A method and device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals

Abstract

The present invention proposes a method and device for determining the damage and failure position of a press-fit power device based on electromagnetic acoustic emission signals. The press-fit power device is press-fitted using a fixture table, and a plurality of acoustic emission sensors are arranged on the circumferential outer surface of the upper fixture of the fixture table. The method comprises: at a first shutdown moment of the press-fit power device, acquiring electromagnetic acoustic emission signals monitored by each acoustic emission sensor, and then performing modal decomposition to obtain a target inherent modal function corresponding to each electromagnetic acoustic emission signal; for each target inherent modal function, performing signal decomposition on the target inherent modal function based on the structural layers of the press-fit power device to obtain decomposition signals corresponding to each structural layer, and obtaining new decomposition signals corresponding to each structural layer at a second shutdown moment; and determining the location of damage or failure based on the peak-to-peak value change rate of the decomposition signals corresponding to the two shutdown moments.

Description

Technical Field

[0001] The present invention relates to the technical field of online monitoring of the health status of power electronic devices, and in particular to a method and device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals. Background Art

[0002] With the development of flexible direct current transmission technology, my country has built a number of flexible direct current converter valves. Press-fit power devices, led by IGCT (Integrated Gate-Commutated Thyristor), have been widely used and have become the core components of converter valve control. Their reliability and lifespan directly affect the reliability of the converter valve system. Health status monitoring of press-fit power devices throughout their life cycle is of great significance to ensuring the safe and reliable operation of the entire system.

[0003] However, currently common detection methods include thermal parameter methods, electrical parameter methods, and acousto-optical force parameter methods, but they all have significant shortcomings. They either require modifying the device's operating circuit or requiring contact with the device's working state before performing offline testing, resulting in excessively high testing costs. Monitoring methods based on electromagnetic acoustic emission have the advantages of low invasiveness, high monitoring sensitivity, and the ability to perform online monitoring. They are gradually being used in the testing of welded devices and new energy batteries. However, there is still a lack of effective methods and devices for determining damage and failure locations in press-fit power devices. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, the first purpose of the present invention is to propose a method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals, so as to better achieve online monitoring and evaluation of the health status of power devices.

[0006] The second object of the present invention is to provide a device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals.

[0007] A third object of the present invention is to provide an electronic device.

[0008] A fourth object of the present invention is to provide a computer-readable storage medium.

[0009] To achieve the above objectives, the present invention, in its first aspect, provides a method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals. The method comprises:

[0010] At a first turn-off moment of the press-fit power device, acquiring electromagnetic acoustic emission signals monitored by each acoustic emission sensor;

[0011] Performing modal decomposition on each electromagnetic acoustic emission signal, and screening out a target natural mode function corresponding to each electromagnetic acoustic emission signal based on the propagation time corresponding frequency of the press-fit power device;

[0012] For each target intrinsic mode function, based on the structural layers of the press-fit power device, performing signal decomposition on the target intrinsic mode function to obtain decomposed signals corresponding to each structural layer;

[0013] At the second turn-off moment of the press-fit power device, the electromagnetic acoustic emission signal is re-obtained to obtain new decomposition signals corresponding to each structural layer;

[0014] Based on the decomposed signals of each structural layer corresponding to the first shutdown moment and the second shutdown moment, determine whether there is a peak-to-peak value change rate of the decomposed signal exceeding the set ratio. If so, determine the location of damage or failure based on the maximum peak-to-peak value change rate exceeding the set ratio and the corresponding decomposed signal.

[0015] In the method of the first aspect of the present invention, the location of damage or failure is determined based on the maximum peak-to-peak rate of change exceeding the set ratio and the corresponding decomposition signal, if any, specifically including: if there is a decomposition signal corresponding to an acoustic emission sensor whose peak-to-peak rate of change exceeds the set ratio, then the decomposition signal corresponding to the maximum peak-to-peak rate of change exceeding the set ratio is determined, and the structural layer of the press-fit power device corresponding to the corresponding decomposition signal is the location of damage or failure; if there are multiple acoustic emission sensors whose peak-to-peak rate of change of the decomposition signals exceeds the set ratio, then the acoustic emission sensor corresponding to the maximum peak-to-peak rate of change exceeding the set ratio is determined, and then the positions of the adjacent acoustic emission sensors on both sides of the corresponding acoustic emission sensor are obtained, and the target position corresponding to the peak point of the Gaussian function is determined based on the maximum peak-to-peak rate of change and the positions of the adjacent acoustic emission sensors on both sides using Gaussian function fitting technology, and the target position is the location of damage or failure.

[0016] In the method of the first aspect of the present invention, the plurality of acoustic emission sensors are arranged on the circumferential outer surface of the upper fixture at equal intervals and heights.

[0017] In the method of the first aspect of the present invention, the modal decomposition of each electromagnetic acoustic emission signal and the screening of the target intrinsic modal function corresponding to each electromagnetic acoustic emission signal based on the frequency corresponding to the propagation time of the press-contact power device include: performing modal decomposition on each electromagnetic acoustic emission signal to obtain a corresponding intrinsic modal function group, each intrinsic modal function group including multiple intrinsic modal functions; calculating the frequency corresponding to the propagation time based on the total thickness and sound velocity of the press-contact power device; for each intrinsic modal function group, selecting the intrinsic modal function that matches the frequency corresponding to the propagation time as the target intrinsic modal function, thereby obtaining the target intrinsic modal function corresponding to each electromagnetic acoustic emission signal.

[0018] In the method of the first aspect of the present invention, the target inherent modal function is subjected to signal decomposition based on the structural layers of the press-contact power device to obtain decomposed signals corresponding to each structural layer, including: calculating the propagation time of the electromagnetic acoustic emission signal in each structural layer based on the thickness and sound velocity of each structural layer of the press-contact power device; selecting a target periodic signal with minimum attenuation from the target inherent modal function, wherein the period of the target periodic signal is equal to the propagation time of the press-contact power device; and performing signal decomposition on the target periodic signal according to the propagation time corresponding to each structural layer to obtain a decomposed signal corresponding to each structural layer.

[0019] In the method of the first aspect of the present invention, the peak-to-peak rate of change of the decomposed signal satisfies:

[0020]

[0021] Where r is the peak-to-peak rate of change, A im0 is the peak-to-peak value of the mth decomposition signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor corresponding to the first shutdown moment, A im ′ is the peak-to-peak value of the mth decomposition signal in the target natural mode function corresponding to the i-th acoustic emission sensor corresponding to the second shutdown moment.

[0022] In the method of the first aspect of the present invention, the Gaussian function fitting satisfies:

[0023]

[0024] Where G is the output value of the Gaussian function, r max is the maximum peak-to-peak rate of change, x is the independent variable, μ is the center position coordinate between two adjacent acoustic emission sensors, and σ is the distance between two adjacent acoustic emission sensors.

[0025] To achieve the above-mentioned purpose, the second aspect of the present invention proposes a device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals, comprising an electromagnetic acoustic emission acquisition module and a host computer module;

[0026] The electromagnetic acoustic emission acquisition module includes a plurality of acoustic emission sensors, which are arranged on the circumferential outer surface of the upper fixture of the fixture table, and the fixture table is used to press-fit the press-fit power device. The plurality of acoustic emission sensors are used to monitor the electromagnetic acoustic emission signal;

[0027] The host computer module is used to obtain the electromagnetic acoustic emission signal monitored by each acoustic emission sensor at the first shutdown moment of the press-contact power device; perform modal decomposition on each electromagnetic acoustic emission signal, and screen out the target inherent modal function corresponding to each electromagnetic acoustic emission signal based on the frequency corresponding to the propagation time of the press-contact power device; for each target inherent modal function, perform signal decomposition on the target inherent modal function based on the structural layer of the press-contact power device to obtain a decomposition signal corresponding to each structural layer; at the second shutdown moment of the press-contact power device, re-obtain the electromagnetic acoustic emission signal and thereby obtain a new decomposition signal corresponding to each structural layer; based on the decomposition signals of each structural layer corresponding to the first shutdown moment and the second shutdown moment, determine whether there is a peak-to-peak value change rate of the decomposition signal exceeding a set ratio, and if so, determine the location of damage or failure based on the maximum peak-to-peak value change rate exceeding the set ratio and the corresponding decomposition signal.

[0028] To achieve the above-mentioned purpose, the third aspect of the present invention proposes an electronic device, comprising: 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 method proposed in the first aspect of the present invention.

[0029] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the method proposed in the first aspect of the present invention.

[0030] The present invention provides a method, system, electronic device, and storage medium for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals. The method comprises: obtaining electromagnetic acoustic emission signals detected by each acoustic emission sensor at a first turn-off instant of the press-fit power device; performing modal decomposition on each electromagnetic acoustic emission signal, and screening out a target intrinsic modal function corresponding to each electromagnetic acoustic emission signal based on a frequency corresponding to a propagation time of the press-fit power device; performing signal decomposition on each target intrinsic modal function based on the structural layers of the press-fit power device to obtain decomposed signals corresponding to each structural layer; at a second turn-off instant of the press-fit power device, reobtaining the electromagnetic acoustic emission signal to obtain new decomposed signals corresponding to each structural layer; and determining, based on the decomposed signals of each structural layer corresponding to the first turn-off instant and the second turn-off instant, whether a peak-to-peak change rate of the decomposed signal exceeds a set ratio, and if so, determining the location of the damage or failure based on the maximum peak-to-peak change rate exceeding the set ratio and the corresponding decomposed signal. In this case, multiple acoustic emission sensors are arranged on the circumferential outer surface of the upper fixture of the fixture table, and the acoustic emission sensors are used to monitor the electromagnetic acoustic emission signals of the press-fit power device at the moment of shutdown. The modal decomposition of each electromagnetic acoustic emission signal is performed, and the decomposition signal corresponding to each structural layer is obtained in combination with the structure of the press-fit power device. Based on the decomposition signals corresponding to each structural layer corresponding to different shutdown moments, it is determined whether the peak-to-peak value change rate of the decomposition signal exceeds the set ratio, and then the location of damage or failure is determined, thereby improving the monitoring sensitivity and the ability to monitor damage or failure of the press-fit power device, and can better give the location of damage or failure of the press-fit power device, and better realize the online monitoring and evaluation of the health status of the power device.

[0031] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram of the installation position of the acoustic emission sensor provided in an embodiment of the present invention;

[0034] Figure 2 A flow chart of a method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals provided by an embodiment of the present invention;

[0035] Figure 3The waveform diagram of the electromagnetic acoustic emission signal provided by the embodiment of the present invention;

[0036] Figure 4 This is a block diagram of a device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0038] The following describes a method and system for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals according to an embodiment of the present invention with reference to the accompanying drawings.

[0039] The embodiment of the present invention provides a method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals, so as to better realize online monitoring and evaluation of the health status of power devices.

[0040] In the present invention, press-fit power devices include but are not limited to press-fit IGBTs (Insulated Gate Bipolar Transistor), IGCTs (Integrated Gate-Commutated Thyristor), and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0041] In the present invention, before determining the location of damage or failure in a press-fit power device, a jig is required to press-fit the device. The jig includes an upper jig and a lower jig. Multiple acoustic emission sensors are arranged on the circumferential outer surface of the upper jig. The multiple acoustic emission sensors are arranged equidistantly (e.g., at equal intervals and heights) on the circumferential outer surface of the upper jig.

[0042] Taking 8 acoustic emission sensors as an example, Figure 1 This is a schematic diagram of the installation position of the acoustic emission sensor provided by the embodiment of the present invention. Figure 1 (a) is the main view, Figure 1 (b) in the figure is the top view of (a). Figure 1 As shown in (a), 1 represents the upper fixture, 2 represents the acoustic emission sensor, 3 represents the press-fit power device, and 4 represents the lower fixture. Figure 1As shown in (a) and (b), eight acoustic emission sensors 2 are arranged at equal intervals and heights on the circumferential outer surface of the upper fixture 1. The upper fixture 1 and the lower fixture 4 of the fixture table clamp the press-fit power device 3 and apply pressure to complete the press-fit.

[0043] Figure 2 The present invention provides a flowchart of a method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals. Figure 3 This is a waveform diagram of the electromagnetic acoustic emission signal provided by an embodiment of the present invention.

[0044] like Figure 2 As shown, the method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals includes the following steps:

[0045] Step S101 : acquiring electromagnetic acoustic emission signals monitored by each acoustic emission sensor at the first turn-off moment of the press-contact power device.

[0046] In step S101, the acoustic emission sensor is used to monitor the electromagnetic acoustic emission signal. The electromagnetic acoustic emission signal is a stress wave signal emitted at the moment the power device is turned off, and the sampling start time is the moment the power device is turned off.

[0047] In step S101, after press-fitting is completed, at the first moment of disconnection of the press-fit power device, the corresponding electromagnetic acoustic emission signals are collected using various acoustic emission sensors. The electromagnetic acoustic emission signals collected at the first moment of disconnection are electromagnetic acoustic emission signals in a healthy state (also known as a brand new state).

[0048] In step S101, since there are multiple acoustic emission sensors, the electromagnetic acoustic emission signals of each acoustic emission sensor at the moment when the power device is turned off can be expressed as S1, S2, ..., S N Where N is the total number of acoustic emission sensors. Figure 3 The electromagnetic acoustic emission signal collected by a certain acoustic emission sensor is shown, where the horizontal axis represents time and the vertical axis represents amplitude.

[0049] Step S102 : performing modal decomposition on each electromagnetic acoustic emission signal, and screening out a target natural mode function corresponding to each electromagnetic acoustic emission signal based on the propagation time corresponding frequency of the press-fit power device.

[0050] In step S102 , modal decomposition includes but is not limited to empirical mode decomposition, variational mode decomposition, ensemble empirical mode decomposition, and the like.

[0051] In step S102, modal decomposition is performed on each electromagnetic acoustic emission signal, and a target intrinsic modal function corresponding to each electromagnetic acoustic emission signal is screened out based on the frequency corresponding to the propagation time of the press-contact power device. The method includes: performing modal decomposition on each electromagnetic acoustic emission signal to obtain a corresponding intrinsic modal function group, each intrinsic modal function group including a plurality of intrinsic modal functions; calculating the frequency corresponding to the propagation time based on the total thickness and sound velocity of the press-contact power device; and selecting, for each intrinsic modal function group, an intrinsic modal function that matches the frequency corresponding to the propagation time as a target intrinsic modal function, thereby obtaining a target intrinsic modal function corresponding to each electromagnetic acoustic emission signal.

[0052] Among them, the intrinsic mode function group corresponding to each acoustic emission sensor includes multiple intrinsic mode functions, each intrinsic mode function has a corresponding center frequency, and for the intrinsic mode function group corresponding to each acoustic emission sensor, the intrinsic mode function that matches the frequency corresponding to the propagation time is selected. The matching process can refer to selecting the center frequency closest to the frequency corresponding to the propagation time. The intrinsic mode function corresponding to the closest center frequency is the target intrinsic mode function, and then the target intrinsic mode function corresponding to each electromagnetic acoustic emission signal is obtained.

[0053] For example, the intrinsic mode function contained in the i-th intrinsic mode function group (i.e., the intrinsic mode function group corresponding to the i-th acoustic emission sensor) can be expressed as l i1 ,l i2 ,…,l in Where n is the number of intrinsic mode functions. in is the nth intrinsic mode function in the set of intrinsic mode functions corresponding to the i-th acoustic emission sensor. Each intrinsic mode function has a corresponding center frequency. From the n intrinsic mode functions, the intrinsic mode function corresponding to the center frequency closest to the frequency corresponding to the propagation time of the press-fit power device is selected as the target intrinsic mode function. This yields the target intrinsic mode function corresponding to the electromagnetic acoustic emission signal collected by the i-th acoustic emission sensor.

[0054] The calculation process of the propagation time corresponding to the frequency of the press-fit power device includes: calculating the propagation time of the electromagnetic acoustic emission signal in the press-fit power device based on the total thickness of the press-fit power device and the sound velocity, and the reciprocal of the propagation time is the propagation time corresponding to the frequency of the press-fit power device. The propagation time Δt is calculated by Calculated. Where L represents the propagation distance. v is the speed of sound in the medium, typically 3500 m / s. When the propagation distance L is the total thickness of the press-fit power device, the calculated propagation time Δt is the propagation time of the electromagnetic acoustic emission signal in the press-fit power device.

[0055] Step S103 : for each target intrinsic mode function, based on the structural layers of the press-fit power device, performing signal decomposition on the target intrinsic mode function to obtain decomposed signals corresponding to each structural layer.

[0056] In step S103, the target intrinsic mode function is decomposed based on the structural layers of the press-contact power device to obtain decomposed signals corresponding to each structural layer. This includes calculating the propagation time of the electromagnetic acoustic emission signal in each structural layer based on the thickness and acoustic velocity of each structural layer of the press-contact power device; selecting a target periodic signal with minimal attenuation from the target intrinsic mode function, where the period of the target periodic signal is equal to the propagation time of the press-contact power device; and decomposing the target periodic signal according to the propagation time corresponding to each structural layer to obtain a decomposed signal corresponding to each structural layer. In this way, a decomposed signal corresponding to each structural layer can be obtained in each target intrinsic mode function.

[0057] In step S103, the propagation time of the electromagnetic acoustic emission signal in each structural layer is also calculated by Calculated. When the propagation distance L is calculated for different structural layer thicknesses, the calculated Δt is the propagation time of the electromagnetic acoustic emission signal in the corresponding structural layer. For example, if a press-fit power device includes three structural layers: a cathode molybdenum sheet, a GCT chip, and an anode molybdenum sheet, the geometric dimensions of the power device determine the characteristics of the power device structural layers. For example, the calculated propagation times are 0.29us, 0.14us, and 0.29us.

[0058] It is easy to understand that the target intrinsic modal function is a periodic function, and the period of the target intrinsic modal function is equal to the propagation time of the press-fit power device. For example, if the press-fit power device includes three structural layers: cathode molybdenum sheet, GCT chip, and anode molybdenum sheet, and the propagation times are 0.29us, 0.14us, and 0.29us, respectively, then the period of the target intrinsic modal function is 0.29us+0.14us+0.29us. The target intrinsic modal function also shows a decreasing trend, so the signal of one period with the smallest attenuation is selected from the target intrinsic modal function as the target periodic signal. The target periodic signal is decomposed according to the propagation time corresponding to each structural layer. The decomposition process can be segmented, and multiple decomposed signals are obtained after decomposition. For example, if the press-fit power device includes three structural layers, then three decomposed signals are obtained after decomposition, and each decomposed signal corresponds to one structural layer.

[0059] In step S103, the electromagnetic acoustic emission signal of an acoustic emission sensor corresponds to a target intrinsic mode function. After the target intrinsic mode function is decomposed, the decomposed signals corresponding to each structural layer are obtained. Each decomposed signal has a corresponding peak-to-peak value. The peak-to-peak value corresponding to the decomposed signal in the i-th target intrinsic mode function (i.e., the target intrinsic mode function corresponding to the i-th acoustic emission sensor) can be expressed as Ai1 ,A i2 ,…,A iM Among them A iM is the peak-to-peak value of the Mth decomposed signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor. M is the number of decomposed signals, which is equal to the number of structural layers of the press-fit power device.

[0060] Step S104 : At the second turn-off moment of the press-fit power device, the electromagnetic acoustic emission signal is re-obtained to obtain new decomposition signals corresponding to each structural layer.

[0061] In step S104, after the device has been used for a period of time, at the second turn-off moment of the press-fit power device, the electromagnetic acoustic emission signals are again collected using each acoustic emission sensor. Referring to the process of steps S102 and S103 above, a new target natural mode function and a new decomposition signal corresponding to each structural layer are obtained. Among them, the peak-to-peak value corresponding to the new decomposition signal in the new i-th target natural mode function can be expressed as A i1 ′,A i2 ′,…,A iM ′.

[0062] Step S105, based on the decomposed signals of each structural layer corresponding to the first shutdown moment and the second shutdown moment, determine whether there is a peak-to-peak value change rate of the decomposed signal that exceeds the set ratio. If so, determine the location of damage or failure based on the maximum peak-to-peak value change rate that exceeds the set ratio and the corresponding decomposed signal.

[0063] In step S105, the decomposed signals of each structural layer in all target intrinsic mode functions corresponding to the first and second shut-off instants are obtained, and the peak-to-peak rate of change of the decomposed signals of each structural layer of the acoustic emission sensor at the first and second shut-off instants is calculated using the target intrinsic mode functions of each acoustic emission sensor at the first and second shut-off instants. The peak-to-peak rate of change of the decomposed signals satisfies:

[0064]

[0065] Where r is the peak-to-peak rate of change, A im0 is the peak-to-peak value of the mth decomposition signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor corresponding to the first shutdown moment, A im ′ is the peak-to-peak value of the mth decomposition signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor at the second turn-off moment. This formula is used to calculate the peak-to-peak rate of change of all decomposition signals in the target intrinsic mode function corresponding to the i-th acoustic emission sensor, and then the peak-to-peak rate of change of all decomposition signals corresponding to all acoustic emission sensors is calculated.

[0066] In step S105, it is determined whether the peak-to-peak change rate of the decomposed signal exceeds a set ratio, such as 5%. If so, it indicates that the structural layer of the power device is damaged or failed.

[0067] In step S105, when a peak-to-peak rate of change exceeds a set ratio, a case-by-case analysis is performed. Specifically, if a peak-to-peak rate of change exceeds the set ratio, the location of damage or failure is determined based on the maximum peak-to-peak rate of change exceeding the set ratio and the corresponding decomposition signal. Specifically, the following steps are performed: if the peak-to-peak rate of change of the decomposition signal corresponding to one acoustic emission sensor exceeds the set ratio, the decomposition signal corresponding to the maximum peak-to-peak rate of change exceeding the set ratio is determined, and the structural layer of the press-fit power device corresponding to the corresponding decomposition signal is the location of damage or failure; if the peak-to-peak rate of change of the decomposition signals corresponding to multiple acoustic emission sensors exceeds the set ratio, the acoustic emission sensor corresponding to the maximum peak-to-peak rate of change exceeding the set ratio is determined, and the positions of the adjacent acoustic emission sensors on both sides of the corresponding acoustic emission sensor are obtained. The target position corresponding to the peak point of the Gaussian function is determined based on the maximum peak-to-peak rate of change and the positions of the adjacent acoustic emission sensors on both sides using Gaussian function fitting technology, and the target position is the location of damage or failure.

[0068] If the peak-to-peak rate of change of the decomposed signal corresponding to a single acoustic emission sensor exceeds a set ratio, then since a single acoustic emission sensor may have multiple peak-to-peak rates of change, if only one peak-to-peak rate of change exceeds the set ratio, then the peak-to-peak rate exceeding the set ratio is considered the maximum peak-to-peak rate of change. If multiple peak-to-peak rates of change exceed the set ratio, then the maximum peak-to-peak rate exceeding the set ratio is selected. The structural layer associated with the decomposed signal corresponding to the maximum peak-to-peak rate of change is the structural layer where damage or failure has occurred.

[0069] If the peak-to-peak change rates of the decomposed signals corresponding to multiple acoustic emission sensors exceed a set ratio, the maximum peak-to-peak change rate exceeding the set ratio and the acoustic emission sensor corresponding to the target intrinsic mode function corresponding to the maximum peak-to-peak change rate are screened out, and the positions of the two adjacent acoustic emission sensors of the corresponding acoustic emission sensor are determined (i.e., the coordinates of the two adjacent acoustic emission sensors). Based on the coordinates of the two adjacent acoustic emission sensors, the center position coordinates and the distance between the two adjacent acoustic emission sensors are determined. The Gaussian function output value is obtained by using the Gaussian function fitting technology in combination with the maximum peak-to-peak change rate, the peak point of the Gaussian function output value is selected, and the target position corresponding to the peak point is determined. The target position is the precise circumferential position of the damage or failure.

[0070] Among them, the Gaussian function fitting satisfies:

[0071]

[0072] Where G is the output value of the Gaussian function, r max is the maximum peak-to-peak rate of change, x is the independent variable, μ is the center position coordinate between two adjacent acoustic emission sensors, and σ is the distance between two adjacent acoustic emission sensors.

[0073] In order to implement the above embodiment, the present invention further proposes a device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals.

[0074] Figure 4 This is a block diagram of a device for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals, provided by an embodiment of the present invention.

[0075] like Figure 4 As shown, the device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals includes an electromagnetic acoustic emission acquisition module and a host computer module, wherein:

[0076] The electromagnetic acoustic emission acquisition module includes a plurality of acoustic emission sensors, which are arranged on the circumferential outer surface of the upper fixture of the fixture table. The fixture table is used to press-fit press-fit power devices. The plurality of acoustic emission sensors are used to monitor electromagnetic acoustic emission signals.

[0077] The upper computer module is used to obtain the electromagnetic acoustic emission signals monitored by each acoustic emission sensor at the first shutdown moment of the press-fit power device; perform modal decomposition on each electromagnetic acoustic emission signal, and screen out the target inherent modal function corresponding to each electromagnetic acoustic emission signal based on the frequency corresponding to the propagation time of the press-fit power device; for each target inherent modal function, perform signal decomposition on the target inherent modal function based on the structural layer of the press-fit power device to obtain the decomposition signal corresponding to each structural layer; at the second shutdown moment of the press-fit power device, re-obtain the electromagnetic acoustic emission signal and then obtain new decomposition signals corresponding to each structural layer; based on the decomposition signals of each structural layer corresponding to the first shutdown moment and the second shutdown moment, determine whether there is a peak-to-peak value change rate of the decomposition signal that exceeds a set ratio, and if so, determine the location of damage or failure based on the maximum peak-to-peak value change rate that exceeds the set ratio and the corresponding decomposition signal.

[0078] Furthermore, in a possible implementation of the embodiment of the present invention, a plurality of acoustic emission sensors in the electromagnetic acoustic emission collection module are arranged at equal intervals and heights on the circumferential outer surface of the upper fixture.

[0079] Furthermore, in a possible implementation of the embodiment of the present invention, the electromagnetic acoustic emission acquisition module further includes a preamplifier, an energy acquisition unit, and a communication antenna.

[0080] Furthermore, in a possible implementation of the embodiment of the present invention, the press-contact power device is selected from press-contact IGBTs, IGCTs, and MOSFETs.

[0081] Furthermore, in one possible implementation of an embodiment of the present invention, the host computer module includes a signal receiving antenna, a central processing unit (CPU), a power supply module, and a data storage and display unit. The CPU is configured to process the collected electromagnetic acoustic emission signals to determine the location of damage or failure of the press-fit power device.

[0082] Furthermore, in a possible implementation of an embodiment of the present invention, the central processing unit of the host computer module is used to perform modal decomposition on each electromagnetic acoustic emission signal and screen out the target intrinsic modal function corresponding to each electromagnetic acoustic emission signal based on the frequency corresponding to the propagation time of the press-fit power device. Specifically, it is used to: perform modal decomposition on each electromagnetic acoustic emission signal to obtain a corresponding intrinsic modal function group, each intrinsic modal function group including multiple intrinsic modal functions; calculate the frequency corresponding to the propagation time based on the total thickness and sound velocity of the press-fit power device; for each intrinsic modal function group, select the intrinsic modal function that matches the frequency corresponding to the propagation time as the target intrinsic modal function, thereby obtaining the target intrinsic modal function corresponding to each electromagnetic acoustic emission signal.

[0083] Furthermore, in a possible implementation of an embodiment of the present invention, the central processing unit of the upper computer module, when used to perform signal decomposition of the target inherent modal function based on the structural layer of the press-fit power device to obtain the decomposed signal corresponding to each structural layer, is specifically used to: calculate the propagation time of the electromagnetic acoustic emission signal in each structural layer based on the thickness and sound velocity of each structural layer of the press-fit power device; select a target periodic signal with minimal attenuation from the target inherent modal function, where the period of the target periodic signal is equal to the propagation time of the press-fit power device; and perform signal decomposition of the target periodic signal according to the propagation time corresponding to each structural layer to obtain the decomposed signal corresponding to each structural layer.

[0084] Furthermore, in a possible implementation of an embodiment of the present invention, the central processing unit of the upper computer module, when used to determine the location of damage or failure based on the maximum peak-to-peak change rate exceeding the set ratio and the corresponding decomposition signal, is specifically used to: if there is a decomposition signal corresponding to an acoustic emission sensor whose peak-to-peak change rate exceeds the set ratio, determine the decomposition signal corresponding to the maximum peak-to-peak change rate exceeding the set ratio, and the structural layer of the press-fit power device corresponding to the corresponding decomposition signal is the location where damage or failure occurs; if there are multiple acoustic emission sensors whose peak-to-peak change rates of the decomposition signals exceed the set ratio, determine the acoustic emission sensor corresponding to the maximum peak-to-peak change rate exceeding the set ratio, and then obtain the positions of the adjacent acoustic emission sensors on both sides of the corresponding acoustic emission sensor, and use Gaussian function fitting technology to determine the target position corresponding to the peak point of the Gaussian function based on the maximum peak-to-peak change rate and the positions of the adjacent acoustic emission sensors on both sides, and the target position is the location of damage or failure.

[0085] Furthermore, in a possible implementation of the embodiment of the present invention, the peak-to-peak rate of change of the target intrinsic mode function in the host computer module satisfies:

[0086]

[0087] Where r is the peak-to-peak rate of change, A im0 is the peak-to-peak value of the mth decomposition signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor corresponding to the first shutdown moment, A im ′ is the peak-to-peak value of the mth decomposition signal in the target natural mode function corresponding to the i-th acoustic emission sensor corresponding to the second shutdown moment.

[0088] Furthermore, in a possible implementation of the embodiment of the present invention, the Gaussian function fitting in the host computer module satisfies:

[0089]

[0090] Where G is the output value of the Gaussian function, r max is the maximum peak-to-peak rate of change, x is the independent variable, μ is the center position coordinate between two adjacent acoustic emission sensors, and σ is the distance between two adjacent acoustic emission sensors.

[0091] It should be noted that the above explanation of the embodiment of the method for determining the damage and failure position of a press-connected power device based on electromagnetic acoustic emission signals is also applicable to the device for determining the damage and failure position of a press-connected power device based on electromagnetic acoustic emission signals in this embodiment, and will not be repeated here.

[0092] In an embodiment of the present invention, a press-fit power device is press-fitted using a fixture table, and a plurality of acoustic emission sensors are arranged on the circumferential outer surface of an upper fixture of the fixture table. The method includes: at a first turn-off moment of the press-fit power device, obtaining electromagnetic acoustic emission signals monitored by each acoustic emission sensor; performing modal decomposition on each electromagnetic acoustic emission signal, and screening out a target inherent modal function corresponding to each electromagnetic acoustic emission signal based on a frequency corresponding to a propagation time of the press-fit power device; for each target inherent modal function, performing signal decomposition on the target inherent modal function based on the structural layer of the press-fit power device to obtain a decomposed signal corresponding to each structural layer; at a second turn-off moment of the press-fit power device, re-obtaining the electromagnetic acoustic emission signal and thereby obtaining a new decomposed signal corresponding to each structural layer; based on the decomposed signals of each structural layer corresponding to the first turn-off moment and the second turn-off moment, determining whether a peak-to-peak change rate of the decomposed signal exceeds a set ratio, and if so, determining a location of damage or failure based on the maximum peak-to-peak change rate exceeding the set ratio and the corresponding decomposed signal. In this case, multiple acoustic emission sensors are arranged on the circumferential outer surface of the upper fixture of the fixture table, and the acoustic emission sensors are used to monitor the electromagnetic acoustic emission signals of the press-fit power device at the moment of shutdown. The modal decomposition of each electromagnetic acoustic emission signal is performed, and the decomposition signal corresponding to each structural layer is obtained in combination with the structure of the press-fit power device. Based on the decomposition signals corresponding to each structural layer corresponding to different shutdown moments, it is determined whether the peak-to-peak value change rate of the decomposition signal exceeds the set ratio, and then the location of damage or failure is determined, thereby improving the monitoring sensitivity and the ability to monitor damage or failure of the press-fit power device, and can better give the location of damage or failure of the press-fit power device, and better realize the online monitoring and evaluation of the health status of the power device.

[0093] According to an embodiment of the present invention, a method and apparatus for determining the location of damage or failure of a press-fit power device based on electromagnetic acoustic emission signals can effectively pinpoint the location of damage or failure in the press-fit power device, offering advantages such as online monitoring, low invasiveness, and high monitoring sensitivity. The present invention can determine whether a press-fit power device is damaged or has failed by analyzing its electromagnetic acoustic emission signals, and can also determine the structural layer and circumferential location of the problem. This method has high monitoring sensitivity and improves the reliability monitoring capabilities of press-fit power devices.

[0094] In order to implement the above embodiments, the present invention also proposes an electronic device, comprising: 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 method provided by the above embodiments.

[0095] In order to implement the above embodiments, the present invention further provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided in the above embodiments.

[0096] In order to implement the above embodiments, the present invention further provides a computer program product, including a computer program, which implements the methods provided in the above embodiments when executed by a processor.

[0097] In the descriptions of the foregoing embodiments, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0098] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0099] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0100] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0101] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0102] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0103] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing module, or each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0104] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals, characterized in that: A press-fit power device is press-fitted using a fixture, wherein a plurality of acoustic emission sensors are arranged on a circumferential outer surface of an upper fixture of the fixture, and the method comprises: At a first turn-off moment of the press-contact power device, acquiring electromagnetic acoustic emission signals monitored by each acoustic emission sensor; Performing modal decomposition on each electromagnetic acoustic emission signal, and screening out a target natural mode function corresponding to each electromagnetic acoustic emission signal based on the propagation time corresponding frequency of the press-fit power device; For each target intrinsic mode function, based on the structural layers of the press-fit power device, performing signal decomposition on the target intrinsic mode function to obtain decomposed signals corresponding to each structural layer; At the second turn-off moment of the press-fit power device, the electromagnetic acoustic emission signal is re-obtained to obtain new decomposition signals corresponding to each structural layer; Based on the decomposed signals of each structural layer corresponding to the first shutdown moment and the second shutdown moment, determine whether there is a peak-to-peak value change rate of the decomposed signal exceeding the set ratio. If so, determine the location of damage or failure based on the maximum peak-to-peak value change rate exceeding the set ratio and the corresponding decomposed signal.

2. The method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals according to claim 1, characterized in that: If present, the location of the damage or failure is determined based on the maximum peak-to-peak rate of change exceeding the set ratio and the corresponding decomposed signal, specifically including: If there is a decomposition signal corresponding to an acoustic emission sensor whose peak-to-peak value change rate exceeds a set ratio, then the decomposition signal corresponding to the maximum peak-to-peak value change rate exceeding the set ratio is determined, and the structural layer of the press-fit power device corresponding to the corresponding decomposition signal is the location where damage or failure occurs; If the peak-to-peak change rates of the decomposed signals corresponding to multiple acoustic emission sensors exceed a set ratio, the acoustic emission sensor corresponding to the maximum peak-to-peak change rate exceeding the set ratio is determined, and then the positions of the adjacent acoustic emission sensors on both sides of the corresponding acoustic emission sensor are obtained. The Gaussian function fitting technology is used to determine the target position corresponding to the peak point of the Gaussian function based on the maximum peak-to-peak change rate and the positions of the adjacent acoustic emission sensors on both sides. The target position is the damaged or failed position.

3. The method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals according to claim 1, wherein: The plurality of acoustic emission sensors are arranged on the circumferential outer surface of the upper clamp at equal intervals and at equal heights.

4. The method for determining damage and failure locations of press-fit power devices based on electromagnetic acoustic emission signals according to claim 1, wherein the modal decomposition of each electromagnetic acoustic emission signal is performed, and the target intrinsic mode function corresponding to each electromagnetic acoustic emission signal is screened out based on the propagation time corresponding frequency of the press-fit power device, comprising: Performing modal decomposition on each electromagnetic acoustic emission signal to obtain a corresponding intrinsic modal function group, each intrinsic modal function group including a plurality of intrinsic modal functions; Calculating the frequency corresponding to the propagation time based on the total thickness and the speed of sound of the press-fit power device; For each intrinsic mode function group, an intrinsic mode function that matches the frequency corresponding to the propagation time is selected as a target intrinsic mode function, thereby obtaining a target intrinsic mode function corresponding to each electromagnetic acoustic emission signal.

5. The method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals according to claim 1, wherein: The signal decomposition of the target intrinsic mode function based on the structural layer of the press-fit power device to obtain the decomposed signal corresponding to each structural layer includes: Calculating the propagation time of the electromagnetic acoustic emission signal in each structural layer based on the thickness and sound velocity of each structural layer of the press-fit power device; Selecting a target periodic signal with minimum attenuation from the target natural mode function, wherein the period of the target periodic signal is equal to the propagation time of the press-fit power device; The target periodic signal is decomposed according to the propagation time corresponding to each structural layer to obtain a decomposed signal corresponding to each structural layer.

6. The method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals according to claim 1, characterized in that: The peak-to-peak rate of change of the decomposed signal satisfies: Where r is the peak-to-peak rate of change, A im0 is the peak-to-peak value of the mth decomposition signal in the target intrinsic mode function corresponding to the i-th acoustic emission sensor corresponding to the first shutdown moment, A im ′ is the peak-to-peak value of the mth decomposition signal in the target natural mode function corresponding to the i-th acoustic emission sensor corresponding to the second shutdown moment.

7. The method for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals according to claim 2, wherein: Gaussian function fitting satisfies: Where G is the output value of the Gaussian function, r max is the maximum peak-to-peak rate of change, x is the independent variable, u is the center position coordinate between two adjacent acoustic emission sensors, and σ is the distance between two adjacent acoustic emission sensors.

8. A device for determining damage and failure positions of press-fit power devices based on electromagnetic acoustic emission signals, characterized in that: Including electromagnetic acoustic emission acquisition module and host computer module; The electromagnetic acoustic emission acquisition module includes a plurality of acoustic emission sensors, which are arranged on the circumferential outer surface of the upper fixture of the fixture table, and the fixture table is used to press-fit the press-fit power device. The plurality of acoustic emission sensors are used to monitor the electromagnetic acoustic emission signal; The host computer module is used to obtain electromagnetic acoustic emission signals monitored by each acoustic emission sensor at the first shutdown moment of the press-contact power device; perform modal decomposition on each electromagnetic acoustic emission signal, and screen out a target intrinsic modal function corresponding to each electromagnetic acoustic emission signal based on the frequency corresponding to the propagation time of the press-contact power device; for each target intrinsic modal function, perform signal decomposition on the target intrinsic modal function based on the structural layer of the press-contact power device to obtain a decomposed signal corresponding to each structural layer; At the second turn-off moment of the press-fit power device, the electromagnetic acoustic emission signal is reacquired to obtain new decomposition signals corresponding to each structural layer; based on the decomposition signals of each structural layer corresponding to the first turn-off moment and the second turn-off moment, it is determined whether a peak-to-peak value change rate of the decomposition signal exceeds a set ratio; if so, the location of the damage or failure is determined based on the maximum peak-to-peak value change rate that exceeds the set ratio and the corresponding decomposition 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 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 are used to implement the method according to any one of claims 1 to 7 when executed by a processor.

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