SiC MOSFET module stress wave source inversion method, apparatus and device, and storage medium

Abstract

The invention provides a SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) module stress wave source inversion method, device and equipment and a storage medium. Relates to the technical field of power device packaging state detection. The method comprises the following steps: constructing a simulation model of transmission of stress waves in a DBC board; wherein the simulation model comprises a DBC board module and a ceramic piezoelectric sensor module arranged below the DBC board module, a stress load is added on the upper surface of the DBC board module as excitation, and the stress load is simulated by Gaussian pulse; determining a transfer function according to the excitation source and the stress wave signal at the bottom of the DBC plate; building a DBC plate stress wave propagation experiment system, and obtaining a stress wave penetration signal; and according to the transfer function and the stress wave penetration signal, calculating to obtain a frequency domain signal and a time domain signal of the stress wave source. According to the invention, the stress wave signal at the bottom of the module is measured, and the signal of the stress wave source is successfully restored.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power device package state detection, in particular to a SiC MOSFET module stress wave source inversion method, device, equipment and storage medium. BACKGROUND

[0002] With the development of high frequency and integration of power systems, power devices are more and more applied to higher voltage and current levels. In the face of high voltage, high frequency and high temperature working environment, the probability of power device failure and failure increases significantly. The detection method based on power device electrical parameters, magnetic parameters and thermal parameters cannot have the characteristics of real-time, rapid and non-invasive, and cannot effectively analyze and judge the accurate fault information inside the device. Therefore, finding a more efficient, more accurate and real-time online power device state detection method is an important direction of current research.

[0003] As a non-destructive real-time detection technology, stress wave detection technology has been widely used in fields such as pipeline leakage detection and material damage detection in recent years. With the discovery that stress waves are generated during the switching process of power devices, and that the amplitude, frequency and phase of the stress wave carry the characteristic information of the power device package when it propagates in the power device, stress wave detection is expected to become a more effective, accurate and real-time online power device state detection method. Existing researches focus on the relationship between stress waves and specific failure types inside the power device, and the relationship between stress wave characteristics and electrical parameters of the power device, but lack research on the signal characteristics of the stress wave source. Identifying the signal characteristics of the stress wave source plays a key role in revealing the transmission characteristics of the stress wave in the power device and establishing an accurate power device state detection model. SUMMARY

[0004] The present application provides a SiC MOSFET module stress wave source inversion method, device, equipment and storage medium to solve the problem that the prior art cannot determine the signal waveform of the stress wave generated in the SiC MOSFET power module. By simulating the transmission of the stress wave in the DBC plate in the finite element software, analyzing the transfer function of the stress wave transmission in the DBC plate, proposing a stress wave source inversion algorithm, and deducing the stress wave source signal according to the measured stress wave signal.

[0005] In a first aspect, the present application provides a SiC MOSFET module stress wave source inversion method, comprising:

[0006] A simulation model of stress wave transmission in the DBC plate is constructed; wherein the simulation model includes a DBC plate module and a ceramic piezoelectric sensor module arranged below the DBC plate module, a stress load is added to the upper surface of the DBC plate module as an excitation, and the stress load is simulated by a Gaussian pulse.

[0007] determining a transfer function according to the stress wave signal of the excitation source and the bottom of the DBC plate;

[0008] building a stress wave propagation experiment system of the DBC plate, and obtaining a stress wave penetration signal;

[0009] calculating a frequency domain signal and a time domain signal of the stress wave source according to the transfer function and the stress wave penetration signal.

[0010] In a possible design, a simulation model of stress wave transmission in the DBC plate is constructed in the following manner:

[0011] constructing a DBC plate module, and taking ceramic as a ceramic piezoelectric sensor module below the DBC plate module to obtain the simulation model,

[0012] setting the physical field of the simulation model as solid mechanics, and setting each module material in the simulation model according to actual parameters of each structural material of the SiC MOSFET power module; wherein each module material in the simulation model is set as a linear elastic material, and Rayleigh damping is used to simulate the damping of each material:

[0013] C=αM+βK

[0014] wherein C is a Rayleigh damping matrix, M is a mass matrix, K is a stiffness matrix, and α and β are Rayleigh damping coefficients, and the Rayleigh damping coefficients are determined by the following formula:

[0015]

[0016] wherein ξ is the damping ratio of the material, and ω1 and ω2 are characteristic frequencies.

[0017] In a possible design, the expression Γ(t) of the Gaussian pulse changing with time t is:

[0018]

[0019] wherein A represents the amplitude of the Gaussian pulse, e represents the natural constant, σ represents the standard deviation of the Gaussian pulse, and t0 represents the center time of the Gaussian pulse.

[0020] In a possible design, the transfer function is determined according to the stress wave signal of the excitation source and the bottom of the DBC plate, and the method comprises the following steps:

[0021] first and second test points A and B are respectively arranged at the excitation source and the bottom of the DBC plate module, and first and second stress wave signals X A and X B at the excitation source and the bottom of the DBC plate are calculated.

[0022] According to the first stress wave signal X A and the second stress wave signal X B Performing fast Fourier transform to obtain the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B ;

[0023] According to the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B Determine the transfer function, denoted as H=Y A / Y B .

[0024] In a possible design, the DBC plate stress wave propagation experiment system comprises a DBC plate, an excitation source transducer and a receiving end transducer; wherein the excitation source transducer and the receiving end transducer are respectively arranged at the upper end and the lower end of the DBC plate, the excitation source transducer generates a wideband stress wave, and after the stress wave penetrates the DBC plate, the receiving end transducer captures the penetrating stress wave waveform and performs digital processing to obtain a stress wave penetration signal.

[0025] In a possible design, the contact interfaces of the upper end and the lower end of the DBC plate and the excitation source transducer and the receiving end transducer are coated with a coupling agent.

[0026] In a possible design, according to the transfer function and the stress wave penetration signal, the frequency domain signal and the time domain signal of the stress wave source are calculated, comprising:

[0027] Performing fast Fourier transform on the stress wave penetration signal to obtain the frequency domain signal Y1 of the penetrating stress wave;

[0028] According to the frequency domain signal of the penetrating stress wave, the frequency domain signal Y0 of the stress wave source is calculated by the following formula:

[0029]

[0030] Wherein H is the transfer function;

[0031] Based on the frequency domain signal of the stress wave source, the time domain signal X0 of the stress wave source is obtained by inverse fast Fourier transform.

[0032] In a second aspect, the present application provides a SiC MOSFET module stress wave source inversion device, the device comprising:

[0033] The simulation model construction module is configured to construct a simulation model of stress wave transmission in the DBC plate; wherein the simulation model comprises a DBC plate module and a ceramic piezoelectric sensor module arranged below the DBC plate module, a stress load is added to the upper surface of the DBC plate module as an excitation, and the stress load is simulated by a Gaussian pulse;

[0034] The transfer function determination module is configured to determine a transfer function according to the stress wave signal of the excitation source and the bottom of the DBC plate.

[0035] The penetrating signal acquisition module is configured to build a DBC plate stress wave propagation experimental system and acquire a stress wave penetrating signal.

[0036] The wave source signal calculation module is configured to calculate the frequency domain signal and the time domain signal of the stress wave source according to the transfer function and the stress wave penetrating signal.

[0037] In a third aspect, an electronic device is provided, comprising at least one processor and a memory; the memory stores computer execution instructions; the at least one processor executes the computer execution instructions stored in the memory, so that the at least one processor executes the SiC MOSFET module stress wave source inversion method as described in the above first aspect and various possible designs of the first aspect.

[0038] In a fourth aspect, a computer readable storage medium is provided, and the computer readable storage medium stores computer execution instructions; when a processor executes the computer execution instructions, the SiC MOSFET module stress wave source inversion method as described in the above first aspect and various possible designs of the first aspect is implemented.

[0039] In a fifth aspect, a computer program product is provided, comprising a computer program; when the computer program is executed by a processor, the SiC MOSFET module stress wave source inversion method as described in the above first aspect and various possible designs of the first aspect is implemented.

[0040] The SiC MOSFET module stress wave source inversion method, device, equipment and storage medium provided by the application have at least the following beneficial effects:

[0041] When the stress wave method is used to detect the packaging state of the SiC MOSFET power module, the signal of the stress wave source is successfully restored by measuring the stress wave signal at the bottom of the module, thereby solving the problem that the prior art cannot determine the signal waveform of the stress wave generated in the SiC MOSFET power module. BRIEF DESCRIPTION OF DRAWINGS

[0042] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0043] Figure 1 A flow chart of a SiC MOSFET module stress wave source inversion method provided for an embodiment of the present application;

[0044] Figure 2 A simulation model and test point setting diagram provided for an embodiment of the present application;

[0045] Figure 3 A transfer function spectrum diagram provided for an embodiment of the present application; wherein (a) is a transfer function amplitude spectrum; (b) is a transfer function phase spectrum;

[0046] Figure 4 A schematic diagram of a stress wave propagation experimental system provided for an embodiment of the present application;

[0047] Figure 5 A time domain signal diagram of a stress wave source provided for an embodiment of the present application;

[0048] Figure 6 A structural diagram of a SiC MOSFET module stress wave source inversion device provided for an embodiment of the present application.

[0049] Through the above-mentioned drawings, the specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0050] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is made with reference to the accompanying drawings in which like reference numerals represent like elements, unless the context of use indicates otherwise. The following exemplary embodiments described in the following detailed description are not meant to be all inclusive or represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the appended claims.

[0051] In the technical solutions of the present application, the collection, storage, use, processing, transmission, provision and disclosure of model data or user data and other information involved in the technical solutions comply with relevant laws and regulations and do not violate public order and good customs.

[0052] It should be noted that in the embodiments of the present application, some industry existing solutions of software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility of the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0053] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0054] To solve the problem that the prior art cannot determine the signal waveform when the stress wave is generated in the SiC MOSFET power module, the embodiments of the present application provide a SiC MOSFET module stress wave source inversion method. In the finite element software, the propagation of the stress wave in the DBC plate is simulated, a Gaussian pulse is used as the excitation source, the signal transmitted to the bottom of the DBC plate is calculated, the Fourier transform is performed on the excitation source signal and the DBC plate bottom signal, the transfer function model of the stress wave transmission through the DBC plate is constructed, and a stress wave source inversion algorithm based on the transfer function is proposed. A wideband Gaussian signal is used to drive the piezoelectric transducer to generate a wideband stress wave. The piezoelectric transducer is placed above the DBC plate, and another transducer is used below to detect the stress wave through the DBC plate. The received stress wave signal is subjected to Fourier transform, the inversion reconstruction of the stress wave source signal is realized by using the inversion algorithm, and the frequency domain signal obtained by inversion is converted back to the time domain by Fourier inverse transform, and the time domain waveform of the stress wave source is restored.

[0055] Specifically, as shown in Figure 1 The SiC MOSFET module stress wave source inversion method provided by the embodiments of the present application includes the following steps S100-S400.

[0056] S100: Construct a simulation model of the transmission of the stress wave in the DBC plate.

[0057] As shown in Figure 2 The simulation model provided by the embodiments of the present application includes a DBC plate module 201 and a ceramic piezoelectric sensor module 202 arranged below the DBC plate module 201. A stress load is added to the upper surface of the DBC plate module 201 as an excitation, and a Gaussian pulse is used to simulate the stress load.

[0058] DBC plate. Therefore, in some embodiments, a DBC plate module 201 having a thickness of 1.6 mm is constructed according to the actual geometric size of the DBC plate, and a ceramic piezoelectric sensor module is formed by placing a ceramic piezoelectric sensor having a thickness of 20 mm below the DBC plate module 201, and the simulation model is constructed as shown in Figure 2

[0059] The physical field is set to solid mechanics, and each material in the simulation model is set according to the actual parameters of each structural material of the SiC MOSFET power module. Figure 2 The materials in the simulation model include copper and alumina ceramic, and the parameter settings are shown in Table 1.

[0060] Table 1: Simulation parameters of each material

[0061] Material Density (kg / m 3 )]]> Young's modulus (GPa) Poisson's ratio Damping ratio Copper 8960 110 0.3 0.01 Alumina ceramic 3890 370 0.24 0.005

[0062] Each material in the simulation model is set as a linear elastic material, and the Rayleigh damping is used to simulate the damping of each material:

[0063] C = aM + bK

[0064] where C is the Rayleigh damping matrix, M is the mass matrix, K is the stiffness matrix, and a and b are the Rayleigh damping coefficients. The Rayleigh damping coefficients can be determined according to the damping ratio ξ and the characteristic frequencies ω1, ω2 of the material:

[0065]

[0066] The characteristic frequencies ω1 = 0.9*50 kHz and ω2 = 1.1*500 kHz are set, and the damping ratios of copper and alumina ceramic are 0.01 and 0.005, respectively.

[0067] A stress load is added to the upper surface of the DBC plate module 201 as an excitation, and a Gaussian pulse is used to simulate the stress load. The expression of the Gaussian pulse varying with time t is:

[0068]

[0069] where the amplitude A of the Gaussian pulse is set to 1 N / m 2 , and the standard deviation σ of the Gaussian pulse is set to 1 x 10 -4 .

[0070] In the mesh division, the maximum mesh size is set to 0.02 mm.

[0071] ​S200: Determine the transfer function according to the stress wave signal of the excitation source and the bottom of the DBC plate.

[0072] In some embodiments, the transfer function is calculated according to the stress wave signal of the excitation source and the bottom of the DBC plate, and the specific process is as follows:

[0073] A test point A and a second test point B are respectively arranged at the excitation source and the bottom of the DBC plate module 201, as shown in Figure 2 The first stress wave signal X A and the second stress wave signal X B at the excitation source and the bottom of the DBC plate module 201 are calculated, and are introduced into MATLAB for FFT to obtain the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B The frequency spectrum and phase spectrum of the transfer function can be calculated according to H=Y A / Y B , as shown in Figure 3 .

[0074] S300: Build a DBC plate stress wave propagation experimental system to obtain a stress wave penetration signal.

[0075] In some embodiments, the DBC plate stress wave propagation experimental system is built as shown in Figure 4 . The DBC plate stress wave propagation experimental system includes a DBC plate 401, an excitation source transducer 402, and a receiving end transducer 403; wherein the excitation source transducer 402 and the receiving end transducer 403 are respectively arranged at the upper end and the lower end of the DBC plate 401, the excitation source transducer 402 generates a wideband stress wave, and the stress wave penetrates the DBC plate to be captured by the receiving end transducer 403 to obtain a stress wave penetration signal X1.

[0076] Specifically, a wideband Gaussian signal generated by an arbitrary waveform signal generator is used to drive a piezoelectric transducer as an excitation source to generate a wideband stress wave signal. The excitation source transducer 402 is installed on the upper surface of the DBC plate 401, and the receiving end transducer 403 is installed on the lower surface. In order to reduce the signal loss caused by acoustic impedance mismatch, coupling agent is coated on all contact interfaces to ensure efficient transmission of acoustic energy. After the stress wave penetrates the DBC plate 401, the penetration stress wave waveform captured by the receiving end transducer 403 is stored as X1.

[0077] S400: Calculate the frequency domain signal and the time domain signal of the stress wave source according to the transfer function and the stress wave penetration signal.

[0078] In this embodiment, the original signal of the stress wave source is inverted according to the stress wave penetration signal. For the digitized waveform data, that is, the stress wave penetration signal X1, the MATLAB is introduced to perform FFT to obtain the frequency domain signal Y1 of the penetration stress wave, and the frequency domain signal Y0 of the stress wave source is calculated through the following formula:

[0079]

[0080] The time domain signal X0 of the stress wave source is obtained through IFFT transformation, as shown in the following formula: Figure 5

[0081] The SiC MOSFET module stress wave source inversion device provided in the embodiments of the present application is shown in the following formula: Figure 6 The SiC MOSFET module stress wave source inversion device includes:

[0082] The simulation model construction module 601 is configured to construct a simulation model of the transmission of the stress wave in the DBC plate. The simulation model includes a DBC plate module and a ceramic piezoelectric sensor module arranged below the DBC plate module. A stress load is added to the upper surface of the DBC plate module as an excitation, and the stress load is simulated by a Gaussian pulse.

[0083] The transfer function determination module 602 is configured to determine a transfer function according to the excitation source and the stress wave signal at the bottom of the DBC plate.

[0084] The penetration signal acquisition module 603 is configured to build a DBC plate stress wave propagation experimental system to obtain a stress wave penetration signal.

[0085] The wave source signal calculation module 604 is configured to calculate the frequency domain signal and the time domain signal of the stress wave source according to the transfer function and the stress wave penetration signal.

[0086] In some embodiments, the simulation model construction module is further configured to construct the simulation model of the transmission of the stress wave in the DBC plate by the following method:

[0087] The DBC plate module is constructed, and the ceramic is used as the ceramic piezoelectric sensor module below the DBC plate module to obtain the simulation model,

[0088] The physical field of the simulation model is set to solid mechanics. According to the actual parameters of each structural material of the SiC MOSFET power module, each module material in the simulation model is set. Each module material in the simulation model is set to linear elastic material, and the damping of each material is simulated by Rayleigh damping:

[0089] C = aM + bK

[0090] ​where C is the Rayleigh damping matrix, M is the mass matrix, K is the stiffness matrix, and a and b are the Rayleigh damping coefficients, which are determined by the following formula:

[0091]

[0092] where x is the damping ratio of the material, and w1 and w2 are the characteristic frequencies.

[0093] In some embodiments, the expression of the Gaussian pulse as a function of time t is:

[0094]

[0095] where A represents the amplitude of the Gaussian pulse, e represents the natural constant, s represents the standard deviation of the Gaussian pulse, and t0 represents the center time of the Gaussian pulse.

[0096] In some embodiments, the transfer function determination module is further configured to:

[0097] A first test point A and a second test point B are respectively arranged at the excitation source and the bottom of the DBC plate module, and the first stress wave signal X A and the second stress wave signal X B at the excitation source and the bottom of the DBC plate are calculated.

[0098] Fast Fourier transform is performed according to the first stress wave signal X A and the second stress wave signal X B , to obtain the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B .

[0099] The transfer function is determined according to the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B , and is represented as H=Y A / Y B .

[0100] In some embodiments, the DBC plate stress wave propagation experimental system comprises a DBC plate, an excitation source transducer, and a receiving end transducer; the excitation source transducer and the receiving end transducer are respectively arranged at the upper end and the lower end of the DBC plate, the excitation source transducer generates a wideband stress wave, and the receiving end transducer captures the penetrating stress wave waveform and performs digital processing to obtain a stress wave penetration signal.

[0101] In some embodiments, the contact interfaces between the upper end and the lower end of the DBC plate and the excitation source transducer and the receiving end transducer are coated with a coupling agent.

[0102] In some embodiments, the wave source signal calculation module is further configured to:

[0103] performing fast Fourier transform on the stress wave penetration signal to obtain a frequency domain signal Y1 of the penetration stress wave;

[0104] calculating a frequency domain signal Y0 of the stress wave source according to the frequency domain signal of the penetration stress wave by the following formula:

[0105]

[0106] wherein H is a transfer function;

[0107] obtaining a time domain signal X0 of the stress wave source by inverse fast Fourier transform based on the frequency domain signal of the stress wave source.

[0108] Embodiments of the present application provide an electronic device. The electronic device can include a processor, a memory, wherein the processor and the memory can communicate; for example, the processor and the memory communicate through a communication bus.

[0109] The processor executes computer execution instructions stored in the memory, so that the processor executes the scheme in the above embodiments. The processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component.

[0110] The communication bus can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The system bus can be divided into an address bus, a data bus, a control bus, etc. The transceiver is used to realize the communication between the database access device and other computers (such as clients, read-write libraries and read-only libraries). The memory can include random access memory (RAM), and can also include non-volatile memory.

[0111] The electronic device provided by the embodiments of the present application can be a terminal device of the above embodiments.

[0112] The embodiment of the present application further provides a computer readable storage medium, which stores computer instructions, and the computer instructions make the computer execute the technical scheme of the SiC MOSFET module stress wave source inversion method in the above embodiment when the computer instructions run on the computer.

[0113] The embodiment of the present application further provides a computer program product, which comprises a computer program stored in a computer readable storage medium, and at least one processor can read the computer program from the computer readable storage medium, and the at least one processor can implement the technical scheme of the SiC MOSFET module stress wave source inversion method in the above embodiment when executing the computer program.

[0114] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other manners. For example, the above-described device embodiments are merely illustrative, and the division of modules can be different, for example, the division of modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the modules shown or discussed can be indirect coupling or communication connection through some interfaces, devices or modules, and can be electrical, mechanical or other forms.

[0115] The modules illustrated as separated components can or can not be physically separated, and the components illustrated as modules can or can not be physical units, that is, can be located in one place, or can be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to implement the embodiment scheme.

[0116] In addition, each functional module in each embodiment of the present application can be integrated in one processing unit, or each module can be physically present alone, or two or more modules can be integrated in one unit. The unit formed by the above modules can be realized in the form of hardware, or in the form of hardware plus software functional unit.

[0117] The integrated modules realized in the form of software functional modules can be stored in a computer readable storage medium. The software functional modules stored in the storage medium comprise a plurality of instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor execute part of the steps of the method of each embodiment of the present application.

[0118] It should be appreciated that referenced processors above can be a central processing unit (CPU), but can also be any conventional processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), etc. A general purpose processor can be a microprocessor, but, alternatively, the processor can be any conventional processor. The steps of a method disclosed in conjunction with the present application can be directly implemented in hardware, or be executed by a hardware processor using a software module.

[0119] The memory can include a high-speed RAM memory, and can also include a non-volatile storage NVM, such as at least one disk memory, and can also be a U disk, a mobile hard disk, a read-only memory, a magnetic disk or an optical disk, etc.

[0120] The bus can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0121] The storage medium described above can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. The storage medium can be any available medium that can be accessed by a general purpose or special purpose computer.

[0122] An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium, and can write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the storage medium can also exist as discrete components in an electronic control unit or a host device.

[0123] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware. The foregoing program can be stored in a computer readable storage medium. The program executes to perform the steps of the above-mentioned method embodiments; and the foregoing storage medium includes various storage media that can store program codes, such as ROM, RAM, magnetic disk or optical disk.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for inverting stress wave sources of SiC MOSFET modules, characterized in that: The method comprises: Construct a simulation model of stress wave transmission in a DBC plate; wherein the simulation model includes a DBC plate module and a ceramic piezoelectric sensor module disposed below the DBC plate module, a stress load is added to the upper surface of the DBC plate module as an excitation, and a Gaussian pulse is used to simulate the stress load; Determine the transfer function based on the stress wave signal between the excitation source and the bottom of the DBC plate; Build a DBC plate stress wave propagation experimental system to obtain stress wave penetration signals; The frequency domain signal and the time domain signal of the stress wave source are calculated based on the transfer function and the stress wave penetration signal.

2. The SiC MOSFET module stress wave source inversion method according to claim 1, characterized in that: The simulation model of stress wave transmission in the DBC plate is constructed as follows: Construct a DBC board module and use ceramic as a ceramic piezoelectric sensor module under the DBC board module to obtain a simulation model. The physical field of the simulation model is set to solid mechanics, and the materials of each module in the simulation model are set according to the actual parameters of each structural material of the SiC MOSFET power module. Among them, the materials of each module in the simulation model are set to linear elastic materials, and the damping of each material is simulated by Rayleigh damping: C=αM+βK Where C is the Rayleigh damping matrix, M is the mass matrix, K is the stiffness matrix, α and β are the Rayleigh damping coefficients, which are determined by the following formula: Where ξ is the damping ratio of the material, and ω1 and ω2 are the characteristic frequencies.

3. The SiC MOSFET module stress wave source inversion method according to claim 1, characterized in that: The expression Γ(t) of the Gaussian pulse changing with time t is: Where A represents the amplitude of the Gaussian pulse, e represents the natural constant, σ represents the standard deviation of the Gaussian pulse, and t0 represents the center time of the Gaussian pulse.

4. The SiC MOSFET module stress wave source inversion method according to claim 1, characterized in that: The transfer function is determined based on the stress wave signal between the excitation source and the bottom of the DBC plate, including: The first test point A and the second test point B are set at the excitation source and the bottom of the DBC board module respectively, and the first stress wave signal X at the excitation source and the bottom of the DBC board are calculated. A and the second stress wave signal X B ; According to the first stress wave signal X A and the second stress wave signal X B Perform fast Fourier transform to obtain the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B ; According to the first stress wave frequency domain signal Y A and the second stress wave frequency domain signal Y B Determine the transfer function, expressed as H = Y A / Y B .

5. The SiC MOSFET module stress wave source inversion method according to any one of claims 1 to 4, characterized in that: The DBC plate stress wave propagation experimental system includes a DBC plate, an excitation source transducer and a receiving end transducer; wherein, the excitation source transducer and the receiving end transducer are respectively arranged at the upper end and the lower end of the DBC plate. The excitation source transducer generates a broadband stress wave. After the stress wave penetrates the DBC plate, the receiving end transducer captures the penetrating stress wave waveform and performs digital processing to obtain a stress wave penetration signal.

6. The SiC MOSFET module stress wave source inversion method according to claim 5, characterized in that: The contact interfaces between the upper end and the lower end of the DBC plate and the excitation source transducer and the receiving end transducer are coated with coupling agent.

7. The SiC MOSFET module stress wave source inversion method according to claim 1, characterized in that: The frequency domain signal and time domain signal of the stress wave source are calculated based on the transfer function and the stress wave penetration signal, including: Performing a fast Fourier transform on the stress wave penetration signal to obtain a frequency domain signal Y1 of the penetration stress wave; According to the frequency domain signal of the penetrating stress wave, the frequency domain signal Y0 of the stress wave source is calculated by the following formula: Where H is the transfer function; Based on the frequency domain signal of the stress wave source, the time domain signal X0 of the stress wave source is obtained by inverse fast Fourier transform.

8. A SiC MOSFET module stress wave source inversion device, characterized in that: The device comprises: a simulation model construction module configured to construct a simulation model of stress wave transmission in a DBC plate; wherein the simulation model includes a DBC plate module and a ceramic piezoelectric sensor module disposed below the DBC plate module, a stress load is applied to the upper surface of the DBC plate module as an excitation, and a Gaussian pulse is used to simulate the stress load; a transfer function determination module configured to determine a transfer function based on a stress wave signal between an excitation source and a bottom portion of the DBC plate; The penetration signal acquisition module is configured to build a DBC plate stress wave propagation experimental system and obtain stress wave penetration signals; The wave source signal calculation module is configured to calculate the frequency domain signal and the time domain signal of the stress wave source according to the transfer function and the stress wave penetration signal.

9. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the SiC MOSFET module stress wave source inversion method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the SiC MOSFET module stress wave source inversion method according to any one of claims 1 to 7.

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