Method and device for constructing IGBT behavior model suitable for short-circuit working condition

Abstract

The invention discloses a construction method and device of an IGBT behavior model suitable for a short-circuit working condition, and belongs to the technical field of semiconductor devices, and the construction method comprises the steps: simulating the static output characteristics of an IGBT cut-off region, a saturation region and an active region based on an IGBT equivalent Darlington structure, and constructing the IGBT behavior model; performing controlled source parameter extraction and capacitance parameter extraction on the IGBT behavior model; the IGBT behavior model is corrected by considering the temperature effect under the short-circuit working condition, and a final IGBT behavior model is obtained; according to the method, the influence of temperature change and self-heating effect on the short-circuit current and dynamic characteristics of the IGBT is considered, and the short-circuit behavior of the IGBT can be well reflected under different working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular, to a method and device for constructing an IGBT behavior model applicable to short - circuit conditions. Background Art

[0002] IGBT is an important power semiconductor device, commonly used in inverters, electric vehicles, and power conversion equipment. Its switching performance is particularly crucial under high - voltage and large - current conditions.

[0003] In these applications, IGBT may face short - circuit faults, resulting in high power losses and thermal stress, making it difficult to accurately predict its current and voltage responses. The short - circuit behavior model of IGBT is of great significance for predicting the magnitude of IGBT short - circuit stress and evaluating the short - circuit safe operating area (SCSOA) of the device. Traditional IGBT behavior models simulate the current and voltage of IGBT through static curve fitting, and add inductance and capacitance elements to simulate parasitic effects and switching dynamic processes. However, they often ignore dynamic characteristics and temperature effects. This method can partially describe the switching process of IGBT, but under short - circuit conditions, due to the significant influence of self - heating, traditional behavior models cannot accurately reflect the changes in dynamic current and voltage. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a method and device for constructing an IGBT behavior model applicable to short - circuit conditions, so as to solve the technical problem that traditional behavior models ignore dynamic characteristics and temperature effects and cannot accurately reflect the changes in dynamic current and voltage.

[0005] To achieve the above - mentioned purpose, the present invention is implemented by the following technical solutions:

[0006] In the first aspect, the present invention provides a method for constructing an IGBT behavior model applicable to short - circuit conditions, including:

[0007] Based on the IGBT equivalent Darlington structure, simulate the static output characteristics of the IGBT cut - off region, saturation region, and active region, and construct an IGBT behavior model;

[0008] Extract the controlled - source parameters and capacitance parameters of the IGBT behavior model;

[0009] Consider the temperature effect under short - circuit conditions to correct the IGBT behavior model, and obtain the final IGBT behavior model.

[0010] Optionally, the IGBT behavior model includes:

[0011] A gate - emitter capacitance connected between the gate and the emitter , the gate-collector capacitance connected between the gate and the collector , the equivalent capacitance connected between the collector and the emitter , the tail capacitance connected between the collector and the emitter and the tail resistance , the current source connected between the collector and the emitter , the gate resistance connected to the gate .

[0012] Optionally, simulating the static output characteristics of the IGBT cut-off region includes:

[0013] Before the IGBT is turned on, the gate drive voltage is negative, the IGBT is in the cut-off state, and it bears the full bus voltage; when the gate turn-on signal arrives, the gate drive voltage changes to positive, and the gate current injects into the IGBT output capacitance ;

[0014] Output capacitance The charging process of conforms to the capacitance charging process of the RC circuit, and the gate voltage gradually rises to the threshold voltage ; In the IGBT cut-off region, the gate voltage is less than the threshold voltage , no current passes through the IGBT, and the voltage across the IGBT remains unchanged, and the IGBT current in the cut-off region can be obtained :

[0015]

[0016]

[0017] In the formula, is the maximum collector voltage when the collector current is negligible.

[0018] Optionally, simulating the static output characteristics of the IGBT saturation region and the active region includes:

[0019] When the gate voltage gradually rises to the threshold voltage , the IGBT starts to conduct; the channel gradually opens, current starts to pass through the IGBT, and the IGBT current gradually increases, and the change in the IGBT current causes an induced voltage in the loop parasitic inductance, reducing the voltage across the IGBT accordingly; when the IGBT current rises to the load current level, the voltage across the IGBT drops rapidly and reaches the IGBT conduction voltage drop;

[0020] Physically describe the IGBT current in the saturation region as follows:

[0021]

[0022] wherein, is the IGBT saturation current, are the channel length and width, is the channel electron mobility, is the oxide capacitance per unit area, is the common-emitter current gain of the transistor;

[0023] Define the controlled source parameters to obtain:

[0024]

[0025] Further derivation gives:

[0026]

[0027]

[0028] wherein, is the maximum collector voltage when the collector current is negligible.

[0029] Optionally, the extraction of the controlled source parameters and the capacitance parameters for the IGBT behavior model includes:

[0030] Calculating the controlled source parameters by taking points in the active region of the IGBT output characteristic curve ;

[0031] Obtaining the capacitance parameters from the IGBT data sheet, specifically including:

[0032] Calculating the gate-collector capacitance :

[0033]

[0034] wherein, is the gate-collector capacitance measured in the data sheet The capacitance value and voltage value at the starting collector voltage during measurement, is the capacitance correction factor;

[0035] Calculating the equivalent capacitance :

[0036]

[0037]

[0038] In the formula, is the active region area, is the silicon dielectric constant, is the base region doping concentration, is the base region width and length, is an intermediate variable, are the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT correction factor;

[0039] Trailing capacitance and trailing resistance are obtained by fitting according to the IGBT trailing time constant.

[0040] Optionally, the correction of the IGBT behavior model considering the temperature effect under short-circuit conditions includes:

[0041] Considering the influence of lattice scattering on the carrier mobility, calculate the lattice mobility :

[0042]

[0043] In the formula, is the equilibrium longitudinal elastic constant, , is the effective mass of the conduction electrons, is the displacement per unit expansion of the conduction band edge, is the Boltzmann constant, is the device temperature of the IGBT;

[0044] Considering the influence of ionized impurity scattering on the carrier mobility, calculate the ionized impurity mobility :

[0045]

[0046] In the formula, is the dielectric constant, is the ionized impurity density, is the conduction electron charge;

[0047] Performing Fourier analysis on the ionized impurity mobility gives:

[0048]

[0049]

[0050] wherein, is an intermediate variable, is the conduction density of conduction electrons;

[0051] Considering the combined effect of lattice scattering and ionized impurities, the carrier mobility of the IGBT changes with temperature. The influence coefficients of lattice scattering and ionized impurities on the carrier mobility are uniformly expressed as:

[0052]

[0053]

[0054] wherein, are the cosine integral function and the sine integral function;

[0055] The influence coefficient is simplified to:

[0056]

[0057] According to the function image, fitting is performed on the simplified influence coefficient :

[0058]

[0059] wherein, are undetermined parameters;

[0060] According to the influence coefficient on the IGBT current the correction gives:

[0061]

[0062]

[0063] Optionally, the device temperature of the IGBT under short - circuit conditions is:

[0064]

[0065] wherein, is the energy borne by the IGBT under short - circuit conditions, is the specific heat capacity of silicon, is the mass of the IGBT, is the external environment temperature of the IGBT, is the external environment temperature correction coefficient of the IGBT;

[0066] By the IGBT external environment temperature under short - circuit conditions of the IGBT current Obtained by fitting the descending section of the numerical value.

[0067] In a second aspect, the present invention provides a device for constructing an IGBT behavior model applicable to short - circuit conditions, including:

[0068] A model construction module, configured to simulate the static output characteristics of the IGBT cut - off region, saturation region, and active region based on the IGBT equivalent Darlington structure, and construct an IGBT behavior model;

[0069] A parameter extraction module, configured to extract controlled - source parameters and capacitance parameters from the IGBT behavior model;

[0070] A model correction module, configured to correct the IGBT behavior model by considering the temperature effect under short - circuit conditions to obtain the final IGBT behavior model.

[0071] Optionally, the IGBT behavior model includes:

[0072] A gate - emitter capacitance connected between the gate and the emitter , a gate - collector capacitance connected between the gate and the collector , an equivalent capacitance connected between the collector and the emitter , a tail capacitance connected between the collector and the emitter and a tail resistance , a current source connected between the collector and the emitter , a gate resistance connected to the gate .

[0073] Optionally, the model construction module includes a first simulation module, and the first simulation module is configured to simulate the static output characteristics of the IGBT cut - off region, including:

[0074] Before the IGBT is turned on, the gate - drive voltage is negative, the IGBT is in the cut - off state, and bears the full bus voltage; when the gate - turn - on signal arrives, the gate - drive voltage changes to positive, and the gate current injects into the IGBT output capacitance ;

[0075] The output capacitance The charging process conforms to the capacitance charging process of the RC circuit, and the gate voltage gradually rises to the threshold voltage ; in the IGBT cut - off region, the gate voltage is less than the threshold voltage , no current passes through the IGBT, and the voltage across the IGBT remains unchanged, and the IGBT current in the cut - off region can be obtained :

[0076]

[0077]

[0078] Wherein, is the maximum collector voltage when the collector current is negligible.

[0079] Optionally, the model building module includes a second simulation module configured to simulate the static output characteristics of the IGBT saturation region and the active region, including:

[0080] When the gate voltage gradually rises to the threshold voltage , the IGBT starts to conduct; the channel gradually opens, and current starts to flow through the IGBT. The IGBT current gradually increases, and the change in the IGBT current causes an induced voltage in the loop parasitic inductance, reducing the voltage across the IGBT correspondingly; when the IGBT current rises to the load current level, the voltage across the IGBT rapidly drops and reaches the conduction voltage drop of the IGBT;

[0081] Physically describe the IGBT current in the saturation region:

[0082]

[0083] Wherein, is the IGBT saturation current, is the channel length and width, is the channel electron mobility, is the oxide capacitance per unit area, is the common-emitter current gain of the transistor;

[0084] Define the controlled source parameter to obtain:

[0085]

[0086] Further derivation gives:

[0087]

[0088]

[0089] Wherein, is the maximum collector voltage when the collector current is negligible.

[0090] Optionally, the extraction of controlled source parameters and capacitance parameters for the IGBT behavior model includes:

[0091] Calculating the controlled source parameters by taking points in the active region of the IGBT output characteristic curve ;

[0092] Obtaining the capacitance parameters from the IGBT data sheet, specifically including:

[0093] Calculating the gate-collector capacitance :

[0094]

[0095] In the formula, is the gate-collector capacitance measured in the data sheet is the capacitance value and voltage value at the starting collector voltage during measurement, is the capacitance correction factor;

[0096] Calculating the equivalent capacitance :

[0097]

[0098]

[0099] In the formula, is the area of the active region, is the silicon dielectric constant, is the base doping concentration, is the base width and length, is an intermediate variable, is the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT correction factor;

[0100] The tail capacitance and the tail resistance are obtained by fitting according to the IGBT tail time constant.

[0101] Optionally, the correction of the IGBT behavior model by considering the temperature effect under short-circuit conditions includes:

[0102] Considering the influence of lattice scattering on the carrier mobility, calculating the lattice mobility :

[0103]

[0104] Where, is the equilibrium longitudinal elastic constant, , is the effective mass of the conduction electrons, is the displacement of the conduction band edge per unit expansion, is the Boltzmann constant, is the device temperature of IGBT;

[0105] Considering the effect of ionized impurity scattering on carrier mobility, calculate the ionized impurity mobility :

[0106]

[0107] Where, is the dielectric constant, is the ionized impurity density, To conduct electronic charge;

[0108] The mobility of the ionized impurities Performing Fourier analysis yields:

[0109]

[0110]

[0111] Where, is an intermediate variable, is the conduction density of conduction electrons;

[0112] Considering the combined effect of lattice scattering and ionized impurities, the carrier mobility of IGBT changes with temperature. The influence coefficient of lattice scattering and ionized impurities on carrier mobility is The unified expression is:

[0113]

[0114]

[0115] Where, are the cosine integral function and the sine integral function;

[0116] The influence coefficient Simplified to:

[0117]

[0118] According to the function graph, the influence coefficient after simplification is drawn Perform the fit:

[0119]

[0120] In the formula, is a parameter to be determined;

[0121] According to the influence coefficient to the IGBT current the correction can be obtained as:

[0122]

[0123]

[0124] Optionally, the device temperature of the IGBT under short - circuit conditions is:

[0125]

[0126] In the formula, is the energy borne by the IGBT under short - circuit conditions, is the specific heat capacity of silicon, is the mass of the IGBT, is the external environment temperature of the IGBT, is the external environment temperature of the IGBT correction coefficient;

[0127] By fitting the descending section of the IGBT current under short - circuit conditions at the IGBT external environment temperature the value of is obtained.

[0128] In a third aspect, the present invention provides an electronic device, including a processor and a storage medium;

[0129] The storage medium is used to store instructions;

[0130] The processor is used to operate according to the instructions to execute the steps of the above - mentioned method.

[0131] In a fourth aspect, the present invention provides a computer - readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the above - mentioned method are implemented.

[0132] Compared with the prior art, the beneficial effects achieved by the present invention:

[0133] A method and device for constructing an IGBT behavior model applicable to short - circuit conditions provided by the present invention correct the current expression of IGBT under short - circuit conditions through theoretical derivation and experimental data fitting, consider the influence of temperature change and self - heating effect on the short - circuit current and dynamic characteristics of IGBT, and can well reflect the short - circuit behavior of IGBT under different working conditions. In addition, this model comprehensively considers the multi - factor influence of gate drive voltage, on - resistance and external ambient temperature, and can accurately simulate the dynamic behavior of IGBT under type - I and type - II short - circuit conditions. This invention improves the accuracy of the IGBT short - circuit behavior model, has good generality and applicability, and can be widely used in the design and fault analysis of power electronics and power conversion equipment. Description of the Drawings

[0134] Figure 1 is a schematic flow chart of a method for constructing an IGBT behavior model applicable to short - circuit conditions provided by an embodiment of the present invention;

[0135] Figure 2 is a schematic structural diagram of an IGBT behavior model provided by an embodiment of the present invention;

[0136] Figure 3 is a schematic diagram for comparing capacitance fitting provided by an embodiment of the present invention;

[0137] Figure 4 is a schematic diagram for comparing output characteristics provided by an embodiment of the present invention;

[0138] Figure 5 is a schematic diagram for comparing the on - off waveforms of the gate voltage of double - pulse provided by an embodiment of the present invention;

[0139] Figure 6 is a schematic diagram for comparing the on - off waveforms of the collector voltage of double - pulse provided by an embodiment of the present invention;

[0140] Figure 7 is a schematic diagram for comparing the on - off waveforms of the collector current of double - pulse provided by an embodiment of the present invention;

[0141] Figure 8 is a schematic diagram for comparing different pulse widths of type - I short - circuit provided by an embodiment of the present invention;

[0142] Figure 9 is a schematic diagram for comparing different pulse widths of type - II short - circuit provided by an embodiment of the present invention;

[0143] Figure 10 is a schematic diagram for comparing different gate voltages of type - I short - circuit provided by an embodiment of the present invention;

[0144] Figure 11 is a schematic diagram for comparing different on - resistances of type - I short - circuit provided by an embodiment of the present invention;

[0145] Figure 12 This is a schematic diagram comparing different temperatures of a short circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0146] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0147] Example 1:

[0148] like Figure 1 As shown, an embodiment of the present invention provides a method for constructing an IGBT behavior model suitable for short-circuit conditions, including:

[0149] Step S1: Based on the IGBT equivalent Darlington structure, the static output characteristics of the IGBT cut-off region, saturation region and active region are simulated to construct an IGBT behavior model.

[0150] The turn-on process of IGBT under inductive load can be roughly divided into four stages.

[0151] 1) Delayed opening phase

[0152] Before the IGBT device is turned on, the IGBT gate drive voltage is negative, the device is in the cut-off state, and bears the full bus voltage. When the gate turn-on signal arrives, the gate drive voltage changes to positive voltage, and the gate current is injected into the IGBT output capacitor. :

[0153] (1)

[0154] Where, is the gate-emitter capacitance, is the gate-collector capacitance.

[0155] This charging process is consistent with the capacitor charging process of the RC circuit. At this time, the gate voltage gradually rises to the threshold voltage. , since the gate voltage of the IGBT is The voltage across the device is lower than the threshold voltage for the device to turn on, so no current flows through the device. Remain unchanged.

[0156] 2) Current rising stage

[0157] When the gate voltage of the IGBT Greater than the threshold voltage When the IGBT starts to conduct, the channel gradually opens and current begins to flow through the device. The collector current Gradually increases. Due to the change of collector current , loop parasitic inductance An induced voltage will be generated, causing the IGBT collector voltage to The relationship can be expressed as follows:

[0158] (2)

[0159] Where, is the bus voltage.

[0160] 3) Current rising stage

[0161] When the collector current of the IGBT rises to the load current IGBT collector voltage after horizontal It drops rapidly and reaches the on-state voltage drop of the IGBT device. ( ) The change curve shows With voltage The decrease gradually increases when The value gradually decreases to hour, Rapid growth, leading to The decrease of the gate current slows down, and the gate current mainly flows through , IGBT devices Almost unchanged, clamped at the Miller voltage.

[0162] 4) Gate voltage rising stage

[0163] The gate current continues to flow to the IGBT output capacitance Charging, devices After passing the Miller platform, it continues to rise and eventually reaches the gate rated voltage.

[0164] 5) When a short circuit occurs

[0165] When a short circuit occurs, the IGBT device Rapidly rises to the external circuit capacitor voltage, collector current From the load current It quickly rises to 5-10 times the rated current, and its maximum value is affected by the gate voltage.

[0166] The IGBT shutdown process can be divided into three stages.

[0167] 1) Shutdown delay stage

[0168] Similar to the turn-on process of IGBT devices, the turn-off delay of IGBT is the input capacitance During the discharge process, when the gate voltage This stage ends when the voltage drops to the Miller plateau voltage.

[0169] 2) Voltage rising stage

[0170] When reaches the Miller plateau, the device begins to rise. At this time has the following relationship:

[0171] (3)

[0172] In the formula, is the gate current, is the driving low-level voltage, is the Miller plateau voltage, is the driving turn-off resistance.

[0173] According to formula (3), when increases, rapidly decreases, resulting in the rising speed gradually accelerating and finally reaching the bus voltage .

[0174] 3) Current falling stage

[0175] When rises to , since the collector current begins to rapidly decrease at this time, a high will induce a voltage spike on the parasitic inductance :

[0176] (4)

[0177] Since the remaining carriers inside the IGBT do not disappear immediately, the collector current will show a tailing phenomenon during the turn-off process, forming a tailing current , which is a function decaying with time and can be expressed as follows:

[0178] (5)

[0179] In the formula, is the initial tailing current, is the time constant of the tailing current.

[0180] Considering that the influence of the IGBT output characteristics on its dynamic characteristics is mainly reflected in the control effect of the gate voltage in the active region on the collector current, starting from the IGBT equivalent Darlington structure, by simulating the static output characteristics of the IGBT cut-off region, saturation region, and active region, an IGBT behavior model is proposed.

[0181] like Figure 2 As shown, the IGBT behavioral model includes:

[0182] Gate-emitter capacitance connected between the gate and emitter , the gate-collector capacitance connected between the gate and collector , the equivalent capacitance connected between the collector and emitter , the tailing capacitor connected between the collector and emitter and tailing resistors , a current source connected between the collector and emitter , Gate resistor connected to the gate .

[0183] Current source in IGBT behavioral model The expression is:

[0184] (6)

[0185] Step S2: extracting controlled source parameters and capacitance parameters from the IGBT behavior model.

[0186] Step S2.1, extracting controlled source parameters, specifically includes:

[0187] Current Source in IGBT Behavioral Model , which mainly characterizes the output characteristics of the IGBT. As for the output characteristics of the IGBT, its characteristics in the active region have a greater impact on the dynamic characteristics, while the characteristics in the saturation region have a greater impact on the turn-on loss. Therefore, this embodiment simplifies the output characteristics of the IGBT to a certain extent.

[0188] According to the IGBT saturation current calculation formula:

[0189] (7)

[0190] (8)

[0191] Where, is the IGBT saturation current, are the channel length and width, is the channel electron mobility, is the oxide layer capacitance per unit area, is the common emitter amplification factor of the transistor;

[0192] Can be used Instead of the device parameters in equation (7), directly use the parameters Describe the output characteristics of the model instead of Correlate with the device gate voltage, parameter It can be calculated from the points on the output characteristic curve of the IGBT in the active region, and its magnitude is shown in the following formula.

[0193] (9)

[0194] Step S2.2, the extraction of capacitor parameters specifically includes:

[0195] As Figure 3 shown, through the data sheet of the IGBT, the capacitance value of the IGBT Miller capacitor ( ) varying with can be obtained. Its variation with voltage can be fitted by the following formula:

[0196]

[0197] In the formula, is the gate-collector capacitance measured in the data sheet at the starting collector voltage , and is the capacitance correction coefficient;

[0198] The tail capacitance and tail resistance in this behavioral model can be fitted by selecting appropriate values according to the IGBT tail time constant. The IGBT tail time constant , the order of magnitude of the tail capacitance is taken as nF, as long as the product of the two satisfies; the resistance is the drive resistance on the drive board, and can be flexibly adjusted according to the actual drive board used. Other fixed capacitors such as , can directly obtain data from the data sheet. is the equivalent capacitance for simulating the base region stored charge effect. Since the stored charge only appears in the on state, will show a large capacitance value during the IGBT turn-off process, and a small capacitance value during the turn-on process. Its specific calculation method can be obtained by the following formula:

[0199] Calculate the equivalent capacitance :

[0200]

[0201]

[0202] In the formula, is the area of the active region, is the silicon dielectric constant, is the base region doping concentration, are the base region width and length, is an intermediate variable, are the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT is the correction factor.

[0203] Step S3: Consider the temperature effect under short-circuit conditions to correct the IGBT behavior model and obtain the final IGBT behavior model.

[0204] Since there is self-heating in the IGBT during the conduction process, and under short-circuit conditions, since the IGBT bears high voltage and large current simultaneously, this self-heating will be more significant. However, the traditional IGBT behavior model cannot accurately describe this process. In this embodiment, from the perspective of semiconductor physics, through theoretical derivation, a correction expression for the self-heating of the IGBT is finally obtained.

[0205] According to semiconductor theory, since the IGBT device has a gate oxide layer and a gate electrode, a capacitance will be generated in the channel, and its capacitance per unit area is:

[0206]

[0207] In the formula, d ox is the oxide thickness, ε r is the relative permittivity, ε0 is the absolute permittivity. When the gate voltage is higher than the IGBT threshold voltage, an inversion layer channel is generated, and its charge quantity can be expressed as:

[0208]

[0209] The carriers forming these charges transport current in the inversion layer channel. Ignoring the pinch-off effect in the channel, the channel resistance can be obtained as:

[0210]

[0211] In the formula, L represents the channel length, W represents the channel width, and μ is the carrier mobility

[0212] According to the relationship between current density, conductivity, and the average drift velocity of carriers:

[0213]

[0214] Where J is the current density; E is the electric field strength across the silicon material; σ is the conductivity; n is the carrier density; q is the carrier charge; and v is the carrier drift velocity.

[0215] Based on the above equation, the relationship between conductivity and the average carrier drift velocity can be derived:

[0216]

[0217] Under weak electric fields, the ratio of the average carrier drift velocity to the electric field strength is the carrier mobility μ. Therefore, the above equation can be expressed as:

[0218]

[0219] From the above equation, it can be seen that the carrier mobility μ is proportional to the conductivity σ.

[0220] Inside the IGBT material, there are five scattering or influencing mechanisms that affect the carrier mobility, namely lattice scattering, ionized impurity scattering, neutral impurity scattering, dislocation scattering, and electron-electron collision effects.

[0221] Among them, lattice scattering and ionized impurity scattering have a greater impact on the carrier mobility, while the other three mechanisms have a smaller impact. Here, only the effects of lattice scattering and ionized impurity scattering on the carrier mobility are considered.

[0222] The effect of lattice scattering on the mobility is shown in the following equation:

[0223]

[0224] Where μ L is the lattice mobility, c ll is the equilibrium longitudinal elastic constant, h is Planck's constant / 2π, m n is the effective mass of the conduction electrons, ε 1n is the displacement per unit expansion of the conduction band edge, k is the Boltzmann constant, and T is the absolute temperature. From the above equation, it can be seen that lattice scattering is affected by temperature and is proportional to the -1.5 power of temperature.

[0225] The effect of ionized impurity scattering on the mobility is shown in the following equation:

[0226]

[0227] Where μ I is the ionized impurity mobility, κ is the dielectric constant, N I is the ionized impurity density, e is the electron charge = 1.60 * -19(C)。

[0228] Performing Fourier analysis on the above equation gives:

[0229]

[0230] where

[0231]

[0232] It can be seen from the above equation that the ionized impurity scattering is affected by temperature and is proportional to the 1.5th power of the temperature, and at the same time is inversely proportional to the ionized impurity concentration.

[0233] The lattice scattering and the ionized impurity scattering act together to cause the carrier mobility of the IGBT device to change with temperature. The effects of the two on the carrier mobility can be uniformly expressed by the following equation:

[0234]

[0235]

[0236] The above equation can be simplified to:

[0237]

[0238] According to the function graph plotting, it is found that the above equation can be well fitted by Equation (26).

[0239]

[0240] Therefore, the above equation can be used as the correction equation for the change of carrier mobility with temperature.

[0241] Use Equation (26) to correct the channel carrier mobility in Equation (7). Finally, the expression of the IGBT saturation current after temperature correction is obtained:

[0242]

[0243] At the same time, to describe the value of T during the short-circuit process, the source of T can be divided into two parts. One part is contributed by the self-heating of the device during the short-circuit process, and the other part is contributed by the external environment. The expression of T obtained by fitting the short-circuit current is:

[0244]

[0245] Where E is the energy borne by the chip during the short - circuit process, C is the specific heat capacity of silicon, m is the mass of the chip, T out is the external temperature, with the unit of °C, and F, G are the correction factors for the external temperature.

[0246] The numerical values of a, c, d, F, and G can be obtained by fitting the falling segment of the short - circuit current at different external temperatures.

[0247] The extraction of the above - mentioned model parameters is shown in Table 1 below.

[0248] Table 1: Extracted model parameter values

[0249]

[0250] As Figure 4 shown, compare the static data measured in the experiment with the static data obtained from the simulation, and compare the output characteristics of the two. According to Figure 4 It can be seen that the error of the behavioral model in this paper is relatively large in the saturation region, but it can fit well with the experimental data in the active region. This is because the variation law of K with respect to the gate voltage and collector voltage in Equation (6) is not considered during the steady - state modeling. However, the output characteristics in the saturation region have little impact on the dynamic characteristics of the IGBT, while the output characteristics in the active region have a greater impact on the dynamic characteristics of the IGBT. Therefore, the model in this paper can well reflect the dynamic characteristics of the IGBT at the output characteristic level.

[0251] As Figure 5 、 6 、Figure 7 shows, build a double - pulse circuit in the simulation software to compare the degree of coincidence between the model in this paper and the commercial IGBT device model during the turn - on and turn - off processes. According to Figure 5 、 6 、Figure 7 and the comparison with the existing simulation model, it can be seen that the model in this paper can well simulate the dynamic characteristics of the IGBT.

[0252] As Figure 8 、 9 shown, build a type - I and type - II short - circuit circuit in the simulation circuit, and use the model in this paper to simulate the type - I and type - II short - circuits of the IGBT. Compare the type - I and type - II short - circuit currents with the experimental data at different pulse widths. Among them, for the type - I short - circuit, the pulse widths are taken as 10 μs, 12 μs, 14 μs, 16 μs, and 18 μs for simulation; for the type - II short - circuit, the pulse widths are taken as 5 μs, 7 μs, and 9 μs for simulation. The parasitic parameters, drive resistance, bus voltage, and load current levels in the simulation circuit are all set the same as those in the experiment. According to Figure 8 、 9It can be seen that by comparing the simulation and experimental data, the short - circuit model established in this paper can well fit the first - type and second - type short - circuit conditions of IGBTs. Moreover, the correction formula for current decline caused by chip self - heating used in this paper satisfies both the first - type and second - type short - circuit conditions and has good universality.

[0253] As Figure 10 shown, the gate - drive voltages in the simulation circuit are respectively set to 12V, 15V, and 18V for simulation. The current waveforms of the simulation model affected by the gate voltage are obtained and compared with the experimental waveforms. According to Figure 10 it can be seen that the simulation model has good universality for different gate voltages and can basically meet the simulation of short - circuit conditions under different gate voltages.

[0254] As Figure 11 shown, the on - resistance in the simulation circuit is respectively set to 12Ω, 20Ω, 42Ω, and 56Ω for simulation. The current waveforms of the simulation model affected by the on - resistance are obtained and compared with the experimental waveforms. According to Figure 11 it can be seen that the fitting accuracy between the model in this paper and the experimental data is very high for different on - resistances, and it can well reflect the influence on short - circuit conditions when using different on - resistances.

[0255] As Figure 12 shown, the external environmental temperature is adjusted in the simulation circuit, and the external environmental temperature is respectively set to 25°C, 50°C, and 75°C for the first - type short - circuit simulation. The comparison between the simulation waveforms and the experimental data is obtained. According to Figure 12 it can be seen that the model in this paper can well simulate the influence of temperature change on the IGBT short - circuit process, verifying that the model in this paper can achieve the simulation of IGBT short - circuit conditions at different temperatures.

[0256] Embodiment 2:

[0257] The embodiment of the present invention provides a device for constructing an IGBT behavior model applicable to short - circuit conditions, including a model construction module, a parameter extraction module, and a parameter extraction module.

[0258] (1) The model construction module is configured to simulate the static output characteristics of the cut - off region, saturation region, and active region of the IGBT based on the IGBT equivalent Darlington structure, and construct an IGBT behavior model.

[0259] Specifically, in this embodiment, the IGBT behavior model includes:

[0260] The gate - emitter capacitance connected between the gate and the emitter , the gate - collector capacitance connected between the gate and the collector , and the equivalent capacitance connected between the collector and the emitter , a tail capacitance connected between the collector and the emitter and a tail resistance , a current source connected between the collector and the emitter , a gate resistance connected to the gate .

[0261] The model building module further includes a first simulation module and a second simulation module.

[0262] The first simulation module is configured to simulate the static output characteristics of the IGBT cut-off region, including:[[]]

[0263] Before the IGBT is turned on, the gate drive voltage is negative, the IGBT is in the cut-off state, and bears the full bus voltage; when the gate turn-on signal arrives, the gate drive voltage changes to positive, and the gate current injects into the IGBT output capacitance ;

[0264] The output capacitance The charging process of conforms to the capacitance charging process of the RC circuit, and the gate voltage gradually rises to the threshold voltage ; In the IGBT cut-off region, the gate voltage is less than the threshold voltage , no current passes through the IGBT, and the voltage across the IGBT remains unchanged, and the IGBT current in the cut-off region can be obtained :[[]]

[0265]

[0266]

[0267] In the formula, is the maximum collector voltage when the collector current is negligible.

[0268] The second simulation module is configured to simulate the static output characteristics of the IGBT saturation region and the active region, including:[[]]

[0269] When the gate voltage gradually rises to the threshold voltage , the IGBT starts to conduct; the channel gradually opens, current starts to pass through the IGBT, and the IGBT current gradually increases, and the change of the IGBT current causes an induced voltage in the loop parasitic inductance, reducing the voltage across the IGBT correspondingly; when the IGBT current rises to the load current level, the voltage across the IGBT Rapidly decrease and reach the IGBT conduction voltage drop;

[0270] Physically describe the IGBT current in the saturation region as follows:

[0271]

[0272] wherein, is the IGBT saturation current, are the channel length and width, is the channel electron mobility, is the oxide capacitance per unit area, is the common-emitter current gain of the transistor;

[0273] Define the controlled source parameters to obtain:

[0274]

[0275] Further derivation gives:

[0276]

[0277]

[0278] wherein, is the maximum collector voltage when the collector current is negligible.

[0279] (2) Parameter extraction module, configured to extract controlled source parameters and capacitance parameters from the IGBT behavior model.

[0280] Specifically, in this embodiment, extracting the controlled source parameters and capacitance parameters from the IGBT behavior model includes:

[0281] Calculating the controlled source parameters by taking points in the active region of the IGBT output characteristic curve ;

[0282] Obtaining the capacitance parameters from the IGBT data sheet, specifically including:

[0283] Calculating the gate-collector capacitance :

[0284]

[0285] wherein, is the gate-collector capacitance measured in the data sheet is the capacitance value and voltage value at the starting collector voltage during measurement, is the capacitance correction factor;

[0286] Calculating the equivalent capacitance :

[0287]

[0288]

[0289] In the formula, is the active area, is the silicon dielectric constant, is the base doping concentration, is the base width and length, is an intermediate variable, are the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT correction factor;

[0290] Trailing capacitance and trailing resistance are obtained by fitting according to the IGBT trailing time constant.

[0291] (3) Parameter extraction module, configured to correct the IGBT behavior model by considering the temperature effect under short-circuit conditions to obtain the final IGBT behavior model.

[0292] Specifically, in this embodiment, correcting the IGBT behavior model by considering the temperature effect under short-circuit conditions includes:

[0293] Considering the influence of lattice scattering on the carrier mobility, calculating the lattice mobility :

[0294]

[0295] In the formula, is the equilibrium longitudinal elastic constant, , is the effective mass of the conduction electrons, is the displacement per unit expansion of the conduction band edge, is the Boltzmann constant, is the device temperature of the IGBT;

[0296] Considering the influence of ionized impurity scattering on the carrier mobility, calculating the ionized impurity mobility :

[0297]

[0298] In the formula, is the dielectric constant, is the ionized impurity density, For the conduction electron charge;

[0299] For the ionization impurity mobility Performing Fourier analysis gives:

[0300]

[0301]

[0302] Wherein, is an intermediate variable, is the conduction density of the conduction electrons;

[0303] Considering the combined effect of lattice scattering and ionization impurities, the carrier mobility of the IGBT varies with temperature. The influence coefficients of lattice scattering and ionization impurities on the carrier mobility are uniformly expressed as:

[0304]

[0305]

[0306] Wherein, are the cosine integral function and the sine integral function;

[0307] The influence coefficient is simplified to:

[0308]

[0309] According to the function graph, fitting is performed on the simplified influence coefficient to obtain:

[0310]

[0311] Wherein, are undetermined parameters;

[0312] According to the influence coefficient the IGBT current is corrected to obtain:

[0313]

[0314] [[ID=6,9]]

[0315] Among them, the device temperature of the IGBT under the short-circuit condition is:

[0316]

[0317] Wherein, is the energy borne by the IGBT under the short-circuit condition, is the specific heat capacity of silicon, is the IGBT mass, is the IGBT external ambient temperature, is the IGBT external ambient temperature correction factor;

[0318] By measuring the IGBT current in the short - circuit condition at the IGBT external ambient temperature and fitting the descending section, the value is obtained.

[0319] Embodiment 2:

[0320] Based on the method for constructing an IGBT behavior model applicable to short - circuit conditions provided in Embodiment 1, an embodiment of the present invention provides an electronic device, including a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the above - mentioned method.

[0321] Embodiment 3:

[0322] Based on the method for constructing an IGBT behavior model applicable to short - circuit conditions provided in Embodiment 1, an embodiment of the present invention provides a computer - readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the above - mentioned method are implemented.

[0323] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can be in the form of a computer program product implemented on one or more computer - usable storage media (including but not limited to disk storage, CD - ROM, optical storage, etc.) containing computer - usable program code.

[0324] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general - purpose computer, a special - purpose computer, an embedded processor, or other programmable data - processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data - processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0325] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more of the processes and / or blocks Figure 1 one or more of the processes and / or blocks Figure 1 specified in one or more of the blocks or blocks.

[0326] These computer program instructions can 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, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the processes and / or blocks Figure 1 one or more of the processes and / or blocks Figure 1 specified in one or more of the blocks or blocks.

[0327] The foregoing are only the preferred embodiments of the present invention, and it should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for constructing an IGBT behavior model applicable to short - circuit conditions, characterized in that, Including: Based on the IGBT equivalent Darlington structure, simulate the static output characteristics of the IGBT cut-off region, saturation region, and active region, and construct an IGBT behavior model; Extract the controlled source parameters and capacitance parameters of the IGBT behavior model; Consider the temperature effect under short-circuit conditions to correct the IGBT behavior model to obtain the final IGBT behavior model.

2. The method for constructing an IGBT behavior model applicable to short-circuit conditions according to claim 1, characterized in that, The IGBT behavior model includes: The gate-emitter capacitance connected between the gate and the emitter , the gate-collector capacitance connected between the gate and the collector , the equivalent capacitance connected between the collector and the emitter , the tail capacitance connected between the collector and the emitter and the tail resistance , the current source connected between the collector and the emitter , the gate resistance connected to the gate .

3. The method for constructing an IGBT behavior model applicable to short-circuit conditions according to claim 2, wherein, Simulating the static output characteristics of the IGBT cut-off region includes: Before the IGBT is turned on, the gate drive voltage is negative, the IGBT is in the cut-off state, and bears the entire bus voltage; when the gate turn-on signal arrives, the gate drive voltage changes to positive voltage, and the gate current is injected into the IGBT output capacitor ; Output capacitor The charging process conforms to the capacitor charging process of the RC circuit, and the gate voltage gradually rises to the threshold voltage ; In the IGBT cut-off region, the gate voltage is less than the threshold voltage , no current passes through the IGBT, and the voltage across the IGBT remains unchanged. The IGBT current in the cut-off region can be obtained : Wherein, is the maximum collector voltage when the collector current is negligible.

4. The method for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 2, characterized in that, Simulating the static output characteristics of the IGBT saturation region and active region includes: When the gate voltage gradually rises to the threshold voltage , the IGBT starts to conduct; the channel gradually opens, and current begins to flow through the IGBT. The IGBT current gradually increases. The change in the IGBT current induces a voltage in the loop parasitic inductance, causing the voltage across the IGBT to decrease accordingly; when the IGBT current rises to the load current level, the voltage across the IGBT rapidly drops and reaches the conduction voltage drop of the IGBT; IGBT current in the saturation region for physical description: Wherein, is the IGBT saturation current, are the channel length and width, is the channel electron mobility, is the oxide capacitance per unit area, is the common-emitter current gain of the transistor; Define the parameters of the controlled source It can be obtained that: Further derivation shows that: wherein, is the maximum collector voltage when the collector current is negligible.

5. The method for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 4, characterized in that, The extraction of the controlled source parameters and capacitance parameters of the IGBT behavior model includes: Calculating the controlled source parameters by taking points in the active region of the IGBT output characteristic curve ; Obtain the capacitance parameters through the IGBT data sheet, specifically including: Calculate the gate-collector capacitance : In the formula, is the gate-collector capacitance measured in the data sheet at the starting collector voltage and the capacitance value and voltage value at that time, is the capacitance correction coefficient; Calculate the equivalent capacitance : In the formula, is the active area, is the silicon dielectric constant, is the base doping concentration, is the base width and length, is an intermediate variable, is the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT is the correction factor; Trailing capacitor and trailing resistor Obtained by fitting according to the IGBT trailing time constant.

6. The method for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 2, wherein The correction of the IGBT behavior model considering the temperature effect under short-circuit conditions includes: Considering the influence of lattice scattering on the carrier mobility, calculate the lattice mobility : wherein, is the equilibrium longitudinal elastic constant, , is the effective mass of the conduction electrons, is the displacement per unit expansion of the conduction band edge, is the Boltzmann constant, is the device temperature of the IGBT; Consider the influence of ionized impurity scattering on the carrier mobility and calculate the ionized impurity mobility : wherein, is the dielectric constant, is the ionized impurity density, is the conduction electron charge; For the ionized impurity mobility Performing Fourier analysis gives: wherein, is an intermediate variable, is the conduction density of conduction electrons; Considering the combined effect of lattice scattering and ionized impurities, the carrier mobility of the IGBT changes with temperature. The influence coefficients of lattice scattering and ionized impurities on the carrier mobility are uniformly expressed as: In the formula, are the cosine integral function and the sine integral function; The influence coefficient is simplified to: Effect of drawing based on function graph on simplified influence coefficient Perform fitting: In the formula, is a parameter to be determined; According to the influence coefficient for the IGBT current the correction can be obtained as follows:

7. The construction method of the IGBT behavior model applicable to short - circuit conditions according to claim 6, characterized in that, IGBT device temperature under short - circuit condition is as follows: In the formula, is the energy borne by the IGBT under short - circuit conditions, is the specific heat capacity of silicon, is the mass of the IGBT, is the external environmental temperature of the IGBT, is the external environmental temperature of the IGBT correction factor; By fitting the IGBT current in the falling segment under the short - circuit condition at the external environmental temperature of the IGBT to obtain the numerical value obtained.

8. An apparatus for constructing an IGBT behavior model applicable to short-circuit conditions, characterized in that, Including: A model construction module configured to simulate the static output characteristics of the IGBT cut-off region, saturation region, and active region based on the IGBT equivalent Darlington structure, and construct an IGBT behavior model; A parameter extraction module configured to extract the controlled source parameters and capacitance parameters of the IGBT behavior model; A model correction module configured to consider the temperature effect under short-circuit conditions to correct the IGBT behavior model to obtain the final IGBT behavior model.

9. The device for constructing an IGBT behavior model applicable to short-circuit conditions according to claim 8, wherein The IGBT behavior model includes: The gate-emitter capacitance connected between the gate and the emitter 、the gate-collector capacitance connected between the gate and the collector 、the equivalent capacitance connected between the collector and the emitter 、the tail capacitance connected between the collector and the emitter and the tail resistance 、the current source connected between the collector and the emitter 、the gate resistance connected to the gate .

10. The device for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 9, characterized in that, The model construction module further includes a first simulation module configured to simulate the static output characteristics of the IGBT cut-off region, including: Before the IGBT is turned on, the gate drive voltage is negative, the IGBT is in the cut-off state, and bears the entire bus voltage; when the gate turn-on signal arrives, the gate drive voltage changes to positive voltage, and the gate current is injected into the IGBT output capacitor ; Output capacitor The charging process of is in line with the capacitor charging process of the RC circuit, and the gate voltage gradually rises to the threshold voltage ; in the IGBT cut-off region, the gate voltage is less than the threshold voltage , no current passes through the IGBT, and the voltage across the IGBT remains unchanged, and the IGBT current in the cut-off region can be obtained as In the formula, is the maximum collector voltage when the collector current can be ignored.

11. The device for constructing the IGBT behavior model applicable to short - circuit conditions according to claim 9, characterized in that, The model construction module further includes a second simulation module configured to simulate the static output characteristics of the IGBT saturation region and active region, including: When the gate voltage gradually rises to the threshold voltage , the IGBT starts to conduct; the channel gradually opens, and current begins to flow through the IGBT. The IGBT current gradually increases. The change in the IGBT current induces a voltage in the loop parasitic inductance, causing the voltage across the IGBT to decrease accordingly. When the IGBT current rises to the load current level, the voltage across the IGBT rapidly drops and reaches the IGBT conduction voltage drop; IGBT current in the saturation region to give a physical description In the formula, is the IGBT saturation current, is the channel length and width, is the channel electron mobility, is the oxide capacitance per unit area, is the common-emitter current gain of the triode; Define the parameters of the controlled source It can be obtained that: Further derivation shows that: Wherein, is the maximum collector voltage when the collector current is negligible.

12. The device for constructing an IGBT behavior model applicable to short-circuit conditions according to claim 11, wherein The extraction of the controlled source parameters and capacitance parameters of the IGBT behavior model includes: Calculating the controlled source parameters by taking points in the active region of the IGBT output characteristic curve ; Obtain the capacitance parameters through the IGBT data sheet, specifically including: Calculating the gate-collector capacitance : In the formula, is the gate-collector capacitance measured in the data sheet at the starting collector voltage for the capacitance value and voltage value, is the capacitance correction factor; Calculate the equivalent capacitance : In the formula, is the active area, is the silicon permittivity, is the base doping concentration, is the base width and length, is an intermediate variable, is the leakage current and the total on-state current; is the energy borne by the IGBT under short-circuit conditions, is the external ambient temperature of the IGBT is the correction factor; Trailing capacitor and trailing resistor Obtained by fitting according to the IGBT trailing time constant.

13. The device for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 9, characterized in that, The correction of the IGBT behavior model considering the temperature effect under short-circuit conditions includes: Consider the influence of lattice scattering on the carrier mobility and calculate the lattice mobility : In the formula, is the equilibrium longitudinal elastic constant, , is the effective mass of the conduction electrons, is the displacement of the conduction band edge per unit expansion, is the Boltzmann constant, is the device temperature of the IGBT; Considering the influence of ionized impurity scattering on the carrier mobility, calculate the ionized impurity mobility : Wherein, is the dielectric constant, is the density of ionized impurities, is the charge of the conduction electrons; For the ionized impurity mobility Performing Fourier analysis gives: In the formula, is an intermediate variable, is the conduction density of conduction electrons; Considering the combined effect of lattice scattering and ionized impurities, the carrier mobility of IGBT varies with temperature. The influence coefficients of lattice scattering and ionized impurities on carrier mobility are uniformly expressed as: In the formula, are the cosine integral function and the sine integral function; The influence coefficient is simplified to: Drawing the influence coefficient after simplification according to the function graph Perform fitting: In the formula, is a parameter to be determined; According to the influence coefficient for the IGBT current the correction can be obtained as follows:

14. The device for constructing an IGBT behavior model applicable to short - circuit conditions according to claim 13, wherein The device temperature of IGBT under short-circuit conditions is as follows: In the formula, is the energy borne by the IGBT under short - circuit conditions, is the specific heat capacity of silicon, is the mass of the IGBT, is the external ambient temperature of the IGBT, is the external ambient temperature of the IGBT correction factor; By analyzing the IGBT current in the short - circuit condition at the external environmental temperature of the IGBT, the obtained numerical value is obtained by fitting the descending section.

15. An electronic device, characterized in that, Including a processor and a storage medium; The storage medium is used to store instructions; The processor is used to operate according to the instructions to execute the steps of the method according to any one of claims 1-7.

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

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