A waveform analysis system and method for dual-pulse testing
By using a waveform analysis system to uniformly format dual-pulse test files and generate intuitive waveform diagrams, the problem of existing oscilloscopes being unable to uniformly format test files has been solved, thus improving analysis and R&D efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- STARPOWER SEMICON LTD
- Filing Date
- 2023-12-07
- Publication Date
- 2026-07-03
AI Technical Summary
In dual-pulse testing, existing oscilloscopes cannot uniformly format test files, forcing researchers to manually read parameters, which wastes time and makes it impossible to intuitively display test results, thus affecting the research and development progress.
A waveform analysis system is provided, including a waveform processing module, a calculation module, and an image generation module. It generates test files in a unified format through preprocessing and calculation, and generates intuitive waveform graphs that display the on, off, and reverse recovery parameters.
It improves the efficiency of test file analysis, generates intuitive waveforms, saves analysis time, and enhances R&D efficiency.
Smart Images
Figure CN117761370B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dual-pulse testing technology, and in particular to a waveform analysis system and method for dual-pulse testing. Background Technology
[0002] In dual-pulse testing, researchers often need to read a large number of parameters. When there are many waveforms, the waveform reading process can consume nearly half of the experimental time. The waveform reading function built into oscilloscopes often cannot cover the parameters required by researchers, and the parameter reading standards are fixed and cannot be modified. If the parameters do not conform to the experimental requirements, manual reading is the only option. Furthermore, different brands of oscilloscopes generate inconsistent reports, and the operation process is complex, often containing a large amount of redundant information that cannot be used directly in meetings.
[0003] In the existing technology, there is a lack of waveform analysis systems for bipulse testing, which forces experimenters to waste a lot of time analyzing and checking the test results, resulting in slow development progress. Furthermore, existing oscilloscopes cannot accurately and simultaneously display the trends and changes of all parameters in the test file in graphical form, preventing experimenters from accurately, timely, and intuitively understanding the test results. Therefore, there is a need to provide a waveform analysis system for bipulse testing to solve the current technical problems. Summary of the Invention
[0004] To address the problems existing in the prior art, the present invention provides a waveform analysis system for dual-pulse testing, comprising:
[0005] The waveform processing module is used to acquire a double-pulse test file and preprocess the double-pulse test file to obtain a processed test file.
[0006] The calculation module, connected to the waveform processing module, is used to process the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process, and then process the parameters, the turn-on node and the turn-off node to obtain the turn-on parameter, the turn-off parameter and the reverse recovery parameter.
[0007] An image generation module, connected to the calculation module, is used to generate a complete waveform diagram based on the parameters in the processed test file, as well as the turn-on parameter, the turn-off parameter, and the reverse recovery parameter. Peak current and peak voltage are obtained by processing the parameters. Then, based on the peak current and peak voltage, turn-on waveform diagram, turn-off waveform diagram, and diode reverse recovery waveform diagram are respectively extracted from the complete waveform diagram.
[0008] Preferably, the waveform processing module includes:
[0009] A redundancy removal unit is used to acquire the double pulse test file and remove redundant information other than parameter data in the double pulse test file. Then, the parameter data is sorted by time as the row and parameter name as the column to obtain a data table.
[0010] The filtering unit, connected to the redundancy removal unit, is used to acquire one row of parameter data from the data table at preset time intervals, starting from the time start point, to obtain the filtered data table as the processed test file.
[0011] Preferably, the parameters in the processed test file include a sequence of gate voltage parameters, collector-emitter voltage parameters, reverse recovery voltage parameters, current parameters, reverse recovery current parameters, and gate voltage parameters arranged in chronological order. The turn-on nodes and turn-off nodes include a first turn-on node and a first turn-off node corresponding to the first pulse, and a second turn-on node and a second turn-off node corresponding to the second pulse. Therefore, the calculation module includes:
[0012] The node calculation unit is used to obtain the positive gate voltage and negative gate voltage from the external input, and find the corresponding time node in the gate voltage parameter column based on the positive gate voltage and the negative gate voltage as the first turn-on node, the first turn-off node, the second turn-on node and the second turn-off node.
[0013] An activation parameter calculation unit, connected to the node calculation unit, is used to calculate multiple activation parameters based on the first activation node, the first deactivation node, the second activation node, the second deactivation node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series.
[0014] A shutdown parameter calculation unit, connected to the node calculation unit, is used to calculate multiple shutdown parameters based on the first turn-on node, the first turn-off node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series.
[0015] A reverse recovery parameter calculation unit, connected to the node calculation unit, is used to calculate multiple reverse recovery parameters based on the second turn-on node, the reverse recovery current parameter series, and the reverse recovery voltage parameter series.
[0016] Preferably, the node computing unit includes:
[0017] The first node calculation subunit is used to obtain the positive gate voltage and negative gate voltage from the external input, and calculate the turn-on voltage based on the negative gate voltage. Then, it searches for the first gate voltage parameter in the gate voltage parameter column that is greater than the turn-on voltage as the first turn-on node. After finding the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the first turn-on node, it takes the first gate voltage parameter that is less than the turn-on voltage as the first turn-off node.
[0018] The second node calculation subunit is connected to the first node calculation unit. Starting from the first turn-off node, it searches for the time point corresponding to the first gate voltage parameter that is greater than the turn-on voltage in the gate parameter column as the second turn-on node. Then, after finding the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the second turn-on node, it takes the time point corresponding to the first gate voltage parameter that is less than the turn-on voltage as the second turn-off node.
[0019] Preferably, the turn-on parameters include the peak current, turn-on time, rise time, turn-on loss, turn-on current change rate, and turn-on voltage change rate. The interval between the first turn-on node and the first turn-off node is a first interval, the interval between the first turn-off node and the second turn-on node is a second interval, and the interval between the second turn-on node and the second turn-off node is a third interval. Therefore, the turn-on parameter calculation unit includes:
[0020] The first calculation subunit is used to find the maximum current parameter between the second turn-on node and the midpoint of the third interval in the current parameter column as the peak current.
[0021] The second calculation subunit, connected to the first calculation unit, is used to find the first time point corresponding to the first gate unit parameter greater than 1.5V between the second turn-on node and the second turn-off node in the gate voltage parameter column, and to find the second time point corresponding to the first current parameter greater than 10% of the peak current between the second turn-on node and the second turn-off node in the current parameter column, and to take the difference between the first time point and the second time point as the turn-on time.
[0022] The third calculation subunit, connected to the first calculation subunit, is used to find the maximum current parameter in the current parameter column between the midpoint of the first interval and the midpoint of the second interval as the maximum collector current, and then between the midpoint of the second interval and the midpoint of the third interval, find the difference between the time points corresponding to the first current parameter in the current parameter column that is greater than 10% of the maximum collector current and the first current parameter that is greater than 90% of the maximum collector current as the rise time.
[0023] The fourth calculation subunit, connected to the third calculation subunit, is used to acquire the externally input bus voltage, and then search between the second turn-on node and the second turn-off node for the third time point corresponding to the first current parameter in the current parameter column that is greater than 10% of the maximum collector current, and the fourth time point corresponding to the first collector-emitter voltage parameter in the collector-emitter voltage parameter column that is greater than 2% of the bus voltage. Then, the current parameter and the collector-emitter voltage parameter corresponding to the time between the third time point and the fourth time point are multiplied to obtain multiple products. The sum of each product is multiplied by the time difference between the third time point and the fourth time point to obtain the turn-on loss.
[0024] The fifth calculation subunit, connected to the first calculation subunit and the third calculation subunit, is used to search in the current parameter column from the second turn-on node backwards for the first current parameter that is greater than half of the maximum collector current and the corresponding fifth time point, and to search for the first second current parameter that is greater than half of the sum of the peak current and the maximum collector current and the corresponding sixth time point. The difference between the first current parameter and the second current parameter is divided by the difference between the sixth time point and the fifth time point to obtain the turn-on current change rate.
[0025] The sixth calculation subunit, connected to the fourth calculation subunit, is used to search, from the second turn-on node backwards, in the collector-emitter voltage parameter column for the first collector-emitter voltage parameter that is less than 90% of the bus voltage and its corresponding seventh time point, and the first collector-emitter voltage parameter that is less than 10% of the bus voltage and its corresponding eighth time point. The difference between the first collector-emitter voltage parameter and the second collector-emitter voltage parameter is divided by the difference between the eighth time point and the seventh time point to obtain the turn-on voltage change rate.
[0026] Preferably, the turn-off parameters include the turn-off current change rate, the turn-off voltage change rate, the turn-off loss, the peak voltage, the fall time, and the turn-off time. Therefore, the turn-off parameter calculation unit includes:
[0027] The seventh calculation subunit is used to find, in the current parameter column, the first third current parameter less than 10% of the maximum collector current and the corresponding ninth time point, and the first fourth current parameter less than 90% of the maximum collector current and the corresponding tenth time point, between the midpoint of the first interval and the first turn-off point, and then divide the difference between the third current parameter and the fourth current parameter by the difference between the ninth time point and the tenth time point to obtain the rate of change of the turn-off current;
[0028] The eighth calculation subunit is used to find, in the collector-emitter voltage parameter column, the first third collector-emitter voltage parameter less than 90% of the bus voltage and its corresponding eleventh time point, and the first fourth collector-emitter voltage parameter less than 10% of the bus voltage and its corresponding twelfth time point, between the midpoint of the first interval and the first turn-off point. Then, the difference between the third collector-emitter voltage parameter and the fourth collector-emitter voltage parameter is divided by the difference between the eleventh time point and the first twelfth time point to obtain the turn-off voltage change rate.
[0029] The ninth calculation subunit is used to find, in the collector-emitter voltage parameter column, the thirteenth time point corresponding to the first collector-emitter voltage parameter less than 10% of the bus voltage between the first turn-on node and the first turn-off node; then, in the current parameter column, the fourteenth time point corresponding to the first current parameter less than 2% of the maximum collector current between the thirteenth time point and the first turn-off node; multiply each collector-emitter voltage parameter corresponding to the time between the thirteenth time point and the fourteenth time point in the collector-emitter voltage parameter column and the current parameter column by each corresponding current parameter to obtain multiple products; and multiply the sum of each product by the difference between the fourteenth time point and the thirteenth time point to obtain the turn-off loss.
[0030] The tenth calculation subunit is used to find the largest collector-emitter voltage parameter between the midpoint of the first interval and the midpoint of the second interval in the collector-emitter voltage parameter column as the peak voltage;
[0031] The eleventh calculation subunit is used to find, in the current parameter column, the fifteenth time point corresponding to the first current parameter less than 10% of the maximum collector current and the sixteenth time point corresponding to the first current parameter less than 90% of the maximum collector current, between the midpoint of the first interval and the first turn-off node; then, in the gate voltage parameter column, it finds the gate voltage parameters corresponding to the sixteenth time point and the fifteenth time point and calculates the difference to obtain the fall time.
[0032] The twelfth calculation subunit is used to find the seventeenth time point corresponding to the first gate voltage parameter less than 13.5 between the midpoint of the first interval and the first turn-off node in the gate voltage parameter column, and to find the eighteenth time point corresponding to the first current parameter less than 90% of the maximum collector current between the midpoint of the first interval and the first turn-off node in the current parameter column, and to take the difference between the gate voltage parameter corresponding to the seventeenth time point and the gate voltage parameter corresponding to the eighteenth time point in the gate voltage parameter column as the turn-off time.
[0033] Preferably, the reverse recovery parameters include reverse charge, reverse recovery peak current, reverse recovery peak voltage, reverse recovery time, and recovery energy; therefore, the reverse recovery parameter calculation unit includes:
[0034] The thirteenth calculation subunit is used to find the largest reverse recovery current parameter in the reverse recovery current parameter column, starting from the second turn-on node, as the reverse recovery peak current.
[0035] The fourteenth calculation subunit is used to find the largest reverse recovery voltage parameter in the reverse recovery voltage parameter column, starting from the second turn-on node, as the reverse peak voltage.
[0036] The fifteenth calculation subunit, connected to the thirteenth calculation subunit, is used to search in the reverse recovery current parameter column backward from the second turn-on node for the nineteenth time point corresponding to the first reverse recovery current parameter that is not less than zero. Then, it searches backward from the nineteenth time point for the twentieth time point corresponding to the first reverse recovery current parameter that is greater than 2% of the reverse recovery peak current. Then, it multiplies the sum of all the reverse recovery current parameters in the reverse recovery current parameter column from the nineteenth time point to the twentieth time point by the difference between the nineteenth time point and the second time point to obtain the reverse charge.
[0037] The sixteenth calculation subunit, connected to the thirteenth calculation subunit, is used to search in the reverse recovery current parameter column from the second turn-on node backwards to find the twenty-first time point corresponding to the first reverse recovery current parameter equal to zero, and then search backwards from the time point corresponding to the reverse recovery peak current to find the twenty-second time point corresponding to the first reverse recovery current parameter less than 2% of the reverse recovery peak current, and then take the difference between the twenty-second time point and the twenty-first time point as the reverse recovery time;
[0038] The seventeenth calculation subunit, connected to the sixteenth calculation subunit, is used to find, from the second turn-on node backward, the twenty-third time point corresponding to the first reverse recovery voltage parameter greater than 1.5V in the reverse recovery voltage parameter column. Then, the reverse recovery voltage parameters and reverse recovery current parameters located between the twenty-second and twenty-third time points in the reverse recovery voltage parameter column and the reverse recovery current parameter column are multiplied according to the time point to obtain multiple products. Then, the sum of the products is multiplied by the difference between the twenty-second and twenty-third time points to obtain the recovery energy.
[0039] Preferably, the image generation module includes:
[0040] The complete waveform generation unit is used to generate corresponding curves in chronological order based on the parameters in the gate voltage parameter series, the collector-emitter voltage parameter series, the reverse recovery voltage parameter series, the current parameter series, the reverse recovery current parameter series, and the gate voltage parameter series of the paired transistor, with time as the horizontal axis, to obtain the complete waveform diagram, and associate it with the turn-on parameter, the turn-off parameter, and the reverse recovery parameter;
[0041] The turn-on waveform generation unit is connected to the complete waveform generation unit. It is used to extract an image within a preset time range from the complete image with the time point corresponding to the peak current as the center, and extract the curves corresponding to the gate voltage parameter series, the collector-emitter voltage parameter series and the current parameter series as the turn-on waveform, and associate them with the turn-on parameters.
[0042] The turn-off waveform generation unit, connected to the complete waveform generation unit, is used to extract an image within a preset time range from the complete image, centered on the time point corresponding to the peak voltage, and extract the curves corresponding to the gate voltage parameter series, the collector-emitter voltage parameter series, and the current parameter series as the turn-off waveform, and associate them with the turn-off parameters.
[0043] A diode reverse recovery waveform generation unit, connected to the complete waveform generation unit, is used to extract an image within a preset time range from the complete image, centered on the time point corresponding to the peak voltage, and extract the curves corresponding to the reverse recovery voltage parameter series, the reverse recovery current parameter series, and the gate voltage parameter series as the diode reverse recovery waveform, and associate the reverse recovery parameters.
[0044] The present invention also provides a waveform analysis method for dual-pulse testing, applied to the aforementioned waveform analysis system, the waveform analysis method comprising:
[0045] Step S1: The waveform analysis system acquires a double pulse test file and preprocesses the double pulse test file to obtain a processed test file.
[0046] Step S2: The waveform analysis system processes the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process. Then, it processes the parameters, the turn-on node and the turn-off node to obtain the turn-on parameter, the turn-off parameter and the reverse recovery parameter.
[0047] Step S3: The waveform analysis system generates a complete waveform diagram based on the parameters in the processed test file, as well as the turn-on parameter, the turn-off parameter, and the reverse recovery parameter. It processes the parameters to obtain the peak current and peak voltage, and then extracts the turn-on waveform diagram, the turn-off waveform diagram, and the diode reverse recovery waveform diagram from the complete waveform diagram based on the peak current and the peak voltage.
[0048] Preferably, step S1 includes:
[0049] Step S11: The waveform analysis system acquires the double pulse test file and removes redundant information other than the parameter data in the double pulse test file. Then, it organizes the parameter data by time as the row and parameter name as the column to obtain a data table.
[0050] Step S12: The waveform analysis system acquires a row of parameter data from the data table starting from the time start point, at preset time intervals, to obtain a filtered data table as the processed test file.
[0051] The above technical solution has the following advantages or beneficial effects: The waveform analysis system provided by this invention can unify the format of test files obtained from different oscilloscopes, improve analysis efficiency, and calculate the turn-on parameters, turn-off parameters, and reverse recovery parameters for evaluating product performance based on the parameters in the test files. It can also generate corresponding complete waveform diagrams, including turn-on waveform diagrams, turn-off waveform diagrams, and diode reverse recovery waveform diagrams, providing intuitive images to facilitate the observation of test results by experimental personnel, saving analysis time and improving R&D efficiency. Attached Figure Description
[0052] Figure 1 A schematic diagram of the structure of a waveform analysis system for dual-pulse testing is shown in a preferred embodiment of the present invention.
[0053] Figure 2 A flowchart illustrating a waveform analysis method for dual-pulse testing is provided in a preferred embodiment of the present invention.
[0054] Figure 3 This is a schematic diagram of the sub-process of step S2 in a preferred embodiment of the present invention. Detailed Implementation
[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within the scope of the present invention.
[0056] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a waveform analysis system for dual-pulse testing is provided, such as... Figure 1 As shown, it includes:
[0057] Waveform processing module 1 is used to acquire the double pulse test file and preprocess the double pulse test file to obtain the processed test file;
[0058] Calculation module 2, connected to waveform processing module 1, is used to process the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process. Then, based on each parameter, each turn-on node and each turn-off node, it processes to obtain the turn-on parameter, turn-off parameter and reverse recovery parameter.
[0059] Image generation module 3, connected to calculation module 2, is used to generate a complete waveform diagram based on the parameters in the processed test file, as well as the turn-on, turn-off, and reverse recovery parameters. Peak current and peak voltage are obtained by processing the parameters. Then, based on the peak current and peak voltage, the turn-on waveform diagram, turn-off waveform diagram, and diode reverse recovery waveform diagram are extracted from the complete waveform diagram.
[0060] Specifically, in this embodiment, after the experimenter completes the double pulse test on the power module, the test results are saved in a designated directory on the computer as a double pulse test file. At this time, the waveform analysis system of the present invention obtains the double pulse test file from the designated directory.
[0061] Because the models and brands of oscilloscopes used for testing are not uniform, the data format or data writing order in the saved dual-pulse test files will be inconsistent. Therefore, the dual-pulse test files need to be preprocessed to improve analysis efficiency.
[0062] Subsequently, based on the parameters in the test file, the activation parameters, deactivation parameters, and reverse recovery parameters used to evaluate product performance were calculated.
[0063] It can also generate corresponding complete waveform diagrams based on the parameters in the test file, including turn-on waveform diagrams, turn-off waveform diagrams, and diode reverse recovery waveform diagrams, providing intuitive images to facilitate the observation of test results by experimental personnel, saving analysis time and improving R&D efficiency.
[0064] In a preferred embodiment of the present invention, such as Figure 1 As shown, waveform processing module 1 includes:
[0065] Redundancy removal unit 11 is used to acquire the double pulse test file and remove redundant information other than parameter data in the double pulse test file. Then, the parameter data is sorted by time as the row and parameter name as the column to obtain a data table.
[0066] The filtering unit 12 is connected to the redundancy removal unit 11. It is used to obtain a row of parameter data from the data table starting from the time start point and at preset time intervals to obtain the filtered data table as the processed test file.
[0067] Specifically, in this embodiment, the dual-pulse test file is preprocessed, and the preprocessing process mainly includes redundancy removal and data filtering;
[0068] Because different brands and models of oscilloscopes will write different non-test parameters in the dual-pulse test file, such as oscilloscope brand and model parameters, experiment start time, etc., so these data other than parameter data in the file are removed as redundant information.
[0069] The parameter data in the file, such as the collector current parameter, corresponds to a time. Since the time in the test file is saved in TIME rows, each parameter in the file is represented as a column, forming a data table with time as rows and parameters as columns. However, due to differences in oscilloscope models, the data storage format varies slightly, for example:
[0070] Data table saved by model A oscilloscope:
[0071] time Parameter A Parameter B Parameter C T1 A1 B1 C1 T2 A2 B2 C2 T3 A3 B3 C3
[0072] or:
[0073] Data table saved by Model B oscilloscope:
[0074] time T1 Parameter A A1 Parameter B B1 time T2 Parameter A A2 Parameter B B2 time T3 Parameter A A3 Parameter B B3 time T4 Parameter A A4 Parameter B B4
[0075] We standardized the data tables saved by all the oscilloscopes to the data table format of the model A oscilloscope in the example. The method of format standardization can be achieved using existing technologies, which will not be elaborated here.
[0076] Since the amount of data obtained from the test is very large, we need to perform filtering to reduce the amount of data and improve the analysis efficiency. We extract one row of parameter data from the data table after it is in a unified format every 10ns (this data is only for illustrative purposes and needs to be set according to the actual test situation). Finally, we merge all the extracted parameter data to obtain the processed test file.
[0077] In a preferred embodiment of the present invention, the parameters in the processed test file include a sequence of gate voltage parameters, a sequence of collector-emitter voltage parameters, a sequence of reverse recovery voltage parameters, a sequence of current parameters, a sequence of reverse recovery current parameters, and a sequence of gate voltage parameters for the transistor, arranged in chronological order. The turn-on and turn-off nodes include a first turn-on node and a first turn-off node corresponding to the first pulse, and a second turn-on node and a second turn-off node corresponding to the second pulse. Then, the calculation module 2 includes:
[0078] The node calculation unit 21 is used to obtain the positive gate voltage and negative gate voltage from the external input, and find the corresponding time node based on the positive gate voltage and negative gate voltage in the gate voltage parameter column as the first turn-on node, the first turn-off node, the second turn-on node and the second turn-off node.
[0079] The turn-on parameter calculation unit 22 and the connection node calculation unit 21 are used to calculate multiple turn-on parameters based on the first turn-on node, the first turn-off node, the second turn-on node, the second turn-off node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series.
[0080] The turn-off parameter calculation unit 23 and the connection node calculation unit 22 are used to calculate multiple turn-off parameters based on the first turn-on node, the first turn-off node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series.
[0081] The reverse recovery parameter calculation unit 24 and the connection node calculation unit 23 are used to calculate multiple reverse recovery parameters based on the second turn-on node, the reverse recovery current parameter series, and the reverse recovery voltage parameter series.
[0082] Specifically, in this embodiment, the processed waveform is calculated to obtain the required parameters. These parameters can be used to represent the performance of the power module, mainly including the calculation of relevant parameters of the IGBT and diode.
[0083] The IGBT portion includes:
[0084] Turn-on parameters: Eon - switching loss, di / dt(on) - rate of change of turn-on current, du / dt(on) - rate of change of turn-on voltage, Icp - peak current, tdon - turn-on time, tr - rise time, di / dt(max) - maximum rate of change of turn-on current, du / dt(max) - maximum rate of change of turn-on voltage;
[0085] Turn-off parameters: Eoff - turn-off loss, di / dt (off 90~10%) - turn-off current change rate, du / dt (off) - turn-off voltage change rate, Vcp - peak voltage, tdoff - turn-off time, tf - fall time, di / dt (max) - maximum turn-off current change rate, du / dt (max) - maximum turn-off voltage change rate;
[0086] The diode section includes:
[0087] Diode reverse recovery parameters: Erec - recovery energy, Qr - reverse charge, Irrm - peak reverse recovery current, Vrp - peak reverse recovery voltage, trr - reverse recovery time, Vgemax - maximum gate voltage of the diode.
[0088] In a preferred embodiment of the present invention, such as Figure 1 As shown, the node computing unit 21 includes:
[0089] The first node calculation subunit 211 is used to obtain the positive gate voltage and negative gate voltage from the external input, and calculate the turn-on voltage based on the negative gate voltage. Then, it searches the gate voltage parameter column from the start of time to find the time point corresponding to the first gate voltage parameter that is greater than the turn-on voltage as the first turn-on node. After finding the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the first turn-on node, it takes the time point corresponding to the first gate voltage parameter that is less than the turn-on voltage as the first turn-off node.
[0090] The second node calculation subunit 212 is connected to the first node calculation unit 211. Starting from the first turn-off node, it searches for the time point corresponding to the first gate voltage parameter that is greater than the turn-on voltage in the gate parameter column as the second turn-on node. Then, starting from the second turn-on node, it searches for the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage and takes the time point corresponding to the first gate voltage parameter that is less than the turn-on voltage as the second turn-off node.
[0091] Specifically, in this embodiment, since it is a double-pulse test, the power module will have two identical turn-on processes and two identical turn-off processes;
[0092] Before conducting the test, the experimenter first inputs the positive gate voltage and negative gate voltage required for the test. The turn-on voltage is first calculated based on the negative gate voltage (the calculation process is to multiply the negative gate voltage by 3 / 5).
[0093] For the first pulse, find the time point corresponding to the first gate voltage parameter that is greater than the turn-on voltage from the start point of the time in the gate voltage parameter column as the first turn-on node k1. Then, find the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the first turn-on node and take the time point corresponding to the first gate voltage parameter that is less than the turn-on voltage as the first turn-off node g1.
[0094] The judgment conditions for the second turn-on node k2 and the second turn-off node g2 corresponding to the second pulse are the same as those for the first pulse. It is only necessary to start the search from the first turn-off node.
[0095] The interval from the first activated node to the first deactivated node is defined as the first interval t1, the interval from the first deactivated node to the second activated node is defined as the second interval t2, and the interval from the second activated node to the second deactivated node is defined as the third interval t3.
[0096] Before calculating each parameter, the program will first subtract the probe drift from the time line. For example, the current drift is taken as g1+(k2-g1) / / 4:k2-(k2-g1) / / 4 in the program. For example, assuming the drift is 5ns, the data in the first 5ns of the data table will be deleted, and the 6th ns will be taken as the starting point of the time. (The waveform analysis system in this invention is programmed in Python. / / is the integer division symbol in Python, that is, 7 / / 2=3).
[0097] In a preferred embodiment of the present invention, the turn-on parameters include peak current, turn-on time, rise time, turn-on loss, turn-on current rate of change, and turn-on voltage rate of change. The interval between the first turn-on node and the first turn-off node is a first interval, the interval between the first turn-off node and the second turn-on node is a second interval, and the interval between the second turn-on node and the second turn-off node is a third interval. Figure 1 As shown, the activation parameter calculation unit 22 includes:
[0098] The first calculation subunit 221 is used to find the maximum current parameter between the second turn-on node and the midpoint of the third interval in the current parameter column as the peak current.
[0099] The second calculation subunit 222 is connected to the first calculation unit 221. It is used to find the first time point corresponding to the first gate unit parameter greater than 1.5V between the second turn-on node and the second turn-off node in the gate voltage parameter column, and to find the second time point corresponding to the first current parameter greater than 10% of the peak current between the second turn-on node and the second turn-off node in the current parameter column. The difference between the first time point and the second time point is taken as the turn-on time.
[0100] The third calculation subunit 223 is connected to the first calculation subunit 221. It is used to find the maximum current parameter in the current parameter column between the midpoint of the first interval and the midpoint of the second interval as the maximum collector current. Then, between the midpoint of the second interval and the midpoint of the third interval, it finds the difference between the time points corresponding to the first current parameter that is greater than 10% of the maximum collector current and the first current parameter that is greater than 90% of the maximum collector current in the current parameter column as the rise time.
[0101] The fourth calculation subunit 224, connected to the third calculation subunit 223, is used to obtain the externally input bus voltage. Then, between the second turn-on node and the second turn-off node, it searches for the third time point corresponding to the first current parameter in the current parameter column that is greater than 10% of the maximum collector current, and the fourth time point corresponding to the first collector-emitter voltage parameter in the collector-emitter voltage parameter column that is greater than 2% of the bus voltage. Then, it multiplies the current parameter and collector-emitter voltage parameter corresponding to the time between the third time point and the fourth time point to obtain multiple products. The sum of each product is multiplied by the time difference between the third time point and the fourth time point to obtain the turn-on loss.
[0102] The fifth calculation subunit 225 is connected to the first calculation subunit 221 and the third calculation subunit 223. It is used to search in the current parameter column from the second turn-on node backwards for the first current parameter that is greater than half of the maximum collector current and the corresponding fifth time point, and to search for the first second current parameter that is greater than half of the sum of the peak current and the maximum collector current and the corresponding sixth time point. The difference between the first current parameter and the second current parameter is divided by the difference between the sixth time point and the fifth time point to obtain the turn-on current change rate.
[0103] The sixth calculation subunit 226, connected to the fourth calculation subunit 224, is used to search in the collector-emitter voltage parameter column from the second turn-on node backwards for the first collector-emitter voltage parameter that is less than 90% of the bus voltage and the corresponding seventh time point, and the first collector-emitter voltage parameter that is less than 10% of the bus voltage and the corresponding eighth time point. The difference between the first collector-emitter voltage parameter and the second collector-emitter voltage parameter is divided by the difference between the eighth time point and the seventh time point to obtain the turn-on voltage change rate.
[0104] In a preferred embodiment of the present invention, the turn-off parameters include the rate of change of turn-off current, the rate of change of turn-off voltage, turn-off loss, peak voltage, fall time, and turn-off time, as follows: Figure 1 As shown, the shutdown parameter calculation unit 23 includes:
[0105] The seventh calculation subunit 231 is used to find, in the current parameter column, the first third current parameter less than 10% of the maximum collector current and the corresponding ninth time point between the midpoint of the first interval and the first turn-off point, and the first fourth current parameter less than 90% of the maximum collector current and the corresponding tenth time point. Then, the difference between the third current parameter and the fourth current parameter is divided by the difference between the ninth time point and the tenth time point to obtain the rate of change of the turn-off current.
[0106] The eighth calculation subunit 232 is used to find, in the collector-emitter voltage parameter series, the first third collector-emitter voltage parameter less than 90% of the bus voltage and the corresponding eleventh time point between the midpoint of the first interval and the first turn-off point, and the first fourth collector-emitter voltage parameter less than 10% of the bus voltage and the corresponding twelfth time point. Then, the difference between the third collector-emitter voltage parameter and the fourth collector-emitter voltage parameter is divided by the difference between the eleventh time point and the twelfth time point to obtain the turn-off voltage change rate.
[0107] The ninth calculation subunit 233 is used to find the thirteenth time point corresponding to the first collector-emitter voltage parameter that is less than 10% of the bus voltage between the first turn-on node and the first turn-off node in the collector-emitter voltage parameter column. Then, in the current parameter column, it is used to find the fourteenth time point corresponding to the first current parameter that is less than 2% of the maximum collector current between the thirteenth time point and the first turn-off node. The collector-emitter voltage parameters and current parameters corresponding to the time between the thirteenth and fourteenth time points in the collector-emitter voltage parameter column and the current parameter column are multiplied by the corresponding current parameters to obtain multiple products. The sum of the products is multiplied by the difference between the fourteenth and thirteenth time points to obtain the turn-off loss.
[0108] The tenth calculation subunit 234 is used to find the maximum collector-emitter voltage parameter between the midpoint of the first interval and the midpoint of the second interval in the collector-emitter voltage parameter column as the peak voltage.
[0109] The eleventh calculation subunit 235 is used to find, in the current parameter column, the fifteenth time point corresponding to the first current parameter less than 10% of the maximum collector current between the midpoint of the first interval and the first turn-off node, and the sixteenth time point corresponding to the first current parameter less than 90% of the maximum collector current. Then, in the gate voltage parameter column, it finds the gate voltage parameters corresponding to the sixteenth time point and the fifteenth time point and calculates the difference to obtain the fall time.
[0110] The twelfth calculation subunit 236 is used to find the seventeenth time point corresponding to the first gate voltage parameter less than 13.5 between the midpoint of the first interval and the first turn-off node in the gate voltage parameter column, and to find the eighteenth time point corresponding to the first current parameter less than 90% of the maximum collector current between the midpoint of the first interval and the first turn-off node in the current parameter column. The difference between the gate voltage parameter corresponding to the seventeenth time point and the gate voltage parameter corresponding to the eighteenth time point in the gate voltage parameter column is used as the turn-off time.
[0111] In a preferred embodiment of the present invention, the reverse recovery parameters include reverse charge, reverse recovery peak current, reverse recovery peak voltage, reverse recovery time, and recovery energy, then as follows: Figure 1 As shown, the reverse recovery parameter calculation unit 24 includes:
[0112] The thirteenth calculation subunit 241 is used to find the largest reverse recovery current parameter in the reverse recovery current parameter column from the second turn-on node to the reverse recovery peak current.
[0113] The fourteenth calculation subunit 242 is used to find the largest reverse recovery voltage parameter in the reverse recovery voltage parameter column, starting from the second turn-on node, as the reverse peak voltage.
[0114] The fifteenth calculation subunit 243, connected to the thirteenth calculation subunit 241, is used to search in the reverse recovery current parameter column from the second turn-on node backwards to find the nineteenth time point corresponding to the first reverse recovery current parameter that is not less than zero, and then search from the nineteenth time point backwards to find the twentieth time point corresponding to the first reverse recovery current parameter that is greater than 2% of the reverse recovery peak current. Then, the sum of all reverse recovery current parameters in the reverse recovery current parameter column from the nineteenth time point to the twentieth time point is multiplied by the difference between the nineteenth time point and the second time point to obtain the reverse charge.
[0115] The sixteenth calculation subunit 244 is connected to the thirteenth calculation subunit 241. It is used to search in the reverse recovery current parameter column from the second turn-on node backwards to find the twenty-first time point corresponding to the first reverse recovery current parameter that is equal to zero. Then, starting from the time point corresponding to the reverse recovery peak current, it searches backwards to find the twenty-second time point corresponding to the first reverse recovery current parameter that is less than 2% of the reverse recovery peak current. Then, the difference between the twenty-second time point and the twenty-first time point is taken as the reverse recovery time.
[0116] The seventeenth calculation subunit 245, connected to the sixteenth calculation subunit 244, is used to search in the reverse recovery voltage parameter column from the second turn-on node to find the twenty-third time point corresponding to the first reverse recovery voltage parameter greater than 1.5V. Then, the reverse recovery voltage parameters and reverse recovery current parameters located between the twenty-second and twenty-third time points in the reverse recovery voltage parameter column and the reverse recovery current parameter column are multiplied according to the time point to obtain multiple products. Then, the sum of the products is multiplied by the difference between the twenty-second and twenty-third time points to obtain the recovery energy.
[0117] Specifically, in this embodiment, the turn-on parameters, turn-off parameters, and reverse recovery parameters used to evaluate product performance are calculated in the manner described above, which facilitates the observation of test results by experimental personnel, saves analysis time, and improves R&D efficiency.
[0118] In a preferred embodiment of the present invention, then as follows: Figure 1 As shown, the image generation module 3 includes:
[0119] The complete waveform generation unit 31 is used to generate corresponding curves in chronological order based on the parameters in the gate voltage parameter series, collector-emitter voltage parameter series, reverse recovery voltage parameter series, current parameter series, reverse recovery current parameter series and gate voltage parameter series of the transistor, with time as the horizontal axis, to obtain a complete waveform diagram, and associate it with the turn-on parameter, turn-off parameter and reverse recovery parameter.
[0120] The turn-on waveform generation unit 32 is connected to the complete waveform generation unit 31. It is used to extract an image within a preset time range from the complete image with the time point corresponding to the peak current as the center, and extract the curves corresponding to the gate voltage parameter series, collector-emitter voltage parameter series and current parameter series as the turn-on waveform, and associate the turn-on parameters.
[0121] The turn-off waveform generation unit 33 is connected to the complete waveform generation unit 31. It is used to extract an image within a preset time range from the complete image with the time point corresponding to the peak voltage as the center, and extract the curves corresponding to the gate voltage parameter series, collector-emitter voltage parameter series and current parameter series as the turn-off waveform, and associate the turn-off parameters.
[0122] The diode reverse recovery waveform generation unit 34 is connected to the complete waveform generation unit 31. It is used to extract an image within a preset time range from the complete image with the time point corresponding to the peak voltage as the center, and extract the curves corresponding to the reverse recovery voltage parameter series, reverse recovery current parameter series and gate voltage parameter series as the diode reverse recovery waveform, and associate the reverse recovery parameters.
[0123] Specifically, in this embodiment, the parameters in the gate voltage parameter series, collector-emitter voltage parameter series, reverse recovery voltage parameter series, current parameter series, reverse recovery current parameter series and gate voltage parameter series of the transistor contained in the preprocessed double pulse test file are first used to generate the corresponding curves in time order to obtain the complete waveform diagram;
[0124] The horizontal axis of the complete waveform graph is the time axis, which includes all data in the entire test process. Users can change the total length of the time axis on the operation panel as needed, and arbitrarily zoom in and out of the waveform curve by adjusting the scale of the time axis. The vertical axis of voltage or current is automatically generated based on the maximum value in the parameters. If users have additional requirements, they can modify them on the operation panel as needed.
[0125] The turn-on waveform diagram takes the time point corresponding to the peak current in the complete waveform diagram as the image center. It takes 1μs before and after the image center in the complete waveform diagram (that is, the time axis of the turn-on waveform diagram is 2μs in total), and only displays the curves corresponding to the gate voltage parameter series, collector-emitter voltage parameter series, and current parameter series, as well as the associated turn-on parameters.
[0126] The turn-off waveform diagram takes the time point corresponding to the peak voltage in the complete waveform diagram as the image center. It takes 1μs before and after the image center in the complete waveform diagram (that is, the time axis of the turn-off waveform diagram is 2μs in total), and only displays the curves corresponding to the gate voltage parameter series, collector-emitter voltage parameter series, and current parameter series, as well as the associated turn-off parameters.
[0127] The diode reverse recovery waveform diagram also uses the time point corresponding to the peak current in the complete waveform diagram as the image center. In the complete waveform diagram, 1μs are taken before and after the image center (i.e., the time axis of the turn-on waveform diagram is 2μs in total). Only the curves corresponding to the reverse recovery voltage parameter series, reverse recovery current parameter series, and gate voltage parameter series are recovered, as well as the associated reverse recovery parameters.
[0128] This invention also provides a waveform analysis method for double-pulse testing, applied to the aforementioned waveform analysis system, such as... Figure 2 As shown, waveform analysis methods include:
[0129] Step S1: The waveform analysis system acquires the double pulse test file and preprocesses the double pulse test file to obtain the processed test file;
[0130] Step S2: The waveform analysis system processes the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process. Then, it processes each parameter, each turn-on node and each turn-off node to obtain the turn-on parameter, turn-off parameter and reverse recovery parameter.
[0131] Step S3: The waveform analysis system generates a complete waveform diagram based on the parameters in the processed test file, as well as the turn-on, turn-off, and reverse recovery parameters. The peak current and peak voltage are obtained by processing the parameters. Then, based on the peak current and peak voltage, the turn-on waveform diagram, turn-off waveform diagram, and diode reverse recovery waveform diagram are extracted from the complete waveform diagram.
[0132] Specifically, the complete waveform diagram, turn-on waveform diagram, turn-off waveform diagram, and diode reverse recovery waveform diagram are saved in an Excel file. Each waveform diagram corresponds to a sheet (in Excel, a sheet refers to a worksheet, which is a component of an Excel document. By default, when you open or create an Excel document, it contains an overall concept called a "workbook," which is composed of multiple worksheets). In addition to displaying the corresponding image, each sheet also lists the associated parameters, making it easier to compare all the data from a single test.
[0133] In a preferred embodiment of the present invention, such as Figure 3 As shown, step S1 includes:
[0134] Step S11: The waveform analysis system acquires the double pulse test file and removes redundant information other than the parameter data in the double pulse test file. Then, it organizes the parameter data by time as the row and parameter name as the column to obtain a data table.
[0135] In step S12, the waveform analysis system acquires a row of parameter data from the data table starting from the time start point, at preset time intervals, and obtains the filtered data table as the processed test file.
[0136] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.
Claims
1. A waveform analysis system for double pulse testing, characterized by, include: The waveform processing module is used to acquire a double-pulse test file and preprocess the double-pulse test file to obtain a processed test file. The calculation module, connected to the waveform processing module, is used to process the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process, and then process the parameters, the turn-on node and the turn-off node to obtain the turn-on parameter, the turn-off parameter and the reverse recovery parameter. An image generation module, connected to the calculation module, is used to generate a complete waveform diagram based on each parameter in the processed test file, as well as the turn-on parameter, the turn-off parameter, and the reverse recovery parameter. Peak current and peak voltage are obtained by processing each parameter. Then, based on the peak current and peak voltage, turn-on waveform diagram, turn-off waveform diagram, and diode reverse recovery waveform diagram are respectively extracted from the complete waveform diagram. The parameters in the processed test file include, in chronological order, a sequence of gate voltage parameters, a sequence of collector-emitter voltage parameters, a sequence of reverse recovery voltage parameters, a sequence of current parameters, a sequence of reverse recovery current parameters, and a sequence of gate voltage parameters for the transistor pair. The turn-on nodes and turn-off nodes include a first turn-on node and a first turn-off node corresponding to the first pulse, and a second turn-on node and a second turn-off node corresponding to the second pulse. Therefore, the calculation module includes: The node calculation unit is used to obtain the positive gate voltage and negative gate voltage from the external input, and find the corresponding time node in the gate voltage parameter column based on the positive gate voltage and the negative gate voltage as the first turn-on node, the first turn-off node, the second turn-on node and the second turn-off node. An activation parameter calculation unit, connected to the node calculation unit, is used to calculate multiple activation parameters based on the first activation node, the first deactivation node, the second activation node, the second deactivation node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series. A shutdown parameter calculation unit, connected to the node calculation unit, is used to calculate multiple shutdown parameters based on the first turn-on node, the first turn-off node, the current parameter series, the gate voltage parameter series, and the collector-emitter voltage parameter series. A reverse recovery parameter calculation unit, connected to the node calculation unit, is used to calculate multiple reverse recovery parameters based on the second turn-on node, the reverse recovery current parameter series, and the reverse recovery voltage parameter series.
2. The waveform analysis system according to claim 1, characterized in that, The waveform processing module includes: A redundancy removal unit is used to acquire the double pulse test file and remove redundant information other than parameter data in the double pulse test file. Then, the parameter data is sorted by time as the row and parameter name as the column to obtain a data table. The filtering unit, connected to the redundancy removal unit, is used to acquire one row of parameter data from the data table at preset time intervals, starting from the time start point, to obtain the filtered data table as the processed test file.
3. The waveform analysis system according to claim 1, characterized in that, The node computing unit includes: The first node calculation subunit is used to obtain the positive gate voltage and negative gate voltage from the external input, and calculate the turn-on voltage based on the negative gate voltage. Then, it searches for the first gate voltage parameter in the gate voltage parameter column that is greater than the turn-on voltage as the first turn-on node. After finding the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the first turn-on node, it takes the first gate voltage parameter that is less than the turn-on voltage as the first turn-off node. The second node calculation subunit is connected to the first node calculation unit. Starting from the first turn-off node, it searches for the time point corresponding to the first gate voltage parameter that is greater than the turn-on voltage in the gate parameter column as the second turn-on node. Then, after finding the first gate voltage parameter that is greater than 4 / 5 of the positive gate voltage from the second turn-on node, it takes the time point corresponding to the first gate voltage parameter that is less than the turn-on voltage as the second turn-off node.
4. The waveform analysis system according to claim 1, characterized in that, The turn-on parameters include peak current, turn-on time, rise time, turn-on loss, turn-on current change rate, and turn-on voltage change rate. The interval between the first turn-on node and the first turn-off node is a first interval, the interval between the first turn-off node and the second turn-on node is a second interval, and the interval between the second turn-on node and the second turn-off node is a third interval. Therefore, the turn-on parameter calculation unit includes: The first calculation subunit is used to find the maximum current parameter between the second turn-on node and the midpoint of the third interval in the current parameter column as the peak current. The second calculation subunit, connected to the first calculation unit, is used to find the first time point corresponding to the first gate unit parameter greater than 1.5V between the second turn-on node and the second turn-off node in the gate voltage parameter column, and to find the second time point corresponding to the first current parameter greater than 10% of the peak current between the second turn-on node and the second turn-off node in the current parameter column, and to take the difference between the first time point and the second time point as the turn-on time. The third calculation subunit, connected to the first calculation subunit, is used to find the maximum current parameter in the current parameter column between the midpoint of the first interval and the midpoint of the second interval as the maximum collector current, and then find the difference between the time points corresponding to the first current parameter in the current parameter column that is greater than 10% of the maximum collector current and the first current parameter that is greater than 90% of the maximum collector current between the midpoint of the second interval and the midpoint of the third interval as the rise time. The fourth calculation subunit, connected to the third calculation subunit, is used to acquire the externally input bus voltage, and then search between the second turn-on node and the second turn-off node for the third time point corresponding to the first current parameter in the current parameter column that is greater than 10% of the maximum collector current, and the fourth time point corresponding to the first collector-emitter voltage parameter in the collector-emitter voltage parameter column that is greater than 2% of the bus voltage. Then, the current parameter and collector-emitter voltage parameter corresponding to the time between the third time point and the fourth time point are multiplied to obtain multiple products. The sum of each product is multiplied by the time difference between the third time point and the fourth time point to obtain the turn-on loss. The fifth calculation subunit, connected to the first calculation subunit and the third calculation subunit, is used to search in the current parameter column from the second turn-on node backwards for the first current parameter that is greater than half of the maximum collector current and the corresponding fifth time point, and to search for the first second current parameter that is greater than half of the sum of the peak current and the maximum collector current and the corresponding sixth time point. The difference between the first current parameter and the second current parameter is divided by the difference between the sixth time point and the fifth time point to obtain the turn-on current change rate. The sixth calculation subunit, connected to the fourth calculation subunit, is used to search, from the second turn-on node backwards, in the collector-emitter voltage parameter column for the first collector-emitter voltage parameter that is less than 90% of the bus voltage and its corresponding seventh time point, and the first collector-emitter voltage parameter that is less than 10% of the bus voltage and its corresponding eighth time point. The difference between the first collector-emitter voltage parameter and the second collector-emitter voltage parameter is divided by the difference between the eighth time point and the seventh time point to obtain the turn-on voltage change rate.
5. The waveform analysis system according to claim 4, characterized in that, The turn-off parameters include the rate of change of turn-off current, the rate of change of turn-off voltage, turn-off loss, the peak voltage, the fall time, and the turn-off time. Therefore, the turn-off parameter calculation unit includes: The seventh calculation subunit is used to find, in the current parameter column, the first third current parameter less than 10% of the maximum collector current and the corresponding ninth time point, and the first fourth current parameter less than 90% of the maximum collector current and the corresponding tenth time point, between the midpoint of the first interval and the first turn-off point, and then divide the difference between the third current parameter and the fourth current parameter by the difference between the ninth time point and the tenth time point to obtain the rate of change of the turn-off current; The eighth calculation subunit is used to find, in the collector-emitter voltage parameter column, the first third collector-emitter voltage parameter less than 90% of the bus voltage and its corresponding eleventh time point, and the first fourth collector-emitter voltage parameter less than 10% of the bus voltage and its corresponding twelfth time point, between the midpoint of the first interval and the first turn-off point. Then, the difference between the third collector-emitter voltage parameter and the fourth collector-emitter voltage parameter is divided by the difference between the eleventh time point and the twelfth time point to obtain the turn-off voltage change rate. The ninth calculation subunit is used to find, in the collector-emitter voltage parameter column, the thirteenth time point corresponding to the first collector-emitter voltage parameter less than 10% of the bus voltage between the first turn-on node and the first turn-off node; then, in the current parameter column, the fourteenth time point corresponding to the first current parameter less than 2% of the maximum collector current between the thirteenth time point and the first turn-off node; multiply the collector-emitter voltage parameters corresponding to the time between the thirteenth and fourteenth time points in the collector-emitter voltage parameter column and the current parameter column by the corresponding current parameters to obtain multiple products; and multiply the sum of the products by the difference between the fourteenth and thirteenth time points to obtain the turn-off loss. The tenth calculation subunit is used to find the largest collector-emitter voltage parameter between the midpoint of the first interval and the midpoint of the second interval in the collector-emitter voltage parameter column as the peak voltage; The eleventh calculation subunit is used to find, in the current parameter column, the fifteenth time point corresponding to the first current parameter less than 10% of the maximum collector current and the sixteenth time point corresponding to the first current parameter less than 90% of the maximum collector current, between the midpoint of the first interval and the first turn-off node; then, in the gate voltage parameter column, it finds the gate voltage parameters corresponding to the sixteenth time point and the fifteenth time point and calculates the difference to obtain the fall time. The twelfth calculation subunit is used to find the seventeenth time point corresponding to the first gate voltage parameter less than 13.5 between the midpoint of the first interval and the first turn-off node in the gate voltage parameter column, and to find the eighteenth time point corresponding to the first current parameter less than 90% of the maximum collector current between the midpoint of the first interval and the first turn-off node in the current parameter column, and to take the difference between the gate voltage parameter corresponding to the seventeenth time point and the gate voltage parameter corresponding to the eighteenth time point in the gate voltage parameter column as the turn-off time.
6. The waveform analysis system according to claim 3, characterized in that, The reverse recovery parameters include reverse charge, reverse recovery peak current, reverse recovery peak voltage, reverse recovery time, and recovery energy. Therefore, the reverse recovery parameter calculation unit includes: The thirteenth calculation subunit is used to find the largest reverse recovery current parameter in the reverse recovery current parameter column, starting from the second turn-on node, as the reverse recovery peak current. The fourteenth calculation subunit is used to find the largest reverse recovery voltage parameter in the reverse recovery voltage parameter column, starting from the second turn-on node, as the reverse peak voltage. The fifteenth calculation subunit, connected to the thirteenth calculation subunit, is used to search in the reverse recovery current parameter column backward from the second turn-on node for the nineteenth time point corresponding to the first reverse recovery current parameter that is not less than zero. Then, it searches backward from the nineteenth time point for the twentieth time point corresponding to the first reverse recovery current parameter that is greater than 2% of the reverse recovery peak current. Then, it multiplies the sum of all the reverse recovery current parameters in the reverse recovery current parameter column from the nineteenth time point to the twentieth time point with the difference between the nineteenth time point and the twentieth time point to obtain the reverse charge. The sixteenth calculation subunit, connected to the thirteenth calculation subunit, is used to search in the reverse recovery current parameter column from the second turn-on node backwards to find the twenty-first time point corresponding to the first reverse recovery current parameter equal to zero, and then search backwards from the time point corresponding to the reverse recovery peak current to find the twenty-second time point corresponding to the first reverse recovery current parameter less than 2% of the reverse recovery peak current, and then take the difference between the twenty-second time point and the twenty-first time point as the reverse recovery time; The seventeenth calculation subunit, connected to the sixteenth calculation subunit, is used to find, from the second turn-on node backward, the twenty-third time point corresponding to the first reverse recovery voltage parameter greater than 1.5V in the reverse recovery voltage parameter column. Then, the reverse recovery voltage parameters and reverse recovery current parameters located between the twenty-second and twenty-third time points in the reverse recovery voltage parameter column and the reverse recovery current parameter column are multiplied according to the time point to obtain multiple products. Then, the sum of the products is multiplied by the difference between the twenty-second and twenty-third time points to obtain the recovery energy.
7. The waveform analysis system according to claim 1, characterized in that, The image generation module includes: The complete waveform generation unit is used to generate corresponding curves in chronological order based on the parameters in the gate voltage parameter series, the collector-emitter voltage parameter series, the reverse recovery voltage parameter series, the current parameter series, the reverse recovery current parameter series, and the gate voltage parameter series of the paired transistor, with time as the horizontal axis, to obtain the complete waveform diagram, and associate it with the turn-on parameter, the turn-off parameter, and the reverse recovery parameter; The turn-on waveform generation unit is connected to the complete waveform generation unit. It is used to extract an image within a preset time range from the complete waveform with the time point corresponding to the peak current as the center, and extract the curves corresponding to the gate voltage parameter series, the collector-emitter voltage parameter series and the current parameter series as the turn-on waveform, and associate them with the turn-on parameters. The turn-off waveform generation unit, connected to the complete waveform generation unit, is used to extract an image within a preset time range from the complete waveform with the time point corresponding to the peak voltage as the center, and extract the curves corresponding to the gate voltage parameter series, the collector-emitter voltage parameter series, and the current parameter series as the turn-off waveform, and associate them with the turn-off parameters; A diode reverse recovery waveform generation unit, connected to the complete waveform generation unit, is used to extract an image within a preset time range from the complete waveform, centered on the time point corresponding to the peak voltage, and extract the curves corresponding to the reverse recovery voltage parameter series, the reverse recovery current parameter series, and the gate voltage parameter series as the diode reverse recovery waveform, and associate the reverse recovery parameters.
8. A waveform analysis method for double-pulse testing, characterized in that, Applied to the waveform analysis system as described in any one of claims 1-7, the waveform analysis method includes: Step S1: The waveform analysis system acquires a double pulse test file and preprocesses the double pulse test file to obtain a processed test file. Step S2: The waveform analysis system processes the parameters contained in the processed test file to obtain the turn-on node and turn-off node corresponding to each pulse in the test process. Then, it processes the parameters, the turn-on node and the turn-off node to obtain the turn-on parameter, the turn-off parameter and the reverse recovery parameter. Step S3: The waveform analysis system generates a complete waveform diagram based on the parameters in the processed test file, as well as the turn-on parameter, the turn-off parameter, and the reverse recovery parameter. It processes the parameters to obtain the peak current and peak voltage, and then extracts the turn-on waveform diagram, the turn-off waveform diagram, and the diode reverse recovery waveform diagram from the complete waveform diagram based on the peak current and the peak voltage.
9. The waveform analysis method according to claim 8, characterized in that, Step S1 includes: Step S11: The waveform analysis system acquires the double pulse test file and removes redundant information other than the parameter data in the double pulse test file. Then, it organizes the parameter data by time as the row and parameter name as the column to obtain a data table. Step S12: The waveform analysis system acquires a row of parameter data from the data table starting from the time start point, at preset time intervals, to obtain a filtered data table as the processed test file.