Junction temperature calibration method, junction temperature detection method and junction temperature detection device of IGBT (Insulated Gate Bipolar Translator) device

Abstract

A junction temperature calibration method, junction temperature detection method and device for an IGBT device belong to the technical field of junction temperature calibration, and the method comprises the following steps: obtaining IGBT junction temperature calibration data; wherein the IGBT junction temperature calibration data comprises conduction voltage drop, junction temperature and conduction current; fitting a junction temperature calibration fitting function according to the IGBT junction temperature calibration data, and determining the relationship among the conduction voltage drop, the junction temperature and the conduction current to obtain a junction temperature calibration relational expression; wherein the junction temperature calibration fitting function is constructed through a diode voltage drop calculation formula and an MOSFET voltage drop calculation formula. The junction temperature calibration fitting function is established based on the physical principle in the IGBT, and the problems that an existing junction temperature calibration function is poor in precision and the calibration process is complex are solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of junction temperature calibration, and particularly relates to a junction temperature calibration method and device for an IGBT (Insulated Gate Bipolar Transistor) and a junction temperature detection method and device. BACKGROUND

[0002] During switching, an IGBT inevitably generates a certain power loss, which is converted into heat energy, thereby causing the device to heat up and the junction temperature to rise. The junction temperature (Tj) of an IGBT is the actual working temperature of the PN junction of a semiconductor chip inside the device, and is one of the important parameters in the operation of an IGBT, which is significant in multiple dimensions such as device reliability, performance, service life, and system safety. The real-time change of the junction temperature can directly reflect the current operating state of the IGBT. By capturing the junction temperature information of the IGBT in the operating state online, the real-time monitoring and management of the operating state of the IGBT system can be achieved, thereby effectively improving the cycle life of the IGBT and providing data support for the life prediction of the IGBT.

[0003] Some physical parameters of a power device have a corresponding mapping relationship with the junction temperature, such as carrier lifetime and mobility, so that the macroscopic electrical characteristics show a temperature-dependent change trend. Therefore, only by selecting a suitable thermosensitive electrical parameter for online measurement, online junction temperature monitoring can be achieved.

[0004] The on-state voltage drop Vce is the most widely studied and most comprehensive temperature-sensitive electrical parameter, which has the advantages of high sensitivity, good linearity, small influence on the existing working mode of the system, simple peripheral circuit, and the like.

[0005] When using Vce for junction temperature monitoring, the junction temperature needs to be calibrated first, and then the online monitoring of the junction temperature is performed through the calibration data. At present, there are two schemes, one is to establish a calibration database for online table lookup, and the other is to perform online calculation on the fitting formula of the junction temperature and Vce.

[0006] Since Vce is not only affected by the junction temperature but also related to the conduction current, if a database for online table lookup is selected, a large amount of data needs to be stored, and the online monitoring efficiency is low through table lookup.

[0007] If the fitting formula calculation method is selected, a binary function of the junction temperature with respect to Vce and the conduction current needs to be fitted, and it is difficult to ensure the accuracy and calculation difficulty of the function at the same time.

[0008] Therefore, it is urgent to develop an IGBT junction temperature calibration method, a junction temperature detection method and device to solve the problems in the prior art. SUMMARY

[0009] The application aims to provide a junction temperature calibration method, a junction temperature detection method and a device of an IGBT device, establish a junction temperature calibration fitting function based on the physical principle inside the IGBT, and solve the problem of poor function accuracy in the existing junction temperature calibration process.

[0010] To solve the above technical problems, the specific technical solutions of the application are as follows:

[0011] A junction temperature calibration method of an IGBT device comprises the following steps:

[0012] Obtain IGBT junction temperature calibration data; wherein the IGBT junction temperature calibration data comprises on-state voltage drop, junction temperature and on-state current;

[0013] Fit a junction temperature calibration fitting function according to the IGBT junction temperature calibration data, determine the relationship among the on-state voltage drop, the junction temperature and the on-state current, and obtain a junction temperature calibration relationship; wherein the junction temperature calibration fitting function is obtained by constructing a diode voltage drop calculation formula and a MOSFET voltage drop calculation formula.

[0014] Further, the construction of the junction temperature calibration fitting function comprises the following steps:

[0015] According to the diode voltage drop calculation formula and the MOSFET voltage drop calculation formula, obtain an IGBT on-state voltage drop calculation formula; wherein the IGBT on-state voltage drop in the IGBT on-state voltage drop calculation formula is equal to the sum of the diode voltage drop and the MOSFET voltage drop.

[0016] Extract the part related to temperature and current in the IGBT on-state voltage drop calculation formula, and convert the remaining part into an undetermined parameter to obtain a first fitting function.

[0017] Further, the IGBT on-state voltage drop calculation formula is as follows:

[0018] ;

[0019] Wherein, is the IGBT on-state voltage drop, is the Boltzmann coefficient, is the temperature, is the elementary charge amount, is the collector current surface density, is the drift region width, is the bipolar diffusion coefficient, is the intrinsic carrier concentration, is the bipolar diffusion length, is the drift region voltage drop; is the cell pitch, is the channel length, is the channel mobility, for gate oxide capacitance, for gate drive voltage, for gate threshold voltage.

[0020] Further, the part of the IGBT on-state voltage drop calculation formula related to temperature and current includes the gate threshold voltage;

[0021] When the unit of the device junction temperature is ℃, the fitting junction temperature calibration fitting function is as follows:

[0022] ;

[0023] Wherein, A, B, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℃, Ic is the on-state current, Vce is the on-state voltage drop;

[0024] When the unit of the device junction temperature is ℉, the fitting junction temperature calibration fitting function is as follows:

[0025] ;

[0026] Wherein, A, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℉, Ic is the on-state current, Vce is the on-state voltage drop.

[0027] Further, the construction of the junction temperature calibration fitting function further includes the following steps:

[0028] Convert the first fitting function into a general polynomial to obtain a second fitting function.

[0029] Further, the part of the IGBT on-state voltage drop calculation formula related to temperature and current includes the gate threshold voltage;

[0030] When the unit of the device junction temperature is ℃, the fitting junction temperature calibration fitting function is as follows:

[0031] ;

[0032] Wherein, A, B, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℃, Ic is the on-state current, Vce is the on-state voltage drop;

[0033] When the unit of the device junction temperature is ℉, the fitting junction temperature calibration fitting function is as follows:

[0034] ;

[0035] Wherein, A, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℉, Ic is the on-state current, Vce is the on-state voltage drop.

[0036] A junction temperature detection method of an IGBT device, comprising the following steps:

[0037] Obtaining IGBT calibration data; wherein the IGBT calibration data comprises on-voltage drop and on-current;

[0038] According to the junction temperature calibration method of the IGBT device, a junction temperature calibration relationship is obtained;

[0039] According to the IGBT calibration data and the junction temperature calibration relationship, the junction temperature of the IGBT is calculated.

[0040] A computer device comprising a memory, a processor and a computer program stored on the memory, the processor executing the computer program to implement the steps of the method.

[0041] A computer readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the steps of the method.

[0042] A computer program product comprising a computer program, the computer program being executed by a processor to implement the steps of the method.

[0043] The present application has the following advantages:

[0044] (1) The present application establishes a junction temperature calibration fitting function based on the physical principle inside the IGBT, and the junction temperature calibration fitting function is constructed by a diode voltage drop calculation formula and a MOSFET voltage drop calculation formula, which greatly improves the accuracy of junction temperature detection after junction temperature calibration. Compared with the existing conventional polynomial, the residual sum of squares of the junction temperature calibration fitting function of the present application is only 0.141, which is reduced by more than 90% compared with the 1.69 of the conventional polynomial. The goodness of fit R 2 also rises from 0.996 of the conventional polynomial to more than 0.9997, and the accuracy is greatly improved.

[0045] (2) The present application converts the fitting function into a general polynomial without quadratic term, which simplifies the calibration process and still has high accuracy.

[0046] Other features and advantages of the present application will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a flowchart of the present application;

[0048] Figure 2 is a sectional structure diagram of an IGBT device;

[0049] Figure 3 is a fitting result of IGBT device junction temperature calibration data using the existing quadratic polynomial fitting function;

[0050] Figure 4 The fitting result of the IGBT device junction temperature calibration data for applying the junction temperature calibration fitting function of the present application. DETAILED DESCRIPTION

[0051] In order to better understand the purpose, structure and function of the present application, the present application will be further described in detail below in combination with the drawings.

[0052] Embodiment one

[0053] A junction temperature calibration method of an IGBT device, as shown in the figure, comprises the following steps: Figure 1

[0054] S1: Obtain IGBT junction temperature calibration data; wherein the IGBT junction temperature calibration data comprises on-state voltage drop, junction temperature and on-state current; in this embodiment, the IGBT junction temperature calibration data is obtained by measurement.

[0055] S2: Fit a junction temperature calibration fitting function according to the IGBT junction temperature calibration data, determine the relationship of on-state voltage drop, junction temperature and on-state current, to obtain a junction temperature calibration relationship; wherein the junction temperature calibration fitting function is constructed by a diode voltage drop calculation formula and a MOSFET voltage drop calculation formula.

[0056] In this embodiment, to ensure the fitting effect, the IGBT junction temperature calibration data in S1 needs to obtain at least 5 equally spaced temperature measurement data points covering the entire IGBT device working temperature range, and the current should also obtain at least 10 equally spaced current measurement data points covering the entire IGBT device working condition range, to construct a Vce-Ic-Tj three-dimensional database. The more calibration data points selected, the better the fitting effect.

[0057] The construction of the junction temperature calibration fitting function in S2 comprises the following steps:

[0058] S21: Obtain an IGBT on-state voltage drop calculation formula according to a diode voltage drop calculation formula and a MOSFET voltage drop calculation formula; wherein the IGBT on-state voltage drop in the IGBT on-state voltage drop calculation formula is equal to the sum of the diode voltage drop and the MOSFET voltage drop.

[0059] Specifically, the IGBT on-state voltage drop calculation formula is as follows:

[0060] ;

[0061] wherein, Vce is the IGBT on-state voltage drop, k is the Boltzmann coefficient, T is the temperature, e is the elementary charge​ The collector current surface density, The width of the drift region. The bipolar diffusion coefficient, Intrinsic carrier concentration, The bipolar diffusion length, For the voltage drop in the drift region; For cell interval, The length of the channel. For channel migration rate, For gate oxide capacitance, This is the gate drive voltage. This is the gate threshold voltage.

[0062] like Figure 2 The diagram shows a cross-sectional view of an IGBT device. When a forward voltage greater than the threshold voltage is applied to the gate G, an N-type channel is induced in the P-region near the emitter E, connecting the N+ and N- drift regions. The collector current can reach the emitter through the PN junction of the injection region and buffer region, the drift region, and the conductive channel. Therefore, the saturation voltage drop of the IGBT device can be equivalent to the PN junction forward voltage drop V from the collector. PN Drift region voltage drop V B MOSFET conductive channel on-state voltage drop V MOS The sum of the three. Therefore, as Figure 3 As shown, when an IGBT is in the on state, it can be equivalent to a diode connected in series with an N-channel MOSFET, and the on-state voltage drop of the IGBT is equivalent to the sum of the diode voltage drop and the MOSFET voltage drop.

[0063] S22: Extract the temperature- and current-related parts from the IGBT on-state voltage drop calculation formula, and convert the remaining parts into undetermined parameters to obtain the first fitting function. In this embodiment, the first fitting function is used as the junction temperature calibration fitting function.

[0064] Specifically, in this embodiment, since the surface current density Jc is proportional to the on-state current Ic, and the temperature T is the junction temperature, all other quantities, except for the threshold voltage, are parameters that are not related to temperature or are only slightly affected by temperature. Therefore, the part of the IGBT on-state voltage drop calculation formula that is related to temperature and current is the gate threshold voltage, and the other parameters are not considered.

[0065] Gate threshold voltage The empirical formula relating temperature T is as follows:

[0066] ;

[0067] In the formula, This is the threshold voltage of the device at 300K, which can be considered a constant. , The unit of V is volt, and the unit of T is Kelvin.

[0068] Therefore, replace Jc with Ic, convert Kelvin to Celsius, and convert the rest to undetermined parameters, and the fitting junction temperature calibration fitting function is as follows:

[0069] ;

[0070] Wherein, A, B, C, D, E, F are undetermined parameters, Tj is the junction temperature of the device, the unit is ℃, Ic is the on current, Vce is the on voltage drop.

[0071] If the Kelvin is not converted to Celsius, the fitting junction temperature calibration fitting function is as follows:

[0072] ;

[0073] Wherein, A, C, D, E, F are undetermined parameters, Tj is the junction temperature of the device, the unit is ℉, Ic is the on current, Vce is the on voltage drop.

[0074] The common junction temperature fitting function fitting generally adopts polynomial fitting. Since the relationship between Vce and junction temperature is complex, the effect of common quadratic polynomial fitting is poor, and the selection of higher order polynomial will significantly increase the difficulty of calculation, which is not conducive to online monitoring. Compared with the common polynomial fitting function, the above two formulas extract the related quantities of temperature and current from the IGBT on voltage drop calculation formula, have the support of physical principle, have higher precision fitting effect, and have higher use value.

[0075] A junction temperature detection method of an IGBT device, comprising the following steps:

[0076] Obtaining IGBT calibration data; wherein the IGBT calibration data includes on voltage drop and on current;

[0077] According to the junction temperature calibration method of the IGBT device, the junction temperature calibration relationship is obtained;

[0078] According to the IGBT calibration data and the junction temperature calibration relationship, the junction temperature of the IGBT is calculated.

[0079] A computer device comprising a memory, a processor and a computer program stored on the memory, the processor executing the computer program to implement the steps of the method.

[0080] A computer program product comprising a computer program which, when executed by a processor, implements the steps of the method.

[0081] A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method.

[0082] Embodiment two

[0083] The difference between this embodiment and embodiment one is that the construction of the junction temperature calibration fitting function further comprises the following steps:

[0084] The first fitting function is converted into a general polynomial to obtain a second fitting function. In this embodiment, the second fitting function is used as the junction temperature calibration fitting function.

[0085] In this embodiment, the first fitting function is converted into a general polynomial by performing Taylor expansion on the fraction in the first fitting function and only taking the first two terms of the Taylor expansion, i.e. only taking the constant term and the first-order term, so as to improve the simplicity of calculation, reduce the consumption of computing resources and speed up the calculation under the condition of ensuring the calculation accuracy.

[0086] Specifically, the Taylor expansion is performed on the fraction as follows:

[0087] .

[0088] Specifically, in this embodiment, the fitting junction temperature calibration fitting function based on the physical principle is as follows:

[0089] When the unit of the device junction temperature is ℃, the junction temperature calibration fitting function is as follows:

[0090] ;

[0091] Wherein, A, B, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℃, Ic is the on-current, Vce is the on-voltage drop;

[0092] When the unit of the device junction temperature is ℉, the junction temperature calibration fitting function is as follows:

[0093] ;

[0094] Wherein, A, C, D, E, F are undetermined parameters, Tj is the device junction temperature, the unit is ℉, Ic is the on-current, Vce is the on-voltage drop.

[0095] The above two formulas are derived from the first fitting function. Compared with the common polynomial fitting function, it has the support of physical principle, has higher precision fitting effect, and is simple to calculate, does not need to solve high-order equations, has high online calculation efficiency, and has high use value.

[0096] Taking a crimped IGBT module with a model number of TG3000SW45ZC-P200 as an example, the nominal working current of the collector electrode is 3000 A, the working junction temperature range is 25-125 DEG C, the current setting of the IGBT junction temperature calibration data in the calibration database is 50 A-4500 A, and the data point current interval is 50 A; the temperature setting is 25 DEG C-125 DEG C, and the data point interval is 10 DEG C. A total of 990 calibration data points are fitted by using a common quadratic polynomial and the junction temperature calibration fitting function in the embodiment, and the software used for fitting is origin.

[0097] Specifically, the common quadratic polynomial is as follows:

[0098] .

[0099] Figure 3 a and Figure 4 In a, the Z axis is the on-voltage Vce, the X axis is the junction temperature Tj, the Y axis is the on-current Ic, the red dots in the figure are the original data, and the color surface is the fitting result.

[0100] From the fitting effect diagram, it can be directly seen that the fitting surface of the junction temperature calibration fitting function in the embodiment has a better coincidence degree with the original data. Figure 3 b and Figure 4 As shown in b, after comparison, the residual sum of squares of the junction temperature calibration fitting function in the embodiment is only 0.141, which is reduced by more than 90% compared with 1.69 of the quadratic polynomial, the fitting precision is greatly improved, and the goodness of fit R 2 is increased from 0.996 to 0.9997. In addition, as Figure 3 c and Figure 4 As shown in c, the result after fitting the to-be-determined parameters, the specific fitting process can refer to the prior art, and the present application will not be described again. In actual engineering application calculation, if the quadratic equation is used, the quadratic equation needs to be solved, and the present application only needs to solve the linear equation to calculate Tj, and the calculation simplicity is greatly improved.

[0101] It can be understood that the present application is described through some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to the features and embodiments without departing from the spirit and scope of the present application. In addition, under the guidance of the present application, the features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope of protection of the present application.

[0102] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A method for calibrating the junction temperature of an IGBT device, characterized in that, Includes the following steps: Obtain IGBT junction temperature calibration data; wherein, the IGBT junction temperature calibration data includes on-state voltage drop, junction temperature, and on-state current; By fitting a junction temperature calibration fitting function based on IGBT junction temperature calibration data, the relationship between on-state voltage drop, junction temperature, and on-state current is determined to obtain the junction temperature calibration formula; wherein, the junction temperature calibration fitting function is constructed by the diode voltage drop calculation formula and the MOSFET voltage drop calculation formula.

2. The junction temperature calibration method for IGBT devices according to claim 1, characterized in that, The construction of the junction temperature calibration fitting function includes the following steps: Based on the formulas for calculating diode voltage drop and MOSFET voltage drop, the formula for calculating IGBT on-state voltage drop is obtained; where the IGBT on-state voltage drop is equal to the sum of the diode voltage drop and the MOSFET voltage drop. Extract the temperature- and current-related parts from the IGBT on-state voltage drop calculation formula, and convert the remaining parts into undetermined parameters to obtain the first fitting function.

3. The junction temperature calibration method for IGBT devices according to claim 2, characterized in that, The formula for calculating the IGBT on-state voltage drop is as follows: ； in, For IGBT on-state voltage drop, Boltzmann coefficient, For temperature, The elementary charge, The collector current surface density, The width of the drift region. The bipolar diffusion coefficient, Intrinsic carrier concentration, The bipolar diffusion length, For the voltage drop in the drift region; Cellular distance, The length of the channel. For channel migration rate, For gate oxide capacitance, This is the gate drive voltage. This is the gate threshold voltage.

4. The junction temperature calibration method for IGBT devices according to claim 2 or 3, characterized in that, The part of the IGBT on-state voltage drop calculation formula that is related to temperature and current includes the gate threshold voltage. When the unit of device junction temperature is ℃, the fitting function for the junction temperature calibration is as follows: ； Where A, B, C, D, E, and F are parameters to be determined, Tj is the junction temperature of the device in °C, Ic is the on-current, and Vce is the on-voltage drop. When the unit of the device junction temperature is °F, the fitting function for the junction temperature calibration is as follows: ； Where A, C, D, E, and F are parameters to be determined, Tj is the junction temperature of the device in °F, Ic is the on-state current, and Vce is the on-state voltage drop.

5. The junction temperature calibration method for IGBT devices according to claim 2, characterized in that, The construction of the junction temperature calibration fitting function also includes the following steps: The first fitting function is transformed into an ordinary polynomial to obtain the second fitting function.

6. The junction temperature calibration method for IGBT devices according to claim 3 or 5, characterized in that, The part of the IGBT on-state voltage drop calculation formula that is related to temperature and current includes the gate threshold voltage. When the unit of device junction temperature is ℃, the fitting function for the junction temperature calibration is as follows: ； Where A, B, C, D, E, and F are parameters to be determined, Tj is the junction temperature of the device in °C, Ic is the on-current, and Vce is the on-voltage drop. When the unit of the device junction temperature is °F, the fitting function for the junction temperature calibration is as follows: ； Where A, C, D, E, and F are parameters to be determined, Tj is the junction temperature of the device in °F, Ic is the on-state current, and Vce is the on-state voltage drop.

7. A method for detecting the junction temperature of an IGBT device, characterized in that, Includes the following steps: Obtain IGBT calibration data; wherein, the IGBT calibration data includes on-state voltage drop and on-state current; According to any one of claims 1-6, the junction temperature calibration method for IGBT devices is used to obtain the junction temperature calibration formula. Calculate the junction temperature of the IGBT based on the IGBT calibration data and the junction temperature calibration formula.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-6 or the steps of the method according to claim 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-6 or the steps of the method according to claim 7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-6 or the steps of the method according to claim 7.

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