An automatic double-pulse test system and test method

Abstract

The application discloses an automatic double-pulse test system and a test method, which comprise an upper computer unit, a controller unit, a capacitor charging and discharging circuit unit, a load inductor unit, an IGBT power unit and an oscilloscope unit; the upper computer unit is interconnected with the controller unit; the controller unit is interconnected with the IGBT power unit; the control end of the controller unit is connected with the input end of the capacitor charging and discharging circuit unit and the load inductor unit; and the output end of the load inductor unit, the capacitor charging and discharging circuit unit and the oscilloscope unit is connected with the IGBT power unit. The whole operation process can be realized through the upper computer. The controller realizes full-automatic control and electrical isolation of the whole double-pulse test circuit, effectively guarantees test safety, the turn-on and turn-off resistance of the IGBT drive can be adjusted on line, operation is convenient, and test efficiency is greatly improved. The automatic double-pulse test system can meet most IGBT double-pulse test scenes, and can directly test the IGBT power module and the capacitor module by quickly connecting the modules with the system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of double pulse test, and particularly relates to an automatic double pulse test system and a test method. BACKGROUND

[0002] As the most representative product of power electronic technology, IGBT realizes electric energy conversion, transmission and control in electrical equipment, is the core component of power electronic equipment, and is the main force of high efficiency, energy saving and emission reduction. With the development of new energy, IGBT modules are applied more and more widely, especially in new energy electric vehicles, power equipment, industry, consumption and other industries. Different power electronic products need to test IGBT in the design process. Different working conditions and parameters will have a great influence on the operation of IGBT, so in order to ensure the stable and reliable operation of IGBT, double pulse test is necessary and the most effective means. Double pulse test can not only obtain the parameters in the switching process of the switch tube to evaluate whether the driving resistance value is appropriate and whether an absorption circuit needs to be added. It can also measure the performance of the switch tube in the actual circuit, mainly including reverse recovery current, turn-off voltage peak, turn-on and turn-off time, and further evaluate the reverse recovery behavior and safety margin of the diode.

[0003] Double pulse test often needs to build a double pulse test system according to the actual working condition. In the test process, the load inductance needs to be replaced, the IGBT driving resistance needs to be replaced, and the IGBT turn-on and turn-off time needs to be adjusted constantly. In the operation process, high voltage and large current are involved, and there are many unsafe factors.

[0004] The double pulse test system currently used still needs to manually adjust the load inductance, replace the IGBT driving resistance and manually control the charging and discharging according to the actual working condition in the test process. The test process and the change of test conditions are relatively cumbersome. The double pulse circuit involves high voltage and large current, and the operation itself has great safety hazards. SUMMARY

[0005] The purpose of the application is to overcome the problem that the double pulse test system needs to manually adjust the inductance and replace the resistance and manually control the charging and discharging, and a kind of automatic double pulse test system and test method are provided.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is as follows:

[0007] The application discloses an automatic double-pulse test system which comprises a host computer unit, a controller unit, a capacitor charging and discharging circuit unit, a load inductance unit, an IGBT power unit and an oscilloscope unit; the host computer unit is interconnected with the controller unit; the controller unit is interconnected with the IGBT power unit; the control end of the controller unit is connected with the input end of the capacitor charging and discharging circuit unit and the load inductance unit; the output end of the load inductance unit, the capacitor charging and discharging circuit unit and the oscilloscope unit is connected with the IGBT power unit respectively.

[0008] The host computer unit is used for setting test loop parameters, issuing working instructions to the control panel of the controller unit, receiving test data fed back by the controller unit and displaying and analyzing the test data.

[0009] The controller unit is used for receiving the working instructions issued by the host computer unit to drive output, loop switching and driving resistance switching and feeding back test data to the host computer unit.

[0010] The capacitor charging and discharging circuit unit is used for storing and releasing test energy.

[0011] The load inductance unit is used for simulating different load conditions of the test.

[0012] The IGBT power unit is used for converting the energy stored in the capacitor charging and discharging circuit unit into test power output and automatically adjusting driving resistance through the control unit.

[0013] The oscilloscope unit is used for monitoring and recording real-time data and waveforms in the test process.

[0014] Further, the capacitor charging and discharging circuit unit comprises a high-voltage direct-current source, a capacitor panel, a pre-charging resistor and a discharging resistor; the high-voltage direct-current source is connected with a direct-current contactor and the capacitor panel; the direct-current contactor is connected with the pre-charging resistor or the discharging resistor.

[0015] Further, before the test starts, the direct-current contactor is connected with the pre-charging resistor through the control panel, the high-voltage direct-current source pre-charges the capacitor, after the test ends, the direct-current contactor is connected with the discharging resistor through the control panel, and the capacitor panel is discharged.

[0016] Further, the load inductance unit comprises a load inductance and a direct-current contactor; the load inductance is connected with the control panel of the control unit through the direct-current contactor; the load inductance adjusts the inductance value through the control panel.

[0017] Further, the IGBT power unit comprises a driving adapter panel, an IGBT driving panel, an IGBT module and a busbar; the IGBT module is connected with the IGBT driving panel through the driving adapter panel; the busbar connects the IGBT with the capacitor panel; the control panel is connected with the IGBT driving unit through a short-circuit line.

[0018] Further, the IGBT power unit simultaneously outputs four-way isolated IGBT driving signals, and is compatible with driving IGBT below 2KV, and the IGBT power unit receives the working instructions issued by the upper computer unit through the control panel to adjust the driving resistance.

[0019] Further, the IGBT power unit adjusts the turn-on resistance and the turn-off resistance respectively, and the adjustment interval is 1 ohm, and the adjustment range is 1-10 ohm.

[0020] Further, the oscilloscope unit comprises an oscilloscope, an isolated voltage probe and a Rogowski coil probe, and the oscilloscope unit is directly connected with the upper computer unit and is used for storing the measurement results of the oscilloscope.

[0021] Further, the upper computer unit switches the test load inductance, the capacitor charging and discharging circuit and the driving resistance through the controller unit.

[0022] An automatic double-pulse test method utilizes the automatic double-pulse test system, and comprises the following steps: setting test circuit parameters in the upper computer unit, selecting a test mode to issue working instructions to the controller unit, the controller unit receives the working instructions issued by the upper computer to prepare for driving output, circuit switching and driving resistance switching operation; and the capacitor charging and discharging circuit unit stores and releases energy.

[0023] The double-pulse test is performed, the controller unit issues a first pulse signal to the IGBT power unit according to the test mode and parameters set by the upper computer, drives the IGBT to turn on, the bus voltage is loaded to the load inductance unit through the IGBT, the inductance current starts to linearly rise, the oscilloscope unit monitors and records the real-time data of the voltage and current in the IGBT turn-on process, after the first pulse ends, the IGBT turns off, the inductance current flows through the freewheeling diode, the current slowly decays, after a set pulse interval, the controller unit issues a second pulse signal to the IGBT power unit to drive the IGBT to turn on again, at this time, the freewheeling diode enters the reverse recovery state, the voltage generated by the stray inductance is superimposed on the direct current voltage to form a voltage spike, and the oscilloscope unit monitors and records the real-time data of the voltage and current in the IGBT turn-on and turn-off process.

[0024] The controller unit feeds back the data collected in the test process to the upper computer unit, the upper computer unit receives and displays the test data, processes and analyzes the test data, and adjusts the driving resistance of the driving circuit according to the test results.

[0025] Compared with the prior art, the present application has the following beneficial technical effects:

[0026] The automatic double-pulse test system optimizes and improves the double-pulse test loop from the perspective of test and engineering application, adopts common power devices, control boards, drive boards and host computers, realizes the automatic test of the double-pulse test system through the host computer software and the controller, and realizes the whole operation process through the host computer. The controller realizes the full-automatic control and electrical isolation of the whole double-pulse test loop, effectively guarantees the test safety; the turn-on and turn-off resistance of the IGBT drive can be adjusted online, the operation is convenient, and the test efficiency is greatly improved; the test system can meet most IGBT double-pulse test scenes, directly connects the IGBT power module and the capacitor module with the system for testing, realizes the automation of the double-pulse test system in the form of a simple circuit, improves the efficiency of the double-pulse test, and guarantees the safety of the test personnel. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes and proportions of the components in the drawings are only illustrative and are used to help understand the present application, and are not specific limitations on the shapes and proportions of the components. In the drawings:

[0028] Figure 1 The structure diagram of the automatic double-pulse test system.

[0029] Figure 2 The structure diagram of the IGBT drive board in the IGBT power unit of the automatic double-pulse test system. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] It is to be understood that the terminology "first", "second" and the like used in the specification and the claims of the application as well as the foregoing drawings is merely intended to distinguish between similar objects and not necessarily to describe a particular sequential or chronological order. It is to be understood that the use of data so designated is not meant to limit, and will not limit, the scope of the application, which is defined solely by the claims. Furthermore, the terms "including", "comprising", and "having" and variations thereof as used in the specification and claims of the application are intended to cover both the inclusive and exclusive cases, that is, the terms are intended to cover both the cases where the process, method, system, product, or device includes the recited steps or units and the cases where the process, method, system, product, or device does not include the recited steps or units.

[0033] Embodiment one

[0034] Referring to Figure 1 An automatic double pulse test system, comprising a host computer unit, a controller unit, a capacitor charging and discharging circuit unit, a load inductance unit, an IGBT power unit and an oscilloscope unit, the host computer unit is interconnected with the controller unit, the controller unit is interconnected with the IGBT power unit, the control end of the controller unit is connected with the input end of the capacitor charging and discharging circuit unit and the load inductance unit, and the output end of the load inductance unit, the capacitor charging and discharging circuit unit and the oscilloscope unit is connected with the IGBT power unit respectively; the host computer unit is used for setting test loop parameters, issuing work instructions to the control panel of the controller unit, receiving test data feedback by the controller unit and displaying and analyzing; the controller unit is used for receiving work instructions issued by the host computer unit for driving output, loop switching and driving resistance switching, and feeding back test data to the host computer unit; the capacitor charging and discharging circuit unit is used for storing and releasing test energy; the load inductance unit is used for simulating different load conditions of the test; the IGBT power unit is used for converting the energy stored in the capacitor charging and discharging circuit unit into test power output, while adjusting the driving resistance; and the oscilloscope unit is used for monitoring and recording real-time data in the test process.

[0035] The automatic double pulse test system provided by the embodiment only needs to connect the actual working condition IGBT power unit and the capacitor unit to the double pulse test system, the test personnel set parameters and test through the host computer, and the test process effectively isolates the test personnel and the test high-voltage loop, effectively reduces the frequency of personnel operating the loop, and ensures the safety of the test personnel. It has high automation, flexibility and universality, can meet the needs of various IGBT double pulse tests, and at the same time ensures the safety and accuracy of the test.

[0036] The capacitor charging and discharging loop unit comprises a high-voltage direct-current source, a capacitor plate, a pre-charging resistor and a discharging resistor, the high-voltage direct-current source is connected with the direct-current contactor and the capacitor plate, and the direct-current contactor is connected with the pre-charging resistor or the discharging resistor. Before the test starts, the control panel controls the direct-current contactor to be connected with the pre-charging resistor, and the high-voltage direct-current source pre-charges the capacitor, and after the test ends, the control panel controls the direct-current contactor to be connected with the discharging resistor, and the capacitor plate is discharged. The load inductor unit comprises a load inductor and a direct-current contactor, the load inductor is connected with the control panel of the control unit through the direct-current contactor, and the load inductor adjusts the inductance value through the control panel. Referring to Figure 2 The IGBT power unit comprises a drive adapter plate, an IGBT drive plate, an IGBT module and a busbar, the IGBT module is connected with the IGBT drive plate through the drive adapter plate, the busbar is connected with the capacitor plate, and the control panel is connected to the IGBT drive unit through a short line. The IGBT power unit simultaneously outputs four isolated IGBT drive signals, is compatible with driving IGBT below 2KV, and adjusts the drive resistor through the control panel receiving the working instruction issued by the upper computer unit. The IGBT power unit adjusts the turn-on resistor and the turn-off resistor respectively, the adjustment interval is 1 ohm, and the adjustment range is 1-10 ohms. The oscilloscope unit comprises an oscilloscope, an isolated voltage probe and a Rogowski coil probe, the oscilloscope unit is directly connected with the upper computer unit, and is used for storing the measurement results of the oscilloscope. The upper computer unit switches the test load inductor, the capacitor charging and discharging loop and the drive resistor through the controller unit.

[0037] The double-pulse test system provided by the embodiment can automatically switch the load inductor, the capacitor charging and discharging loop and the drive resistor through the upper computer, the turn-on resistor and the turn-off resistor of the IGBT drive can be adjusted online, the precision is 1 ohm, the time for replacing the drive resistor is greatly saved, the operation is safe and convenient, and the test efficiency is greatly improved. The IGBT drive unit can simultaneously output four isolated drives, the output drive voltage can be adjusted, and most IGBT models below 2KV can be driven. On the basis of the double-pulse test system of the energy storage converter, the efficiency, safety and convenience of the double-pulse test are effectively improved in combination with the related principles of automatic control.

[0038] Embodiment two

[0039] An automatic double-pulse test method uses the double-pulse test system provided in embodiment one, sets test loop parameters in the upper computer unit, selects a test mode to issue a working instruction to the controller unit, the controller unit receives the working instruction issued by the upper computer to prepare for drive output, loop switching and drive resistor switching operation; the capacitor charging and discharging loop unit stores and releases energy;

[0040] The double pulse test is performed. The controller unit sends a first pulse signal to the IGBT power unit to drive the IGBT to turn on. The bus voltage is loaded onto the load inductor unit through the IGBT. The inductor current starts to rise linearly. The oscilloscope unit monitors and records the real-time data of the voltage and current during the IGBT turn-on process. After the first pulse ends, the IGBT turns off. The inductor current flows through the freewheeling diode. The current slowly decays. After a set pulse interval, the controller unit sends a second pulse signal to the IGBT power unit to drive the IGBT to turn on again. At this time, the freewheeling diode enters the reverse recovery state. The voltage generated by the stray inductance is superimposed on the DC voltage to form a voltage spike. The oscilloscope unit monitors and records the real-time data of the voltage and current during the IGBT turn-on and turn-off processes.

[0041] The controller unit feeds back the data collected during the test to the host computer unit. The host computer unit receives and displays the test data, processes and analyzes the test data, and adjusts the drive resistance of the drive circuit according to the test results.

[0042] Embodiment three

[0043] The embodiment provides an automatic double pulse test system. The double pulse test is widely used in the power electronics industry. In order to find out the characteristic parameters of the selected IGBT, a double pulse test platform needs to be built according to the actual working conditions. Different IGBTs and different application conditions need to be tested by double pulse test, so that the IGBT can work in a safe interval, thereby improving the reliability of the power electronic product. With the increase of product types and IGBT models, the workload of double pulse test increases rapidly. In view of the comprehensive test, safety and production cost requirements, the embodiment effectively improves the efficiency, safety and convenience of the double pulse test on the basis of the energy storage converter double pulse test system and in combination with the related principles of automatic control. The double pulse test system provided by the embodiment takes a control board as a core, effectively connects the IGBT double pulse test loop, sends a command to the control board through a host computer, and can select a load inductor, an IGBT drive resistance, an IGBT drive pulse length and a voltage on the host computer interface. After the setting is completed, the double pulse test is clicked, the system automatically powers on to charge the capacitor, and automatically discharges the capacitor after the test is completed. The double pulse test system comprises a host computer unit, a controller unit, a drive unit, an IGBT power unit, a capacitor charging and discharging loop unit, a load inductor unit and an oscilloscope unit.

[0044] Specifically, the host computer unit is connected to the control board through a network cable. Test loop parameters are set through an interface to realize effective isolation of test personnel and the test loop.

[0045] The controller unit is the core of the double pulse test system and is mainly responsible for communication with the host computer, drive output, loop switching, drive resistance switching and other work according to the instructions of the host computer.

[0046] The capacitor charging and discharging circuit unit comprises a high-voltage direct-current source, a capacitor plate, a pre-charging resistor and a discharging resistor, a direct-current contactor is controlled through a control panel, and then the high-voltage direct-current unit outputs a high-voltage loop to pre-charge the capacitor, and after the test is completed, the discharging loop is automatically switched to discharge the capacitor plate, so as to ensure the safety of the test.

[0047] The load inductance unit comprises a load inductance and a direct-current contactor, and the inductance value of the load inductance can be adjusted online through the control panel.

[0048] The IGBT power unit is an IGBT power unit built according to actual working conditions, which is connected with the capacitor plate through a busbar, and the IGBT module is connected with the IGBT drive panel through a drive adapter panel, and the control panel is connected to the IGBT drive unit through a short line. The IGBT drive unit can simultaneously output four IGBT drive signals, and the drive resistance can be adjusted online through the upper computer, and the turn-on resistance and the turn-off resistance can be adjusted respectively, the adjustment interval is 1 ohm (adjustment range 1-10 ohm), and different types of IGBT modules can be compatible.

[0049] The oscilloscope unit comprises an oscilloscope, an isolated voltage probe and a Rogowski coil probe. The oscilloscope is directly connected with the upper computer, and the measurement results are automatically stored.

[0050] The following gives the specific process steps of the automatic double-pulse test method performed by the automatic double-pulse test system provided by the embodiment:

[0051] Step one, initializing the system and setting parameters

[0052] The upper computer unit is set through the upper computer interface to set the test loop parameters such as bus voltage, test current, pulse width, pulse interval, etc. Select the test mode, such as double-pulse test, multi-pulse test, etc., and configure the corresponding test sequence. The controller unit receives the work instructions issued by the upper computer, and prepares to perform operations such as drive output, loop switching and drive resistance switching. The controller unit is initialized to ensure that each functional module is in standby state.

[0053] Step two, the capacitor charging and discharging circuit unit operates the high-voltage direct-current source charging and the capacitor energy storage

[0054] The high-voltage direct-current source is connected to the capacitor plate through the direct-current contactor to charge the capacitor plate to the set bus voltage. During the charging process, the pre-charging resistor is used to limit the charging current to protect the high-voltage direct-current source and the capacitor plate from the impact of excessive current. The capacitor plate stores the energy required for the test after the charging is completed. The discharging resistor remains disconnected during the test to prevent the energy on the capacitor plate from being released accidentally.

[0055] Step three, performing double-pulse test

[0056] First pulse test: The controller unit sends a first pulse signal to the IGBT power unit, driving the IGBT to turn on. The bus voltage is loaded onto the load inductance unit through the IGBT, and the inductance current starts to rise linearly. The oscilloscope unit monitors and records real-time data such as voltage and current during the IGBT turn-on process. After the first pulse ends, the IGBT turns off, and the inductance current flows through the freewheeling diode, and the current slowly decays.

[0057] Second pulse test: After a set pulse interval, the controller unit sends a second pulse signal to the IGBT power unit, driving the IGBT to turn on again. At this time, the freewheeling diode enters the reverse recovery state, and the voltage generated by the stray inductance is superimposed on the DC voltage to form a voltage spike. The oscilloscope unit monitors and records real-time data such as voltage and current during the IGBT turn-on and turn-off processes, and pays special attention to observing whether there is oscillation phenomenon in the gate waveform.

[0058] Step four, feedback test data and analysis

[0059] The controller unit feeds back the data collected during the test to the host computer unit. The host computer unit receives and displays the test data, including voltage waveform, current waveform, turn-on loss, turn-off loss, and other key parameters. The host computer unit processes and analyzes the test data, and according to the test results, optimizes the design of the drive circuit, adjusts the drive resistance and other parameters, and improves the performance and reliability of the device.

[0060] Step five, safety protection and fault handling during the test process

[0061] During the test process, the system should monitor the output voltage and current of the high-voltage power supply in real time to ensure that it does not exceed the withstand voltage and rated current of the device being tested. After the test is completed, the system automatically disconnects the high-voltage power supply and discharges the capacitor plate to ensure the safety of the test personnel. If abnormal conditions occur during the test, such as excessively high voltage spikes and excessively large current oscillations, the system should immediately stop the test and issue an alarm signal. The test personnel should check the test circuit and the device being tested according to the alarm information, and retest after troubleshooting.

[0062] Through the coordinated work of the host computer unit, the controller unit, the capacitor charging and discharging circuit unit, the load inductance unit, the IGBT power unit, and the oscilloscope unit, the automatic double-pulse test system proposed in this embodiment can realize automatic double-pulse testing and real-time display and analysis of test data.

[0063] Many embodiments and many applications other than those described herein will be apparent to those skilled in the art from consideration of the specification and practice of the teachings herein. Therefore, the scope of the present teachings should be determined by the appended claims and equivalents thereof, rather than by the description alone. All articles and references, including patent applications and publications, are incorporated herein by reference for all that they contain. Any aspect of the subject matter disclosed herein that is not recited in the claims is hereby abandoned. Nothing herein is to be construed as an admission that the subject matter disclosed herein is not entitled to antedate any prior art disclaimer.

[0064] The above description is further detailed of the present application, and cannot be considered as limiting the specific embodiments of the present application, and for those skilled in the art, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as belonging to the present application, which is determined by the claims submitted.

Claims

1. An automated dual pulse test system, characterized by, The application relates to a test system for IGBT, which comprises a host computer unit, a controller unit, a capacitor charging and discharging circuit unit, a load inductor unit, an IGBT power unit and an oscilloscope unit. The host computer unit is used for setting test loop parameters, issuing working instructions to the control panel of the controller unit, receiving test data fed back by the controller unit and displaying and analyzing the test data. The controller unit is used for receiving the working instructions issued by the host computer unit to drive output, loop switching and driving resistance switching and feeding back test data to the host computer unit. The capacitor charging and discharging circuit unit is used for storing and releasing test energy. The load inductor unit is used for simulating different load conditions in the test. The IGBT power unit is used for converting the energy stored in the capacitor charging and discharging circuit unit into test power output and automatically adjusting the driving resistance through the control unit. The oscilloscope unit is used for monitoring and recording real-time data and waveforms in the test process.

2. The automatic dual pulse testing system of claim 1, wherein, The capacitor charging and discharging circuit unit comprises a high-voltage direct-current source, a capacitor panel, a pre-charging resistor and a discharging resistor.

3. The automatic dual pulse testing system of claim 2, wherein, Before the test starts, the high-voltage direct-current source pre-charges the capacitor by connecting the direct-current contactor and the pre-charging resistor.

4. The automatic dual pulse testing system of claim 1, wherein, After the test ends, the control panel controls the direct-current contactor to be connected with the discharging resistor to discharge the capacitor panel.

5. The automatic dual pulse testing system of claim 4, wherein, The load inductor unit comprises a load inductor and a direct-current contactor.

6. The automatic dual pulse testing system of claim 1, wherein, The load inductor is connected with the control panel of the control unit through the direct-current contactor, and the inductance value of the load inductor is adjusted through the control panel.

7. The automatic dual pulse testing system of claim 1, wherein, The IGBT power unit comprises a driving adapter panel, an IGBT driving panel, an IGBT module and a busbar.

8. The automatic dual pulse testing system of claim 1, wherein, The IGBT module is connected with the IGBT driving panel through the driving adapter panel, the busbar connects the IGBT and the capacitor panel, and the control panel is connected with the IGBT driving unit through a short-circuit wire.

9. An automated double-pulse testing method using the automated double-pulse testing system as claimed in any one of claims 1 to 8, characterized in that, The IGBT power unit simultaneously outputs four isolated IGBT driving signals and is compatible with IGBTs below 2KV. The oscilloscope unit comprises an oscilloscope, an isolated voltage probe and a Rogowski coil probe. The oscilloscope unit is directly connected with the host computer unit and is used for storing the measurement results of the oscilloscope. The host computer unit switches the test load inductor, the capacitor charging and discharging circuit and the driving resistance through the controller unit. The application further discloses a test method for IGBT, which comprises the following steps: setting test loop parameters in the host computer unit, selecting a test mode to issue working instructions to the controller unit, receiving the working instructions issued by the host computer to prepare for driving output, loop switching and driving resistance switching operations, and storing and releasing energy in the capacitor charging and discharging circuit unit. The double pulse test is performed. The controller unit sends a first pulse signal to the IGBT power unit according to the test mode and parameters set by the upper computer, drives the IGBT to turn on, the bus voltage is loaded on the load inductance unit through the IGBT, the inductance current starts to linearly rise, the oscilloscope unit monitors and records the real-time data of the voltage and current in the IGBT on-off process, after the first pulse ends, the IGBT is turned off, the inductance current is continued through the freewheeling diode, the current slowly decays, after the set pulse interval, the controller unit sends a second pulse signal to the IGBT power unit, drives the IGBT to turn on again, at this time, the freewheeling diode enters the reverse recovery state, the voltage generated by the stray inductance is superimposed on the direct current voltage to form a voltage spike, the oscilloscope unit monitors and records the real-time data of the voltage and current in the IGBT on-off process; The controller unit feeds back the data collected in the test process to the upper computer unit, the upper computer unit receives and displays the test data, processes and analyzes the test data, and adjusts the driving resistance of the driving circuit according to the test result.

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