CN118226216A

CN118226216A - IGBT module state detection method and device, storage medium and processor

Info

Publication number: CN118226216A
Application number: CN202410231199.2A
Authority: CN
Inventors: 王俊波; 李新; 张殷; 唐琪; 欧繁; 陈道品; 李国伟; 赵伟; 范心明; 董镝; 梁年柏; 王智娇; 曾烨; 王云飞; 何思捷
Original assignee: Guangdong Power Grid Co Ltd; Foshan Power Supply Bureau of Guangdong Power Grid Corp
Current assignee: Guangdong Power Grid Co Ltd; Foshan Power Supply Bureau of Guangdong Power Grid Corp
Priority date: 2024-02-29
Filing date: 2024-02-29
Publication date: 2024-06-21

Abstract

The application provides a method and a device for detecting the state of an IGBT module, a storage medium and a processor. The method comprises the following steps: acquiring a change rate to be measured, wherein the change rate to be measured is the rate of saturation voltage drop of the IGBT module to be measured along with the change of collector current of the IGBT module to be measured; under the condition that the change rate to be measured meets the first preset condition, determining that the IGBT module to be measured is in a failure state, under the condition that the change rate to be measured does not meet the first preset condition and meets the second preset condition, determining that the IGBT module to be measured is in a sub-health state, and under the condition that the change rate to be measured does not meet the first preset condition and does not meet the second preset condition, determining that the IGBT module to be measured is in a health state. The method solves the problem that in the prior art, the saturated voltage is not considered to be influenced by not only the falling of the bonding wire, but also the current of the collector, so that the state detection accuracy of the IGBT module is lower.

Description

IGBT module state detection method and device, storage medium and processor

Technical Field

The application relates to the technical field of IGBT (insulated gate bipolar transistor), in particular to a detection method of an IGBT module state, a detection device of the IGBT module state, a storage medium, a processor and electronic equipment.

Background

The most commonly used method for monitoring the health state of the IGBT module is a monitoring method based on saturation voltage drop, and when the saturation voltage drop of the IGBT module is increased by 5%, the IGBT module is considered to be invalid.

The state monitoring method of the IGBT module bonding wire in the prior art has the following defects:

As shown in fig. 1, in the saturation region, the saturation voltage drop V _CE of the IGBT module is positively correlated with the collector current i _C, but in the prior art, the saturation voltage is not considered to be affected by not only the falling of the bonding wire but also the injection current, which results in lower accuracy of detecting the state of the IGBT module;

As shown in fig. 1, the saturation voltage drop V _CE of the IGBT module is positively related to the junction temperature, but in the prior art, the saturation voltage is not considered to be affected by not only the falling of the bonding wire but also the junction temperature, resulting in lower accuracy of detecting the IGBT module state;

The number of detached bonding wires cannot be determined.

Disclosure of Invention

The application mainly aims to provide a detection method of an IGBT module state, a detection device of the IGBT module state, a storage medium, a processor and electronic equipment, which at least solve the problem that in the prior art, the saturated voltage is not considered to be influenced by not only falling of a bonding wire but also collector current, so that the detection accuracy of the IGBT module state is lower.

In order to achieve the above object, according to one aspect of the present application, there is provided a method for detecting a state of an IGBT module, the method comprising: acquiring a change rate to be measured, wherein the change rate to be measured is the rate of saturation voltage drop of an IGBT module to be measured along with the change of collector current of the IGBT module to be measured; under the condition that the change rate to be measured meets a first preset condition, determining that the IGBT module to be measured is in a failure state, under the condition that the change rate to be measured does not meet the first preset condition and meets a second preset condition, determining that the IGBT module to be measured is in a sub-health state, under the condition that the change rate to be measured does not meet the first preset condition and does not meet the second preset condition, determining that the IGBT module to be measured is in a health state, wherein the first preset condition is that the change rate to be measured is larger than a first preset value, the failure state indicates that the function of the IGBT module to be measured fails, the second preset condition is that the change rate to be measured is larger than a second preset value, the first preset value is larger than the second preset value, the sub-health state indicates that the function of the IGBT module to be measured is unstable, and the health state indicates that the function of the IGBT module to be measured is stable.

Optionally, after obtaining the rate of change to be measured, the method further comprises: acquiring a plurality of detection data sets, wherein one detection data set comprises a plurality of groups of detection data, one detection data set corresponds to one detection shedding quantity, the detection shedding quantity is the quantity of the shedding bonding wires in the detection IGBT module, the detection IGBT module and the IGBT module to be detected are of the same type, one group of detection data corresponds to one junction temperature, and one group of detection data comprises a plurality of collector currents of the detection IGBT module and a corresponding saturation voltage drop of the detection IGBT module under one detection shedding quantity and one junction temperature; Fitting the detection data sets under a first coordinate system to obtain a plurality of groups of detection voltage drop current line segments, wherein the first coordinate system comprises a first coordinate axis and a second coordinate axis, the first coordinate axis comprises a plurality of saturation voltage drops, the second coordinate axis comprises a plurality of collector currents, one group of detection voltage drop current line segments corresponds to one detection falling number, one detection voltage drop current line segment in one group of detection voltage drop current line segments corresponds to one junction temperature, and the detection voltage drop current line segments represent the corresponding detection falling number and the corresponding mapping relation between the saturation voltage drop of the detection IGBT module and the collector current of the detection IGBT module under the junction temperature; Determining a plurality of groups of first detection change rates according to all groups of detection voltage drop current line segments, wherein one group of first detection change rates correspond to one group of detection voltage drop current line segments, the first detection change rates in one group of first detection change rates correspond to the detection voltage drop current line segments in the corresponding group of detection voltage drop current line segments one by one, and the first detection change rates are slopes of the corresponding detection voltage drop current line segments; Processing the first detection change rates of all groups according to a formula a '=a+k× (T _B-T_C) to obtain a plurality of groups of second detection change rates, wherein a' is the second detection change rate, a is the first detection change rate, T _B is a predetermined junction temperature, T _C is the junction temperature corresponding to the first detection change rate, a set of the second detected change rates corresponds to a set of the first detected change rates, the second detected change rates in a set of the second detected change rates being in one-to-one correspondence with the first detected change rates in a corresponding set of the first detected change rates; Determining a plurality of detection sequences according to the second detection change rates of all groups, wherein the detection sequences consist of a plurality of second detection change rates, the detection shedding numbers corresponding to all the second detection change rates in the detection sequences are the same, and the second detection change rates in the detection sequences are arranged in the order from smaller junction temperatures to larger junction temperatures; determining the first preset value and the second preset value according to all the detection sequences and the preset number, wherein the first preset value is larger than the largest second detection change rate in a first target sequence, the first target sequence is the detection sequence corresponding to the detection shedding number with the preset number, the second preset value is smaller than the smallest second detection change rate in a second target sequence, and the second target sequence is the detection sequence corresponding to the detection shedding number with the value of 1.

Optionally, after obtaining the rate of change to be measured, the method further comprises: under the condition that the change rate to be measured meets the first preset condition, determining that the number of falling off to be measured is larger than the preset number, under the condition that the change rate to be measured does not meet the first preset condition and meets the second preset condition, determining that the number of falling off to be measured is in a preset number range, under the condition that the change rate to be measured does not meet the first preset condition and does not meet the second preset condition, determining that the number of falling off to be measured is 0, the number of falling off to be measured is the number of falling bonding wires in the IGBT module to be measured, the upper limit value of the preset number range is the preset number, the lower limit value of the preset number range is 1, and the preset number is larger than 1.

Optionally, before determining the first predetermined value and the second predetermined value according to all the detection sequences and the predetermined number, the method further comprises: determining a third target sequence according to the first detection change rates of all groups, wherein the third target sequence consists of a plurality of first detection change rates, the junction temperatures corresponding to all the first detection change rates in the third target sequence are the same, and the first detection change rates in the third target sequence are arranged according to the sequence from small to large of the corresponding detection shedding numbers; according to the third target sequence and formulaDetermining a fourth target sequence, wherein the fourth target sequence comprises first target percentages corresponding to all the first detection change rates in the third target sequence, and the first target percentages in the fourth target sequence are arranged in the order from the smaller corresponding detection drop number to the larger detection drop number, N is the first target percentage corresponding to the first detection change rate, P is the first detection change rate, and Q is the first detection change rate in the third target sequence; determining a fifth target sequence according to the fourth target sequence, wherein the fifth target sequence comprises second target percentages corresponding to all the first target percentages in the fourth target sequence, the second target percentages in the fifth target sequence are arranged in the order from small to large according to the corresponding detection shedding number, and the second target percentages are differences between the first target percentages and the first target percentages before the first target percentages; determining at least one third target percentage from the fifth target sequence, the third target percentage being the second target percentage satisfying a third predetermined condition, the third predetermined condition being that the difference between the second target percentage and each of the second target percentages preceding this second target percentage is greater than a predetermined percentage; determining a fourth target percentage according to at least one third target percentage, wherein the fourth target percentage is the third target percentage with the minimum detection shedding number corresponding to all the third target percentages; and determining that the detected falling number corresponding to the fourth target percentage is reduced by 1 to be the preset number.

Optionally, before processing the first detected change rates of all groups according to the formula a' =a+k× (T _B-T_C) to obtain a plurality of groups of second detected change rates, the method further comprises: determining a target group detection change rate according to the first detection change rates of all groups, wherein the target group detection change rate comprises a plurality of first detection change rates, and the detection falling numbers corresponding to the first detection change rates in the target group detection change rates are the same; fitting the first detection change rate and the corresponding junction temperature in the target group detection change rate under a second coordinate system to obtain a detection change rate junction temperature line segment, wherein the second coordinate system comprises a third coordinate axis and a fourth coordinate axis, the third coordinate axis comprises a plurality of first detection change rates, and the fourth coordinate axis comprises a plurality of junction temperatures of the IGBT module to be detected; and determining the slope of the junction temperature line segment with the detection change rate as k.

Optionally, obtaining the rate of change to be measured includes: acquiring corresponding saturation voltage drops of the IGBT module to be tested under a plurality of collector currents of the IGBT module to be tested, wherein one collector current of the IGBT module to be tested corresponds to one saturation voltage drop of the IGBT module to be tested; fitting a plurality of collector currents of the IGBT module to be tested and corresponding saturation voltage drops of the IGBT module to be tested under a first coordinate system to obtain a voltage drop current line segment to be tested, wherein the first coordinate system comprises a first coordinate axis and a second coordinate axis, the first coordinate axis comprises a plurality of saturation voltage drops, the second coordinate axis comprises a plurality of collector currents, and the voltage drop current line segment to be tested represents a mapping relation between the collector currents of the IGBT module to be tested and the saturation voltage drops of the IGBT module to be tested; and determining the slope of the voltage drop current line segment to be detected as the change rate to be detected under the first coordinate system.

According to another aspect of the present application, there is provided a detection apparatus for IGBT module status, the apparatus including: the device comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring a change rate to be detected, wherein the change rate to be detected is the rate that the saturation voltage drop of an IGBT module to be detected changes along with the collector current of the IGBT module to be detected; the determining unit is configured to determine that the IGBT module to be tested is in a failure state when the change rate to be tested satisfies a first predetermined condition, determine that the IGBT module to be tested is in a sub-health state when the change rate to be tested does not satisfy the first predetermined condition and satisfies a second predetermined condition, and determine that the IGBT module to be tested is in a health state when the change rate to be tested does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, the first predetermined condition is that the change rate to be tested is greater than a first predetermined value, the failure state indicates that the function of the IGBT module to be tested fails, the second predetermined condition is that the change rate to be tested is greater than a second predetermined value, the first predetermined value is greater than the second predetermined value, the sub-health state indicates that the function of the IGBT module to be tested is unstable, and the health state indicates that the function of the IGBT module to be tested is stable.

According to still another aspect of the present application, there is provided a computer readable storage medium, where the computer readable storage medium includes a stored program, and when the program runs, the device in which the computer readable storage medium is controlled to execute any one of the methods for detecting the IGBT module status.

According to still another aspect of the present application, there is provided a processor for running a program, wherein the program runs to execute any one of the methods for detecting the IGBT module status.

According to an aspect of the present application, there is provided an electronic apparatus including: the device comprises one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise a detection method for executing any one of the IGBT module states.

By applying the technical scheme of the application, the state of the IGBT module is determined by adopting the rate that the saturation voltage drop of the IGBT module to be detected changes along with the collector current of the IGBT module to be detected, the influence of the collector current on the saturation voltage is eliminated, and the state detection accuracy of the IGBT module is further improved, so that the problem that the state detection accuracy of the IGBT module is lower because the influence of the bonding wire falling and the collector current is not considered in the prior art is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

Fig. 1 shows a schematic diagram of a saturation voltage drop-collector current curve of an IGBT module according to an embodiment of the application;

fig. 2 is a block diagram showing a hardware configuration of a mobile terminal for performing a method of detecting a state of an IGBT module according to an embodiment of the application;

fig. 3 is a schematic flow chart of a method for detecting an IGBT module status according to an embodiment of the application;

fig. 4 shows a schematic diagram of a saturation voltage drop-collector current-junction temperature curve of an IGBT module according to an embodiment of the application;

fig. 5 is a schematic diagram showing an equivalent structure of an IGBT module according to an embodiment of the application in a healthy state;

Fig. 6 shows a schematic diagram of a saturation voltage drop-collector current curve of an IGBT module according to an embodiment of the application;

Fig. 7 is a schematic diagram showing an equivalent structure of an IGBT module according to an embodiment of the application, where the IGBT module drops off one bonding wire IGBT module;

Fig. 8 shows a schematic diagram of detecting a variation trend of the IGBT module dV _CE/di_C after temperature normalization according to an embodiment of the present application;

Fig. 9 shows a schematic diagram of detecting a change of the IGBT module dV _CE/di_C with the number of detected drops according to an embodiment of the present application;

Fig. 10 shows a schematic diagram for detecting a change of the IGBT module dV _CE/di_C with a junction temperature according to an embodiment of the application;

Fig. 11 shows a block diagram of a detection apparatus for IGBT module status according to an embodiment of the application.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

For convenience of description, the following will describe some terms or terminology involved in the embodiments of the present application:

Junction temperature of IGBT module: the junction temperature of the IGBT module refers to the junction temperature of the IGBT chip in the working process. This temperature refers to the temperature in the structure inside the IGBT chip, typically in degrees celsius (°c). In the working process, the junction temperature of the IGBT module can be influenced by various factors such as external environment, current load, radiator and the like. It is important to keep the IGBT module junction temperature in a proper range, and excessive junction temperature can affect the performance and lifetime of the IGBT module. Therefore, effective monitoring and control of the junction temperature of the IGBT module is required.

As described in the background art, in the prior art, the influence of not only the bonding wire falling off but also the collector current is not considered, so that the state detection accuracy of the IGBT module is lower.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The method embodiments provided in the embodiments of the present application may be performed in a mobile terminal, a computer terminal or similar computing device. Taking the mobile terminal as an example, fig. 2 is a block diagram of a hardware structure of the mobile terminal according to a method for detecting the IGBT module status according to an embodiment of the present application. As shown in fig. 2, the mobile terminal may include one or more (only one is shown in fig. 2) processors 102 (the processor 102 may include, but is not limited to, a microprocessor MCU or a processing device such as a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may further include a transmission device 106 for communication functions and an input-output device 108. It will be appreciated by those skilled in the art that the structure shown in fig. 2 is merely illustrative and not limiting of the structure of the mobile terminal described above. For example, the mobile terminal may also include more or fewer components than shown in fig. 2, or have a different configuration than shown in fig. 2.

The memory 104 may be used to store a computer program, for example, a software program of application software and a module, such as a computer program corresponding to a display method of device information in an embodiment of the present invention, and the processor 102 executes the computer program stored in the memory 104 to perform various functional applications and data processing, that is, to implement the above-described method. Memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, which may be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or transmit data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, simply referred to as a NIC) that can connect to other network devices through a base station to communicate with the internet. In one example, the transmission device 106 may be a Radio Frequency (RF) module, which is configured to communicate with the internet wirelessly.

In the present embodiment, a method for detecting the status of an IGBT module operating on a mobile terminal, a computer terminal, or a similar computing device is provided, and it should be noted that the steps illustrated in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in an order different from that herein.

Fig. 3 is a flowchart of a method of detecting a state of an IGBT module according to an embodiment of the application. As shown in fig. 3, the method comprises the steps of:

Step S201, obtaining a to-be-detected change rate, wherein the to-be-detected change rate is the rate of change of saturation voltage drop of an IGBT module to be detected along with collector current of the IGBT module to be detected;

Specifically, as shown in fig. 1, in the saturation region, the saturation voltage drop V _CE of the IGBT module is in a linear relationship with the collector current i _C, as shown in fig. 4, as the aging process of the IGBT module deepens, the number of bonding wires falling off in the IGBT module increases, and dV _CE/di_C in the saturation region at the same junction temperature T _j is in an increasing trend, so that dV _CE/di_C is used to monitor the state of the IGBT module, dV _CE/di_C is the rate at which the saturation voltage drop of the IGBT module changes with the collector current of the IGBT module, and in fig. 4, different gray scales represent different falling off numbers.

Specifically, in the saturation region, the determination process that the saturation voltage drop of the IGBT module is in a linear relation with the collector current is as follows:

As shown in fig. 5, in the equivalent structure of the IGBT module in a healthy state, R _t1 and R _t2 are equivalent resistances between the power supply end and the DBC copper layer, R _c is equivalent resistance from the DBC copper layer to the collector of the IGBT chip, and mainly includes a DBC copper layer resistance on the collector side, a solder layer resistance connected to the collector side of the IGBT chip, and a contact resistance thereof, R _wire is a bonding wire resistance and a contact resistance thereof, R _e is a DBC copper layer resistance on the emitter side of the IGBT chip, a current flowing through the IGBT module is i _C,V_ce is a voltage of the IGBT chip, V _CE is a voltage drop across the IGBT module, and V _R is a sum of voltage drops generated by packaging the IGBT module, based on which the voltage drops across the IGBT module are:

Where V _CE is determined primarily by V _R and V _ce, and V _R depends on i _C;

The planar gate structure of the IGBT chip can be regarded as a bipolar device of the MOSFET driving BJT, the equivalent circuit thereof is a darlington structure composed of PNP transistor and MOSFET, and the voltage of the IGBT chip is:

V_ce＝V_P+N++V_B+V_MOS(2)；

Wherein V _P+N+ is collector PN junction voltage drop, V _B is base region resistor voltage drop, and V _MOS is saturation voltage drop of an equivalent MOS structure;

from the theoretical knowledge of semiconductor physics, it can be deduced that the partial pressure drop expressions are:

Wherein q is an electron charge constant of 1.6X10 ^-19 C, A is a chip effective area, mu _n is electron mobility, D is a bipolar transport coefficient, N _i is an intrinsic carrier concentration, mu _p is hole mobility, alpha is an internal PNP transistor current amplification coefficient of the IGBT, epsilon _si is a Si dielectric constant, V _bc is a PNP transistor base-collector voltage in the IGBT chip, T is temperature, P ₀ is an N-base region minority carrier boundary concentration, N _B is a base region doping concentration, C _gd is a MOS structure grid-drain equivalent capacitance, L is a base region width, k is a Boltzmann constant, N _eff is an N-base region effective charge density, and W is a bipolar diffusion length;

combining (1), (2), (3), (4) and (5) gives the IGBT module a voltage drop across:

As can be seen from equation (6), dV _CE/di_C is constant in the saturation region of the IGBT module, i.e., V _CE and i _C show a linear relationship, and as shown in fig. 6, dV _CE/di_C is constant in the saturation region of the IGBT module, i.e., V _CE and i _C show a linear relationship.

Specifically, as the aging process of the IGBT module deepens, the number of bonding wires falling off in the IGBT module increases, and the determination process in the saturation region, which is in an increasing trend, is as follows:

Under the condition that the IGBT module drops off one bonding wire, the equivalent structure of the IGBT module is as shown in fig. 7, and the voltage drop at two ends of the IGBT module is as follows:

As can be seen from comparison of the formulas (1) and (7), when the bonding wire of the IGBT module drops by one, the bonding wire resistance increases from R _wire/8 to R _wire/7,dV_CE/di_C, that is, as the number of the bonding wires that drop increases, the bonding wire resistance continuously increases, and further, dV _CE/di_C is caused to exhibit a growing trend.

Step S202, determining that the IGBT module to be tested is in a failure state when the change rate to be tested meets a first preset condition, determining that the IGBT module to be tested is in a sub-health state when the change rate to be tested does not meet the first preset condition and meets a second preset condition, and determining that the IGBT module to be tested is in a health state when the change rate to be tested does not meet the first preset condition and does not meet the second preset condition;

The first predetermined condition is that the change rate to be measured is greater than a first predetermined value, the failure state indicates that the function of the IGBT module to be measured fails, the second predetermined condition is that the change rate to be measured is greater than a second predetermined value, the first predetermined value is greater than the second predetermined value, the sub-health state indicates that the function of the IGBT module to be measured is unstable, and the health state indicates that the function of the IGBT module to be measured is stable.

Through the embodiment, the state of the IGBT module is determined by adopting the rate that the saturation voltage drop of the IGBT module to be detected changes along with the collector current of the IGBT module to be detected, the influence of the collector current on the saturation voltage is eliminated, and further the state detection accuracy of the IGBT module is improved, so that the problem that the state detection accuracy of the IGBT module is lower because the influence of the fact that the saturation voltage is not influenced by the falling of the bonding wire and the influence of the collector current is not considered in the prior art is solved.

In an alternative embodiment, the step S201 may be implemented as:

Acquiring corresponding saturation voltage drops of the IGBT module to be tested under the condition that a plurality of collector currents of the IGBT module to be tested correspond to one saturation voltage drop of the IGBT module to be tested;

Fitting a plurality of collector currents of the IGBT module to be tested and corresponding saturation voltage drops of the IGBT module to be tested under a first coordinate system to obtain a voltage drop current line segment to be tested, wherein the first coordinate system comprises a first coordinate axis and a second coordinate axis, the first predetermined coordinate axis comprises a plurality of saturation voltage drops, the second predetermined coordinate axis comprises a plurality of collector currents, and the voltage drop current line segment to be tested represents a mapping relation between the saturation voltage drops of the IGBT module to be tested and the collector currents of the IGBT module to be tested;

Specifically, in some embodiments, the type of the IGBT module to be tested is FF450R17ME4, and the current line segment of the voltage drop to be tested is obtained by measuring and recording the saturation voltage drops of the IGBT module to be tested under different collector currents, and fitting the collector currents of the IGBT module to be tested and the corresponding saturation voltage drops.

And determining the slope of the voltage drop current line segment to be detected as the change rate to be detected under the first coordinate system.

In an alternative embodiment, after the step S201, the method further includes:

Step S301, a plurality of detection data sets are obtained, one detection data set comprises a plurality of groups of detection data, one detection data set corresponds to one detection shedding quantity, the detection shedding quantity is the quantity of the shedding bonding wires in the detection IGBT module, the detection IGBT module and the IGBT module to be detected are of the same type, one group of detection data corresponds to one junction temperature, and one group of detection data comprises a plurality of collector currents of the detection IGBT module and corresponding saturation voltage drops of the detection IGBT module under one detection shedding quantity and one junction temperature;

Specifically, as shown in table 1, the saturation voltage drop under different collector currents i _C of the detected IGBT module is measured and recorded under the same detection drop number and the same junction temperature T _j, the detection drop number to BE measured is 0,1, 2, 3, 4,5, 6, the junction temperature to BE measured is 40 ℃, 80 ℃,100 ℃, 120 ℃, wherein in order to ensure the same junction temperature, the detected IGBT module is placed in an incubator, the model of the incubator is WGLL-30BE, and constant junction temperature can BE provided for the detected IGBT module in the process of detecting the saturation voltage drop under different collector currents of the IGBT module under the same detection drop number at the same junction temperature.

TABLE 1

Step S302, fitting the detected data set under a first coordinate system to obtain a plurality of groups of detected voltage drop current line segments, where the first coordinate system includes a first coordinate axis and a second coordinate axis, the first coordinate axis includes a plurality of saturated voltage drops, the second coordinate axis includes a plurality of collector currents, one group of detected voltage drop current line segments corresponds to a detected drop number, one group of detected voltage drop current line segments corresponds to the junction temperature, and the detected voltage drop current line segments represent the corresponding detected drop number and a mapping relationship between the saturated voltage drop of the detected IGBT module and the collector current of the detected IGBT module at the corresponding junction temperature;

Specifically, fitting is performed on collector currents and corresponding saturation voltage drops of the detection IGBT modules under the same detection shedding number and the same junction temperature, so that voltage drop current line segments are detected under the same detection shedding number and the same junction temperature.

Step S303, determining a plurality of groups of first detection change rates according to all groups of the detection voltage drop current line segments, wherein one group of the first detection change rates corresponds to one group of the detection voltage drop current line segments, the first detection change rates in one group of the first detection change rates correspond to the detection voltage drop current line segments in the corresponding group of the detection voltage drop current line segments one by one, and the first detection change rates are slopes of the corresponding detection voltage drop current line segments;

Specifically, the gradient (first detection change rate) of the current line segment of the detected voltage drop at the same junction temperature of the same detected drop number is the rate of the change of the saturation voltage drop of the detected IGBT module with the collector current of the detected IGBT module at the same junction temperature of the detected drop number, and as shown in table 2, the rate dV _CE/di_C of the change of the saturation voltage drop of the detected IGBT module with the collector current of the detected IGBT module at the junction temperature of 0, 1, 2, 3, 4,5, 6 of the detected drop number and the junction temperature T _j, 40 ℃, 80 ℃, 100 ℃,120 ℃ is determined respectively.

TABLE 2

Step S304, processing the first detection change rates of all groups according to a formula a '=a+k× (T _B-T_C), to obtain a plurality of groups of second detection change rates, where a' is the second detection change rate, a is the first detection change rate, T _B is a predetermined junction temperature, T _C is the junction temperature corresponding to the first detection change rate, one group of second detection change rates corresponds to one group of first detection change rates, and the second detection change rate in one group of second detection change rates corresponds to the first detection change rate in one group of first detection change rates;

Specifically, in order to solve the problem that in the prior art, the saturated voltage is not considered to be influenced by not only the falling of the bonding wire but also the junction temperature, so that the state detection accuracy of the IGBT module is lower.

Step S305, determining a plurality of detection sequences according to the second detection change rates of all groups, wherein the detection sequences are composed of a plurality of the second detection change rates, the detection falling numbers corresponding to all the second detection change rates in the detection sequences are the same, and the second detection change rates in the detection sequences are arranged in the order from the corresponding junction temperatures to the larger ones;

specifically, as shown in fig. 8, a variation trend of the saturation voltage drop of the detected IGBT module along with the variation rate dV _CE/di_C of the collector current of the detected IGBT module after the temperature normalization can be drawn according to the detection sequence.

Step S306, determining the first predetermined value and the second predetermined value according to all the detection sequences and a predetermined number, wherein the first predetermined value is greater than a maximum second detection change rate in a first target sequence, the first target sequence is the detection sequence corresponding to the detection shedding number with the predetermined number, the second predetermined value is less than a minimum second detection change rate in a second target sequence, and the second target sequence is the detection sequence corresponding to the detection shedding number with the value 1.

Specifically, as shown in fig. 8, the predetermined number is 5, the first predetermined value is greater than a speed dV _CE/di_C of detecting a saturation voltage drop of the IGBT module with the change of the collector current of the IGBT module at the detection drop number 5 and the junction temperature of 120 ℃, the second predetermined value is smaller than a speed dV _CE/di_C of detecting a saturation voltage drop of the IGBT module with the change of the collector current of the IGBT module at the detection drop number 1 and the junction temperature of 80 ℃, and according to a change trend of dV _CE/di_C after the temperature normalization, the states of the IGBT module can be divided into: the state of the IGBT module can be accurately determined at any junction temperature by using the normalized change trend of the dV _CE/di_C in the failure state, the sub-health state and the health state, and the state of the IGBT module is not influenced by the junction temperature basically, so that the problem that the state detection accuracy of the IGBT module is lower because the influence of the falling of the bonding wire and the junction temperature of the saturated voltage is not considered in the prior art is solved.

In an alternative embodiment, after the step S201, the method further includes:

And determining that the number of dropped wires to be tested is greater than the predetermined number when the first predetermined condition is satisfied by the rate of change to be tested, determining that the number of dropped wires to be tested is within a predetermined number range when the first predetermined condition is not satisfied and the second predetermined condition is satisfied by the rate of change to be tested, determining that the number of dropped wires to be tested is 0 when the first predetermined condition is not satisfied and the second predetermined condition is not satisfied by the rate of change to be tested, determining that the upper limit value of the predetermined number range is the predetermined number, and determining that the lower limit value of the predetermined number range is 1, wherein the predetermined number is greater than 1.

Specifically, as shown in fig. 8, the predetermined number is 5, in the case that dV _CE/di_C of the IGBT module to be tested is greater than the first predetermined value, the number of dropped wires to be tested is determined to be greater than 5, in the case that dV _CE/di_C of the change to be tested is less than or equal to the first predetermined value and dV _CE/di_C is greater than the second predetermined value, the number of dropped wires to be tested is determined to be within [1,5], and in the case that the change to be tested is less than or equal to the second predetermined value, the number of dropped wires to be tested is determined to be 0, thereby solving the problem that the state monitoring method of the IGBT module bonding wires in the prior art cannot determine the number of dropped bonding wires.

In an alternative embodiment, before the step S306, the method further includes:

Step S401, determining a third target sequence according to the first detection change rates of all groups, where the third target sequence is composed of a plurality of first detection change rates, the junction temperatures corresponding to all the first detection change rates in the third target sequence are the same, and the first detection change rates in the third target sequence are arranged in order from smaller to larger corresponding detection drop numbers;

Specifically, as shown in fig. 9, a third target sequence may be determined by selecting dV _CE/di_C at a junction temperature of T _j ℃ at 40 ℃, 80 ℃,100 ℃ or 120 ℃, and according to the third target sequence, a trend of detecting the saturation voltage drop of the IGBT module at the selected junction temperature along with the number of detected drops may be drawn.

Step S402, according to the third target sequence and formulaDetermining a fourth target sequence, wherein the fourth target sequence comprises first target percentages corresponding to all the first detection change rates in the third target sequence, and the first target percentages in the fourth target sequence are arranged in the order from the smaller corresponding detection drop number to the larger detection drop number, N is the first target percentage corresponding to the first detection change rate, P is the first detection change rate, and Q is the first detection change rate in the third target sequence;

specifically, as shown in table 3, in the case where the junction temperature T _j is 40 ℃, the first target percentages in the case where the number of detected abscissions is 0,1, 2, 3, 4, 5, 6 in this order are 0%, 11%, 23%, 34%, 46%, 57%, and 88% in this order.

TABLE 3 Table 3

Step S403, determining a fifth target sequence according to the fourth target sequence, where the fifth target sequence includes second target percentages corresponding to all the first target percentages in the fourth target sequence, and the second target percentages in the fifth target sequence are arranged in order of the corresponding detected shedding number from small to large, where the second target percentages are differences between the first target percentages and the first target percentages that are the first target percentages before the first target percentages;

step S404, determining at least one third target percentage according to the fifth target sequence, wherein the third target percentage is the second target percentage satisfying a third predetermined condition, and the third predetermined condition is that the difference between the second target percentage and each of the second target percentages before the second target percentage is greater than a predetermined percentage;

Specifically, as shown in table 3, in the case of detecting the number of drops 1, the first target percentage was 11%, in the case of detecting the number of drops 0, the first target percentage was 0%, in the case of detecting the number of drops 1, compared to the case of detecting the number of drops 0, the first target percentage was 11%, in the case of detecting the number of drops 2, the first target percentage was 23%, in the case of detecting the number of drops 2, compared to the case of detecting the number of drops 1, the first target percentage was 34%, in the case of detecting the number of drops 3, compared to the case of detecting the number of drops 2, the first target percentage was 11%, in the case of detecting the number of drops 4, the first target percentage was 46%, in the case of detecting the number of drops 4, compared to the case of detecting the number of drops 3, the first target percentage was 12%, in the case of detecting the number of drops 5, the first target percentage was 57%, in the case of detecting the number of drops 5, compared to the number of drops 4, the first target percentage was 11%, in the case of detecting the number of drops 6, the first target percentage was 88%, in the case of dropping 6, in the case of detecting the number of drops 6, the first target percentage was 11%, in the case of dropping 6%, in the case of detecting the number of drops 6%, and the first target percentage was increased by the first target percentage by 33%.

Step S405, determining a fourth target percentage according to at least one of the third target percentages, where the fourth target percentage is the third target percentage with the smallest detection shedding number corresponding to all the third target percentages;

Step S406, determining that the detected shedding number corresponding to the fourth target percentage is reduced by 1 to the predetermined number.

Specifically, in the case of detecting the number of drops 6, the first target percentage is 88%, and in the case of detecting the number of drops 6, the first target percentage is increased by 33% compared with the case of detecting the number of drops 5, at which time it can be determined that the IGBT module is in the failure state, and the predetermined number is 5.

In an alternative embodiment, before the step S304, the method further includes:

determining a target group detection change rate according to the first detection change rates of all groups, wherein the target group detection change rate comprises a plurality of first detection change rates, and the detection falling numbers corresponding to the first detection change rates in the target group detection change rates are the same;

Specifically, as shown in fig. 10, when the same number of detected drops is selected, the saturation voltage drop of the IGBT module is detected at a rate dV _CE/di_C that changes with the collector current of the IGBT module when the junction temperature T _j is 40 ℃, 80 ℃, 100 ℃, 120 ℃.

Fitting the first detection change rate and the corresponding junction temperature in the target group detection change rate under a second coordinate system to obtain a detection change rate junction temperature line segment, wherein the second coordinate system comprises a third coordinate axis and a fourth coordinate axis, the third coordinate axis comprises a plurality of first detection change rates, and the fourth coordinate axis comprises a plurality of junction temperatures of the IGBT module to be detected;

Specifically, as shown in fig. 9, under the same detection drop number, a detection change rate junction temperature line segment is obtained by fitting a detection IGBT module saturation voltage drop rate dV _CE/di_C and a junction temperature T _j (40 ℃, 80 ℃, 100 ℃, 120 ℃) with a detection IGBT module collector current change rate dV _CE/di_C at a junction temperature T _j of 40 ℃, 80 ℃, 100 ℃, 120 ℃, and a detection change rate junction temperature line segment formula is as follows:

dV_CE/di_C＝6×10^-5T_j+0.0068(R²＝0.9911)。

and determining the slope of the junction temperature line segment with the detection change rate as k.

It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowcharts, in some cases the steps illustrated or described may be performed in an order other than that illustrated herein.

The embodiment of the application also provides a device for detecting the state of the IGBT module, and the device for detecting the state of the IGBT module can be used for executing the method for detecting the state of the IGBT module. The device is used for realizing the above embodiments and preferred embodiments, and is not described in detail. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

The following describes a detection device for the IGBT module status provided by the embodiment of the application.

Fig. 11 is a schematic diagram of a detection apparatus for IGBT module status according to an embodiment of the application. As shown in fig. 11, the apparatus includes:

An obtaining unit 10, configured to obtain a to-be-detected change rate, where the to-be-detected change rate is a rate at which a saturation voltage drop of an IGBT module to be detected changes with a collector current of the IGBT module to be detected;

A determining unit 20, configured to determine that the IGBT module to be tested is in a failure state when the change rate to be tested satisfies a first predetermined condition, determine that the IGBT module to be tested is in a sub-health state when the change rate to be tested does not satisfy the first predetermined condition and satisfies a second predetermined condition, and determine that the IGBT module to be tested is in a health state when the change rate to be tested does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, the first predetermined condition being that the change rate to be tested is greater than a first predetermined value, the failure state being that the IGBT module to be tested is failed, the second predetermined condition being that the change rate to be tested is greater than a second predetermined value, the first predetermined value being greater than the second predetermined value, the sub-health state being that the IGBT module to be tested is unstable, and the health state being that the IGBT module to be tested is stable.

The detecting device for the IGBT module state comprises a processor and a memory, wherein the acquiring unit, the determining unit and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions. The modules are all located in the same processor; or the above modules may be located in different processors in any combination.

The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The inner core can be provided with one or more, and the problem that the state detection accuracy of the IGBT module is low because the saturated voltage is not considered to be influenced by the falling of the bonding wire and the collector current in the prior art is solved by adjusting the parameters of the inner core.

The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.

The embodiment of the invention provides a computer readable storage medium, which comprises a stored program, wherein the program is used for controlling equipment where the computer readable storage medium is located to execute the method for detecting the state of the IGBT module.

The embodiment of the invention provides a processor, which is used for running a program, wherein the method for detecting the state of an IGBT module is executed when the program runs.

The embodiment of the invention provides equipment, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, wherein the processor realizes at least the following steps when executing the program:

The device herein may be a server, PC, PAD, cell phone, etc.

The application also provides a computer program product adapted to perform, when executed on a data processing device, a program initialized with at least the following method steps:

It will be appreciated by those skilled in the art that the modules or steps of the invention described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may be implemented in program code executable by computing devices, so that they may be stored in a storage device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Disks (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

1) In the method for detecting the state of the IGBT module, the state of the IGBT module is determined by adopting the rate that the saturation voltage drop of the IGBT module to be detected changes along with the collector current of the IGBT module to be detected, so that the influence of the collector current on the saturation voltage is eliminated, and the state detection accuracy of the IGBT module is further improved, and the problem that the state detection accuracy of the IGBT module is lower because the influence of the bonding wire falling and the collector current is not considered in the prior art is solved.

2) In the IGBT module state detection device, the state of the IGBT module is determined by adopting the rate that the saturation voltage drop of the IGBT module to be detected changes along with the collector current of the IGBT module to be detected, so that the influence of the collector current on the saturation voltage is eliminated, and the IGBT module state detection accuracy is further improved, and the problem that the influence of the saturation voltage not only caused by the falling of a bonding wire but also caused by the influence of the collector current in the prior art is solved, so that the IGBT module state detection accuracy is lower.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for detecting a state of an IGBT module, the method comprising:

Acquiring a change rate to be measured, wherein the change rate to be measured is the rate of saturation voltage drop of an IGBT module to be measured along with the change of collector current of the IGBT module to be measured;

Under the condition that the change rate to be measured meets a first preset condition, determining that the IGBT module to be measured is in a failure state, under the condition that the change rate to be measured does not meet the first preset condition and meets a second preset condition, determining that the IGBT module to be measured is in a sub-health state, under the condition that the change rate to be measured does not meet the first preset condition and does not meet the second preset condition, determining that the IGBT module to be measured is in a health state, wherein the first preset condition is that the change rate to be measured is larger than a first preset value, the failure state indicates that the function of the IGBT module to be measured fails, the second preset condition is that the change rate to be measured is larger than a second preset value, the first preset value is larger than the second preset value, the sub-health state indicates that the function of the IGBT module to be measured is unstable, and the health state indicates that the function of the IGBT module to be measured is stable.

2. The method of claim 1, wherein after obtaining the rate of change to be measured, the method further comprises:

Acquiring a plurality of detection data sets, wherein one detection data set comprises a plurality of groups of detection data, one detection data set corresponds to one detection shedding quantity, the detection shedding quantity is the quantity of the shedding bonding wires in the detection IGBT module, the detection IGBT module and the IGBT module to be detected are of the same type, one group of detection data corresponds to one junction temperature, and one group of detection data comprises a plurality of collector currents of the detection IGBT module and a corresponding saturation voltage drop of the detection IGBT module under one detection shedding quantity and one junction temperature;

Fitting the detection data sets under a first coordinate system to obtain a plurality of groups of detection voltage drop current line segments, wherein the first coordinate system comprises a first coordinate axis and a second coordinate axis, the first coordinate axis comprises a plurality of saturation voltage drops, the second coordinate axis comprises a plurality of collector currents, one group of detection voltage drop current line segments corresponds to one detection falling number, one detection voltage drop current line segment in one group of detection voltage drop current line segments corresponds to one junction temperature, and the detection voltage drop current line segments represent the corresponding detection falling number and the corresponding mapping relation between the saturation voltage drop of the detection IGBT module and the collector current of the detection IGBT module under the junction temperature;

Determining a plurality of groups of first detection change rates according to all groups of detection voltage drop current line segments, wherein one group of first detection change rates correspond to one group of detection voltage drop current line segments, the first detection change rates in one group of first detection change rates correspond to the detection voltage drop current line segments in the corresponding group of detection voltage drop current line segments one by one, and the first detection change rates are slopes of the corresponding detection voltage drop current line segments;

Processing the first detection change rates of all groups according to a formula a '=a+k× (T _B-T_C), to obtain a plurality of groups of second detection change rates, where a' is the second detection change rate, a is the first detection change rate, T _B is a predetermined junction temperature, T _C is the junction temperature corresponding to the first detection change rate, a group of second detection change rates corresponds to a group of first detection change rates, and the second detection change rates in a group of second detection change rates correspond to the first detection change rates in a corresponding group of first detection change rates one to one;

determining a plurality of detection sequences according to the second detection change rates of all groups, wherein the detection sequences consist of a plurality of second detection change rates, the detection shedding numbers corresponding to all the second detection change rates in the detection sequences are the same, and the second detection change rates in the detection sequences are arranged in the order from smaller junction temperatures to larger junction temperatures;

Determining the first preset value and the second preset value according to all the detection sequences and the preset number, wherein the first preset value is larger than the largest second detection change rate in a first target sequence, the first target sequence is the detection sequence corresponding to the detection shedding number with the preset number, the second preset value is smaller than the smallest second detection change rate in a second target sequence, and the second target sequence is the detection sequence corresponding to the detection shedding number with the value of 1.

3. The method of claim 2, wherein after obtaining the rate of change to be measured, the method further comprises:

under the condition that the change rate to be measured meets the first preset condition, determining that the number of falling off to be measured is larger than the preset number, under the condition that the change rate to be measured does not meet the first preset condition and meets the second preset condition, determining that the number of falling off to be measured is in a preset number range, under the condition that the change rate to be measured does not meet the first preset condition and does not meet the second preset condition, determining that the number of falling off to be measured is 0, the number of falling off to be measured is the number of falling bonding wires in the IGBT module to be measured, the upper limit value of the preset number range is the preset number, the lower limit value of the preset number range is 1, and the preset number is larger than 1.

4. The method of claim 2, wherein prior to determining the first predetermined value and the second predetermined value based on all of the detection sequences and a predetermined number, the method further comprises:

determining a third target sequence according to the first detection change rates of all groups, wherein the third target sequence consists of a plurality of first detection change rates, the junction temperatures corresponding to all the first detection change rates in the third target sequence are the same, and the first detection change rates in the third target sequence are arranged according to the sequence from small to large of the corresponding detection shedding numbers;

according to the third target sequence and formula Determining a fourth target sequence, wherein the fourth target sequence comprises first target percentages corresponding to all the first detection change rates in the third target sequence, and the first target percentages in the fourth target sequence are arranged in the order from the smaller corresponding detection drop number to the larger detection drop number, N is the first target percentage corresponding to the first detection change rate, P is the first detection change rate, and Q is the first detection change rate in the third target sequence;

Determining a fifth target sequence according to the fourth target sequence, wherein the fifth target sequence comprises second target percentages corresponding to all the first target percentages in the fourth target sequence, the second target percentages in the fifth target sequence are arranged in the order from small to large according to the corresponding detection shedding number, and the second target percentages are differences between the first target percentages and the first target percentages before the first target percentages;

Determining at least one third target percentage from the fifth target sequence, the third target percentage being the second target percentage satisfying a third predetermined condition, the third predetermined condition being that the difference between the second target percentage and each of the second target percentages preceding this second target percentage is greater than a predetermined percentage;

Determining a fourth target percentage according to at least one third target percentage, wherein the fourth target percentage is the third target percentage with the minimum detection shedding number corresponding to all the third target percentages;

And determining that the detected falling number corresponding to the fourth target percentage is reduced by 1 to be the preset number.

5. The method of claim 2, wherein before processing the first detected rates of change for all groups according to the formula a' =a+kx (T _B-T_C) to obtain a plurality of sets of second detected rates of change, the method further comprises:

6. The method of claim 1, wherein obtaining the rate of change to be measured comprises:

Acquiring corresponding saturation voltage drops of the IGBT module to be tested under a plurality of collector currents of the IGBT module to be tested, wherein one collector current of the IGBT module to be tested corresponds to one saturation voltage drop of the IGBT module to be tested;

Fitting a plurality of collector currents of the IGBT module to be tested and corresponding saturation voltage drops of the IGBT module to be tested under a first coordinate system to obtain a voltage drop current line segment to be tested, wherein the first coordinate system comprises a first coordinate axis and a second coordinate axis, the first coordinate axis comprises a plurality of saturation voltage drops, the second coordinate axis comprises a plurality of collector currents, and the voltage drop current line segment to be tested represents a mapping relation between the collector currents of the IGBT module to be tested and the saturation voltage drops of the IGBT module to be tested;

7. A device for detecting a state of an IGBT module, the device comprising:

The device comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring a change rate to be detected, wherein the change rate to be detected is the rate that the saturation voltage drop of an IGBT module to be detected changes along with the collector current of the IGBT module to be detected;

The determining unit is configured to determine that the IGBT module to be tested is in a failure state when the change rate to be tested satisfies a first predetermined condition, determine that the IGBT module to be tested is in a sub-health state when the change rate to be tested does not satisfy the first predetermined condition and satisfies a second predetermined condition, and determine that the IGBT module to be tested is in a health state when the change rate to be tested does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, the first predetermined condition is that the change rate to be tested is greater than a first predetermined value, the failure state indicates that the function of the IGBT module to be tested fails, the second predetermined condition is that the change rate to be tested is greater than a second predetermined value, the first predetermined value is greater than the second predetermined value, the sub-health state indicates that the function of the IGBT module to be tested is unstable, and the health state indicates that the function of the IGBT module to be tested is stable.

8. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored program, wherein the device in which the computer-readable storage medium is controlled to execute the method for detecting the IGBT module state according to any one of claims 1 to 6 when the program is run.

9. A processor, characterized in that the processor is configured to run a program, wherein the program runs to perform the method for detecting the IGBT module status according to any one of claims 1 to 6.

10. An electronic device, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising a method for performing the IGBT module state detection of any of claims 1 to 6.