CN117647756A

CN117647756A - Method, device, equipment and storage medium for testing short-circuit transient junction temperature of power device

Info

Publication number: CN117647756A
Application number: CN202410116711.9A
Authority: CN
Inventors: 王宏跃; 王萌; 贺致远; 陈义强
Original assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Current assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Priority date: 2024-01-29
Filing date: 2024-01-29
Publication date: 2024-03-05
Anticipated expiration: 2044-01-29
Also published as: CN117647756B

Abstract

The application relates to a power device short circuit transient junction temperature test method, a device, a computer device, a storage medium and a computer program product. The method comprises the following steps: controlling the working time point of the shooting equipment to be earlier than or equal to the time point of short circuit of the power device to be detected; under the condition that the power devices to be tested are short-circuited, shooting surface images of a plurality of the power devices to be tested through the shooting equipment; according to the shot multiple surface images, determining the reflectivity corresponding to the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited; acquiring a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device to be tested; and generating junction temperature thermal imaging when the power device to be tested is in a short circuit state based on the reflectivity corresponding to different moments and the preset mapping relation. By adopting the method, the accuracy of the test can be improved.

Description

Method, device, equipment and storage medium for testing short-circuit transient junction temperature of power device

Technical Field

The present disclosure relates to the field of thermal imaging technologies, and in particular, to a method, an apparatus, a computer device, a storage medium, and a computer program product for testing a short-circuit transient junction temperature of a power device.

Background

In recent years, along with the miniaturization and high efficiency development demands of fields such as automobile electronics, motor drive, power inverter and the like, power devices having advantages such as high breakdown voltage, high operating frequency, low on-resistance and the like are gradually moving to large-scale commercial application. The high power density of the high power device makes the high power device bear higher bus voltage and current when the circuit is short-circuited, and the instantaneous high electric field and high heat generated by the high power device cause the device to fail in a short time. The short-circuit failure time of a part of the power device is usually several microseconds, and the junction temperature of the device rises rapidly in a short time, so that the device burns out.

At present, a common transient junction temperature testing method for a power device comprises an electrical method, namely, testing the electrical parameters of the device by utilizing the relation between the electrical parameters (such as on resistance, gate diode voltage, gate resistance and the like) of the device and the temperature, so as to obtain the junction temperature of the device.

However, the electrical test depends on the relationship between the electrical parameter and the average temperature of the device, and thus the obtained temperature is the average temperature of the device, and it is difficult to obtain an image of the entire temperature distribution of the device. In addition, when the power device is in a short circuit state, the drain electrode bears high bus voltage (usually 100V, 650V and 1200V), the grid electrode is opened, a large amount of high-energy carriers exist in a device channel at the moment, the electrical parameters of the device are obviously influenced, the linear relation between the electrical parameters and the temperature is difficult to verify, the junction temperature extracted by the method is influenced by the device carriers, defects, traps and the linearity between the device carriers, defects, traps and the temperature, analysis is complex, and the error of a test result is large.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a power device short-circuit transient junction temperature test method, apparatus, computer device, storage medium, and computer program product that can improve test accuracy.

In a first aspect, the present application provides a method for testing a short-circuit transient junction temperature of a power device, the method comprising:

controlling the working time point of the shooting equipment to be earlier than or equal to the time point of short circuit of the power device to be detected;

under the condition that the power devices to be tested are short-circuited, shooting surface images of a plurality of the power devices to be tested through the shooting equipment;

according to the shot multiple surface images, determining the reflectivity corresponding to the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited;

acquiring a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device to be tested;

and generating junction temperature thermal imaging when the power device to be tested is in a short circuit state based on the reflectivity corresponding to different moments and the preset mapping relation.

In one embodiment, the controlling the working time point of the shooting device is earlier than or equal to the time point of the short circuit of the power device to be tested, including:

And controlling the time point of the short circuit of the power device to be detected to be synchronous with the working time point of the shooting equipment, wherein the working time length of the shooting equipment is longer than or equal to the short circuit time length of the power device to be detected.

controlling the working time point of shooting equipment to be earlier than the time point of short circuit of a power device to be detected, and determining the time interval between the working time point of the shooting equipment and the time point of short circuit of the power device to be detected;

and determining the working time length of the shooting equipment based on the time interval and the short-circuit time length of the power device to be detected.

In one embodiment, the photographing apparatus includes a light source and a camera, the time point of controlling the power device to be tested to generate a short circuit is synchronous with the working time point of the photographing apparatus, and the working time length of the photographing apparatus is greater than or equal to the short circuit time length of the power device to be tested, including:

setting a light source pulse signal, a camera trigger signal and a short circuit trigger signal to synchronously trigger so that the time sequence of the short circuit of the power device to be tested is synchronous with the working time sequence of shooting equipment;

Setting the time delay of the light source pulse signal and the camera trigger signal to be greater than or equal to the time delay of the short-circuit trigger signal, so that the working time length of the light source and the camera is greater than or equal to the short-circuit time length of the power device to be tested;

the short-circuit trigger signal is used for controlling the power device to be tested to be in a short-circuit state; the camera trigger signal is used for driving the camera to work; the light source pulse signal is used for driving the light source to generate test light, the test light acts on the surface of the power device to be tested through the objective lens and forms reflected light, and the reflected light enters the camera through the objective lens.

In one embodiment, the generating the junction thermal imaging when the power device to be tested is in the short-circuit state based on the reflectivity corresponding to different moments and the preset mapping relation includes:

determining the temperature of the surface of the power device to be tested at different moments based on the reflectivity corresponding to the different moments and the preset mapping relation;

generating a thermal imaging frame of the power device to be tested at the time based on the temperature of the surface of the power device to be tested at the time;

And generating a junction temperature thermal imaging corresponding to the power device to be detected in a short circuit state based on the thermal imaging frame of the power device to be detected at each moment.

In one embodiment, the generating, based on the thermal imaging frames of the power device to be tested at each time, the junction temperature thermal imaging corresponding to the power device to be tested in the short-circuit state includes:

determining a thermal imaging frame in a short circuit period from thermal imaging frames of the power device to be tested at each moment based on a preset temperature threshold and the temperature of the surface of the power device to be tested at each moment;

and generating corresponding junction temperature thermal imaging when the power to be detected is in a short circuit state based on the thermal imaging frame in the short circuit period.

In one embodiment, the method further comprises:

placing a power device at different environmental temperatures, and acquiring corresponding reflectivities of the power device at different environmental temperatures through the shooting equipment;

and determining the mapping relation based on the association relation between the ambient temperature and the reflectivity.

In a second aspect, the application also provides a power device short-circuit transient junction temperature testing device. The device comprises:

The driving module is used for controlling the working time point of the shooting equipment to be earlier than or equal to the time point of short circuit of the power device to be detected;

the shooting module is used for shooting surface images of a plurality of power devices to be tested through the shooting equipment under the condition that the power devices to be tested are short-circuited;

the reflectivity determining module is used for determining the reflectivity corresponding to the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited according to a plurality of shot surface images;

the acquisition module is used for acquiring a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device to be tested;

and the thermal imaging generation module is used for generating junction temperature thermal imaging when the power device to be tested is in a short circuit state based on the reflectivity corresponding to different moments and the preset mapping relation.

In a third aspect, the present application also provides a computer device. The computer equipment comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the power device short circuit transient junction temperature testing method when executing the computer program.

In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium has stored thereon a computer program which when executed by a processor implements the steps of the power device short circuit transient junction temperature test method described above.

In a fifth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, realizes the steps of the power device short circuit transient junction temperature testing method.

According to the method, the device, the computer equipment, the storage medium and the computer program product for testing the short-circuit transient junction temperature of the power device, the working time point of the shooting equipment is controlled to be earlier than or equal to the time point of short-circuit of the power device to be tested, so that the required surface image can be captured at the key moment, and accurate and timely basic information is provided for the follow-up generation of junction temperature thermal imaging; under the condition that the power device to be tested is short-circuited, a plurality of surface images are shot through shooting equipment, the reflectivity of the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited can be determined according to the shot plurality of surface images, and the surface state and the temperature change of the power device to be tested can be analyzed through the change of the reflectivity; by acquiring a preset mapping relation, the relation characterizes the relation between the reflectivity and the temperature of the surface of the power device to be tested, the reflectivity data can be quickly and accurately converted into the temperature data, the data analysis process is greatly simplified, and based on the mapping relation between the reflectivity and the temperature, the junction temperature thermal imaging of the power device to be tested in a short circuit state is generated, so that the scheme of generating the junction temperature thermal imaging by replacing the relation between the electrical parameter and the average temperature in the traditional scheme is replaced, and the testing accuracy is improved.

Drawings

FIG. 1 is an application environment diagram of a method for testing a short-circuit transient junction temperature of a power device in one embodiment;

FIG. 2 is a flow chart of a method for testing a short-circuit transient junction temperature of a power device according to an embodiment;

FIG. 3 is a block diagram of a power device short circuit transient junction temperature thermography test system according to one embodiment;

FIG. 4 is a schematic diagram of a relationship between an operating time point of a photographing apparatus and a short-circuit time point of a power device under test in one embodiment;

fig. 5 is a schematic diagram of a relationship between an operation time point of a photographing apparatus and a short-circuit time point of a power device to be tested in another embodiment;

FIG. 6 is a schematic diagram showing a relationship between an operation time point of a photographing apparatus and a short-circuit time point of a power device under test according to still another embodiment;

FIG. 7 is a block diagram of a power device short transient junction temperature test apparatus in one embodiment;

fig. 8 is an internal structural diagram of a computer device in one embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

The method for testing the short-circuit transient junction temperature of the power device, which is provided by the embodiment of the application, can be applied to an application environment shown in fig. 1. The tester 102 is connected to a photographing device 104, which is used for photographing the power device to be tested 106 and obtaining multiple surface images of the power device to be tested 106. The tester 102 controls the working time point of the shooting device 104 to be earlier than or equal to the time point when the power device 106 to be tested is short-circuited; under the condition that the power devices 106 to be tested are short-circuited, the tester 102 shoots surface images of the plurality of power devices 106 to be tested through the shooting equipment 104; the tester 102 determines the reflectivity corresponding to the surface of the power device 106 to be tested at different moments under the condition that the power device 106 to be tested is short-circuited according to the plurality of shot surface images; the tester 102 acquires a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device 106 to be tested; the tester 102 generates junction temperature thermal imaging when the power device 106 to be tested is in a short-circuit state based on the reflectivity corresponding to different moments and a preset mapping relation. The tester 102 may be, but is not limited to, various dynamic thermal resistance testers, junction temperature testers, oscilloscopes, etc. The photographing device 104 may be a video camera, a digital camera with an image sensor, a motion camera, or the like.

In one embodiment, as shown in fig. 2, a method for testing a short-circuit transient junction temperature of a power device is provided, and the method is applied to the tester in fig. 1 for illustration, and includes the following steps:

step 202, controlling the working time point of the shooting equipment to be earlier than or equal to the time point of short circuit of the power device to be detected.

The shooting device is used for recording videos or shooting pictures. For example, the photographing device is a CCD camera (i.e., a camera with a charge coupled device (charge coupled device)). The tester controls the working time point of the shooting equipment by generating a trigger signal of the shooting equipment, wherein the trigger signal is a level signal with a certain pulse width, the shooting equipment starts working after receiving the trigger signal, and the working time length of the shooting equipment is determined by the pulse width of the trigger signal.

The working time point of the shooting device refers to the specific time when the shooting device starts working, and the working time point of the shooting device is determined according to the moment when the shooting device receives the trigger signal.

The power device to be tested refers to a power device which needs to be tested and evaluated. In particular, this may refer to various different types of power semiconductor devices, such as transistors, MOSFETs (metal oxide semiconductor field effect transistors), IGBTs (insulated gate bipolar transistors), etc.

The power device to be tested is short-circuited, namely, the positive electrode and the negative electrode of the power device to be tested or the power supply and the ground are accidentally connected together, so that current directly flows without passing through a load. Short circuits typically result in a rapid increase in current, generating a significant amount of heat and electrical power, causing damage to the circuits and devices.

It should be noted that: the method for testing the short-circuit transient junction temperature of the power device is applied to a short-circuit testing scene of the power device to be tested, the power device to be tested is controlled to generate short circuit under the scene, and the junction temperature distribution of the power device to be tested caused by the short circuit is accurately tested under the condition that the power device to be tested generates short circuit.

When the short circuit state of the power device to be detected is measured, the following method can be adopted to cause the power device to be detected to generate short circuit: 1) An external voltage method: and applying voltage exceeding rated voltage to the input end of the power device to be tested, so that the positive electrode and the negative electrode of the power device or the power source and the ground are accidentally connected together, and a short circuit is generated. 2) Manufacturing failure method: the power device under test is shorted by manufacturing a fault inside it. For example, the short circuit may be made by introducing a wire or other conductive material. 3) External circuit method: and the power device to be tested is short-circuited through the connection of an external circuit. For example, a short circuit may be made by directly connecting two pins together.

In order to facilitate control of the time point of the short circuit of the power device to be tested, the embodiment adopts an external voltage method to control the time point of the short circuit of the power device to be tested, specifically, the tester outputs a short circuit trigger signal of the power device to be tested, the short circuit trigger signal is a level signal with a certain pulse width, and the time point of the short circuit of the power device to be tested is controlled by controlling the trigger time of the short circuit trigger signal.

Specifically, the tester generates a trigger signal of the photographing device and a short-circuit trigger signal for controlling the power device to be tested to generate a short circuit, and adjusts the working time point of the photographing device according to the short-circuit trigger signal. If shooting is required before the short circuit occurs, a pre-trigger time may be set to enable the shooting device to start operating for a period of time before the short circuit occurs. If shooting is required while short circuit occurs, a trigger signal of shooting equipment and a short circuit trigger signal can be set to trigger the shooting equipment and the power device to be tested at the same time.

And 204, shooting surface images of a plurality of power devices to be tested through shooting equipment under the condition that the power devices to be tested are short-circuited.

The surface image of the power device to be tested comprises information such as surface temperature distribution information, color change information, burning marks and the like of the power device to be tested. By observing the surface image, the cause of occurrence of short circuits, such as manufacturing defects, metal migration, thermal fatigue, and the like, can be analyzed. This is very valuable for fault diagnosis and failure analysis, helping to improve design or optimize manufacturing processes. In addition, the surface image may provide direct evidence regarding the performance of the power device under test. For example, by observing the temperature distribution and the color change, the heat dissipation performance and reliability of the device can be evaluated.

Specifically, under the condition that the power device to be tested is short-circuited, the shooting equipment starts shooting the surface image of the power device to be tested in advance or at the same time of short-circuiting, and transmits the surface image to the tester.

And 206, determining the reflectivity of the surface of the power device to be tested corresponding to different moments under the condition that the power device to be tested is short-circuited according to the plurality of shot surface images.

The reflectivity of the surface of the power device to be measured at different time points refers to the degree of light reflected by the surface of the power device to be measured at different time points. Reflectance is a measure of the ability of an object to reflect light, typically expressed in fractions or percentages, ranging from 0% (fully absorbed) to 100% (fully reflected).

Specifically, the tester determines reflection spectrum data corresponding to the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited through a plurality of surface images shot by shooting equipment, wherein the reflection spectrum data comprises information such as wavelength, intensity and angle of reflected light. And the tester calculates the reflectivity of the surface of the power device to be tested according to the reflection spectrum data.

In some embodiments, the reflectivity of the surface of the power device to be measured corresponding to different moments may also be calculated by the photographing device. For example, a camera records a reflected image of the surface of the power device under test, and then calculates the reflectivity through image processing and analysis.

Step 208, obtaining a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device to be tested.

The preset mapping relation is summarized by a large amount of test data. For example, a reflectivity thermal imaging system is built, the system comprises an LED light source, a temperature control module and a CCD camera, the temperature of the temperature control module is set, the LED light source is turned on, LED light enters the surface of a device to be detected through an objective lens, reflected light enters the CCD camera through the objective lens to be imaged, a plurality of surface images are obtained, the reflectivity corresponding to the surface images is determined through the CCD camera or a tester, a curve of the reflectivity of the surface of the power device to be detected along with the temperature change is obtained based on the reflectivity and the temperature of the temperature control module, and the slope of the curve is a coefficient Cth between the reflectivity and the temperature.

Specifically, the tester retrieves a preset mapping relation from a local or server.

Step 210, based on the reflectivity corresponding to different moments and a preset mapping relation, generating junction temperature thermal imaging when the power device to be tested is in a short circuit state.

The junction temperature thermal imaging refers to junction temperature of the power device to be tested in a short circuit state. The junction temperature refers to the temperature of the PN junction inside the power device when the power device is in operation.

Specifically, the tester determines temperatures corresponding to reflectivities of the power device to be tested at different moments based on a preset mapping relation, and generates junction temperature thermal imaging when the power device to be tested is in a short-circuit state based on the temperatures corresponding to different moments.

In the method for testing the short-circuit transient junction temperature of the power device, the working time point of the shooting equipment is controlled to be earlier than or equal to the time point of short-circuit of the power device to be tested, so that the required surface image can be captured at the key moment, and accurate and timely basic information is provided for the follow-up generation of junction temperature thermal imaging; under the condition that the power device to be tested is short-circuited, a plurality of surface images are shot through shooting equipment, the reflectivity of the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited can be determined according to the shot plurality of surface images, and the surface state and the temperature change of the power device to be tested can be analyzed through the change of the reflectivity; by acquiring a preset mapping relation, the relation characterizes the relation between the reflectivity and the temperature of the surface of the power device to be tested, the reflectivity data can be quickly and accurately converted into the temperature data, the data analysis process is greatly simplified, and based on the mapping relation between the reflectivity and the temperature, the junction temperature thermal imaging of the power device to be tested in a short circuit state is generated, so that the scheme of generating the junction temperature thermal imaging by replacing the relation between the electrical parameter and the average temperature in the traditional scheme is replaced, and the testing accuracy is improved.

In one embodiment, the method for testing the transient junction temperature commonly used by the power device further comprises an infrared transient temperature measurement method. The principle of infrared temperature measurement is to test the surface temperature of a device by utilizing the intensity of infrared rays radiated by the device. And the transient junction temperature test after the device is powered up is realized by synchronizing the switching signal of the device with the infrared acquisition switch. However, the transient test of the infrared temperature measurement method needs to collect a plurality of infrared radiation images after the device is started, so that the transient time capable of being captured is long, usually hundreds of microseconds to milliseconds at maximum, and the short-circuit time of a high-power device is usually several microseconds, and the junction temperature transient change of the power device under the short-circuit condition cannot be captured by adopting the infrared temperature measurement method.

Therefore, in order to solve the above problem, the embodiment controls the time when the power device to be tested is short-circuited to be synchronous with the working time of the shooting device, so that when the power device to be tested is short-circuited, the shooting device can immediately capture the surface image of the power device to be tested at the beginning of the short circuit, and the working time length of the shooting device is set to be longer than or equal to the short circuit time length, so that the working time length of the shooting device completely covers the short circuit time length in the period of the power device to be tested, that is, the shooting device can completely capture the surface image corresponding to the period when the power device to be tested is short-circuited, and further the junction temperature transient change of the power device to be tested under the short circuit condition is obtained.

In some embodiments, controlling the working time point of the shooting device to be earlier than or equal to the time point of the short circuit of the power device to be tested includes:

Specifically, the tester is connected with the power device to be tested and the shooting equipment to establish a communication and control channel. Logic is written in control software or firmware of the tester to control short circuit of the power device to be tested and work of shooting equipment at the same time. When the power device to be tested is triggered to generate short circuit, the shooting equipment is synchronously triggered to work so as to realize time synchronization between the power device to be tested and the shooting equipment. When the shooting equipment and the power device to be detected are triggered, the working time length of the shooting equipment is set, and the working time length of the shooting equipment is ensured to be more than or equal to the short-circuit time length of the power device to be detected.

In this embodiment, since the time point when the power device to be tested is short-circuited is set to be synchronous with the working time point of the shooting device, and the working time length of the shooting device is greater than or equal to the short-circuit time length of the power device to be tested, the shooting device can immediately capture the surface image of the power device to be tested at the beginning of the short-circuit when the power device to be tested is short-circuited, and the working time length of the shooting device completely covers the short-circuit time length during the power device to be tested, namely, the corresponding surface image of the power device to be tested during the short-circuit can be completely captured, and then the junction temperature transient change of the power device to be tested under the short-circuit condition is obtained. The short-circuit time length of the power device to be tested is microsecond, the working time point and the working time length of the shooting equipment are set to be closely related to the short-circuit of the power device to be tested, so that the time resolution of the shooting equipment can reach tens of nanoseconds to milliseconds, the time resolution of a thermal imaging test is greatly improved, the device is suitable for the short-circuit junction temperature test of the power device, and the reliability improvement and failure research of the high-power device are promoted.

In one embodiment, it can be known from the foregoing embodiment that, in order to obtain a surface image corresponding to a short circuit start time of a power device to be tested, the foregoing embodiment sets a time point when the power device to be tested is short-circuited to be synchronous with an operating time point of a shooting device, but in practical application, the operating time point of the shooting device is not synchronous with the short circuit start time of the power device to be tested due to other reasons such as network delay and poor contact of hardware connection, so that a junction temperature transient change corresponding to a complete short circuit period of the power device to be tested cannot be obtained, and a problem that the junction temperature transient change test precision of the power device to be tested is low is caused.

Therefore, in order to solve the above-mentioned problem, the working time point of the photographing device is set to be earlier than the time point when the power device to be tested is short-circuited, that is, the photographing device is allowed to photograph the surface image of the power device to be tested when the power device to be tested is not short-circuited in advance, so that the photographing device can obtain the surface image of the starting time of the short-circuit of the power device to be tested even due to delay control. Further, in order to obtain a junction temperature transient change corresponding to a short circuit period of a complete power device to be tested, the embodiment further sets a time interval between a working time point of the shooting device and a time point of the short circuit of the power device to be tested and a short circuit duration of the power device to be tested, and determines the working duration of the shooting device, so that the working duration of the shooting device completely covers the short circuit duration of the power device to be tested.

controlling the working time point of the shooting equipment to be earlier than the time point of the short circuit of the power device to be detected, and determining the time interval between the working time point of the shooting equipment and the time point of the short circuit of the power device to be detected; and determining the working time of the shooting equipment based on the time interval and the short-circuit time of the power device to be detected.

The working time point of the shooting equipment, the time point of the short circuit of the power device to be detected and the short circuit time length are written into the tester in advance, the tester can be written into the tester in advance according to the preset short circuit time length, the working time length of the shooting equipment is further set, and the working time length of the shooting equipment is written into the tester. After all the control logic is written into the tester, the tester firstly triggers the shooting equipment according to the control logic, and then starts the short circuit of the power device to be tested when the short circuit moment of the power device to be tested is reached.

The time interval may be determined based on a difference between a time point at which the power device to be measured is shorted and an operating time point of the photographing apparatus.

Specifically, the tester is connected with the power device to be tested and the shooting equipment to establish a communication and control channel. Writing logic in control software or firmware of the tester, writing a working time point T1 of the shooting equipment, a time point T2 of short circuit of the power device to be tested and a short circuit time length T of the power device to be tested into the tester in advance, and determining a time interval Deltat between the working time point of the shooting equipment and the time point of short circuit of the power device to be tested according to a difference value between T2 and T1; the tester determines the working time of the shooting equipment according to the time interval delta T and the short-circuit time T.

In some embodiments, the operational time period of the photographing apparatus is equal to or greater than the sum of the time interval Δt and the short-circuit time period T.

In this embodiment, the working time point of the photographing device is set to be earlier than the time point when the power device to be tested is short-circuited, that is, the photographing device is enabled to photograph the surface image of the power device to be tested when the power device to be tested is not short-circuited in advance, so that even for the reason of delay control, the photographing device can acquire the surface image of the starting time of the short circuit of the power device to be tested. Further, the working time of the shooting equipment is determined based on the time interval between the working time point of the shooting equipment and the time point of the short circuit of the power device to be detected and the short circuit time length of the power device to be detected, so that the working time length of the shooting equipment completely covers the short circuit time length of the power device to be detected, the corresponding junction temperature transient change of the complete power device to be detected in the short circuit time period can be obtained, the control precision of the short circuit transient junction temperature of the power device to be detected is improved, the time resolution of a thermal imaging test is greatly improved, the thermal imaging test is suitable for the short circuit junction temperature test of the power device, and the reliability improvement and failure research of the high-power device are promoted.

In one embodiment, FIG. 3 is a block diagram of a power device short circuit transient junction temperature thermography test system according to one embodiment, as shown in FIG. 3, including testing The device comprises an instrument, shooting equipment, a grid driving module, a power device to be tested and a short-circuit protection device. The shooting equipment comprises a light source and a camera, wherein the light source is used for providing required illumination for a power device to be tested so as to perform junction temperature thermal imaging. The camera is used for shooting the power device to be tested and obtaining a surface image; as shown in fig. 3, the camera adopts a CCD camera. The short-circuit protection device is used to protect the test system from over-current and over-voltage due to a short circuit of the power device. As shown in fig. 3, the short-circuit protection device includes a resistor R _G Resistance R _G And the power device is connected with the grid electrode of the power device to be tested to provide protection for the grid electrode of the power device to be tested. The grid driving module, the power device to be tested and the short-circuit protection device are all arranged on the short-circuit test circuit board.

The tester is respectively connected with the light source and the camera and is used for controlling the light source and the camera to work; the tester is also connected with the grid electrode of the power device to be tested through a short circuit trigger port, a grid electrode driving module and a short circuit protection device passing through the short circuit test circuit board.

It should be noted that: bus power supply V in FIG. 3 _DC Is a capacitor C _DC Charging is performed to make the capacitor C _DC Storing the electrical energy. Once the test is needed, the system uses the control circuit to control the capacitor C _DC Discharging to the power device to be tested. In this process, capacitor C _DC The buffer function is achieved, so that the power supply can provide stable and continuous current for the power device to be tested, and the influence of power supply fluctuation or excessive transient current on a test result is avoided.

In some embodiments, controlling a time point when a power device to be tested is short-circuited to be synchronous with an operating time point of the photographing apparatus, where an operating time period of the photographing apparatus is greater than or equal to a short-circuit period of the power device to be tested, including:

setting a light source pulse signal, a camera trigger signal and a short circuit trigger signal to synchronously trigger so that the time sequence of the short circuit of the power device to be tested is synchronous with the working time sequence of the shooting equipment; and setting the time delay of the light source pulse signal and the camera trigger signal to be greater than or equal to the time delay of the short-circuit trigger signal, so that the working time length of the light source and the camera is greater than or equal to the short-circuit time length of the power device to be tested.

The short circuit trigger signal is used for controlling the power device to be tested to be in a short circuit state; the camera trigger signal is used for driving the camera to work; the light source pulse signal is used for driving the light source to generate test light, the test light acts on the surface of the power device to be tested through the objective lens and forms reflected light, and the reflected light enters the camera through the objective lens.

Wherein, the time delay refers to the triggering time of the triggering signal. The longer the time delay of the trigger signal is, the longer the working time of the controlled object is. For example, the longer the delay of the short trigger signal, the longer the short duration.

Specifically, the tester is connected with the shooting equipment and the power device to be tested in hardware to ensure that signal transmission can be carried out between the tester and the shooting equipment and between the tester and the power device to be tested. The tester synchronously generates a light source pulse signal, a camera trigger signal and a short circuit trigger signal, when the power device to be tested receives the short circuit trigger signal, the power device to be tested is in short circuit, and meanwhile, software or firmware of the light source and the camera receives a shooting equipment trigger signal and starts to work, so that a corresponding surface image when the power device to be tested is in short circuit can be obtained. The tester sets a light source pulse signal and a camera trigger signal with a pulse width larger than or equal to that of a short-circuit trigger signal of the power device to be tested, the working time of the light source and the camera are related to the pulse width of the trigger signal of the shooting equipment, and the short-circuit time of the power device to be tested is related to the pulse width of the short-circuit trigger signal.

For example, fig. 4 is a schematic diagram of a relationship between an operating time point of a photographing device and a short circuit time point of a power device to be tested in an embodiment, as shown in fig. 4, a light source pulse signal, a camera trigger signal and a short circuit trigger signal are triggered synchronously, and a time delay of the light source pulse signal and the camera trigger signal is greater than or equal to a time delay of the short circuit trigger signal.

In this embodiment, by setting the light source pulse signal, the camera trigger signal and the short circuit trigger signal to synchronously trigger, so that the time sequence of the short circuit of the power device to be tested is synchronous with the working time sequence of the shooting device, by synchronous triggering, it can be ensured that the shooting device can immediately respond and record the key time sequence when the short circuit of the power device to be tested occurs, and because all devices synchronously work, data deviation or omission caused by inconsistent response time of different devices can be reduced. Further, the time delay of the light source pulse signal and the camera trigger signal is set to be greater than or equal to the time delay of the short-circuit trigger signal, so that the working time of the light source and the camera is greater than or equal to the short-circuit time of the power device to be tested, and enough lighting and shooting records can be ensured in the whole process of short-circuit occurrence, so that complete short-circuit time sequence information is obtained. The above processes are controlled automatically and precisely, so that the test flow can be simplified, errors caused by manual operation are reduced, and the consistency and reliability of the test are improved.

In one embodiment, controlling the working time point of the shooting device to be earlier than the time point of the short circuit of the power device to be tested includes:

The triggering time of the light source pulse signal and the camera triggering signal is set to be earlier than the triggering time of the short-circuit triggering signal, so that the working time point of the shooting equipment is earlier than the time point of the short circuit of the power device to be detected.

Fig. 5 is a schematic diagram of a relationship between an operating time point of a photographing device and a short-circuit time point of a power device to be tested in another embodiment, as shown in fig. 5, a trigger time of a light source pulse signal and a trigger signal of a camera is earlier than a trigger time of the short-circuit trigger signal to trigger synchronously, and an operating time length of the light source and the camera is greater than or equal to a sum of a time interval between the operating time point of the photographing device and the time point of the short-circuit of the power device to be tested and a short-circuit time length of the power device to be tested.

In this embodiment, the trigger time of the light source pulse signal and the camera trigger signal is set to be earlier than the trigger time of the short circuit trigger signal, so that the working time point of the shooting device is earlier than the time point of the short circuit of the power device to be tested, and the working time length of the light source and the camera is set to be greater than or equal to the sum of the time interval between the working time point of the shooting device and the time point of the short circuit of the power device to be tested and the short circuit time length of the power device to be tested. By triggering the shooting equipment in advance, delay or interruption possibly occurring in the test process can be reduced, so that the overall efficiency of the test is improved; by accurately controlling and recording the triggering time points of the pulse signals of each light source, the triggering signals of the camera and the short-circuit triggering signals, the characteristics and changes of each stage in the short-circuit generating process can be more accurately analyzed, and therefore the analysis precision is improved.

In one embodiment, generating junction temperature thermal imaging when the power device to be tested is in a short-circuit state based on reflectivity corresponding to different moments and a preset mapping relation includes:

determining the temperature of the surface of the power device to be measured at different moments based on the corresponding reflectivity at the different moments and a preset mapping relation; for each moment, generating a thermal imaging frame of the power device to be tested at the moment based on the temperature of the surface of the power device to be tested at the moment; and generating a corresponding junction temperature thermal imaging when the power device to be tested is in a short circuit state based on the thermal imaging frame of the power device to be tested at each moment.

Wherein, the thermal imaging frame refers to an image captured by a thermal imaging technology, and can display the temperature distribution of an object. A thermal imaging frame refers to an image frame corresponding to a certain moment. And (5) continuously connecting the continuous thermal imaging frames to obtain junction temperature thermal imaging when the power device to be tested is in a short circuit state.

Specifically, the tester obtains the reflectivities of the power device to be tested at different moments; the tester establishes mapping relations between different reflectivities and temperatures according to historical data or experimental results; the tester calculates the surface temperature of the power device to be tested based on the reflectivity measured value at the current moment and the mapping relation, and generates a thermal imaging frame of the power device to be tested at the moment based on the surface temperature; the acquired thermal imaging frames are processed, such as denoising, contrast enhancement, etc., to improve image quality. And capturing thermal imaging of the power device to be tested by using a thermal infrared imager in a short circuit state of the power device to be tested.

In the embodiment, the working state and the temperature change of the power device to be tested can be monitored in real time by capturing the thermal imaging frame in real time, and the temperature is determined by adopting a calculation method based on the reflectivity and the mapping relation, so that the limitation of the traditional temperature measurement method is avoided, and the testing efficiency and the accuracy are improved.

In one embodiment, as can be seen from the foregoing embodiment, the working time point of the photographing device is earlier than the time point of the short circuit of the power device to be tested, or the working time of the photographing device is longer than the short circuit time length, so that the surface image photographed by the photographing device may include an image during a non-short circuit period and an image during the short circuit period.

In some embodiments, generating a junction temperature thermal image corresponding to a power device under test in a short circuit state based on thermal image frames of the power device under test at each time includes:

Determining a thermal imaging frame in a short circuit period from thermal imaging frames of the power device to be tested at each moment based on a preset temperature threshold and the temperature of the surface of the power device to be tested at each moment; and generating corresponding junction temperature thermal imaging when the power to be detected is in a short circuit state based on the thermal imaging frame in the short circuit period.

The thermal imaging frame in the short circuit period can be determined according to the temperature corresponding to the thermal imaging frame, and the temperature corresponding to the short circuit period is much higher than the temperature in the non-short circuit period, so that the thermal imaging frame corresponding to the temperature abrupt change position or the thermal imaging frame with the temperature larger than the preset temperature threshold value can be determined as the thermal imaging frame in the short circuit period.

Specifically, the tester sets a preset temperature threshold that can be used to determine whether the power device is in a short circuit condition. When the temperature of the power device under test exceeds the threshold, it can be considered that a short circuit has occurred. The tester determines which frames correspond to the short-circuit period by comparing the temperature with a preset temperature threshold in the thermal imaging frames at each instant. And generating junction temperature thermal imaging when the power to be detected is in a short circuit state by using temperature data in the short circuit period.

In some embodiments, the thermal imaging frames during the short circuit may also be determined from the time of the short circuit. For example, when the time t0 is the short-circuit time, it is determined that the thermal imaging frame corresponding to the time t0 is the thermal imaging frame during the short-circuit period.

In some embodiments, in order to obtain a large amount of test data when a short-circuit transient junction temperature test is performed, the short-circuit trigger signal is set as a periodic trigger signal, fig. 6 is a schematic diagram of a relationship between an operation time point of the photographing device and a short-circuit time point of a power device to be tested in still another embodiment, as shown in fig. 6, where the short-circuit trigger signal is periodically triggered according to a preset time interval, during which the operation time point of the photographing device is earlier than or equal to a time point when the short-circuit occurs in the power device to be tested, and besides setting the operation time period of the photographing device to be related to the short-circuit time period, the photographing device may be set to be in an operation state since the start of operation, that is, the operation time period of the photographing device is stopped after the test is finished, in which case, the photographing device obtains a large amount of thermal imaging frames during the short-circuit period and thermal imaging frames during the non-short-circuit period, so, in order to avoid interference of the thermal imaging frames during the non-short-circuit period to the test result, the thermal imaging frames during the short-circuit period are screened from the thermal imaging frames corresponding to each time point, and the thermal imaging frames corresponding to the thermal imaging frames during the short-circuit period to be detected when the short-circuit power is in the short-circuit state is generated based on the thermal imaging frames corresponding to be selected during the short-circuit period to be detected.

In this embodiment, thermal imaging frames in a short circuit period are screened out from thermal imaging frames corresponding to each moment based on a temperature threshold value, and junction temperature thermal imaging corresponding to the short circuit state of power to be measured is generated based on the thermal imaging frames in the short circuit period, so that interference of thermal imaging frames in a non-short circuit period to a test result can be avoided, and measurement accuracy is improved.

In one embodiment, a method for testing a short-circuit transient junction temperature of a power device further includes:

placing the power device at different environmental temperatures, and acquiring the corresponding reflectivity of the power device at the different environmental temperatures through shooting equipment; and determining a mapping relation based on the association relation between the ambient temperature and the reflectivity.

Specifically, a power device short-circuit transient junction temperature thermal imaging test system as shown in fig. 3 is built, test environments with different temperatures are built through a temperature control module, a power device is placed in the test environments with different temperatures, reflectivities of the power device at different environment temperatures are obtained through shooting equipment, data fitting is conducted based on the reflectivities at different environment temperatures, and a mapping relation between the environment temperatures and the reflectivities is obtained.

In the embodiment, the performance of the power device at different temperatures can be deeply known by measuring the reflectivity at different ambient temperatures, and key parameter basis is provided for evaluating the stability and reliability of the power device; by determining the mapping relation between the ambient temperature and the reflectivity, the surface characteristics of the power device can be better understood by the temperature, the performance of the power device at different temperatures can be predicted, and the basis is provided for the optimal design.

In a detailed embodiment, a method for testing a short-circuit transient junction temperature of a power device includes the steps of:

1. placing the power device at different environmental temperatures, and acquiring the corresponding reflectivity of the power device at the different environmental temperatures through shooting equipment; determining a mapping relation based on the association relation between the ambient temperature and the reflectivity; and executing the second step or the third step.

2. Setting a light source pulse signal, a camera trigger signal and a short circuit trigger signal to synchronously trigger so that the time sequence of the short circuit of the power device to be tested is synchronous with the working time sequence of the shooting equipment; setting the time delay of the light source pulse signal and the camera trigger signal to be greater than or equal to the time delay of the short-circuit trigger signal, so that the working time length of the light source and the camera is greater than or equal to the short-circuit time length of the power device to be tested; executing the fourth step;

3. Controlling the working time point of the shooting equipment to be earlier than the time point of the short circuit of the power device to be detected, and determining the time interval between the working time point of the shooting equipment and the time point of the short circuit of the power device to be detected; determining the working time of shooting equipment based on the time interval and the short-circuit time of the power device to be detected; and executing the fourth step.

4. And under the condition that the power devices to be tested are short-circuited, shooting surface images of a plurality of power devices to be tested through shooting equipment.

5. And determining the reflectivity of the surface of the power device to be tested corresponding to different moments under the condition that the power device to be tested is short-circuited according to the plurality of shot surface images.

6. And acquiring a preset mapping relation, wherein the mapping relation represents the association relation between the reflectivity and the temperature of the surface of the power device to be tested.

7. And determining the temperature of the surface of the power device to be measured at different moments based on the corresponding reflectivity at the different moments and a preset mapping relation.

8. For each moment, generating a thermal imaging frame of the power device to be tested at the moment based on the temperature of the surface of the power device to be tested at the moment.

9. And determining a thermal imaging frame in a short circuit period from the thermal imaging frames of the power device to be tested at each moment based on a preset temperature threshold and the temperature of the surface of the power device to be tested at each moment.

10. And generating corresponding junction temperature thermal imaging when the power to be detected is in a short circuit state based on the thermal imaging frame in the short circuit period.

In the embodiment, the working time point of the shooting equipment is controlled to be earlier than or equal to the time point of short circuit of the power device to be detected, so that the required surface image can be captured at the key moment, and accurate and timely basic information is provided for the follow-up generation of junction temperature thermal imaging; under the condition that the power device to be tested is short-circuited, a plurality of surface images are shot through shooting equipment, the reflectivity of the surface of the power device to be tested at different moments under the condition that the power device to be tested is short-circuited can be determined according to the shot plurality of surface images, and the surface state and the temperature change of the power device to be tested can be analyzed through the change of the reflectivity; by acquiring a preset mapping relation, the relation characterizes the association between the reflectivity and the temperature of the surface of the power device to be tested, and can rapidly and accurately convert the reflectivity data into temperature data, so that the data analysis process is greatly simplified and the test accuracy is improved; by controlling the working time sequence and the working time length of the shooting equipment, the working time length of the shooting equipment completely covers the short-circuit time length in the period of the power to be detected, so that the junction temperature transient change corresponding to the period of the short-circuit of the complete power device to be detected can be obtained, and the short-circuit transient junction temperature control precision of the power to be detected is improved.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.

Based on the same inventive concept, the embodiment of the application also provides a power device short-circuit transient junction temperature testing device for realizing the power device short-circuit transient junction temperature testing method. The implementation scheme of the device for solving the problem is similar to that described in the method, so the specific limitation in the embodiments of the device for testing the short-circuit transient junction temperature of one or more power devices provided below can be referred to the limitation of the method for testing the short-circuit transient junction temperature of the power devices hereinabove, and will not be repeated here.

In one embodiment, as shown in fig. 7, there is provided a power device short-circuit transient junction temperature testing apparatus, including:

the driving module 701 is configured to control an operation time point of the photographing apparatus to be earlier than or equal to a time point when a short circuit occurs in the power device to be tested.

The shooting module 702 is configured to shoot, by using a shooting device, surface images of a plurality of power devices to be tested in case of a short circuit of the power devices to be tested.

The reflectivity determining module 703 is configured to determine, according to the captured plurality of surface images, the reflectivity of the surface of the power device to be tested corresponding to different times when the power device to be tested is short-circuited.

The obtaining module 704 is configured to obtain a preset mapping relationship, where the mapping relationship characterizes a correlation relationship between a reflectivity of a surface of the power device to be tested and a temperature.

The thermal imaging generating module 705 is configured to generate junction temperature thermal imaging when the power device to be tested is in a short-circuit state based on the reflectivity corresponding to different moments and a preset mapping relation.

In one embodiment, the driving module 701 is further configured to control the time point when the power device to be tested is short-circuited to be synchronous with the working time point of the photographing apparatus, and the working time of the photographing apparatus is longer than or equal to the short-circuit time of the power device to be tested.

In one embodiment, the driving module 701 is further configured to control an operation time point of the photographing apparatus to be earlier than a time point when the power device to be tested is short-circuited, and determine a time interval between the operation time point of the photographing apparatus and the time point when the power device to be tested is short-circuited; and determining the working time of the shooting equipment based on the time interval and the short-circuit time of the power device to be detected.

In one embodiment, the photographing apparatus includes a light source and a camera, and the driving module 701 is further configured to set a light source pulse signal, a camera trigger signal, and a short circuit trigger signal to trigger synchronously, so that a timing sequence of occurrence of a short circuit of the power device to be tested is synchronous with an operation timing sequence of the photographing apparatus; setting the time delay of the light source pulse signal and the camera trigger signal to be greater than or equal to the time delay of the short-circuit trigger signal, so that the working time length of the light source and the camera is greater than or equal to the short-circuit time length of the power device to be tested; the short circuit trigger signal is used for controlling the power device to be tested to be in a short circuit state; the camera trigger signal is used for driving the camera to work; the light source pulse signal is used for driving the light source to generate test light, the test light acts on the surface of the power device to be tested through the objective lens and forms reflected light, and the reflected light enters the camera through the objective lens.

In one embodiment, the thermal imaging generating module 705 is further configured to determine a temperature of a surface of the power device to be measured at different moments based on the reflectivity corresponding to the different moments and a preset mapping relationship; for each moment, generating a thermal imaging frame of the power device to be tested at the moment based on the temperature of the surface of the power device to be tested at the moment; and generating a corresponding junction temperature thermal imaging when the power device to be tested is in a short circuit state based on the thermal imaging frame of the power device to be tested at each moment.

In one embodiment, the thermal imaging generating module 705 is further configured to determine, from thermal imaging frames of the power device to be tested at each moment, a thermal imaging frame during a short circuit based on a preset temperature threshold and a temperature of a surface of the power device to be tested at each moment; and generating corresponding junction temperature thermal imaging when the power to be detected is in a short circuit state based on the thermal imaging frame in the short circuit period.

In one embodiment, the obtaining module 704 is further configured to place the power device at different ambient temperatures, and obtain, by using the photographing device, a reflectivity of the power device corresponding to the different ambient temperatures; and determining a mapping relation based on the association relation between the ambient temperature and the reflectivity.

All or part of each module in the power device short-circuit transient junction temperature testing device can be realized by software, hardware and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and the internal structure thereof may be as shown in fig. 8. The computer device includes a processor, a memory, an input/output interface, a communication interface, a display unit, and an input means. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input/output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program when executed by a processor is used for realizing a power device short circuit transient junction temperature testing method. The display unit of the computer equipment is used for forming a visual picture, and can be a display screen, a projection device or a virtual reality imaging device, wherein the display screen can be a liquid crystal display screen or an electronic ink display screen, the input device of the computer equipment can be a touch layer covered on the display screen, can also be a key, a track ball or a touch pad arranged on a shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the structure shown in fig. 8 is merely a block diagram of some of the structures associated with the present application and is not limiting of the computer device to which the present application may be applied, and that a particular computer device may include more or fewer components than shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the method embodiments described above when the computer program is executed.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the method embodiments described above.

In an embodiment, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the steps of the method embodiments described above.

It should be noted that, the user information (including, but not limited to, user equipment information, user personal information, etc.) and the data (including, but not limited to, data for analysis, stored data, presented data, etc.) referred to in the present application are information and data authorized by the user or sufficiently authorized by each party, and the collection, use and processing of the related data are required to comply with the related laws and regulations and standards of the related countries and regions.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the various embodiments provided herein may include at least one of relational databases and non-relational databases. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processors referred to in the embodiments provided herein may be general purpose processors, central processing units, graphics processors, digital signal processors, programmable logic units, quantum computing-based data processing logic units, etc., without being limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims

1. A method for testing a short-circuit transient junction temperature of a power device, the method comprising:

2. The method according to claim 1, wherein the controlling the operation time point of the photographing device is earlier than or equal to the time point when the power device to be tested is short-circuited, comprising:

3. The method according to claim 1, wherein the controlling the operation time point of the photographing device is earlier than or equal to the time point when the power device to be tested is short-circuited, comprising:

4. The method according to claim 2, wherein the photographing apparatus includes a light source and a camera, the time point of controlling the short circuit of the power device to be measured is synchronized with the operation time point of the photographing apparatus, and the operation time period of the photographing apparatus is longer than or equal to the short circuit period of the power device to be measured, comprising:

5. The method of claim 1, wherein generating junction temperature thermal imaging of the power device under test in a short circuit state based on the reflectivity corresponding to different times and the preset mapping relation comprises:

6. The method of claim 5, wherein generating a junction temperature thermal image corresponding to the power device under test in a short circuit state based on the thermal image frames of the power device under test at each time instant comprises:

7. The method according to claim 1, wherein the method further comprises:

8. A power device short circuit transient junction temperature testing device, the device comprising:

9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.