Short circuit testing device for power devices

Abstract

This application relates to a short-circuit testing device for power devices. This application relates to the field of semiconductor device reliability testing technology. The device includes: a controller, an energy storage circuit, a power supply, a power device under test (DUT), and a computer device; the controller is used to receive periodic test commands sent by the computer device, and according to the test commands, control the DUT to turn off and the power supply to charge the energy storage circuit; the controller is also used to stop charging the energy storage circuit if the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, and control the DUT to turn on, and discharge the DUT through the energy storage circuit within a preset time period to obtain the short-circuit test result. Using this device, short-circuit testing of power devices can be automatically and repeatedly performed, improving short-circuit testing efficiency.

Description

Technical Field

[0001] This application relates to the field of semiconductor device reliability testing technology, and in particular to a short-circuit testing device for power devices. Background Technology

[0002] With the widespread application of third-generation semiconductor devices, power devices have demonstrated excellent performance in power electronics applications. However, in actual power electronic systems, power devices do not always operate within their relatively safe electrical and thermal operating range. Due to human error or load failure, power devices frequently operate under short-circuit (SC) current conditions. Although these extreme conditions are very brief, they can affect the electrical performance of the device and even cause it to fail. Therefore, it is necessary to perform short-circuit current tests on power devices.

[0003] In traditional technology, short-circuit current testing of power devices is performed by manually controlling a signal transmitter. However, since a manual signal transmitter can only perform a single short-circuit current test at a time, multiple manual signal transmitter controls are required to perform multiple short-circuit current tests, making the test time-consuming, labor-intensive, and inefficient.

[0004] Since short-circuit faults in power devices are usually repeated multiple times in practical applications, and traditional technologies cannot automatically and repeatedly perform short-circuit tests on power devices, the testing efficiency is low. Summary of the Invention

[0005] Therefore, it is necessary to provide a short-circuit testing device for power devices that can improve the efficiency of short-circuit testing, in order to address the above-mentioned technical problems.

[0006] This application provides a short-circuit testing device for power devices. The device includes: a controller, an energy storage circuit, a power supply, the power device under test, and a computer device;

[0007] The controller is configured to receive periodic test commands sent by the computer device, and control the power device under test to turn off and the power supply to charge the energy storage circuit according to the test commands.

[0008] The controller is further configured to stop charging the energy storage circuit if the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, control the power device under test to be turned on, and discharge the power device under test through the energy storage circuit within a preset time period to obtain a short-circuit test result.

[0009] In one embodiment, the device further includes a first switch, a first terminal of which is connected to the energy storage circuit, a second terminal of which is connected to the power supply, and a third terminal of which is connected to the controller.

[0010] The controller is configured to control the first switch to close according to the test command, so that the energy storage circuit is charged by the power supply when the first switch is closed.

[0011] In one embodiment, the device further includes a second switch, a first terminal of which is connected to a first terminal of the first switch, a second terminal of which is connected to the drain of the power device under test, and a third terminal of which is connected to the controller.

[0012] The controller is configured to control the second switch to close according to the test command, so as to obtain the drain current of the power device under test when it is turned off when the second switch is closed;

[0013] If the drain current of the power device under test is less than a preset current threshold when it is turned off, and the charging voltage of the energy storage circuit is greater than or equal to the preset voltage threshold, then the charging of the energy storage circuit is stopped, and the power device under test is turned on.

[0014] In one embodiment, the device further includes a third switch, the first terminal of which is grounded, the second terminal of which is connected to the source of the power device under test, and the third terminal of which is connected to the controller.

[0015] The controller is further configured to, if the charging voltage of the energy storage circuit is greater than or equal to the preset voltage threshold, disconnect the first switch to stop charging the energy storage circuit, and close the third switch to control the power device under test to conduct.

[0016] In one embodiment, the energy storage circuit includes a first energy storage module and a second energy storage module. The first energy storage module includes a plurality of first capacitors and a first selection switch corresponding to each of the plurality of first capacitors. The first terminal of each first capacitor is connected to the power supply, the second terminal of each first capacitor is connected to the first terminal of the corresponding first selection switch, the second terminal of the first selection switch is connected to the first terminal of the first switch, and the third terminal of the first selection switch is connected to the controller.

[0017] The second energy storage module includes a plurality of second capacitors and a second selection switch corresponding to each of the plurality of second capacitors. The first end of each second capacitor is connected to the power supply, the second end of each second capacitor is connected to the first end of the corresponding second selection switch, the second end of the second selection switch is connected to the first end of the first switch, and the third end of the second selection switch is connected to the controller.

[0018] In one embodiment, the device further includes a current probe and an oscilloscope, a first end of the current probe being grounded, a second end of the current probe being connected to a first end of the third switch, and a third end of the current probe being connected to the computer device via the oscilloscope.

[0019] The current probe is used to detect the test result of the short-circuit current obtained by discharging the power device under test through the energy storage circuit within the preset time period, wherein the short-circuit test result includes the test result of the short-circuit current.

[0020] The oscilloscope is used to measure the waveform of the short-circuit current.

[0021] In one embodiment, the device further includes a voltage probe, a first end of which is connected to the drain of the power device under test, a second end of which is connected to the first end of the third switch and the second end of the current probe, and a third end of which is connected to the computer device via the oscilloscope.

[0022] The voltage probe is used to detect the test result of the short-circuit voltage obtained by discharging the power device under test through the energy storage circuit within the preset time period, wherein the short-circuit test result includes the test result of the short-circuit voltage;

[0023] The oscilloscope is also used to measure the waveform of the short-circuit voltage.

[0024] In one embodiment, the device further includes a first resistor, the controller includes a drain current detection circuit, a processing circuit, and a gate control circuit, a first terminal of the first resistor is connected to the drain current detection circuit and the source of the power device under test, and a second terminal of the first resistor is grounded.

[0025] The drain current detection circuit and the gate control circuit are connected to the processing circuit.

[0026] In one embodiment, the controller further includes an interface circuit and a drive circuit, the interface circuit being connected to the computer device, and the interface circuit and the drive circuit being connected to the processing circuit.

[0027] The interface circuit is used to receive periodic test commands sent by the computer device and send the test commands to the drive circuit so that the drive circuit controls the first switch to close and the second switch to close according to the test commands.

[0028] In one embodiment, the controller further includes a voltage measurement circuit connected to the processing circuit;

[0029] The voltage measurement circuit is used to measure the charging voltage of the energy storage circuit and send the charging voltage to the processing circuit, so that the processing circuit can determine whether the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold based on the charging voltage.

[0030] The aforementioned short-circuit testing device for power devices includes a controller, an energy storage circuit, a power supply, a power device under test (DUT), and a computer. The controller receives periodic test commands from the computer and, according to the test commands, controls the DUT to turn off and the power supply to charge the energy storage circuit. The controller also stops charging the energy storage circuit if the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, controls the DUT to turn on, and discharges the DUT through the energy storage circuit within a preset time period to obtain the short-circuit test result. In other words, this embodiment of the application receives periodic test commands from a computer device via a controller. Based on these commands, the controller shuts down the power device under test (DUT) and charges the energy storage circuit via the power supply. When the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, the controller stops charging the energy storage circuit and turns on the DUT. This allows the DUT to discharge through the energy storage circuit within a preset time period, obtaining a short-circuit test result. Because the controller can receive periodic test commands from the computer device, it can control the DUT's on / off state according to these commands, keeping the DUT in a repetitive short-circuit test process. This automatically repeats the short-circuit test, improving testing efficiency. For example, the controller receives a test command at regular intervals, such as 1 minute. If the controller receives the first test command at 10:00 AM, it performs a test according to the method provided in this embodiment to obtain the corresponding short-circuit test result. Then, at 10:01 AM, it receives another test command, and the test is automatically repeated in this manner, saving manpower and improving short-circuit test efficiency. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a circuit used in the prior art to perform short-circuit testing on power devices;

[0032] Figure 2A schematic diagram of a short-circuit testing device for a power device provided in an embodiment of this application;

[0033] Figure 3 A circuit diagram of a short-circuit testing device for a power device provided in an embodiment of this application;

[0034] Figure 4 This application provides a schematic diagram of the internal structure of a controller according to an embodiment of the present application;

[0035] Figure 5 This is a circuit diagram of a short-circuit test device for a power device, provided as another embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0037] With the widespread application of third-generation semiconductor devices, power devices have demonstrated excellent performance in power electronics applications. As typical representatives of power devices, silicon carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs) and gallium nitride high electron mobility transistors (GaN HEMTs) offer significant advantages in terms of usable power range and reliability. SiC MOSFETs and GaN HEMTs can operate in high-voltage environments. Due to their higher switching frequency, thinner active layer, higher power density, and better heat dissipation, SiC MOSFETs and GaN HEMTs achieve improved efficiency, enhanced reliability, reduced system size, simplified control, and lower system costs. Currently, the main reliability issues of SiC MOSFETs and GaN HEMTs include ohmic contact reliability, gate reliability, hot electron effects, and inverse piezoelectric effects. However, in practical power electronic systems, power devices do not always operate within a relatively safe electrical and thermal operating range. When human error or load failure occurs, power devices often operate under short-circuit (SC) current conditions. Although these extreme conditions are very brief, they can affect the electrical performance of the device and even cause device failure. Therefore, it is necessary to perform short-circuit current tests on power devices.

[0038] Studies on the short-circuit characteristics of power devices typically involve repeated short-circuit current stress tests to simulate the actual operating environment of the power devices. However, traditional techniques require an external signal generator, such as a gate pulse generator, to perform short-circuit current tests on power devices. A single gate pulse is manually generated by the gate pulse generator to induce a short circuit in the power device, thus achieving a single short-circuit current test. Figure 1 , Figure 1 This is a schematic diagram of a circuit for short-circuit testing of power devices in the prior art. The specific testing process is as follows:

[0039] First, adjust the ambient temperature to the specified value, then use the adjustable voltage source V. DD Make the drain-source voltage V ds Set the value to the specified value and adjust the single-pulse gate-source voltage V according to the specifications of the power device. G The gate pulse width (i.e., short-circuit withstand time) is a specified value, and the signal is transmitted through an external signal generator, namely the gate pulse generator V. GG A single gate pulse causes a short circuit in the power device. Since each gate pulse performs a short-circuit current test on the power device, the gate pulse generator V is manually controlled multiple times. GG This allows the power devices to undergo short-circuit testing with a specified number of pulses and repetition rate.

[0040] However, in practical applications, short-circuit faults in power devices are often repeated multiple times. Manually controlling the signal transmitter can only perform a single short-circuit current test at a time. If multiple short-circuit current tests are to be performed, the signal transmitter needs to be manually controlled multiple times, which leads to time-consuming and labor-intensive testing with low efficiency.

[0041] To address the aforementioned technical problems, embodiments of this application provide a short-circuit testing device for power devices. (Refer to...) Figure 2 , Figure 2 This is a schematic diagram of a short-circuit testing device for a power device provided in an embodiment of this application. The device includes: a controller 21, an energy storage circuit 23, a power supply 24, a power device under test 22, and a computer device 20. The controller 21 is used to receive periodic test commands sent by the computer device 22, and according to the test commands, control the power device under test 22 to turn off and the power supply 24 to charge the energy storage circuit 23. The controller 21 is also used to stop charging the energy storage circuit 23 if the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, and control the power device under test 22 to turn on, and discharge the power device under test 22 through the energy storage circuit 23 within a preset time to obtain the short-circuit test result.

[0042] Optionally, the power supply 24 can be, for example, a programmable adjustable high-voltage DC power supply HVG. The controller 21 receives periodic test commands from the computer device 20 and controls the gate-source voltage V of the power device under test 22 according to the test commands. gsWhen the voltage is less than or equal to the threshold voltage, the power device under test 22 is turned off, and the programmable adjustable high-voltage DC power supply HVG is controlled to charge the energy storage circuit 23. The power supply 24 includes, but is not limited to, the programmable adjustable high-voltage DC power supply HVG. This embodiment does not limit the specific type of the power supply 24, as long as it can achieve the function of charging the energy storage circuit 23.

[0043] Optionally, referring to the above example, after the charging voltage of the energy storage circuit 23 reaches the preset voltage threshold, the controller 21 controls the programmable adjustable high-voltage DC power supply HVG to stop charging the energy storage circuit 23, and controls the gate-source voltage V of the power device under test 22. gs If the voltage exceeds the threshold voltage, the source and drain electrodes of the power device under test 22 will be turned on instantaneously, causing the power device under test 22 to be directly short-circuited. Then, within a preset time period, the energy in the energy storage circuit 23 will pass through the source and drain electrodes of the power device under test 22 to obtain the short-circuit test result.

[0044] It should be noted that: if the gate-source voltage V of the power device under test is 22... gs If the voltage is less than or equal to the threshold voltage, the power device under test 22 is turned off; if the gate-source voltage V of the power device under test 22 is less than or equal to the threshold voltage, the device is turned off. gs If the voltage exceeds the threshold voltage, the power device under test 22 will turn on. Examples of power devices under test include SiC MOSFETs and GaN HEMTs.

[0045] The aforementioned short-circuit testing device for power devices includes a controller 21, an energy storage circuit 23, a power supply 24, a power device under test 22, and a computer device 20. The controller 21 is used to receive periodic test commands sent by the computer device 20, and according to the test commands, control the power device under test 22 to turn off and the power supply 24 to charge the energy storage circuit 23. The controller 21 is also used to stop charging the energy storage circuit 23 if the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, and control the power device under test 22 to turn on, and discharge the power device under test 22 through the energy storage circuit 23 within a preset time to obtain the short-circuit test result. In other words, in this embodiment, the controller 21 receives periodic test commands sent by the computer device 20, and controls the power device under test 22 to turn off and the power supply 24 to charge the energy storage circuit 23 according to the test commands. When the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, the controller 21 controls the power supply 24 to stop charging the energy storage circuit 23 and controls the power device under test 22 to turn on, so that the power device under test 22 is discharged through the energy storage circuit 23 within a preset time to obtain the short circuit test result. Since the controller 21 can receive periodic test commands sent by the computer device 20, it can control the power device under test 22 to turn on and off according to the test commands, so that the power device under test 22 is in the process of repeated short circuit test, thereby automatically repeating the short circuit test on the power device under test 22 and improving the test efficiency. For example, controller 21 receives a test command at regular intervals, such as 1 minute. After receiving the first test command at 10 o'clock, controller 21 performs a test in accordance with the method provided in this embodiment to obtain the short circuit test result corresponding to the test. Then, at 10:01, it receives a new test command and automatically repeats the test in this way, thereby saving manpower and improving the efficiency of short circuit testing.

[0046] In one embodiment, such as Figure 3 As shown, Figure 3 The circuit diagram provided in this application embodiment is a short-circuit test device for a power device. The device also includes a first switch 31, the first end of which is connected to an energy storage circuit 23, the second end of which is connected to a power supply 24, and the third end of which is connected to a controller 21. The controller 21 is used to control the first switch 31 to close according to a test command, so that when the first switch 31 is closed, the energy storage circuit 23 is charged through the power supply 24.

[0047] In the example above, the controller 21 controls the first switch 31 to close according to the test command, so that when the first switch 31 is closed, the energy storage circuit 23 is charged through the programmable adjustable high voltage DC power supply HVG.

[0048] In this embodiment, the device further includes a first switch 31. A first terminal of the first switch 31 is connected to the energy storage circuit 23, a second terminal of the first switch 31 is connected to the power supply 24, and a third terminal of the first switch 31 is connected to a controller 21. The controller 21 is used to control the first switch 31 to close according to a test command, so that when the first switch 31 is closed, the energy storage circuit 23 is charged through the power supply 24. That is, in this embodiment, the controller 21 controls the first switch 31 to close according to a test command, so that when the first switch 31 is closed, the energy storage circuit 23 is charged through the power supply 24, thereby enabling the energy storage circuit 23 to discharge the power device 22 under test to obtain a short-circuit test result.

[0049] In one embodiment, the device further includes a second switch 32, the first end of which is connected to the first end of the first switch 31, the second end of which is connected to the drain of the power device under test 22, and the third end of which is connected to the controller 21. The controller 21 is configured to control the second switch 32 to close according to a test command, so as to obtain the drain current of the power device under test 22 when it is turned off when the second switch 32 is closed. If the drain current of the power device under test 22 when it is turned off is less than a preset current threshold, and the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, then the charging of the energy storage circuit 23 is stopped, and the power device under test 22 is turned on.

[0050] Optional, combined Figure 3 To explain, controller 21 controls the second switch 32 to close according to the test command, and controls the gate-source voltage V of the power device under test 22. gs The voltage is less than or equal to the threshold voltage, causing the power device under test 22 to turn off, so that the drain current of the power device under test 22 when it is turned off can be obtained when the second switch 32 is closed. The drain current is the current flowing from the drain of the power device under test 22 to the source of the power device under test 22, i.e., leakage current.

[0051] If the drain current of the power device under test (DUT) 22 is less than a preset current threshold when it is turned off, and the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, then charging of the energy storage circuit 23 is stopped, and the DUT 22 is turned on to discharge through the energy storage circuit 23 within a preset time period to obtain the short-circuit test result. If the drain current of the DUT 22 is greater than or equal to a preset current threshold when it is turned off, then the DUT 22 or the test socket used to carry the DUT 22 is determined to be short-circuited, that is, the DUT 22 or the test socket is damaged, and the short-circuit test is terminated.

[0052] It should be noted that the preset current threshold is the permissible leakage current of the power device under test 22. If the leakage current of the power device under test 22 exceeds the permissible leakage current, the power device under test 22 is determined to be damaged.

[0053] In this embodiment, the device further includes a second switch 32. The first end of the second switch 32 is connected to the first end of the first switch 31, the second end of the second switch 32 is connected to the drain of the power device under test 22, and the third end of the second switch 22 is connected to a controller 21. The controller 21 is used to control the second switch 32 to close according to a test command, so as to acquire the drain current of the power device under test 22 when it is turned off. If the drain current of the power device under test 22 when it is turned off is less than a preset current threshold, and the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, then charging of the energy storage circuit 23 is stopped, and the power device under test 22 is turned on. In other words, in this embodiment, the controller 21 acquires the drain current of the power device under test 22 when it is turned off according to a test command when the second switch 32 is closed, thereby determining whether the power device under test 22 is damaged based on whether the drain current is less than a preset current threshold, thus avoiding invalid short-circuit testing and saving test costs.

[0054] In one embodiment, the device further includes a third switch 33, the first end of which is grounded, the second end of which is connected to the source of the power device under test 22, and the third end of which is connected to the controller 21. The controller 21 is further configured to, if the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, disconnect the first switch 31 to stop charging the energy storage circuit 23, and close the third switch 33 to control the power device under test 22 to conduct.

[0055] Optional, combined Figure 3 To explain, if the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, the controller 21 controls the first switch 31 to open to stop the power supply 24 from charging the energy storage circuit 23 and controls the third switch 33 to close, and controls the gate-source voltage V of the power device under test 22. gs If the voltage exceeds the threshold voltage, the power device under test 22 will be turned on, that is, the power device under test 22 will be short-circuited. Then the energy of the energy storage circuit 23 will be obtained through the drain and source electrodes of the power device under test 22 to obtain the short-circuit test result.

[0056] In this embodiment, the device further includes a third switch 33. The first terminal of the third switch 33 is grounded, the second terminal of the third switch 33 is connected to the source of the power device under test 22, and the third terminal of the third switch 33 is connected to the controller 21. The controller 21 is further configured to, if the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold, disconnect the first switch 31 to stop charging the energy storage circuit 23, and close the third switch 33 to control the power device under test 22 to conduct. That is, in this embodiment, when the charging voltage of the energy storage circuit 23 is greater than or equal to the preset voltage threshold, the controller 21 controls the first switch 31 to disconnect and the third switch 33 to close, and controls the power device under test 22 to conduct, so that the energy storage circuit 23 can discharge the power device under test 22 to obtain a short-circuit test result.

[0057] In one embodiment, the energy storage circuit 23 includes a first energy storage module 38 and a second energy storage module 39. The first energy storage module 38 includes a plurality of first capacitors and a first selection switch corresponding to each of the plurality of first capacitors. The first end of each first capacitor is connected to the power supply 24, the second end of each first capacitor is connected to the first end of the corresponding first selection switch, the second end of the first selection switch is connected to the first end of the first switch 31, and the third end of the first selection switch is connected to the controller 21. The second energy storage module 39 includes a plurality of second capacitors and a second selection switch corresponding to each of the plurality of second capacitors. The first end of each second capacitor is connected to the power supply 24, the second end of each second capacitor is connected to the first end of the corresponding second selection switch, the second end of the second selection switch is connected to the first end of the first switch 31, and the third end of the second selection switch is connected to the controller 21.

[0058] Optionally, based on the energy storage capacity required for the short-circuit test, the controller 21 controls the number of closed switches in the first energy storage module 38 and the second energy storage module 39 to adjust the energy storage capacity in the energy storage circuit 23. For example, with Figure 3 Taking this as an example, if the energy storage capacity required for the short circuit test is 3μF, then the controller 21 controls the S21 and S22 corresponding to the first capacitor C11 with a specification of 1μF and the first capacitor C12 with a specification of 2μF in the first energy storage module 38 to close respectively.

[0059] Optionally, the first energy storage module 38 includes C11-C13, and the first selection switch corresponding to C11-C13 is S21-S23. The second energy storage module 39 includes C14-C16, and the first selection switch corresponding to C14-C16 is S24-S27. C11-C16 is used to short-circuit the energy storage capacitor.

[0060] In this embodiment, the energy storage circuit 23 includes a first energy storage module 38 and a second energy storage module 39. The first energy storage module 38 includes multiple first capacitors and a first selection switch corresponding to each of the multiple first capacitors. The first terminal of each first capacitor is connected to the power supply 24, the second terminal of each first capacitor is connected to the first terminal of the corresponding first selection switch, the second terminal of the first selection switch is connected to the first terminal of the first switch 31, and the third terminal of the first selection switch is connected to the controller 21. The second energy storage module 39 includes multiple second capacitors and a second selection switch corresponding to each of the multiple second capacitors. The first terminal of each second capacitor is connected to the power supply 24, the second terminal of each second capacitor is connected to the first terminal of the corresponding second selection switch, the second terminal of the second selection switch is connected to the first terminal of the first switch 31, and the third terminal of the second selection switch is connected to the controller 21. Since this embodiment controls the number of closed first and second selection switches through the controller 21, the preset voltage threshold of the energy storage circuit 23 can be adjusted, thereby achieving continuously adjustable short-circuit voltage.

[0061] In one embodiment, the device further includes a current probe 35 and an oscilloscope 37. The first end of the current probe 35 is grounded, the second end of the current probe 35 is connected to the first end of the third switch 33, and the third end of the current probe 35 is connected to the computer device 20 via the oscilloscope 37. The current probe 35 is used to detect the test result of the short-circuit current obtained by discharging the power device 22 under test through the energy storage circuit 23 within a preset time period, wherein the short-circuit test result includes the test result of the short-circuit current. The oscilloscope 37 is used to measure the waveform of the short-circuit current.

[0062] Among them, combined Figure 3 To explain, if the controller 21 detects that the charging voltage of the energy storage circuit 23 has reached a preset voltage threshold, it will control the power supply 24 to stop charging the energy storage circuit 23 and control the gate-source voltage V of the power device under test 22. gs If the voltage exceeds the threshold voltage, the power device under test 22 is turned on. Since the power device under test 22 is turned on, it is directly short-circuited. Within a preset time period, the energy storage circuit 23 discharges through the source and drain electrodes of the power device under test 22 to obtain the test result of the short-circuit current. The current probe 35 connected in series with the power device under test 22 measures the short-circuit current. The waveform of the short-circuit current is measured by the oscilloscope 22 connected to the current probe 35, and the current I curve is recorded and stored in the computer device 20.

[0063] In this embodiment, the device further includes a current probe 35 for detecting the short-circuit current test result obtained by discharging the power device 22 under test through the energy storage circuit 23 within a preset time period, and an oscilloscope 37 for measuring the short-circuit current waveform. The first end of the current probe 35 is grounded, the second end of the current probe 35 is connected to the first end of the third switch 33, and the third end of the current probe 35 is connected to the computer device 20 through the oscilloscope 37. That is, in this embodiment, the current probe 35 detects the short-circuit current obtained by discharging the power device 22 under test through the energy storage circuit 23 within a preset time period, and the oscilloscope 37 measures the waveform of the short-circuit current, thereby measuring the value and waveform of the short-circuit current, and transforming the invisible current signal into a visible current curve, which is convenient for researchers to study the change process of the short-circuit current.

[0064] In one embodiment, the device further includes a voltage probe 36, the first end of which is connected to the drain of the power device under test 22, the second end of which is connected to the first end of the third switch 33 and the second end of the current probe 35, and the third end of which is connected to the computer device 20 via an oscilloscope 37. The voltage probe 36 is used to detect the test result of the short-circuit voltage obtained by discharging the power device under test 22 through the energy storage circuit 23 within a preset time period, wherein the short-circuit test result includes the test result of the short-circuit voltage. The oscilloscope 37 is also used to measure the waveform of the short-circuit voltage.

[0065] Among them, combined Figure 3 To explain, if the controller 21 detects that the charging voltage of the energy storage circuit 23 has reached a preset voltage threshold, it will control the power supply 24 to stop charging the energy storage circuit 23 and control the gate-source voltage V of the power device under test 22. gs If the voltage exceeds the threshold voltage, the power device under test 22 is turned on. Since the power device under test 22 is turned on, it is directly short-circuited. Within a preset time period, the energy storage circuit 23 discharges through the source and drain electrodes of the power device under test 22 to obtain the test result of the short-circuit voltage. The voltage probe 36 connected in parallel with the power device under test 22 measures the short-circuit voltage. The waveform of the short-circuit voltage is measured by the oscilloscope 37 connected to the voltage probe 36, and the voltage V curve is recorded and stored in the computer device 20.

[0066] In this embodiment, the device further includes a voltage probe 36 for detecting the short-circuit voltage test result obtained by discharging the power device 22 under test through the energy storage circuit 23 within a preset time period, and an oscilloscope 37 for measuring the short-circuit voltage waveform. The first end of the voltage probe 37 is connected to the drain of the power device 22 under test, the second end of the voltage probe 37 is connected to the first end of the third switch 33 and the second end of the current probe 35, and the third end of the voltage probe 36 is connected to the computer device 20 through the oscilloscope 37. That is, in this embodiment, the voltage probe 36 detects the short-circuit voltage obtained by discharging the power device 22 under test through the energy storage circuit 23 within a preset time period, and the oscilloscope 37 measures the waveform of the short-circuit voltage, thereby measuring the value and waveform of the short-circuit voltage, and converting the voltage signal invisible to the naked eye into a voltage curve visible to the naked eye, which is convenient for researchers to study the change process of the short-circuit voltage.

[0067] In one embodiment, the device further includes a first resistor 34. (See reference...) Figure 4 , Figure 4 This is a schematic diagram of the internal structure of a controller provided in an embodiment of this application. The controller 21 includes a drain current detection circuit 44, a processing circuit 47, and a gate control circuit 45. The first end of the first resistor 34 is connected to the drain current detection circuit 44 and the source of the power device under test 22, and the second end of the first resistor 34 is grounded. The drain current detection circuit 44 and the gate control circuit 45 are connected to the processing circuit 47.

[0068] The controller 21 includes a drain current detection circuit 44, a processing circuit 47, and a gate control circuit 45, with the drain current detection circuit 44 and the gate control circuit 45 connected to the processing circuit 47.

[0069] In this embodiment, since the current flows from the drain of the power device under test 22 to the source of the power device under test 22, the drain current detection circuit 44 detects the drain current of the power device under test 22 through the first resistor 34. If the drain current exceeds the permissible drain current of the power device under test 22, it is determined that the power device under test 22 or the test socket used to carry the power device under test 22 is short-circuited. That is to say, the power device under test 22 or the test socket is damaged and the short-circuit test is terminated.

[0070] The drain current detection circuit 44 detects the drain current of the power device under test 22 through the first resistor 34. If the drain current does not exceed the permissible drain current of the power device under test 22, it is determined that the power device under test 22 or the test socket used to carry the power device under test 22 is not short-circuited, that is, the power device under test 22 or the test socket is intact. When the controller 21 detects that the charging voltage of the energy storage circuit 23 reaches the preset voltage threshold, the gate control circuit 45 of the controller 21 controls the gate-source voltage V of the power device under test 22 according to the charging voltage of the energy storage circuit 23 reaching the preset voltage threshold. gs If the voltage exceeds the threshold voltage, the power device under test 22 is turned on, causing the power device under test 22 to be directly short-circuited. Then, within a preset time period, the power device under test 22 is discharged through the energy storage circuit 23 to obtain the short-circuit test result.

[0071] In this embodiment, the controller 21 includes a processing circuit connected to the drain current detection circuit 44 and the gate control circuit 45, respectively. The first terminal of the first resistor 34 is connected to the drain current detection circuit 44 and the source of the power device under test 22, and the second terminal of the first resistor 34 is grounded. Because this embodiment uses a processing circuit connected to the drain current detection circuit 44 and the gate control circuit 45, the controller 21 can control the gate-source voltage V of the power device under test 22. gs By continuously switching between positive and negative values, the power device under test 22 is kept in a repetitive short-circuit process, which enables automatic and repeated short-circuit testing, making it convenient to evaluate the short-circuit current reliability of the power device under test 22.

[0072] In one embodiment, the controller 21 further includes an interface circuit 42 and a drive circuit 46. The interface circuit 42 is connected to the computer device 20, and the interface circuit 42 and the drive circuit 46 are connected to the processing circuit 47. The interface circuit 42 is used to receive periodic test commands sent by the computer device 20 and send test commands to the drive circuit 46 so that the drive circuit 46 controls the first switch 31 to close and the second switch 32 to close according to the test commands.

[0073] In this embodiment, combined with Figure 4To illustrate, the controller 21 also includes an interface circuit 42 and a drive circuit 46. The interface circuit 42 is connected to the computer device 20, and both the interface circuit 42 and the drive circuit 46 are connected to the processing circuit 47. The interface circuit 42 receives periodic test commands sent by the computer device 20. Based on the periodic test commands sent by the interface circuit 42, the drive circuit 46 controls the first switch 31 and the second switch 32 to close, and sends the switch status signals of the first switch 31 and the second switch 32 to the processing circuit 47. The processing circuit 47 sends the switch status signals to the gate control circuit 45, and the gate control circuit 45 controls the gate-source voltage V of the power device under test 22 according to the switch status signals. gs If the voltage is less than or equal to the threshold voltage, the power device under test 22 is turned off, and the energy storage circuit 23 is charged through the programmable adjustable high voltage DC power supply HVG.

[0074] In this embodiment, the controller 21 further includes an interface circuit 42 and a drive circuit 46 connected to the computer device 20. The interface circuit 42 and drive circuit 46 are connected to the processing circuit 47. The interface circuit 42 receives periodic test commands sent by the computer device 20 and sends test commands to the drive circuit 46, so that the drive circuit 46 controls the first switch 31 and the second switch 32 to close according to the test commands. In other words, in this embodiment, the interface circuit 42 receives periodic test commands sent by the computer device 20 and sends test commands to the drive circuit 46, so that the drive circuit 46 controls the first switch 31 and the second switch 32 to close according to the test commands.

[0075] In one embodiment, the controller 21 further includes a voltage measurement circuit 43 connected to the processing circuit 47. The voltage measurement circuit 43 is used to measure the charging voltage of the energy storage circuit 23 and send the charging voltage to the processing circuit 47 so that the processing circuit 47 can determine whether the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold based on the charging voltage.

[0076] Among them, combined Figure 4 To illustrate, the voltage measurement circuit 43 in controller 21 is connected to the processing circuit 47, which in turn is connected to the gate control circuit 45. The voltage measurement circuit 43 measures the charging voltage of the energy storage circuit 23 and sends it to the processing circuit 47. When the processing circuit 47 determines that the charging voltage of the energy storage circuit 23 has reached a preset voltage threshold, it sends the charging voltage information to the gate control circuit 45 and the drive circuit 46. The gate control circuit 45 controls the gate-source voltage V of the power device under test 22 based on the charging voltage information. gsWhen the voltage exceeds the threshold voltage, the power device under test 22 is turned on. At the same time, the drive circuit 46 controls the first switch 31 to open and the third switch 33 to close based on the charging voltage information.

[0077] In this embodiment, the controller 21 further includes a voltage measurement circuit 43, which is connected to the processing circuit 47. The voltage measurement circuit 43 measures the charging voltage of the energy storage circuit 23 and sends the charging voltage to the processing circuit 47, so that the processing circuit 47 can determine whether the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold. That is, in this embodiment, the voltage measurement circuit 43 is connected to the processing circuit 47, so that the controller 21 can determine whether the charging voltage of the energy storage circuit 23 is greater than or equal to a preset voltage threshold.

[0078] Optionally, the controller 21 may also include a power supply circuit 41 connected to the processing circuit 47, which provides power to the controller 21.

[0079] Optionally, the device further includes a second resistor 48 and a fourth switch 49. The first end of the second resistor 48 is connected to the first end of the first switch 31 and the second end of the first selector switch. The second end of the second resistor 48 is connected to the first end of the fourth switch 49. The second end of the fourth switch 49 is connected to the power supply 24. The third end of the fourth switch 49 is connected to the controller 21. The second resistor 48 is used after the short-circuit test is completed to detect whether the charging voltage in the energy storage circuit 23 has been cleared by the voltage measurement circuit 43. If the charging voltage has not been cleared, the voltage measurement circuit 43 sends the remaining charging voltage to the processing circuit 47. The drive circuit 46 then controls the second switch 32 to open and the fourth switch 49 to close based on the remaining charging voltage sent by the processing circuit 47, thereby clearing the charge in the energy storage circuit 23.

[0080] Optionally, the device further includes a liquid crystal display (LCD), which is connected to the computer device 20. The computer device 20 and the LCD are used to set test parameters and display the test parameters and curves during the short-circuit test. The specific test parameters are shown in Table 1, where the test interval is the time interval between each short-circuit test, and the number of tests is the number of times the short-circuit test is repeated. The number of tests and the test interval can be preset before the test, and the test is repeated based on the number of tests and the test interval.

[0081] Table 1 Test Parameter Description

[0082]

[0083] To facilitate a clearer understanding of the short-circuit testing device provided in this application by those skilled in the art, this application is combined with... Figure 5A short-circuit testing apparatus for power devices provided in another embodiment of this application will be described in detail. Figure 5 This is a circuit diagram of a short-circuit test device for a power device, provided as another embodiment of this application. Figure 5 The high-voltage DC power supply VS1 is the power supply 24, the computer PC is the computer equipment 20, S11 is the first switch 31, S12 is the second switch 32, S14 is the third switch 33, the capacitor bank is the energy storage circuit 23, the central controller is the controller 21, the USB oscilloscope is the oscilloscope 37, the fourth switch 49 is S13, R2 is the first resistor, the current probe 35 is the current probe P1, the voltage probe 36 is the high-voltage differential probe P2, and the second resistor is R1. The drive circuit 46 is a relay array drive circuit, the interface circuit 42 is the host computer control circuit, the voltage measurement circuit 43 is the capacitor bank voltage measurement circuit, the drain current detection circuit 44 is the ADC acquisition circuit, the gate control circuit 45 is the gate control circuit for the device under test, and the processing circuit 41 is an MCU+FPGA, specifically including the following steps:

[0084] S501. Before the test begins, set the capacity of the capacitor bank (C11-C17) to the set value according to the capacity required for the short circuit test. The power supply circuit 41 of the central controller starts to supply power. By controlling the number of closed switches (S21-S27) of the central controller, the capacity of the capacitor bank is made consistent with the set value.

[0085] S502: The host computer control circuit in the central controller receives the test command sent by the PC and sends the test command to the relay array drive circuit. The relay array drive circuit controls S11 to close and sends the switch status signal of S11 closure to the MCU+FPGA. The MCU+FPGA sends the switch status signal to the gate control circuit of the device under test. The gate control circuit of the device under test controls the gate-source voltage V of the power device under test according to the switch status signal. gs When the voltage drops below the threshold voltage, the power device under test is turned off, and the high-voltage DC power supply VS1 charges the capacitor bank. Here, FPGA stands for Field Programmable Gate Array, and MCU stands for Microcontroller Unit.

[0086] S503: The host computer control circuit in the central controller receives the test command from the PC and sends it to the relay array drive circuit. The relay array drive circuit controls S12 to close and sends the switch status signal of S12 closure to the MCU+FPGA. The MCU+FPGA then sends the switch status signal to the gate control circuit of the device under test (DUT). The gate control circuit of the DUT controls the gate-source voltage V of the power device under test according to the switch status signal.gs If the voltage is less than the threshold voltage, the power device under test is turned off so that the leakage current of the power device under test can be detected by the ADC acquisition circuit through R2. If the leakage current exceeds the permissible value, the power device under test is determined to be damaged and the test is terminated.

[0087] S504, the capacitor group voltage measurement circuit detects that the charging voltage of the capacitor group has reached a preset voltage threshold and sends this charging voltage information to the MCU+FPGA. The relay array drive circuit, based on the charging voltage information sent by the MCU+FPGA, controls S11 to open and S14 to close. Simultaneously, the gate control circuit of the device under test, based on the charging voltage information sent by the MCU+FPGA, controls the gate-source voltage V of the power device under test. gs When the voltage exceeds the threshold voltage, the source and drain terminals of the power device under test are momentarily connected, causing the power device under test to short-circuit. The energy of the capacitor bank is passed through the source and drain terminals of the power device under test to perform a short-circuit test. The current probe P1 connected in series in the circuit and the high-voltage differential probe P2 connected in parallel on both sides of the power device under test detect the short-circuit current and short-circuit voltage during the short-circuit test and record the V / I curve, which is then stored in the computer PC.

[0088] S505. After a preset time, the gate control circuit of the device under test controls the gate-source voltage V of the power device under test. gs If the voltage is less than or equal to the threshold voltage, the power device under test will be turned off, and the short-circuit test will be completed.

[0089] S506. The entire test setup is controlled by a computer (PC). The gate control circuit of the device under test controls the gate-source voltage V of the power device under test. gs The voltage continuously changes between being greater than or equal to and less than a threshold voltage, subjecting the power device under test to a repetitive short-circuit test process.

[0090] S507 After all short-circuit tests are completed, the central controller controls S12 to open and S13 to close, in order to clear the charge inside the capacitor bank.

[0091] The aforementioned short-circuit testing device for power devices includes a controller, an energy storage circuit, a power supply, a power device under test (DUT), and a computer. The controller receives periodic test commands from the computer and, according to the test commands, controls the DUT to turn off and the power supply to charge the energy storage circuit. The controller also stops charging the energy storage circuit if the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, controls the DUT to turn on, and discharges the DUT through the energy storage circuit within a preset time period to obtain the short-circuit test result. In other words, this embodiment of the application receives periodic test commands from a computer device via a controller. Based on these commands, the controller shuts down the power device under test (DUT) and charges the energy storage circuit via the power supply. When the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, the controller stops charging the energy storage circuit and turns on the DUT. This allows the DUT to discharge through the energy storage circuit within a preset time period, obtaining a short-circuit test result. Because the controller can receive periodic test commands from the computer device, it can control the DUT's on / off state according to these commands, keeping the DUT in a repetitive short-circuit test process. This automatically repeats the short-circuit test, improving testing efficiency. For example, the controller receives a test command at regular intervals, such as 1 minute. If the controller receives the first test command at 10:00 AM, it performs a test according to the method provided in this embodiment to obtain the corresponding short-circuit test result. Then, at 10:01 AM, it receives another test command, and the test is automatically repeated in this manner, saving manpower and improving short-circuit test efficiency.

[0092] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0093] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A short-circuit testing device for power devices, characterized in that, The device includes a controller, an energy storage circuit, a power supply, a power device under test, and a computer. The controller is configured to receive periodic test commands sent by the computer device, and control the power device under test to turn off and the power supply to charge the energy storage circuit according to the test commands. The controller is further configured to, if the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold, stop charging the energy storage circuit, control the power device under test to conduct, and discharge the power device under test through the energy storage circuit within a preset time period to obtain a short-circuit test result. The device further includes a first switch, a first end of which is connected to the energy storage circuit, a second end of which is connected to the power supply, and a third end of which is connected to the controller. The controller is configured to control the first switch to close according to the test command, so that the energy storage circuit is charged through the power supply when the first switch is closed. The device further includes a second switch, the first end of which is connected to the first end of the first switch, the second end of which is connected to the drain of the power device under test, and the third end of which is connected to the controller. The controller is configured to control the second switch to close according to the test command, so as to obtain the drain current of the power device under test when it is turned off when the second switch is closed; If the drain current of the power device under test is less than a preset current threshold when it is turned off, and the charging voltage of the energy storage circuit is greater than or equal to the preset voltage threshold, then the charging of the energy storage circuit is stopped, and the power device under test is turned on.

2. The apparatus according to claim 1, characterized in that, The device further includes a third switch, the first terminal of which is grounded, the second terminal of which is connected to the source of the power device under test, and the third terminal of which is connected to the controller. The controller is further configured to, if the charging voltage of the energy storage circuit is greater than or equal to the preset voltage threshold, disconnect the first switch to stop charging the energy storage circuit, and close the third switch to control the power device under test to conduct.

3. The apparatus according to claim 2, characterized in that, The energy storage circuit includes a first energy storage module and a second energy storage module. The first energy storage module includes a plurality of first capacitors and a first selection switch corresponding to each of the plurality of first capacitors. The first end of each first capacitor is connected to the power supply, the second end of each first capacitor is connected to the first end of the corresponding first selection switch, the second end of the first selection switch is connected to the first end of the first switch, and the third end of the first selection switch is connected to the controller. The second energy storage module includes a plurality of second capacitors and a second selection switch corresponding to each of the plurality of second capacitors. The first end of each second capacitor is connected to the power supply, the second end of each second capacitor is connected to the first end of the corresponding second selection switch, the second end of the second selection switch is connected to the first end of the first switch, and the third end of the second selection switch is connected to the controller.

4. The apparatus according to claim 3, characterized in that, The device also includes a current probe and an oscilloscope. The first end of the current probe is grounded, the second end of the current probe is connected to the first end of the third switch, and the third end of the current probe is connected to the computer equipment through the oscilloscope. The current probe is used to detect the test result of the short-circuit current obtained by discharging the power device under test through the energy storage circuit within the preset time period, wherein the short-circuit test result includes the test result of the short-circuit current. The oscilloscope is used to measure the waveform of the short-circuit current.

5. The apparatus according to claim 4, characterized in that, The device further includes a voltage probe, the first end of which is connected to the drain of the power device under test, the second end of which is connected to the first end of the third switch and the second end of the current probe, and the third end of which is connected to the computer equipment via the oscilloscope. The voltage probe is used to detect the test result of the short-circuit voltage obtained by discharging the power device under test through the energy storage circuit within the preset time period, wherein the short-circuit test result includes the test result of the short-circuit voltage; The oscilloscope is also used to measure the waveform of the short-circuit voltage.

6. The apparatus according to claim 1, characterized in that, The device further includes a first resistor, and the controller includes a drain current detection circuit, a processing circuit, and a gate control circuit. The first end of the first resistor is connected to the drain current detection circuit and the source of the power device under test, and the second end of the first resistor is grounded. The drain current detection circuit and the gate control circuit are connected to the processing circuit.

7. The apparatus according to claim 6, characterized in that, The controller further includes an interface circuit and a drive circuit. The interface circuit is connected to the computer device, and the interface circuit and the drive circuit are connected to the processing circuit. The interface circuit is used to receive periodic test commands sent by the computer device and send the test commands to the drive circuit so that the drive circuit controls the first switch to close and the second switch to close according to the test commands.

8. The apparatus according to claim 7, characterized in that, The controller further includes a voltage measurement circuit, which is connected to the processing circuit. The voltage measurement circuit is used to measure the charging voltage of the energy storage circuit and send the charging voltage to the processing circuit, so that the processing circuit can determine whether the charging voltage of the energy storage circuit is greater than or equal to a preset voltage threshold based on the charging voltage.

Images