-fitted stable temperature calculation formula. The stable temperature calculation formula is obtained by performing a univariate regression fitting based on the target stable temperature corresponding to each experimental current value; the target stable temperature corresponding to each experimental current value is determined based on a first stable temperature and a second stable temperature corresponding to the experimental current value; the first stable temperature is the stable temperature corresponding to the experimental current value in the heating experiment test used to fit the heating formula, and the second stable temperature is the stable temperature corresponding to the experimental current value in the cooling experiment test used to fit the cooling formula.

[0093] As mentioned above, during the experimental phase, heating and cooling experiments can be conducted for each experimental current value. In the heating experiment for each experimental current value, the experimental current value will be continuously applied until the temperature stabilizes. This stable temperature is recorded as the first stable temperature Y corresponding to that experimental current value. 升 In the cooling test of each experimental current value, the experimental current value will be continuously applied until the temperature stabilizes. This stable temperature will be recorded as the second stable temperature Y corresponding to that experimental current value. 降 Therefore, as Figure 5 As shown, the first stable temperature Y for each experimental current value in the heating experiment can be determined. 升 And determine the second stable temperature Y for each experimental current value in the cooling experiment test. 降 Furthermore, the first stable temperature Y corresponding to each experimental current value can be determined. 升 Second stable temperature Y 降 The target stable temperature Y corresponding to each experimental current value is obtained by averaging the values. For example, Y = (Y 升 +Y 降 ) / 2. Then, based on the current-temperature data pairs, the dataset is organized. A univariate regression formula is fitted based on the organized dataset, and the fitted steady-state temperature calculation formula is saved.

[0094] Specifically, the stable temperature calculation formula Y=f(x) can be obtained by fitting the target stable temperature Y corresponding to multiple experimental current values. The purpose of this stable temperature calculation formula is to reflect the relationship between the final stable temperature (thermal equilibrium state) at the crimping point and the current when a certain experimental current value is applied to the power module. For example, the stable temperature calculation formula can be obtained through univariate regression fitting, such as Y=0.002x. 2 +25 reflects the positive correlation between the square of the current x and the steady-state temperature.

[0095] In some examples, after fitting the above formulas, a set of operating condition data can be edited for verification testing to obtain the measured temperature. This verifies the accuracy of the fitted formula. If the deviation between the measured temperature and the temperature predicted by the formula exceeds a preset temperature range (e.g., ±20℃), a recalibration process is triggered, prompting the user to supplement experimental test data and re-perform the experiment to refit the formula. If the temperature deviation does not exceed the preset temperature range, the fitted formula can be used for temperature prediction during the operating condition editing stage.

[0096] like Figure 6 As shown, in one embodiment, another method for controlling the test conditions of a power module is provided, the method comprising the following steps:

[0097] (1) Preprocess the edited working condition file to generate a one-dimensional array. Each element in the one-dimensional array includes the test current value of a gear and the corresponding preset duration.

[0098] (2) Set the initial crimping temperature T to the stable temperature at the crimping point when the current is 0A, and set the total test duration to 0 (i.e., let t 总 =0).

[0099] It should be understood that the stable temperature at the crimp point when the current is 0A is the ambient temperature.

[0100] (3) Traverse the one-dimensional array and obtain the test current value and the corresponding preset duration of the current element.

[0101] (4) Substitute the test current value into the steady-state temperature calculation formula to calculate the corresponding steady-state temperature.

[0102] (5) Determine whether the stable temperature is greater than the corresponding current initial pressing temperature.

[0103] If yes, execute (6); otherwise, execute (9).

[0104] (6) Substitute the test current value, ambient temperature and current initial crimping temperature into the heating formula to calculate the first compensation time.

[0105] (7) Calculate the target duration t1 based on the preset duration and the first compensation duration.

[0106] (8) Substitute the test current value and the target duration t1 into the heating formula to calculate the end temperature of the segment.

[0107] (9) Substitute the test current value, protection temperature and current initial crimping temperature into the cooling formula to calculate the second compensation time.

[0108] (10) Calculate the target duration t2 based on the preset duration and the second compensation duration.

[0109] (11) Substitute the test current value and the target duration t2 into the cooling formula to calculate the end temperature of the segment.

[0110] (12) Determine whether the end temperature of the section is less than or equal to the protection temperature.

[0111] If yes, execute (13); otherwise, execute (16).

[0112] (13) Update the current initial pressing temperature (i.e., let T = T) 末 ), and update the total test duration (i.e., let t) 总 = t 总 +Target duration (t1 or t2)).

[0113] (14) Determine whether the traversal is complete.

[0114] If not, return to execution (3) to continue iterating over the next element in the one-dimensional array. If yes, execute (15).

[0115] (15) Generate a temperature change trend graph to determine whether to save the operating condition file.

[0116] In the temperature change trend graph, the X-axis represents time (the time on the X-axis can be based on t). 总 (Confirmed), the Y-axis represents the temperature at the crimping point.

[0117] (16) A pop-up warning is issued, prohibiting the saving of operating condition files.

[0118] In the above solution, considering the dynamic fluctuation of contact resistance at the copper busbar crimping point, a three-order logic of "parameter preset (peak current, protection temperature, current step size) - actual measurement fitting - trend verification" is used to achieve current control and adapt to individual differences in crimping, thus avoiding efficiency loss or protection failure caused by relying on manual experience.

[0119] To facilitate understanding, a specific example will be used to illustrate the method in this application. Assume that the peak current I is preset. peak =500A, protection temperature T protect=200℃, preset step size γ=100A, ambient temperature 25℃.

[0120] (I) Experimental Phase:

[0121] 1. Heating test

[0122] First, from 0A to 500A (peak current I) peak The current was divided into six experimental current values: 0A, 100A, 200A, 300A, 400A, and 500A, according to a preset step size γ=100A. Then, a temperature rise experiment was conducted for each experimental current value to obtain the temperature change data corresponding to the six experimental current values.

[0123] Taking an experimental current of 100A as an example, t=0s→25℃ (meaning that at 0s, the corresponding temperature is the ambient temperature of 25℃), t=10s→50℃, t=30s→80℃ (stable). That is, with gradual temperature increase, a first-order fit can be performed based on the time-temperature data (i.e., temperature change data) corresponding to 100A to obtain the univariate temperature increase formula y=25+55*(1-e^(-1 / 2)) for the experimental current of 100A. -t / 15 Furthermore, a second-order fit can be performed based on the univariate heating formula corresponding to the six experimental current values ​​to obtain the bivariate heating formula: y = 25 + 0.001x 2 t(1-ee -t / 20 ).

[0124] 2. Cooling Experiment Test

[0125] From 200℃ (protection temperature T) protect To begin, a cooling experiment was conducted on the six experimental current values ​​defined above, and the temperature change data corresponding to the six experimental current values ​​were obtained.

[0126] Furthermore, through first-order and second-order fitting, a binary cooling formula is obtained:

[0127] y=200e -t / (5x) +25(1- e -t / (5x) ).

[0128] 3. Fitting the steady-state temperature calculation formula

[0129] Based on the target stable temperature corresponding to the six experimental current values, the formula for calculating the stable temperature was obtained by fitting: Y = 0.002x 2 +25.

[0130] (II) Test Condition Editing Stage

[0131] Edit operating condition data: "200A / 30s → 300A / 20s". Taking 200A / 30s as an example, 200A is the test current value, and 30s is the corresponding preset duration. Assume the initial temperature is 25℃ (the stable temperature at the crimping point when the current value is 0A, i.e., the ambient temperature).

[0132] First gear or first segment [200A, 30s]:

[0133] Substituting 200A into the steady-state temperature calculation formula: Y = 0.002x 2 In +25, the stable temperature T1 corresponding to 200A is calculated to be 0.002 × 200. 2 +25=105℃≥25℃ (that is, the initial pressing temperature of the first segment is 25℃), so the temperature trend is rising. Using the above binary heating formula based on x=200A, t=30s, the first compensation time Δt1 is calculated, and the target time t1=30s+Δt1.

[0134] Furthermore, using a binary heating formula, the final temperature T of the first stage is predicted based on the test current value of 200A and the target duration t1. 末 =F(200,30s+Δt1), assuming the end temperature T of the first stage. 末 If 105℃ ≤ protection temperature 200℃, then the end temperature T of the first segment can be set. 末 =105℃ is used as the starting temperature for the second section's crimping.

[0135] Second gear or second segment [300A, 20s]:

[0136] Using 300A as the new current test current value for the current gear, and substituting it into the stable temperature calculation formula, the stable temperature T1 corresponding to 300A is calculated as T1 = 0.002 × 300² + 25 = 205℃ ≥ 105℃ (i.e., the initial pressing temperature of the second segment). The temperature trend is also upward. Therefore, using the above binary temperature rise formula based on x = 300A and t = 20s, the new first compensation duration Δt1 is calculated, and the new target duration t1 = 20s + Δt1. Furthermore, using the binary temperature rise formula, based on the new current test current value of 300A and the new target duration t1, the end temperature T of the second gear segment is predicted. 末 =F(300, 20s+Δt1), assuming the end temperature T of the second stage. 末 If the temperature is less than or equal to the protection temperature of 200℃, then stop the test.

[0137] Furthermore, a temperature change trend graph was generated based on the test data. The temperature change trend graph showed that the temperature rose to 105℃ in 0-40s and to 200℃ in 40-75s, without exceeding the over-temperature limit (the protection temperature was not exceeded), and the operating condition data of "200A / 30s→300A / 20s" could be saved.

[0138] Although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. At least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least a portion of steps or stages in other steps.

[0139] Based on the same inventive concept, this application also provides a test condition control device for implementing the power module involved above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more power module test condition control device embodiments provided below can be found in the limitations of the power module test condition control method above, and will not be repeated here.

[0140] In one embodiment, such as Figure 7 As shown, a test condition control device for a power module is provided. The device includes:

[0141] The acquisition module 701 is used to acquire the edited operating condition file during the test condition editing stage of the power module; the operating condition file includes test current values ​​for multiple ranges and corresponding preset durations.

[0142] The temperature prediction module 702 is used to predict the stable temperature at the crimping point during testing based on the test current value of each current range among multiple ranges; the crimping point is the crimping position between the copper busbar and the power module in the test equipment.

[0143] The trend prediction module 703 is used to compare the difference between the initial crimping temperature and the stable temperature corresponding to the test current value to determine the temperature change trend.

[0144] The temperature prediction module 702 is also used to predict the end temperature of the segment based on the temperature change trend and the preset duration; the end temperature is the temperature at the crimping point after the test current value has been continuously tested for the preset duration.

[0145] The operating condition verification module 704 is used to verify the rationality of the operating condition file based on the end-of-segment temperature predicted by the temperature prediction module.

[0146] Each module in the aforementioned power module test condition control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independently of it, or stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of each module.

[0147] In one embodiment, an electronic device is provided, which may be a host computer. The internal structure diagram of the electronic device can be as follows: Figure 8 As shown, this electronic device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for controlling the test conditions of a power module.

[0148] Those skilled in the art will understand that Figure 8 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 electronic device to which the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0149] In one embodiment, an electronic device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the embodiments of this application.

[0150] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the embodiments of this application.

[0151] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the embodiments of this application.

[0152] It should be noted that the user information (including but not limited to user device information, user attribute content, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0153] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processors, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited thereto.

[0154] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. As long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, but should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. The protection scope of this application should be determined by the appended claims.

Claims

1. A method for controlling the test conditions of a power module, characterized in that, The method includes: During the power module's test condition editing phase, the edited test condition file is obtained; the test condition file includes multiple test current values ​​and corresponding preset durations; For each current gear among the multiple gears, predict the stable temperature at the crimping point during testing based on the test current value; the crimping point is the crimping position between the copper busbar and the power module in the testing equipment. The temperature change trend is determined by comparing the difference between the initial crimping temperature corresponding to the test current value and the stable temperature; wherein, the initial crimping temperature corresponding to the test current value of the first gear is the ambient temperature; the initial crimping temperature corresponding to the test current value of other gears is the predicted end temperature after testing based on the test current value of the previous gear. The end-of-segment temperature is predicted based on the temperature change trend and the preset duration; the end-of-segment temperature is the temperature at the crimping point after the preset duration of continuous testing based on the test current value. The rationality of the operating condition file is verified based on the predicted end-of-segment temperature.

2. The method according to claim 1, characterized in that, The predicted end temperature is calculated based on a temperature change formula corresponding to the temperature change trend; the temperature change formula is obtained by fitting the temperature change data corresponding to multiple experimental current values ​​in the experimental test; wherein, the temperature change data corresponding to each experimental current value includes the temperature value at each time point when the crimping point changes with time from the target initial temperature during the experimental test based on the experimental current value.

3. The method according to claim 2, characterized in that, The method of predicting the end temperature of the segment based on the temperature change trend and the preset duration includes: The compensation time is calculated based on the temperature change formula corresponding to the temperature change trend; the compensation time is the time required for the crimping point to change from the target initial temperature to the initial crimping temperature; The target duration is determined based on the compensation duration and the preset duration. The target duration is substituted into the temperature change formula to predict the end-of-segment temperature.

4. The method according to claim 3, characterized in that, When the initial pressing temperature is less than or equal to the stable temperature, the temperature change trend is an upward temperature trend, the temperature change formula is a heating formula, the target initial temperature is the ambient temperature, and the compensation duration is a first compensation duration; the first compensation duration is the time required for the ambient temperature to rise to the initial pressing temperature.

5. The method according to claim 3, characterized in that, When the initial pressing temperature is greater than the stable temperature, the temperature change trend is a temperature decrease trend, the temperature change formula is a cooling formula, the target initial temperature is a preset protection temperature, and the compensation duration is a second compensation duration, which is the time required for the protection temperature to decrease to the initial pressing temperature.

6. The method according to claim 2, characterized in that, Before predicting the end-of-segment temperature based on the temperature change trend and the preset duration, the method further includes: For each experimental current value, before conducting the experimental test based on the experimental current value, the temperature of the crimping point is controlled to the target initial temperature. Starting from the target initial temperature, the experimental test is conducted based on the experimental current value, and the temperature value of the crimping point at each time point is recorded to obtain the temperature change data corresponding to each experimental current value. Based on the temperature change data corresponding to each experimental current value, a univariate temperature change formula corresponding to the experimental current value is fitted. Based on the univariate temperature change formula corresponding to the multiple experimental current values, a bivariate temperature change formula is obtained by performing multivariate regression fitting.

7. The method according to claim 6, characterized in that, Before conducting experimental testing based on the experimental current value, the step of controlling the temperature of the crimping point to the target initial temperature, and then conducting experimental testing based on the experimental current value starting from the target initial temperature, includes: When the temperature change formula is a heating formula, before conducting the experimental test based on the experimental current value, the temperature of the crimping point is controlled to the ambient temperature by natural cooling. Then, starting from the ambient temperature, the experimental test is conducted based on the experimental current value. or, When the temperature change formula is a cooling formula, before conducting experimental tests based on the experimental current value, the power module is continuously tested based on a preset peak current until the temperature at the crimping point of the power module stabilizes at a preset protection temperature. Then, the peak current is stopped from being used for testing, and experimental tests are conducted based on the experimental current value starting from the ambient temperature.

8. The method according to claim 2, characterized in that, The temperature change formula is a pre-fitted heating or cooling formula; the stable temperature is calculated by substituting the test current value into the pre-fitted stable temperature calculation formula. The stable temperature calculation formula is obtained by performing a univariate regression fitting based on the target stable temperature corresponding to each experimental current value; the target stable temperature corresponding to each experimental current value is determined based on the first stable temperature and the second stable temperature corresponding to the experimental current value; the first stable temperature is the stable temperature corresponding to the experimental current value in the heating experiment test used to fit the heating formula, and the second stable temperature is the stable temperature corresponding to the experimental current value in the cooling experiment test used to fit the cooling formula.

9. The method according to any one of claims 1 to 8, characterized in that, The rationality verification of the operating condition file based on the predicted end-of-segment temperature includes: If the predicted end-of-segment temperature is less than or equal to the preset protection temperature, the predicted end-of-segment temperature is updated to the starting crimping temperature corresponding to the test current value of the next gear, and the next gear is used as the new current gear for further processing. If the predicted end-of-section temperature is greater than the protection temperature, the validity check of the operating condition file is deemed to have failed.

10. A test condition control device for a power module, characterized in that, The device includes: The acquisition module is used to acquire the edited operating condition file during the test condition editing stage of the power module; the operating condition file includes test current values ​​at multiple levels and corresponding preset durations; The temperature prediction module is used to predict the stable temperature at the crimping point during testing based on the test current value of each current gear among the multiple gears; the crimping point is the crimping position between the copper busbar and the power module in the testing equipment. The trend prediction module is used to compare the difference between the initial crimping temperature corresponding to the test current value and the stable temperature to determine the temperature change trend; wherein, the initial crimping temperature corresponding to the test current value of the first gear is the ambient temperature; the initial crimping temperature corresponding to the test current value of other gears is the predicted end temperature after testing based on the test current value of the previous gear. The temperature prediction module is also used to predict the end temperature of the segment based on the temperature change trend and the preset duration; the end temperature is the temperature of the crimping point after the preset duration of continuous testing based on the test current value. The operating condition verification module is used to verify the rationality of the operating condition file based on the end-of-segment temperature predicted by the temperature prediction module.

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