CN109188232A - A kind of construction method of IGBT module status assessment and predicting residual useful life model - Google Patents
A kind of construction method of IGBT module status assessment and predicting residual useful life model Download PDFInfo
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Abstract
The present invention relates to the construction methods of a kind of IGBT module status assessment and predicting residual useful life model, comprising the following steps: the electric heating parameter of IGBT module under different degree of agings is measured by testing；Establish the function model of average crust thermal resistance change rate-mean power cycle-index of IGBT module test sample and the function model of average saturation voltage drop change rate-mean power cycle-index；Ageing state assessment is carried out to IGBT module according to above-mentioned function model, with the ageing state of the real number expression IGBT on section [0,1], obtains state evaluation result；The computation model of IGBT module remaining life is established according to condition evaluation results.The present invention establishes the mathematical model of electrical parameter and thermal parameter and power cycle number according to power cycle accelerated aging test, the model comprehensively considers the influence of electrical parameter and thermal parameter to assessment result, the deficiency for compensating for one-parameter assessment can be accurately obtained the ageing state of IGBT module under the conditions of certain crust thermal resistance and saturation voltage drop.
Description
Technical field
The invention belongs to power electronic devices technical field, especially a kind of IGBT module status assessment and remaining life are pre-
Survey the construction method of model.
Background technique
IGBT power module is the core power device in the fields such as railway, new energy and automobile, is safely and reliably run
It is the basis for ensureing all trades and professions sustainable and stable development.But since IGBT power module is more fragile, studies its state and comment
Estimate and plays a significant role with reliability of the remaining life evaluation method to equipment where it.Due to the crust heat of IGBT power module
Resistance can express the degree of fatigue of solder layer, and saturation voltage drop can express the degree of aging of IGBT bonding line, therefore, above-mentioned parameter
Be characterize IGBT power module ageing state and its place system can stable operation important feature parameter.In IGBT power
In the ager process of module, solder layer will appear fatigue and bonding line will appear and fall off, and find solder layer and bonding line in time
Degree of aging facilitate the reliable and stable operation of system.Therefore the crust thermal resistance of research IGBT and saturation voltage drop and ageing state
Relationship be of great significance.
Currently, the state evaluating method of IGBT mainly has the status assessment method based on model and the state based on electrical parameter to comment
Estimate method.
Status assessment method based on model mainly establishes different faults type reliability model according to statistical data, assessment
IGBT module different parts, such as the state of solder layer, lead.Research comparative maturity is solder layer Tiredness model at present, right
Though the damage research retrieval section achievement of lead and DCB plate, still needs to being continually striving to for researcher.Solder layer Tiredness model master
Have: the Tiredness model based on plastic strain, such as Coffin-Manson Tiredness model and Engelmaier Tiredness model；Base
In the Tiredness model of energy, for example, Morrow propose using strain energy density as the Tiredness model of parameter；Based on fracture mechanics base
The Tiredness model of plinth, such as typical Darveaux Tiredness model；Tiredness model based on creep strain, such as Syed proposition
Thermal Fatigue Damage life model.Status assessment method based on model will appreciate that the different types of failure of IGBT module, but due to
Module failure type is more, while detecting a variety of reliability models that all fault type requirement detection systems include, practical
It operates relatively difficult.Reliability model is generally established by historical data analysis, when device actual condition changes, model
Accuracy will be greatly lowered.
Status assessment method based on electrical parameter be exactly choose relevant to IGBT module aging parameter, such as saturation voltage drop,
Crust steady state heat resistance, switch time, module case temperature and gate signal etc., and determines corresponding survey for different characteristic parameters
Amount method, and then the value by monitoring electrical parameter assesses module ageing state.The saturation voltage drop of IGBT and module aging
Degree is closely related, but since it is influenced by junction temperature and collector current, needs to carry out reduction to the saturation voltage drop measured,
The saturation voltage drop of IGBT just has comparativity under the same terms, could be with this evaluation module ageing state.The change of crust steady state heat resistance
Change reflection module welding layer fatigue aging degree；Switch time can directly reflect the ageing state of IGBT module, but due to
IGBT switch time is very short, this requirement to measuring device resolution ratio is very high；The gate signal of IGBT module is old with module
Change and variations injunction temperature and change, but influence of the gate signal vulnerable to stray parameter so that measurement inaccuracy, and the survey of gate signal
Measure the high requirements on the equipment.
Currently, the life estimation method of IGBT mainly includes analytic modell analytical model and physical model.Analytic modell analytical model analysis method
Major parameter is junction temperature, is predicted according to parameters such as the variation range of junction temperature, mean values device, but such method is mentioning
When taking junction temperature, accuracy fluctuation is very big and more demanding to the extraction of the temperature cycle times of device.Physical model analysis side
Method mainly utilizes experimental method, and this method is higher to the required precision of experimental facilities, and cost is larger, and it should be understood that IGBT mould
Mechanics effect caused by thermal expansion coefficient is different between block internal structure and the characteristic and a variety of materials of material, implements
It is more difficult.
Summary of the invention
It is an object of the invention to overcome the deficiencies in the prior art, a kind of IGBT module status assessment and remaining life are proposed
The construction method of prediction model passes through analysis electric heating parameter (crust thermal resistance and saturation voltage drop) and IGBT module ageing state
Relationship is utilized respectively polynomial fitting method and establishes averagely crust thermal resistance change rate-mean power cycle-index and averagely satisfy
With change in pressure drop rate-mean power cycle-index function model, the aging of electric heating parameter reflection solder layer and bonding line is utilized
The precision of IGBT ageing state assessment can be improved in state, and then the ageing state of comprehensive assessment IGBT.
The present invention solves its technical problem and adopts the following technical solutions to achieve:
A kind of construction method of IGBT module status assessment and predicting residual useful life model, comprising the following steps:
Step 1, the electric heating parameter that IGBT module under different degree of agings is measured by testing；
Step 2, establish IGBT module test sample average crust thermal resistance change rate-mean power cycle-index function
The function model of model and average saturation voltage drop change rate-mean power cycle-index；
Step 3 carries out ageing state assessment to IGBT module according to above-mentioned function model, with one on section [0,1]
Real number expresses the ageing state of IGBT, obtains state evaluation result；
Step 4, the computation model that IGBT module remaining life is established according to condition evaluation results.
Further, the concrete methods of realizing of the step 1 are as follows: use △ TcPower cycle test method to IGBT module into
The complete life test of row, in test, crust thermal resistance relative to initial value increase 20% and saturation voltage drop relative to initial value
5% is increased, stops test when the crust thermal resistance of the IGBT module measured increases 20% and saturation voltage drop increases 5%；In function
In rate cyclic process, the crust thermal resistance and different junction temperatures and current condition of an IGBT module are measured for every power cycle 100 times
Under saturation voltage drop；Crust thermal resistance is measured using IGBT module thermal resistance tester；Under the difference junction temperature and current condition
Saturation voltage drop measure method are as follows: completely new IGBT module is put into insulating box, then value setting insulating box at regular intervals
Temperature, and under the conditions of different set temperatures, after the mild junction temperature of the shell of IGBT module reaches thermal balance, width is passed to IGBT
The pulse trigger current that value is worth variation at certain intervals carries out pulse test, measures under different junction temperatures and collector current
The saturation voltage drop and record of IGBT；According to △ TcPower cycle tests to obtain the crust thermal resistance under different capacity cycle-index and satisfies
And pressure drop, it is to be used to establish tables of data.
Further, the step 2 concrete methods of realizing the following steps are included:
(1) averagely crust thermal resistance change rate-mean power cycle-index function model is established, the method is as follows: to multiple
IGBT module carries out △ TcPower cycle test, records when the crust thermal resistance of each IGBT module is more than 20% with respect to initial value
The terminal life of each module, and sought under the terminal life average value and different capacity cycle-index of each IGBT module respectively
Crust thermal resistance average value；Averagely crust thermal resistance variation is established according to the average crust thermal resistance of IGBT under different capacity cycle-index
Rate-mean power cycle-index function model；
(2) the function model of average saturation voltage drop change rate-mean power cycle-index is established, the method is as follows: to multiple
IGBT module carries out △ TcPower cycle test carries out pulse survey to IGBT module after certain power cycle number
It has a try and tests to obtain the saturation pressure depreciation under different junction temperatures and current condition, when the saturation voltage drop of each IGBT module is relatively initial
Value records the terminal life of each module and stops testing when being more than 5%, the saturation voltage drop of IGBT has been with respect to initial value at this time
More than 5%；Seek the saturation voltage drop under the terminal life average value and different capacity cycle-index of each IGBT module respectively again
Average value；It is flat that average saturation voltage drop change rate-can be established according to the average saturation voltage drop of the IGBT under different capacity cycle-index
The function model of equal power cycle number.
Further, the thermal resistance change rate that averagely crustsCalculating formula it is as follows:
The average saturation voltage drop change rateCalculating formula it is as follows:
Wherein,For average crust thermal resistance change rate,For average crust thermal resistance, Rth0For the thermal resistance of completely new IGBT；For average saturation voltage drop change rate,For average saturation voltage drop, Vce0For the saturation voltage drop of completely new IGBT.
Further, the concrete methods of realizing of the step 3 are as follows: by on-line measurement crust thermal resistance and saturation voltage drop and combine
Above-mentioned model obtains the currently active operational lifetime number, to obtain IGBT ageing state assessment result.
Further, the computation model of the IGBT module remaining life of the step 4 are as follows:
Wherein, kVFor effective life duty cycle；kRFor the currently active operational lifetime,For under crust thermal resistance standard
Average life span,For the substandard average life span of saturation voltage drop, SRFor the substandard remaining life of thermal resistance that crusts, SVFor saturation
Remaining life under pressure drop specifications.
The advantages and positive effects of the present invention are:
1, the present invention can establish electrical parameter and thermal parameter and power cycle number according to power cycle accelerated aging test
Mathematical model, which comprehensively considers the influence of electrical parameter and thermal parameter to assessment result, compensates for one-parameter assessment not
Foot can be accurately obtained the ageing state of IGBT module under the conditions of certain crust thermal resistance and saturation voltage drop.
2, the present invention can simulate IGBT actual condition, and be obtained according to measured dataWithFunction
Different ageing state assessment results can be obtained according to the model for model, pass through the crust thermal resistance and saturation of IGBT in operation
Its current ageing state is predicted in pressure drop in real time, this has important meaning for the stable operation of IGBT module or even whole system
Justice is conducive to the transfer efficiency for improving IGBT.
3, the present invention can accurately learn the aging shape of the module according to the IGBT saturation voltage drop and crust thermal resistance of measurement
State, and by the trust verification accuracy of assessment result, so as to further estimate the remaining life of module,
This feature system higher for reliability requirement provides very valuable information.
4, the present invention can further obtain the remaining life of IGBT on the basis of assessment by predicting residual useful life model,
Improve application range.
5, the present invention is versatile, is not limited to ageing state assessment and the remaining life of IGBT in power converter
Calculating, extend also in the IGBT module of any system.
Detailed description of the invention
Fig. 1 is the block diagram of status assessment and life prediction of the invention；
Fig. 2 is the Δ T of IGBT module in the embodiment of the present inventioncPower cycle pilot system block diagram；
Fig. 3 is the Δ T of IGBT module in the embodiment of the present inventioncPower cycle accelerated aging test circuit diagram；
Fig. 4 is the test circuit diagram of IGBT module in the embodiment of the present invention；
Fig. 5 is the pulse test circuit diagram of IGBT module in the embodiment of the present invention；
Fig. 6 is that IGBT averagely crusts the graph of relation of thermal resistance change rate and power cycle number in the embodiment of the present invention；
Fig. 7 is that IGBT is averaged the graph of relation of saturation voltage drop change rate and power cycle number in the embodiment of the present invention；
Fig. 8 is that IGBT averagely crusts the relationship of thermal resistance change rate and the currently active operational lifetime in the embodiment of the present invention
Curve graph；
Fig. 9 is that IGBT is averaged the relationship of saturation voltage drop change rate and the currently active operational lifetime in the embodiment of the present invention
Curve graph.
Specific embodiment
The embodiment of the present invention is further described below in conjunction with attached drawing.
The present invention provides a kind of status assessment for comprehensively considering IGBT module electric heating parameter and predicting residual useful life model,
By measuring the saturation voltage drop and crust thermal resistance of IGBT, the thermal resistance change rate-mean power cycle-index that averagely crusts is establishedAnd average saturation voltage drop change rate-mean power cycle-indexFunction model, utilize the model
Carry out the ageing state of evaluation module, and with the ageing state of the real number expression IGBT on section [0,1], and evaluates aging shape
The confidence level of state assessment result finally establishes the computation model of IGBT module remaining life.Utilize above-mentioned status assessment and residue
Life Prediction Model can compensate for the deficiency for being unable to comprehensive assessment IGBT ageing state, by the crust heat in different ager process
Resistance is recorded with saturation voltage drop, and obtains the function model of above-mentioned parameter and ageing state according to polynomial fitting method.It will be online
It measures obtained saturation voltage drop and crust thermal resistance is brought into the ageing state that current IGBT can be obtained in above-mentioned functional relation, i.e.,
The ageing state of online evaluation IGBT can be achieved and obtain its remaining life.
Fig. 1 gives the status assessment of IGBT module and the block diagram of life prediction.Its detailed process is as follows: (1) utilizing △
TcPower cycle accelerated aging test is by IGBT module aging；(2) the crust thermal resistance of the gradually IGBT module of aging is constantly measured
And saturation voltage drop, until RthIncrease 20% or more and V compared with initial valueceWhen increasing 5% compared with initial value, R is recordedthCompared with initial value
Maximum power cycle-index N when increasing 20%RAnd VceMaximum power cycle-index N when compared with initial value increase 20%V；(3)
Stop testing and carries out data processing；(4) R is establishedthWith the function model and V of power cycle frequency nceWith power cycle frequency n
Function model；(5) relevant parameter is updated to above-mentioned model, the big person of power cycle number be subject to is commented with this
Estimate the ageing state of current IGBT module；(6) it is 1 using the bulk life time of IGBT, carries out residue in conjunction with ageing state result
Life prediction.
Originally in embodiment, IGBT module selects the MMG75S120B of Macmic company.The model IGBT module is integrated with
Two duplicate IGBT and freewheeling diode, nominal working conditions 1200V/75A.The model IGBT module is tried
Test with test and obtain the electric heating parameter of IGBT, and according to recorded data establish IGBT module status assessment and the service life it is pre-
Model is surveyed, specific step and test process are as described below.
Step 1, the electric heating parameter for measuring IGBT module under different degree of agings, detailed process is as follows:
1, Δ T is carried out to IGBT power modulecPower cycle accelerated aging test
As shown in Figures 2 and 3, the hookup by IGBT module, control switch, prevent current break module, thermocouple,
The composition such as programmable power supply, current source and radiator, wherein IGBT module is located above air-cooled radiator, and in the groove of radiator
Interior installation K-type thermocouple carrys out the temperature of measurement module；With the control switch S in Labview software controlled circuitry1To open and close
Deenergizing；Inductance L is to prevent current break module, mainly prevents main circuit current from mutating and IGBT module is caused to damage；
Diode D1Effect be main circuit close when to inductive discharge；Power supply VG15V is set as to ensure that IGBT can be fully on；
Test ambient temperature is 25 DEG C.This degradation tests the upper tube of IGBT module, and the grid of down tube connects backward voltage
It is held off, the circuit diagram for testing IGBT module is as shown in Figure 4.
IGBT power module Δ TcPower cycle test process is divided into following steps:
(1) 8 completely new IGBT test products are put into insulating box, are passed through 100mA low current to IGBT test product at a set temperature
And the saturation voltage drop of IGBT test product at this time is measured, complete the temperature calibration of IGBT under 100mA low current.
(2) it is closed control switch S1, programme-controlled dc power V is setdcOutput electric current is 50A, grid voltage VG(15V) driving
IGBT conducting, IGBT test product generate power loss so as to cause the rising of module junction temperature and shell temperature, at this process air-cooled radiator
In off-position.
(3) when K-type thermocouple detects that the shell temperature of IGBT test product reaches 125 DEG C, control switch S is disconnected1, closure switch
S2, it is passed through the saturation voltage drop of 100mA small current measurement IGBT test product；Air-cooled radiator is powered on during main circuit turns off, this
Process IGBT is nearly free from power loss, and the junction temperature and shell temperature of IGBT test product decline rapidly, until shell temperature drops to environment temperature
A power cycle is completed when spending 25 DEG C, junction temperature fluctuation range is 25 DEG C~150 DEG C.
(4) step (2), (3) are repeated, repetition turn-on and turn-off is carried out to IGBT test product, until completing complete life test,
That is the crust thermal resistance of IGBT stops test when increasing 20% and its saturation voltage drop increase 5%.
2, the electric heating parameter of IGBT module under different capacity cycle-index is measured
In Δ TcIt is every to recycle 100 crust thermal resistances for measuring 18 IGBT test product in power cycle test.In order to obtain
More accurate power cycle number, when the thermal resistance that crusts will increase 20%, every circulation primary measures primary crust thermal resistance, until
Find power cycle number when crust thermal resistance increases 20%.The test for the thermal resistance that crusts uses the limited public affairs of Xi'an friendship nation electronics technology
The YB-6911 thermo-resistance measurement system of department, the test macro meet JEDEC51-1 standard, and test heated current is 20A, and precision is
±10mA。
In order to study the saturation voltage drop of IGBT power module and the relationship of degree of aging, to 8 models
The upper tube of the two-tube semi-bridge type IGBT of MMG75S120B carries out Δ TcIn power cycle test process, 100 pauses one of every circulation
Secondary test carries out pulse test to IGBT module and obtains its junction temperature, electric current and saturation voltage drop.More accurate function in order to obtain
Rate cycle-index, when saturation voltage drop will increase 5%, every circulation primary measures a saturation voltage drop, until finding saturation pressure
Drop increases power cycle number when 5%.Pulse tests circuit as shown in figure 5, R is power resistor, V in figuredcFor programmed direct
Galvanic electricity source.
IGBT saturation voltage drop is influenced by junction temperature and electric current, therefore experimental test point need to consider junction temperature and electric current to full simultaneously
With the influence of pressure drop, test point is chosen in the following manner, and temperature increases since 25 DEG C, increases by 10 DEG C every time, until 125 DEG C；
Electric current increases since 5A, increases 5A every time, until 150A.
Test process is as follows: (1) IGBT being put into insulating box, and set gradually the temperature of insulating box according to temperature test point
Degree reaches thermal balance to IGBT after temperature test point is arranged in (2), it is believed that and IGBT junction temperature is the temperature of insulating box setting,
(3) setting gradually controllable direct current power supply control circuit electric current is current test point, and passes to pulse trigger current to IGBT, is surveyed
Take its saturation pressure depreciation.
The maximum power cycle-index obtained according to the crust thermal resistance of IGBT increase 20% is as shown in table 1, according to IGBT's
It is as shown in table 2 that saturation voltage drop increases the maximum power cycle-index that 5% obtains.
The maximum power cycle-index of each IGBT test product of table 1
The maximum power cycle-index of each IGBT test product of table 2
Step 2, the average crust thermal resistance change rate-mean power cycle-index for establishing IGBT moduleFunction
Model and average saturation voltage drop change rate-mean power cycle-indexFunction model.
In order to find the function model more applicable to this model IGBT, the present invention, which passes through, seeks 8 IGBT that test measures
Crust thermal resistance average value come establish it is average crust thermal resistance change rate and power cycle number function model, different capacity recycle
The average crust thermal resistance of IGBT and its change rate are as shown in table 3 under number.
The average crust thermal resistance and its change rate of IGBT under 3 different capacity cycle-index of table
Wherein averagely crust thermal resistance change rateCalculating formula it is as follows:
Since under different junction temperatures and electric current, the saturation voltage drop of IGBT is different, it is therefore desirable to carry out research to each condition and build
Vertical database.The present invention is in junction temperature TjIt is 75 DEG C, electric current IcResearch method to be studied under conditions of 85A, under other conditions
It is consistent with the method that the present invention introduces.In order to find the function model more applicable to this model IGBT, the present invention is by seeking trying
The saturation voltage drop average value for 8 IGBT that test obtains establishes the Function Modules of average saturation voltage drop change rate and power cycle number
Type.Similarly, the average saturation voltage drop of IGBT and its change rate are as shown in table 4 under different capacity cycle-index.
The average saturation voltage drop and its change rate of IGBT under 4 different capacity cycle-index of table
Wherein be averaged saturation voltage drop change rateCalculating formula it is as follows:
Averagely the relation curve of crust thermal resistance change rate and power cycle number is as shown in fig. 6, average saturation voltage drop variation
Rate and the relation curve of power cycle number are as shown in Figure 7.
Relation curve in Fig. 6 and Fig. 7 is fitted according to the following formula respectively,
Fitting result is respectively as follows:
With
For the model IGBT module, R-square is respectively 0.9998 and 0.9994, is illustrated using quartic polynomial
The precision of fitting is higher.
Step 3 carries out ageing state assessment to IGBT module according to above-mentioned function model, with one on section [0,1]
Real number expresses the ageing state of IGBT, and evaluates the confidence level of ageing state assessment result.
The ageing state of IGBT is assessed in order to find more specific parameter, and the present invention is with a real number table on [0,1]
Show, the abscissa of Fig. 6 is transformed into the currently active operational lifetime parameterUse kRIt indicates, ordinate is constant, obtains
Relation curve is as shown in Figure 8.
The curve in Fig. 8 is fitted using polynomial fitting method, the functional relation after fitting are as follows:
Some IGBT crust thermal resistance that certain moment measures, which is input to above formula, can be obtained its currently active work Life Cycle
Phase kR.By taking IGBT1 as an example, at power cycle 4000 times, crust thermal resistance change rate is 9.57%, obtains proposition AR: IGBT1
Effective life duty cycle kRIt is 0.69, defines proposition ARConfidence level:
In formula,For average life span,For the standard deviation in IGBT test product service life.
It is calculated according to test dataIt can be seen that proposition ARConfidence level it is very high.At this point, should
The ageing state of IGBT module at this time is 0.69.
Similarly, for the ageing state of more specific assessment IGBT, equally with a real number representation on [0,1], by Fig. 7
Abscissa be transformed into the currently active operational lifetime parameterUse kVIt indicates, ordinate is constant, obtained relation curve
As shown in Figure 9.
The curve in Fig. 9 is fitted using polynomial fitting method, the functional relation obtained after fitting such as following formula:
Under certain specific junction temperature and electric current, some the IGBT saturation voltage drop measured is input in corresponding functional relation,
Its currently active operational lifetime k can be obtainedV.By taking IGBT1 as an example, power cycle 4000 times saturation voltage drop change rates are
1.2953%, obtain proposition AV: effective life duty cycle k of IGBT1VIt is 0.62.Define proposition AVConfidence level:
In formula,For average life span,For the standard deviation in IGBT test product service life.
It is calculated according to test dataIt can be seen that proposition AVConfidence level it is very high.At this point, should
The ageing state of IGBT module is 0.62.
Due to the result more aging obtained by the thermal resistance that crusts, the ageing state of the IGBT module is 0.69.
Step 4, the computation model that IGBT module remaining life is established according to condition evaluation results.
The IGBT module ageing state obtained according to step 3 calculates the remaining life S of IGBT using following formula.
Since obtained ageing state is 0.69, by kR=0.69 is updated in formula (6), remaining life
In practical applications, while the corresponding ageing state of two parameters is calculated, the parameter with assessment result more aging is
Reliable assessment parameter, and the ageing state is updated in formula (6) or formula (7) to the residue for obtaining IGBT module under current state
Service life.
It is emphasized that embodiment of the present invention be it is illustrative, without being restrictive, therefore packet of the present invention
Include and be not limited to embodiment described in specific embodiment, it is all by those skilled in the art according to the technique and scheme of the present invention
The other embodiments obtained, also belong to the scope of protection of the invention.
Claims (6)
1. a kind of construction method of IGBT module status assessment and predicting residual useful life model, it is characterised in that including following step
It is rapid:
Step 1, the electric heating parameter that IGBT module under different degree of agings is measured by testing；
Step 2, establish IGBT module test sample average crust thermal resistance change rate-mean power cycle-index function model
And the function model of average saturation voltage drop change rate-mean power cycle-index；
Step 3 carries out ageing state assessment to IGBT module according to above-mentioned function model, with a real number on section [0,1]
The ageing state for expressing IGBT, obtains state evaluation result；
Step 4, the computation model that IGBT module remaining life is established according to condition evaluation results.
2. the construction method of a kind of IGBT module status assessment and predicting residual useful life model according to claim 1,
It is characterized in that: the concrete methods of realizing of the step 1 are as follows: use △ TcPower cycle test method carries out IGBT module complete
Life test, in test, crust thermal resistance increases 20% relative to initial value and saturation voltage drop is increased relative to initial value
5%, stop test when the crust thermal resistance of the IGBT module measured increases 20% and saturation voltage drop increases 5%；In power cycle
In the process, the crust thermal resistance an of IGBT module and full under different junction temperatures and current condition is measured for every power cycle 100 times
And pressure drop；Crust thermal resistance is measured using IGBT module thermal resistance tester；Saturation under the difference junction temperature and current condition
Pressure drop measures method are as follows: completely new IGBT module is put into insulating box, then the temperature of value setting insulating box at regular intervals, and
Under the conditions of different set temperatures, after the mild junction temperature of the shell of IGBT module reaches thermal balance, amplitude is passed to one to IGBT
The pulse trigger current for determining spacing value variation carries out pulse test, measures the full of IGBT under different junction temperatures and collector current
With pressure drop and record；According to △ TcPower cycle tests to obtain crust thermal resistance and saturation voltage drop under different capacity cycle-index,
It is to be used to establish tables of data.
3. the construction method of a kind of IGBT module status assessment and predicting residual useful life model according to claim 1,
Be characterized in that: the concrete methods of realizing of the step 2 the following steps are included:
(1) averagely crust thermal resistance change rate-mean power cycle-index function model is established, the method is as follows: to multiple IGBT moulds
Block carries out △ TcPower cycle test, records each mould when the crust thermal resistance of each IGBT module is more than 20% with respect to initial value
The terminal life of block, and the crust under the terminal life average value and different capacity cycle-index of each IGBT module is sought respectively
Thermal resistance average value；It is flat that averagely crust thermal resistance change rate-is established according to the average crust thermal resistance of IGBT under different capacity cycle-index
The function model of equal power cycle number；
(2) the function model of average saturation voltage drop change rate-mean power cycle-index is established, the method is as follows: to multiple IGBT moulds
Block carries out △ TcPower cycle test carries out pulse testing experiment to IGBT module after certain power cycle number
The saturation pressure depreciation under different junction temperatures and current condition is obtained, when the saturation voltage drop of each IGBT module is more than with respect to initial value
The terminal life of each module is recorded when 5% and stops testing, and the saturation voltage drop of IGBT is alreadyd exceed with respect to initial value at this time
5%；The saturation voltage drop sought respectively under the terminal life average value and different capacity cycle-index of each IGBT module again is average
Value；Average saturation voltage drop change rate-can be established according to the average saturation voltage drop of the IGBT under different capacity cycle-index to be averaged function
The function model of rate cycle-index.
4. the construction method of a kind of IGBT module status assessment and predicting residual useful life model according to claim 3,
It is characterized in that: the thermal resistance change rate that averagely crustsCalculating formula it is as follows:
The average saturation voltage drop change rateCalculating formula it is as follows:
Wherein,For average crust thermal resistance change rate,For average crust thermal resistance, Rth0For the thermal resistance of completely new IGBT；
For average saturation voltage drop change rate,For average saturation voltage drop, Vce0For the saturation voltage drop of completely new IGBT.
5. the construction method of a kind of IGBT module status assessment and predicting residual useful life model according to claim 1,
It is characterized in that: the concrete methods of realizing of the step 3 are as follows: by on-line measurement crust thermal resistance and saturation voltage drop and combine above-mentioned mould
Type obtains the currently active operational lifetime number, to obtain IGBT ageing state assessment result.
6. the construction method of a kind of IGBT module status assessment and predicting residual useful life model according to claim 1,
It is characterized in that: the computation model of the IGBT module remaining life of the step 4 are as follows:
Wherein, kVFor effective life duty cycle；kRFor the currently active operational lifetime,It is substandard flat for crust thermal resistance
The equal service life,For the substandard average life span of saturation voltage drop, SRFor the substandard remaining life of thermal resistance that crusts, SVFor saturation voltage drop
Substandard remaining life.
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