CN114924176A - Power module aging parameter quasi-online identification method and junction temperature calibration method and system - Google Patents

Power module aging parameter quasi-online identification method and junction temperature calibration method and system Download PDF

Info

Publication number
CN114924176A
CN114924176A CN202210524777.2A CN202210524777A CN114924176A CN 114924176 A CN114924176 A CN 114924176A CN 202210524777 A CN202210524777 A CN 202210524777A CN 114924176 A CN114924176 A CN 114924176A
Authority
CN
China
Prior art keywords
test
junction temperature
main power
calibration
power switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210524777.2A
Other languages
Chinese (zh)
Inventor
郑丹
宁圃奇
范涛
温旭辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Electrical Engineering of CAS
Original Assignee
Institute of Electrical Engineering of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institute of Electrical Engineering of CAS filed Critical Institute of Electrical Engineering of CAS
Priority to CN202210524777.2A priority Critical patent/CN114924176A/en
Publication of CN114924176A publication Critical patent/CN114924176A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2601—Apparatus or methods therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2642—Testing semiconductor operation lifetime or reliability, e.g. by accelerated life tests
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Individual Semiconductor Devices (AREA)

Abstract

A power module aging parameter quasi-online identification method and a junction temperature calibration method and system are provided, the system comprises: the system comprises a first junction temperature calibration module, a second junction temperature calibration module, a first data fitting module, a second data fitting module, a first sampling module, a first junction temperature test acquisition unit, an emergency stop control module, a second sampling module, a second junction temperature test acquisition unit, an aging parameter acquisition module and a correction unit. The method and the system have the advantages that the accuracy of the obtained aging parameters is high, and the test difficulty is reduced.

Description

Power module aging parameter quasi-online identification method and junction temperature calibration method and system
Technical Field
The invention relates to the field of power semiconductor device testing, in particular to a power module aging parameter quasi-online identification method and a junction temperature calibration method and system.
Background
Junction temperature is an important parameter characterizing the operating and health conditions of power semiconductor devices. The chip in the power semiconductor device is packaged in the module and works in a high-voltage and high-current environment, so that the junction temperature of the chip cannot be directly measured. Therefore, it is very difficult to monitor the junction temperature of the power semiconductor device in an operating state on line, and it is also a hot spot of current research.
The traditional method for detecting the junction temperature of the power semiconductor chip is mainly based on the research of SiIG BT, and comprises four major methods of a physical contact method, an optical measurement method, a model prediction method and a thermal inductance parameter method (TSEPs). At present, a thermosensitive electro-parameter method (TSEPs) is mostly applied, and the core idea of the method is to use a device to be measured as a temperature sensing component and establish a mapping model of temperature and external electrical variables. The large-current conduction voltage drop method is quick in response, high in resolution, low in intrusiveness to hardware and software of the original inverter, and is the most potential junction temperature real-time online monitoring technology at present.
The implementation process of the conduction voltage drop method under large current is as follows: obtaining different working currents I by laboratory calibration c Lower junction temperature T J Conduction voltage drop V CE Fitting a junction temperature expression T by a three-dimensional data network J ＝f(I C ，V CE ). Under the condition of on-line work, the on-state current and the on-state voltage drop obtained by on-line test are brought into T by measuring the on-state current and the on-state voltage drop of the power semiconductor chip in real time J ＝f(I C ：V CE ) And the on-line calculation of the junction temperature is realized.
However, most of the thermal sensitive electrical parameters are affected by the aging characteristics of the power module, which is a general challenge to the online monitoring of junction temperature by applying the thermal sensitive electrical parameter method. The effect of aging on the conduction voltage drop is mainly reflected in the conduction voltage drop V caused by the breakage and the falling of the bonding wire CE And (4) increasing. In order to ensure the accuracy of junction temperature online monitoring results in the whole life cycle of the power module, the aging parameters need to be monitored and decoupled during the long-term operation of the power module. However, the current research on the aging parameters is still in a starting stage in a laboratory, the main aging parameter identification methods are all measurement methods in the laboratory, and an effective identification method is lacked under the condition of module installation.
Disclosure of Invention
The invention aims to solve the technical problems of low precision and high test difficulty of the aging parameters obtained in the prior art, and provides a power module aging parameter quasi-online identification method and a junction temperature calibration method and system.
In order to solve the above technical problem, the present invention provides a quasi-online identification system for aging parameters of a power module, which is adapted to monitor a junction temperature of a main power switch tube to be measured in the power module, wherein the power module includes a bonding wire connected to the main power switch tube, and the quasi-online identification system includes: the first junction temperature calibration module is suitable for injecting a first calibration conduction current to the main power switch tube to be tested in the forward direction and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and the first calibration junction temperature of the main power switch tube to be tested; the second junction temperature calibration module is suitable for injecting a second constant calibration current into the main power switching tube to be tested, and acquiring a second mapping relation between a second calibration conduction saturation voltage drop of the main power switching tube to be tested in an off-line state and a second calibration junction temperature of the main power switching tube to be tested, wherein the second constant calibration current is far smaller than the first calibration conduction current; the first data fitting module is suitable for fitting data in the first mapping relation to obtain a first functional relation, and the first functional relation takes the first calibrated conduction saturation voltage drop and the first calibrated conduction current as independent variables and the first calibrated junction temperature as a dependent variable; the second data fitting module is suitable for fitting the data in the second mapping relation to obtain a second functional relation, and the second functional relation takes a second calibration conduction saturation voltage drop as an independent variable and a second calibration junction temperature as a dependent variable; the first sampling module is suitable for injecting a first test current to a main power switch tube to be tested in the converter under a quasi online working state in a forward direction and acquiring a first test conduction voltage drop of the main power switch tube to be tested; the first test junction temperature obtaining unit is suitable for obtaining a first test junction temperature, and the first test junction temperature is a numerical value of a first calibrated junction temperature corresponding to data of a first test conduction voltage drop and a first test current in a first functional relation; the emergency stop control module is suitable for applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state; the second sampling module is suitable for injecting a second test current into the main power switch tube to be tested in the converter in the quasi online working state and acquiring a second test conduction voltage drop of the main power switch tube to be tested after the emergency stop control module applies a forced turn-off signal to all the main power switch tubes in the converter in the quasi online working state, wherein the second test current is equal to a second constant calibration current; the second test junction temperature obtaining unit is suitable for obtaining a second test junction temperature, and the second test junction temperature is a value of a second calibrated junction temperature corresponding to the second test conduction voltage drop data in a second function relation; and the aging parameter obtaining module is suitable for obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop when the absolute value of the difference value between the first test junction temperature and the second test junction temperature is larger than the threshold value.
Optionally, the aging parameter obtaining module includes: a first submodule adapted to vary a parameter Δ R (T) according to an equivalent resistance of the bonding wire at a characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance variation parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a A second sub-module adapted to conduct a voltage drop V according to the first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) Obtaining a first test calibration turn-on voltage drop V Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a A third sub-module adapted to calibrate a conduction voltage drop V according to a first test Z1 A first test current I C1 And a second test junction temperature T C2 And obtaining the equivalent resistance change parameter delta R (T) under the characteristic temperature by the first functional relation t )。
Optionally, the comparing module is adapted to compare whether an absolute value of a difference between the first tested junction temperature and the second tested junction temperature is greater than a threshold.
Optionally, the threshold is 1mA to 100 mA.
Optionally, the main power switch tube includes an IGBT.
The present invention also provides a junction temperature calibration system, comprising: the invention relates to a power module aging parameter quasi-online identification system; and the correcting unit is suitable for calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter.
Optionally, the method further includes: the online sampling module is suitable for injecting a third test current to the main power switching tube to be tested in the current transformer under the online working state in the forward direction and acquiring a third test conduction voltage drop of the main power switching tube to be tested; and the online junction temperature acquisition unit is suitable for acquiring the online junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first correction function relation.
Optionally, the first function relationship is T B1 ＝f 1 (I B1 ，V B1 ) (ii) a The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of junction temperature, I B1 For the first calibration of the conduction current, T t K is the temperature coefficient of resistance of the bonding wire, Δ R (T) for the characteristic temperature t ) Is the equivalent resistance variation parameter, V, of the bonding wire at a characteristic temperature B1 The first nominal conduction saturation drop is achieved.
Optionally, the method further includes: the first condition judgment unit is suitable for judging whether the on-line operation time of the converter is greater than a time threshold value or not; the second condition judgment unit is suitable for judging whether the converter meets a quasi-online working state or not; the first sampling module is suitable for injecting a first test current to a main power switch tube to be tested in the converter in a quasi-online working state in a forward direction and acquiring a first test conduction voltage drop of the main power switch tube to be tested when the on-line running time of the converter is larger than a time threshold value and the converter meets the quasi-online working state.
The invention also provides a quasi-online identification method for the aging parameters of the power module, which is suitable for monitoring the junction temperature of a main power switch tube to be detected in the power module, wherein the power module comprises a bonding wire connected with the main power switch tube, and the method comprises the following steps: step S1: injecting a first calibration conduction current into the main power switch tube to be tested in the forward direction, and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and a first calibration junction temperature of the first calibration conduction current and the main power switch tube to be tested; step S2: fitting the data in the first mapping relation to obtain a first functional relation, wherein the first functional relation takes a first calibration conduction saturation voltage drop and a first calibration conduction current as independent variables and a first calibration junction temperature as a dependent variable; step S3: injecting a second constant calibration current into the main power switching tube to be tested, and acquiring a second mapping relation between a second calibration conduction saturation voltage drop of the main power switching tube to be tested in an off-line state and a second calibration junction temperature of the main power switching tube to be tested, wherein the second constant calibration current is far smaller than the first calibration conduction current; step S4: fitting the data in the second mapping relation to obtain a second functional relation, wherein the second functional relation takes a second calibration conduction saturation voltage drop as an independent variable and a second calibration junction temperature as a dependent variable; step S5: a first test current is injected into a main power switch tube to be tested in a converter under a quasi-online working state in a forward direction, and a first test conduction voltage drop of the main power switch tube to be tested is obtained; step S6: acquiring a first test junction temperature, wherein the first test junction temperature is a numerical value of a first calibration junction temperature corresponding to data of a first test conduction voltage drop and a first test current in a first functional relation; step S7: after the first test junction temperature is obtained, applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state; step S8: after a forced turn-off signal is applied to all main power switch tubes in the converter in a quasi-online working state, injecting a second test current into the main power switch tube to be tested in the converter in the quasi-online working state and acquiring a second test conduction voltage drop of the main power switch tube to be tested, wherein the second test current is equal to a second constant calibration current; step S9: acquiring a second test junction temperature, wherein the second test junction temperature is a numerical value of a second calibrated junction temperature corresponding to the data of the second test conduction voltage drop in a second functional relation; step S10: and when the absolute value of the difference between the first test junction temperature and the second test junction temperature is larger than the threshold, obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop.
Optionally, the step of obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current, and the first test conduction voltage drop includes: according to the equivalent resistance change parameter delta R (T) of the bonding wire at the characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a Adapted to pass a voltage drop V according to a first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) Obtaining a first test calibration turn-on voltage drop V Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a Calibrating the conduction voltage drop V according to the first test Z1 A first test current I C1 And a second test junction temperature T C2 And the firstObtaining equivalent resistance change parameter delta R (T) under characteristic temperature by a functional relation t )。
Optionally, the main power switch tube includes an IGBT.
The invention also provides a junction temperature calibration method, which comprises the following steps: the invention relates to a power module aging parameter quasi-online identification method; and calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter.
Optionally, the method further includes: injecting a third test current to a main power switch tube to be tested in the converter under an online working state in a forward direction and acquiring a third test conduction voltage drop of the main power switch tube to be tested; and acquiring the online junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first correction function relation.
Optionally, the first function relationship is T B1 ＝f 1 (I B1 ，V B1 ) (ii) a The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, T t For characteristic temperature, k is the temperature coefficient of resistance of the bonding wire, Δ R (T) t ) Is an equivalent resistance variation parameter, V, of the bonding wire at a characteristic temperature B1 The first nominal conduction saturation drop is achieved.
Optionally, the method further includes: before the step S5 is carried out, whether the on-line operation time of the converter is greater than a time threshold value or not and whether the converter meets a quasi-on-line working state or not is judged; if the online operation time of the converter is greater than the time threshold value and the converter meets the quasi online working state, performing step S5; and if the on-line operation time of the converter is less than or equal to the time threshold value and/or if the converter does not meet the quasi-on-line working state, injecting a third test current to the main power switching tube to be tested in the converter under the on-line working state in the forward direction, acquiring a third test conduction voltage drop of the main power switching tube to be tested, and acquiring the on-line junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first function relation.
The technical scheme of the invention has the following advantages:
the power module aging parameter quasi-online identification method provided by the technical scheme of the invention injects a first test current to a main power switch tube to be tested in a converter under a quasi-online working state in a forward direction and obtains a first test conduction voltage drop of the main power switch tube to be tested, and the quasi-online working state meets the following requirements: the power module is in a current transformer, and the current transformer is in a self-checking or standby state; and acquiring a first test junction temperature, wherein the first test junction temperature is a numerical value of a first calibrated junction temperature corresponding to the data of the first test conduction voltage drop and the first test current in a first functional relation. And then, applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero. Because the forced turn-off signals are applied to all the main power switch tubes in the converter, the power switch tube units enter a rapid follow current mode, so that the current in the load inductor electrically connected with the main power switch tube to be tested is rapidly recovered to zero, at the moment, the branch circuit where the load inductor electrically connected with the main power switch tube to be tested is disconnected and cannot continue damping oscillation return to zero, and the time for applying the forced turn-off signals to all the main power switch tubes in the converter in a quasi-online working state is less. And then, injecting a second test current into the main power switch tube to be tested in the converter under the quasi-online working state and obtaining a second test conduction voltage drop of the main power switch tube to be tested, wherein the second test current is equal to a second constant calibration current, and a second test junction temperature is obtained, the second test junction temperature is a second calibration junction temperature value corresponding to the second test conduction voltage drop data in a second function relation, and the data of the second test junction temperature obtained by the small current injection method after the emergency stop control is more accurate, namely, the small current method is used for calibrating the online junction temperature monitoring data to obtain a junction temperature true value of the main power switch tube to be tested under the aging state. And when the absolute value of the difference between the first test junction temperature and the second test junction temperature is greater than the threshold, obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop, so that the accuracy of the equivalent resistance change parameter of the bonding wire at the characteristic temperature is higher. The second test junction temperature is obtained through testing in a quasi-online state, so that a main power switch tube to be tested does not need to be taken out in the process of using the converter, and the data of the second test junction temperature are obtained through a small current injection method after sudden stop control, so that the test difficulty is low.
According to the junction temperature calibration method provided by the technical scheme of the invention, the first functional relation is calibrated into a first correction functional relation according to the equivalent resistance change parameter. Because the first correction function relation considers the equivalent resistance change parameter of the bonding wire at the characteristic temperature, the first correction function relation can test the junction temperature of the main power switching tube to be tested in an online state with higher precision.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a graph obtained from a prior art junction temperature monitoring method;
fig. 2 is a diagram illustrating a system for quasi-online identification of aging parameters of a power module according to an embodiment of the present invention;
fig. 3 is a topology structure of the converter in online operation according to an embodiment of the present invention;
FIG. 4 is a timing diagram provided in accordance with an embodiment of the present invention;
fig. 5 is a junction temperature calibration system according to an embodiment of the present invention;
fig. 6 is a topological structure of online sampling according to an embodiment of the present invention.
Detailed Description
For the identification of aging parameters in the course of the application of power modules, the main point isThe studies to be conducted were conducted under laboratory conditions mainly using the constant pulse current method. The implementation method of the constant pulse current method comprises the following steps: keeping constant environment temperature, conducting the power module, injecting short pulse constant current I, and measuring conduction voltage drop V CE1 And the conduction voltage drop V of the initial state of the health module CE0 Calculating to obtain the equivalent aging impedance
Figure BDA0003643739820000071
Because the fixed environment temperature and the fixed current source can be realized under the laboratory condition according to the requirements, the test difficulty under the online condition is higher, and the method has no application value under the service condition of equipment.
The other method is a inflection point method which utilizes V 'at different junction temperatures' CE －I c The curve (cf. FIG. 1) presents an inflection point, V' CE For junction temperature (T) J ) The variation insensitive characteristic measures the aging characteristic parameter. Because the temperature limit is reduced, certain on-line test conditions are provided. But the current at the inflection point is generally smaller, the voltage change caused by the degenerative impedance change is also smaller, and the measurement is relatively difficult. In addition, it is difficult to ensure constant current under on-line conditions.
On this basis, an embodiment of the present invention provides a quasi-online identification system for aging parameters of a power module, which is adapted to monitor a junction temperature of a main power switch tube to be measured in the power module, where the power module includes a bonding wire connected to the main power switch tube, and with reference to fig. 2, the quasi-online identification system includes:
the first temperature-calculating calibration module 100 is suitable for injecting a first calibration conduction current to the main power switching tube to be tested in the forward direction, and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switching tube to be tested in an off-line state and the first calibration junction temperature of the main power switching tube to be tested;
a second junction temperature calibration module 200, where the second junction temperature calibration module 200 is adapted to inject a second constant calibration current into the main power switching tube to be tested, and obtain a second mapping relationship between a second calibration conduction saturation voltage drop of the main power switching tube to be tested in an offline state and a second calibration junction temperature of the main power switching tube to be tested, and the second constant calibration current is much smaller than the first calibration conduction current;
a first data fitting module 110, where the first data fitting module 110 is adapted to fit data in the first mapping relationship to obtain a first functional relationship, where the first functional relationship takes the first calibrated conduction saturation voltage drop and the first calibrated conduction current as independent variables, and the first calibrated junction temperature as a dependent variable;
a second data fitting module 210, where the second data fitting module 210 is adapted to fit data in the second mapping relationship to obtain a second functional relationship, where the second functional relationship takes the second calibrated conduction saturation voltage drop as an independent variable and the second calibrated junction temperature as a dependent variable;
the first sampling module 300 is adapted to inject a first test current to a main power switch tube to be tested in the converter in a quasi-online working state in a forward direction and obtain a first test conduction voltage drop of the main power switch tube to be tested;
a first test junction temperature obtaining unit 310, where the first test junction temperature obtaining unit 310 is adapted to obtain a first test junction temperature, and the first test junction temperature is a value of a first calibrated junction temperature corresponding to data of a first test conduction voltage drop and a first test current in a first functional relationship;
the emergency stop control module 400 is adapted to apply a forced turn-off signal to all main power switching tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state;
the second sampling module 500 is adapted to inject a second test current into the main power switch tube to be tested in the converter in the quasi online working state and obtain a second test conduction voltage drop of the main power switch tube to be tested after the emergency stop control module applies a forced turn-off signal to all the main power switch tubes in the converter in the quasi online working state, wherein the second test current is equal to a second constant calibration current;
a second junction temperature obtaining unit 510, where the second junction temperature obtaining unit 510 is adapted to obtain a second junction temperature to be tested, and the second junction temperature to be tested is a second calibrated junction temperature value corresponding to the second testing conduction voltage drop data in a second functional relationship;
the aging parameter obtaining module 600 is adapted to obtain an equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second junction temperature, the first test current, and the first test conduction voltage drop when the absolute value of the difference between the first test junction temperature and the second test junction temperature is greater than the threshold.
Referring to fig. 3, the current transformer includes: direct current network, alternating current network and bridge type power switch tube circuit, have a plurality of power switch tube units in the bridge type power switch tube circuit, each power switch tube unit includes: the power supply comprises a main power switch tube and a diode connected with the main power switch tube in an inverse parallel mode; the alternating current network comprises a load inductor electrically connected with the main power switch tube, and the direct current network comprises a load resistor and a direct current bus power supply U which are connected in series DC 。
In an embodiment, the converter is exemplified as a three-phase full-bridge converter, and referring to fig. 3, a bridge type power switch tube circuit in the converter includes a first power switch tube unit, a second power switch tube unit, a third power switch tube unit, a fourth power switch tube unit, a fifth power switch tube unit and a sixth power switch tube unit. The first power switch tube unit comprises a first main power switch tube T1 and a first diode D1 connected with the first main power switch tube T1 in an anti-parallel mode; the second power switch tube unit comprises a second main power switch tube T2 and a second diode D2 connected with the second main power switch tube T2 in an anti-parallel mode; the third power switch tube unit comprises a third main power switch tube T3 and a third diode D3 connected with the third main power switch tube T3 in an anti-parallel mode; the fourth power switch tube unit comprises a fourth main power switch tube T4 and a fourth diode D4 connected with the fourth main power switch tube T4 in an anti-parallel mode; the fifth power switch tube unit comprises a fifth main power switch tube T5 and a fifth main power switch tubeA fifth diode D5 connected in reverse parallel with the power switch tube T5; the sixth power switch cell includes a sixth main power switch T6 and a sixth diode D6 connected in anti-parallel with the sixth main power switch T6. The collector of the first main power switch tube T1, the collector of the third main power switch tube T3 and the collector of the fifth main power switch tube T5 are connected together and are connected with a direct current bus power supply U DC The emitter of the second main power switch tube T2, the emitter of the fourth main power switch tube T4 and the emitter of the sixth main power switch tube T6 are connected together and connected with a dc bus power supply U DC Is connected. The first main power switch tube T1, the second main power switch tube T2, the third main power switch tube T3, the fourth main power switch tube T4, the fifth main power switch tube T5 and the sixth main power switch tube T6 are all IGBTs (insulated gate bipolar transistors).
In fig. 3, the power module of the present invention includes several pairs of power switch tube units located at the upper bridge position and the lower bridge position. The pair of power switch tube units located at the upper bridge position and the lower bridge position is, for example, a first power switch tube unit and a second power switch tube unit, or is, for example, a third power switch tube unit and a fourth power switch tube unit, or is, for example, a fifth power switch tube unit and a sixth power switch tube unit.
The bonding wire in the power module includes: the power module is connected with bonding wires among different power switch tube units and the bonding wires between the power switch tube units and leading-out terminals of the power module.
Referring to fig. 3, the current transformer further includes: first load inductance L A First load inductance L A Is electrically connected to the emitter of the first main power switch T1 and the collector of the second main power switch T2; and a first load inductor L A A first load resistor R connected in series A First load inductance L A And the other end of the first load resistor R A Is connected with one end of the connecting rod; second load inductance L B Second load inductance L B Is electrically connected to the emitter of the third main power switch T3 and the collector of the fourth main power switch T4; and a second load inductorL B A second load resistor R connected in series B Second load inductance L B And the other end of the first resistor and a second load resistor R B Is connected with one end of the connecting rod; third load inductance L C Third load inductance L C Is electrically connected to the emitter of the fifth main power switch T5 and the collector of the sixth main power switch T6; and a third load inductance L C Third load resistor R connected in series C Third load inductance L C And the other end of the third load resistor R C Is connected with one end of the connecting rod; a first load resistor R A The other end of (2), a second load resistor R B And the other end of the third load resistor R C The other ends of the two are connected together; first load inductance L A And a first load resistor R A Total voltage of upper output is U AN Second load inductance L B And a second load resistor R B Total voltage of upper output is U BN Third load inductance L C And a third load resistor R C Total voltage of upper output is U CN (ii) a Flows through the first load inductor L A And a first load resistor R A Is a first current I A Through the second load inductance L B And a second load resistor R B Is a second current I B Through the third load inductor L C And a third load resistor R C Is a third current I C . The sixth main power switch tube T6 to be tested has a conduction saturation voltage drop V CE . In this embodiment, the sixth main power switch T6 is selected as the main power switch to be tested. Of course, in other embodiments, other main power switch tubes may be arbitrarily selected as the main power switch tube to be tested.
In this embodiment, the first temperature-scaling module 100 injects the first scaling on-current from the collector of the main power switch to be tested in the forward direction into the main power switch to be tested, and specifically, selectively injects the second constant scaling current into the sixth main power switch T6. The value range of the first calibration conduction current injected to the main power switch tube to be tested in the forward direction is the working current of the converter in the normal operation process.
In the process that the first temperature-junction-calibration module 100 injects the first calibration conduction current to the main power switch tube to be tested in the forward direction, the main power switch tube to be tested is suitable for being placed on the heating platform, and the junction temperature of the main power switch tube to be tested in the first mapping relation is calibrated by the temperature of the heating platform.
The first temperature calibration module 100 includes a first constant current source, and the first constant current source injects a large current to the main power switching tube to be tested in the forward direction, so as to obtain a set of mapping data of a first calibration conduction current and a first calibration conduction saturation voltage drop, and by adjusting the temperature of the heating table, mapping data of the first calibration conduction current and the first calibration conduction saturation voltage drop of the main power switching tube to be tested at different first calibration junction temperatures can be obtained, so as to obtain a first mapping relation between the first calibration conduction saturation voltage drop, the first calibration conduction current and the first calibration junction temperature of the main power switching tube to be tested in an off-line state.
The first functional relationship to be fitted by the first data fitting module 110 may be a polynomial or trigonometric function.
The first function relationship is T B1 ＝f 1 (I B1 ，V B1 ). Wherein, T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, V B1 The first nominal conduction saturation drop is achieved.
In the process that the second junction temperature calibration module 200 injects the second constant calibration current into the main power switch tube to be tested, the main power switch tube to be tested is suitable for being placed on the heating platform, and the junction temperature of the main power switch tube to be tested in the second mapping relation is calibrated by the temperature of the heating platform. The second constant calibration current is much smaller than the first calibration conduction current.
In this embodiment, the main power switch to be tested is an IGBT, and the second junction temperature calibration module 200 injects a second constant calibration current to the main power switch to be tested in the forward direction. When the main power switch tube to be tested has other structures, the second constant calibration current can be injected reversely, for example, the second constant calibration current is injected reversely for the MOSFET. When the main power switch tube is a MOSFET, each power switch tube unit comprises the main power switch tube but does not comprise a diode.
In one embodiment, the second junction temperature calibration module 200 injects a second constant calibration current from the collector of the main power switch under test into the main power switch under test in a forward direction, specifically, selectively injects the second constant calibration current into the sixth main power switch T6. The second constant calibration current is 5 mA-200 mA, such as 5mA, 10mA, 50mA, 100mA, 150mA or 200mA, so that the second constant calibration current is small, and the phenomenon that the conduction current in the main power switch tube to be tested is overlarge to generate heat can be avoided.
The second junction temperature calibration module 200 includes a second constant current source adapted to generate a constant current and inject the constant current into the main power switching tube to be tested in a forward direction, and in a process of injecting the constant current into the main power switching tube to be tested in the forward direction by the second junction temperature calibration module 200, a negative end of the second constant current source is connected to a collector of the main power switching tube to be tested, and the main power switching tube to be tested is adapted to be placed on the heating platform. In the process of calibrating the main power switching tube to be tested by the second junction temperature calibration module 200, the injected constant current is kept unchanged all the time, and mapping data of second calibration conduction saturation voltage drop of the main power switching tube to be tested at different second calibration junction temperatures can be obtained by adjusting the temperature of the heating platform, so that a second mapping relation between the second calibration conduction saturation voltage drop of the main power switching tube in an off-line state and the second calibration junction temperature of the main power switching tube to be tested is obtained, and the second constant calibration current is far smaller than the first calibration conduction current. The junction temperature of the main power switch tube to be measured in the second mapping relation is calibrated by the temperature of the heating platform.
The turn-on saturation voltage drop at a fixed value of low current (mA level) is linearly inversely related to the junction temperature. The second junction temperature calibration module 200 refers to a small current conduction voltage drop method by using the junction temperature measurement method with the relation. As a standard method for off-line junction temperature measurement in a laboratory, it is not affected by aging, but a laboratory measurement method is generally not applied on-line.
In this embodiment, the off-line state is that the main power switch tube to be tested is taken out from the converter and tested in a laboratory.
The second functional relationship to be fitted by the second data fitting module 210 may be a polynomial or trigonometric function. In this embodiment, at a constant small current, the conduction saturation voltage drop of the IGBT and the junction temperature are approximately linear, that is, the second functional relationship can be fitted by a unary first-order polynomial.
The second function is T B2 ＝f 2 (V B2 ). Wherein, T B2 For a second calibration of junction temperature, V B2 And the second calibration conduction saturation voltage drop.
It should be noted that, in this embodiment, specific limitations are not imposed on the first data fitting module 110 and the second data fitting module 210, as long as the first data fitting module 110 realizes fitting to the first functional relationship according to the first mapping relationship, and as long as the second data fitting module 210 realizes fitting to the second functional relationship according to the second mapping relationship.
The first sampling module 300 is adapted to forward inject a first test current I into a main power switch tube to be tested in a converter under a quasi-online working state C1 And obtaining a first test conduction voltage drop V of a main power switch tube to be tested C1 The quasi-online working state meets the following conditions: the power module is in the converter, and the converter is in the state of self-checking or standby.
The first junction temperature testing obtaining unit 310 is adapted to obtain a first junction temperature T C1 First test junction temperature T C1 For the first test conduction voltage drop V C1 And a first test current I C1 Is measured at a first nominal junction temperature T corresponding to the data in the first functional relationship B1 The numerical value of (c). That is, the first test conduction voltage drop V obtained by the test C1 Is assigned to V B1 Applying a first test current I C1 Is assigned to I B1 T calculated by the first functional relationship B1 As the first test junction temperature T C1 。
The emergency stop control module 400 is adapted to apply a forced turn-off signal to all main power switching tubes in the converter in a quasi-online operating state until all currents in all load inductors in the converter are zero.
Referring to fig. 4, fig. 4 is a timing diagram of the first sampling module 300, the emergency stop control module 400, and the second sampling module 500, where the timing diagram corresponds to the converter of fig. 3, and in fig. 4, states of the converter include an on-line state, a quasi-on-line state, and an off-line state, where the on-line state refers to that the converter is in an operating state and outputs a certain power, the main power switch tubes are alternately turned on, gates of the main power switch tubes are driven by Pulse Width Modulation (PWM) signals of the converter, and different main power switch tubes have timings corresponding to the PWM signals required by their own operations. The off-line state refers to that the main power switch tube to be tested is detached from the converter and sent to a laboratory for detection. The quasi-online state refers to a state that a main power switching tube to be tested is in a current transformer and the current transformer is in a self-checking state or a standby state, and the quasi-online state is taken as an example in fig. 4. And when the converter is in a quasi-online state, the converter does not output power.
The scram control module 400 applies a forced turn-off signal to all main power switch tubes in the converter in the quasi-online working state from the first time t1 to the third time t3 until all currents in all load inductors in the converter are zero, and the process lasts for ms, namely all main power switch tubes in the converter are turned off in a short time. The scram control module 400 does not allow current to flow through each main power switch in a phase where a forced turn-off signal is continuously applied to the gates of all the main power switches. Specifically, for the converter in fig. 3, the emergency stop control module 400 applies a forced turn-off signal to the first main power switch tube T1, the second main power switch tube T2, the third main power switch tube T3, the fourth main power switch tube T4, the fifth main power switch tube T5 and the sixth main power switch tube T6 from the first time T1 until the third time T3, the first load inductance L A A second load inductor L B And a third loadFeeling L C All are zero at a third time t 3. The third time t3 is the time when the current in all the load voltages electrically connected to the main power switch tube is exactly zero, specifically, for the current transformer in fig. 4, the third time t3 is the time when the first load inductor L is set A A second load inductor L B And a third load inductance L C Is just all zero. In the period from the first time t1 to the third time t3, the current in the partial load inductor may become zero first, and the current in the partial load inductor may become zero later until the current in all the load voltages is zero at the third time t 3. For the current transformer in fig. 3, when the sixth main power switch transistor T6 is the main power switch transistor to be tested, the third load inductor L C After the current in (1) has first become zero at a second time t2, the first load inductance L A Current in and second load inductance L B The current in (b) becomes zero synchronously at a third time t 3.
Since the forced turn-off signal is applied to all the main power switch tubes in the converter from the first time t1, the power switch tube unit enters the fast freewheeling mode. Specifically, when a main power switch tube unit to be tested performs fast follow current on an inductor electrically connected with a main power switch tube to be tested, the main power switch tube to be tested is in a turn-off state, current does not flow through the main power switch tube to be tested, a diode connected with the main power switch tube to be tested in reverse parallel conducts through overcurrent, reverse voltage is applied to two ends of a load inductor electrically connected with the main power switch tube to be tested, so that the current in the load inductor electrically connected with the main power switch tube to be tested is fast returned to zero, and at the moment, a branch circuit where the load inductor electrically connected with the main power switch tube to be tested is located is disconnected and damping oscillation cannot continue to return to zero; when a certain main power switch tube which is not to be tested carries out rapid follow current on an inductor which is electrically connected with the main power switch tube which is not to be tested, the main power switch tube which is not to be tested is in a turn-off state, current does not flow through the main power switch tube which is not to be tested, a diode which is reversely connected in parallel with the main power switch tube which is not to be tested is conducted to flow through the current, reverse voltage is applied to two ends of a load inductor which is electrically connected with the main power switch tube which is not to be tested, so that the current in the load inductor which is electrically connected with the main power switch tube which is not to be tested is rapidly returned to zero, and at the moment, a branch circuit where the load inductor which is electrically connected with the main power switch tube which is not to be tested is located is disconnected, and damping oscillation is not continuously returned to zero. In summary, the interval between the first time t1 and the third time t3 is made smaller.
In one embodiment, (t 3-t 1) is 1ms to 5 ms.
The second sampling module 500 is adapted to inject a second test current into the main power switch tube to be tested in the converter in the quasi online working state and obtain a second test conduction voltage drop of the main power switch tube to be tested after the emergency stop control module applies a forced turn-off signal to all the main power switch tubes in the converter in the quasi online working state. The second sampling module 500 is adapted to inject a second test current into the main power switch tube to be tested in the converter in the quasi online operating state after the third time t3 and before the fourth time t4, and obtain a second test conduction voltage drop of the main power switch tube to be tested. The second sampling module 500 applies a high level to the gate of the main power switch transistor to be tested after the third time T3 and before the fourth time T4 to turn on, specifically, the gate of the sixth main power switch transistor T6 applies a high level to turn on, and the gates of the first to fifth main power switch transistors T1 to T5 apply a low level to continue to maintain the off state. The second test current is 5 mA-200 mA, such as 5mA, 10mA, 50mA, 100mA, 150mA, or 200 mA.
The fourth time t4 differs from the third time t3 by milliseconds.
The second test current is equal to the second constant calibration current, so that the accuracy of the finally obtained verification junction temperature is improved.
The second junction temperature test obtaining unit 510 is adapted to obtain a second junction temperature test T C2 Second test junction temperature T C2 For the second test conduction voltage drop V C2 In a second functional relationship, corresponding to a second nominal junction temperature T B2 The numerical value of (c). That is, the second test conduction voltage drop V obtained by the test C2 Is assigned to V B2 Calculated by a second functional relationshipT of (A) B2 As the second test junction temperature T C2 。
The aging parameter acquiring module 600 includes: a first submodule adapted to vary a parameter Δ R (T) according to an equivalent resistance of the bonding wire at a characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a A second sub-module adapted to conduct a voltage drop V according to the first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) Obtaining a first test calibration turn-on voltage drop V Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a A third sub-module adapted to calibrate a conduction voltage drop V according to a first test Z1 A first test current I C1 And a second test junction temperature T C2 And obtaining the equivalent resistance change parameter delta R (T) under the characteristic temperature by the first functional relation t ). Specifically, a first test current I is applied C1 Is assigned to I B1 Second test junction temperature T C2 Assigned to T B1 A V is measured C1 －ΔR(T C2 )＊I C1 Assigned to V B1 Calculating to obtain an equivalent resistance change parameter delta R (T) under the characteristic temperature according to the first functional relation t )。
In one embodiment, the characteristic temperature is between 10 degrees Celsius and 40 degrees Celsius. In the present embodiment, the characteristic temperature is exemplified by 25 degrees celsius.
In this embodiment, the power module aging parameter quasi-online identification system further includes: a comparison module adapted to compare whether an absolute value of a difference between the first junction temperature and the second junction temperature is greater than a threshold. In one embodiment, the threshold is 1 mA-100 mA.
Another embodiment of the present invention further provides a junction temperature calibration system, referring to fig. 5, including: the power module aging parameter quasi-online identification system provided by the embodiment; a correction unit 700, said correction unit 700 being adapted to calibrate the first functional relationship to a first correction functional relationship based on the equivalent resistance variation parameter.
The first function relationship is T B1 ＝f 1 (I B1 ，V B1 ). The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, T t Is a characteristic temperature, k is a temperature coefficient of resistance of the bonding wire, V B1 The conduction saturation voltage drop is calibrated for the first time.
In this embodiment, the junction temperature calibration system further includes: the first condition judgment unit is suitable for judging whether the on-line operation time of the converter is greater than a time threshold value or not; the second condition judgment unit is suitable for judging whether the converter meets a quasi-online working state or not; the first sampling module is suitable for injecting a first test current to a main power switch tube to be tested in the converter in a quasi-online working state in a forward direction and acquiring a first test conduction voltage drop of the main power switch tube to be tested when the on-line running time of the converter is larger than a time threshold value and the converter meets the quasi-online working state.
In this embodiment, the junction temperature calibration system further includes: the online sampling module is suitable for injecting a third test current to the main power switch tube to be tested in the converter under an online working state in the forward direction and acquiring a third test conduction voltage drop of the main power switch tube to be tested; and the online junction temperature acquisition unit is suitable for acquiring the online junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first correction function relation.
Fig. 6 is a topology structural diagram of online sampling provided in this embodiment, where the online sampling module includes an online current sampling module and an online conducting voltage sampling module. The main power switch tube that awaits measuring is the working element of power equipment module, and the power equipment module includes: the online current sampling module can be a current sampling internal module in the power equipment module. The output end of the current sampling internal module is suitable for being connected with the input end of the main control module, and the output end of the main control module is suitable for providing working time sequences for each main power switch tube in the converter. The power equipment module further includes: a CPU (central processing unit).
Another embodiment of the present invention further provides a method for quasi online identifying an aging parameter of a power module, which is adapted to monitor a junction temperature of a main power switch tube to be tested in the power module, where the power module includes a bonding wire connected to the main power switch tube, and the method includes:
step S1: injecting a first calibration conduction current into the main power switch tube to be tested in the forward direction, and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and a first calibration junction temperature of the first calibration conduction current and the main power switch tube to be tested;
step S2: fitting the data in the first mapping relation to obtain a first functional relation, wherein the first functional relation takes a first calibration conduction saturation voltage drop and a first calibration conduction current as independent variables and a first calibration junction temperature as a dependent variable;
step S3: injecting a second constant calibration current into the main power switching tube to be tested, and acquiring a second mapping relation between a second calibration conduction saturation voltage drop of the main power switching tube to be tested in an off-line state and a second calibration junction temperature of the main power switching tube to be tested, wherein the second constant calibration current is far smaller than the first calibration conduction current;
step S4: fitting the data in the second mapping relation to obtain a second functional relation, wherein the second functional relation takes the second calibrated conduction saturation voltage drop as an independent variable and the second calibrated junction temperature as a dependent variable;
step S5: a first test current is injected into a main power switch tube to be tested in a converter under a quasi-online working state in a forward direction, and a first test conduction voltage drop of the main power switch tube to be tested is obtained;
step S6: acquiring a first test junction temperature, wherein the first test junction temperature is a first calibration junction temperature value corresponding to data of a first test conduction voltage drop and a first test current in a first functional relation;
step S7: after the first test junction temperature is obtained, applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state;
step S8: after a forced turn-off signal is applied to all main power switch tubes in the converter in the quasi-online working state, injecting a second test current into the main power switch tube to be tested in the converter in the quasi-online working state and obtaining a second test conduction voltage drop of the main power switch tube to be tested, wherein the second test current is equal to a second constant calibration current;
step S9: acquiring a second test junction temperature, wherein the second test junction temperature is a numerical value of a second calibrated junction temperature corresponding to the data of the second test conduction voltage drop in a second functional relation;
step S10: and when the absolute value of the difference between the first test junction temperature and the second test junction temperature is larger than the threshold, obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop.
The step of obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop comprises the following steps: according to the equivalent resistance change parameter delta R (T) of the bonding wire at the characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a Adapted to pass a voltage drop V according to a first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) ObtainCalibrating conduction voltage drop V by taking first test Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a Calibrating the conduction voltage drop V according to the first test Z1 A first test current I C1 And a second test junction temperature T C2 And obtaining the equivalent resistance change parameter delta R (T) under the characteristic temperature by the first functional relation t )。
The main power switch tube comprises an IGBT.
Another embodiment of the present invention further provides a junction temperature calibration method, including: the power module aging parameter quasi-online identification method provided by the embodiment; and calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter.
The first function relationship is T B1 ＝f 1 (I B1 ，V B1 ) (ii) a The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, T t K is the temperature coefficient of resistance of the bonding wire, Δ R (T) for the characteristic temperature t ) Is an equivalent resistance variation parameter, V, of the bonding wire at a characteristic temperature B1 The first nominal conduction saturation drop is achieved.
In this embodiment, the method further includes: before performing step S5, the method further includes: performing first condition judgment, namely judging whether the online running time of the converter is greater than a time threshold value; and if the online operation time of the converter is less than or equal to the time threshold, injecting a third test current to the main power switch tube to be tested in the converter in the online working state in the forward direction, acquiring a third test conduction voltage drop of the main power switch tube to be tested, and acquiring the online junction temperature of the main power switch tube to be tested according to the third test current, the third test conduction voltage drop and the first functional relation.
In this embodiment, the method further includes: after the first condition judgment is carried out, carrying out second condition judgment, namely judging whether the converter meets a quasi-online working state or not; and if the converter does not meet the quasi-online working state, injecting a third test current to the main power switch tube to be tested in the converter under the online working state in the forward direction, acquiring a third test conduction voltage drop of the main power switch tube to be tested, and acquiring the online junction temperature of the main power switch tube to be tested according to the third test current, the third test conduction voltage drop and the first functional relation.
In this embodiment, if the online operation time of the converter is greater than the time threshold and the converter satisfies the quasi online operating state, the step S5 is performed.
In this embodiment, after the first functional relationship is calibrated to the first correction functional relationship according to the equivalent resistance variation parameter, a third test current is injected into the main power switching tube to be tested in the converter under the online working state in the forward direction, and a third test conduction voltage drop of the main power switching tube to be tested is obtained, and the online junction temperature of the main power switching tube to be tested is obtained according to the third test current, the third test conduction voltage drop and the first correction functional relationship.
It should be noted that the concept of the present invention can also obtain the verified junction temperature of other main power switch tubes in the current transformer in fig. 3. The concept of the invention can also obtain the verification junction temperature of the main power switch to be tested of the current transformer with other structures. Other configurations of converters are for example those of H-bridge circuits and those of single-phase half-bridge circuits.
The method greatly improves the accuracy of junction temperature on-line monitoring after the power module generates degenerative change in practical application. Meanwhile, by applying the method, the health state of the power module in the using process can be monitored, and a basis is provided for the life prediction of the power module.
In this embodiment, a main power switch tube to be tested in the converter under the quasi-online working state injects a first test current in the forward direction and obtains a first test conduction voltage drop of the main power switch tube to be tested, and the quasi-online working state satisfies: the main power switch tube to be tested is positioned in the current transformer, and the current transformer is in a self-checking or standby state; and acquiring a first test junction temperature, wherein the first test junction temperature is a first calibration junction temperature value corresponding to the data of the first test conduction voltage drop and the first test current in a first functional relation. And then, applying a forced turn-off signal to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero. Because the forced turn-off signals are applied to all the main power switch tubes in the converter, the power switch tube units enter a rapid follow current mode, so that the current in the load inductor electrically connected with the main power switch tube to be tested is rapidly recovered to zero, at the moment, the branch circuit where the load inductor electrically connected with the main power switch tube to be tested is disconnected and cannot continue damping oscillation return to zero, and the time for applying the forced turn-off signals to all the main power switch tubes in the converter in a quasi-online working state is less. And then, injecting a second test current into the main power switch tube to be tested in the converter under the quasi-online working state and obtaining a second test conduction voltage drop of the main power switch tube to be tested, wherein the second test current is equal to a second constant calibration current, and a second test junction temperature is obtained, wherein the second test junction temperature is a second calibration junction temperature value corresponding to the data of the second test conduction voltage drop in a second function relation. And when the absolute value of the difference between the first test junction temperature and the second test junction temperature is larger than the threshold, obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop. And calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter. Because the equivalent resistance change parameter of the bonding wire at the characteristic temperature is considered in the first correction mapping relation, the first correction function relation can test the junction temperature of the main power switching tube to be tested in an online state with higher precision. The second test junction temperature is obtained by testing in a quasi-online state, so that a main power switch tube to be tested does not need to be taken out in the process of using the converter, and the second test junction temperature data is relatively easy to obtain by a small current injection method after the sudden stop control, and the test difficulty is low.
In a comparative experimentThe high-precision sampling module and the sampling calibration method are applied to carry out online test, and the verification method is applied to carry out comparison. Firstly, the junction temperature on-line monitoring result of the new module is compared and verified, and the error is less than 5 ℃. The method comprises the steps of carrying out 30 ten thousand times of power cycle accelerated aging on a module in a laboratory, then respectively comparing and verifying junction temperature online measurement results before and after aging calibration, wherein the error of uncalibrated online monitoring data after aging reaches 22 ℃. The aging calibration method of the invention is applied to obtain the equivalent resistance change parameter delta R (T) t ) The online monitoring data after calibration is controlled within 7 ℃ in error at 35m omega.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. And obvious variations or modifications derived therefrom are intended to be within the scope of the invention.

Claims (16)

1. A power module aging parameter quasi-online identification system is suitable for monitoring the junction temperature of a main power switch tube to be tested in a power module, the power module comprises a bonding wire connected with the main power switch tube, and the power module aging parameter quasi-online identification system is characterized by comprising:
the first junction temperature calibration module is suitable for injecting a first calibration conduction current to the main power switch tube to be tested in the forward direction and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and the first calibration junction temperature of the main power switch tube to be tested;
the second junction temperature calibration module is suitable for injecting a second constant calibration current into the main power switching tube to be tested, and acquiring a second mapping relation between a second calibration conduction saturation voltage drop of the main power switching tube to be tested in an off-line state and a second calibration junction temperature of the main power switching tube to be tested, wherein the second constant calibration current is far smaller than the first calibration conduction current;
the first data fitting module is suitable for fitting data in the first mapping relation to obtain a first functional relation, and the first functional relation takes the first calibrated conduction saturation voltage drop and the first calibrated conduction current as independent variables and the first calibrated junction temperature as a dependent variable;
the second data fitting module is suitable for fitting the data in the second mapping relation to obtain a second functional relation, and the second functional relation takes a second calibration conduction saturation voltage drop as an independent variable and a second calibration junction temperature as a dependent variable;
the first sampling module is suitable for injecting a first test current to a main power switch tube to be tested in the converter under a quasi online working state in a forward direction and acquiring a first test conduction voltage drop of the main power switch tube to be tested;
the first test junction temperature obtaining unit is suitable for obtaining a first test junction temperature, and the first test junction temperature is a numerical value of a first calibrated junction temperature corresponding to data of a first test conduction voltage drop and a first test current in a first functional relation;
the emergency stop control module is suitable for applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state;
the second sampling module is suitable for injecting a second test current into the main power switch tube to be tested in the converter in the quasi online working state and acquiring a second test conduction voltage drop of the main power switch tube to be tested after the emergency stop control module applies a forced turn-off signal to all the main power switch tubes in the converter in the quasi online working state, wherein the second test current is equal to a second constant calibration current;
the second test junction temperature obtaining unit is suitable for obtaining a second test junction temperature, and the second test junction temperature is a value of a second calibrated junction temperature corresponding to the second test conduction voltage drop data in a second function relation;
and the aging parameter obtaining module is suitable for obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop when the absolute value of the difference value between the first test junction temperature and the second test junction temperature is larger than the threshold value.
2. The power module aging parameter quasi-online identification system of claim 1, wherein the aging parameter acquisition module comprises: a first submodule adapted to vary a parameter Δ R (T) according to an equivalent resistance of the bonding wire at a characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance variation parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a A second sub-module adapted to conduct a voltage drop V according to the first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) Obtaining a first test calibration turn-on voltage drop V Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a A third sub-module adapted to calibrate a conduction voltage drop V according to a first test Z1 A first test current I C1 And a second test junction temperature T C2 And obtaining the equivalent resistance change parameter delta R (T) under the characteristic temperature by the first functional relation t )。
3. The power module aging parameter quasi-online identification system of claim 1, further comprising: a comparison module adapted to compare whether an absolute value of a difference between the first tested junction temperature and the second tested junction temperature is greater than a threshold.
4. The power module aging parameter quasi-online identification system of claim 1, wherein the threshold is 1 mA-100 mA.
5. The power module aging parameter quasi-online identification system of claim 1, wherein the main power switch tube comprises an IGBT.
6. A junction temperature calibration system, comprising:
the power module burn-in parameter quasi online identification system of any of claims 1 to 5;
and the correcting unit is suitable for calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter.
7. The junction temperature calibration system of claim 6, further comprising:
the online sampling module is suitable for injecting a third test current to the main power switching tube to be tested in the current transformer under the online working state in the forward direction and acquiring a third test conduction voltage drop of the main power switching tube to be tested;
and the online junction temperature acquisition unit is suitable for acquiring the online junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first correction function relation.
8. The junction temperature calibration system of claim 6, wherein the first function relationship is T B1 ＝f 1 (I B1 ，V B1 ) (ii) a The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, T t For characteristic temperature, k is the temperature coefficient of resistance of the bonding wire, Δ R (T) t ) Is an equivalent resistance variation parameter, V, of the bonding wire at a characteristic temperature B1 The conduction saturation voltage drop is calibrated for the first time.
9. The junction temperature calibration system of claim 6, further comprising:
the first condition judgment unit is suitable for judging whether the on-line operation time of the converter is greater than a time threshold value or not;
the second condition judgment unit is suitable for judging whether the converter meets a quasi-online working state or not;
the first sampling module is suitable for injecting a first test current to a main power switch tube to be tested in the converter in a quasi-online working state in a forward direction and acquiring a first test conduction voltage drop of the main power switch tube to be tested when whether the online running time of the converter is greater than a time threshold value and whether the converter meets the quasi-online working state.
10. A quasi-online identification method for aging parameters of a power module is suitable for monitoring the junction temperature of a main power switch tube to be tested in the power module, the power module comprises a bonding wire connected with the main power switch tube, and the method is characterized by comprising the following steps:
step S1: injecting a first calibration conduction current into the main power switch tube to be tested in the forward direction, and acquiring a first mapping relation between a first calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and a first calibration junction temperature of the first calibration conduction current and the main power switch tube to be tested;
step S2: fitting the data in the first mapping relation to obtain a first functional relation, wherein the first functional relation takes the first calibration conduction saturation voltage drop and the first calibration conduction current as independent variables and the first calibration junction temperature as a dependent variable;
step S3: injecting a second constant calibration current into the main power switch tube to be tested, and acquiring a second mapping relation between a second calibration conduction saturation voltage drop of the main power switch tube to be tested in an off-line state and a second calibration junction temperature of the main power switch tube to be tested, wherein the second constant calibration current is far smaller than the first calibration conduction current;
step S4: fitting the data in the second mapping relation to obtain a second functional relation, wherein the second functional relation takes the second calibrated conduction saturation voltage drop as an independent variable and the second calibrated junction temperature as a dependent variable;
step S5: a first test current is injected into a main power switch tube to be tested in a converter under a quasi-online working state in a forward direction, and a first test conduction voltage drop of the main power switch tube to be tested is obtained;
step S6: acquiring a first test junction temperature, wherein the first test junction temperature is a numerical value of a first calibration junction temperature corresponding to data of a first test conduction voltage drop and a first test current in a first functional relation;
step S7: after the first test junction temperature is obtained, applying forced turn-off signals to all main power switch tubes in the converter in a quasi-online working state until all currents in all load inductors in the converter are zero; the quasi-online working state meets the following conditions: the power module is in a current transformer, and the current transformer is in a self-checking or standby state;
step S8: after a forced turn-off signal is applied to all main power switch tubes in the converter in a quasi-online working state, injecting a second test current into the main power switch tube to be tested in the converter in the quasi-online working state and acquiring a second test conduction voltage drop of the main power switch tube to be tested, wherein the second test current is equal to a second constant calibration current;
step S9: acquiring a second test junction temperature, wherein the second test junction temperature is a second calibrated junction temperature value corresponding to the second test conduction voltage drop data in a second function relation;
step S10: and when the absolute value of the difference between the first test junction temperature and the second test junction temperature is larger than the threshold, obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature according to the second test junction temperature, the first test current and the first test conduction voltage drop.
11. The method of claim 10, wherein the power module aging parameter is identified quasi-online according to a second junction temperature test and a first test currentThe step of obtaining the equivalent resistance change parameter of the bonding wire at the characteristic temperature by the first test conduction voltage drop comprises the following steps: according to the equivalent resistance change parameter delta R (T) of the bonding wire at the characteristic temperature t ) Temperature coefficient of resistance k of bonding wire and second test junction temperature T C2 Characteristic temperature T t Obtaining the second test junction temperature T of the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 )，ΔR(T C2 )＝ΔR(T t )*(1+k*(T C2 -T t ) (ii) a Adapted to conduct a voltage drop V according to a first test C1 A first test current I C1 And testing the junction temperature T at the second position by the bonding wire C2 Equivalent resistance change parameter Δ R (T) of C2 ) Obtaining a first test calibration turn-on voltage drop V Z1 ，V Z1 ＝V C1 －ΔR(T C2 )＊I C1 (ii) a Calibrating the conduction voltage drop V according to a first test Z1 A first test current I C1 And a second test junction temperature T C2 And obtaining the equivalent resistance change parameter delta R (T) under the characteristic temperature by the first functional relation t )。
12. The power module aging parameter quasi-online identification method of claim 10, wherein the main power switch tube comprises an IGBT.
13. A method of junction temperature calibration, comprising:
the power module aging parameter quasi-online identification method of any of claims 10 to 12;
and calibrating the first functional relation into a first correction functional relation according to the equivalent resistance change parameter.
14. The junction temperature calibration method of claim 13, further comprising: injecting a third test current to a main power switch tube to be tested in the current transformer under the online working state in the forward direction and obtaining a third test conduction voltage drop of the main power switch tube to be tested; and acquiring the online junction temperature of the main power switch tube to be tested according to the third test current, the third test conduction voltage drop and the first correction function relation.
15. The junction temperature calibration method of claim 13, wherein the first function relationship is T B1 ＝f 1 (I B1 ，V B1 ) (ii) a The first correction function relationship is T B1 ＝f 1 (I B1 ，V B1 －[ΔR(T t )*(1+k*(T B1 -T t )]*I B1 )；T B1 For a first calibration of the junction temperature, I B1 For the first calibration of the conduction current, T t For characteristic temperature, k is the temperature coefficient of resistance of the bonding wire, Δ R (T) t ) Is an equivalent resistance variation parameter, V, of the bonding wire at a characteristic temperature B1 The first nominal conduction saturation drop is achieved.
16. The junction temperature calibration method according to claim 13, further comprising: before step S5, judging whether the online operation time of the converter is greater than a time threshold value and whether the converter meets a quasi online working state; if the online operation time of the converter is greater than the time threshold value and the converter meets the quasi online working state, performing step S5; and if the on-line operation time of the converter is less than or equal to the time threshold value and/or if the converter does not meet the quasi-on-line working state, injecting a third test current to the main power switching tube to be tested in the converter under the on-line working state in the forward direction, acquiring a third test conduction voltage drop of the main power switching tube to be tested, and acquiring the on-line junction temperature of the main power switching tube to be tested according to the third test current, the third test conduction voltage drop and the first function relation.
CN202210524777.2A 2022-05-13 2022-05-13 Power module aging parameter quasi-online identification method and junction temperature calibration method and system Pending CN114924176A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210524777.2A CN114924176A (en) 2022-05-13 2022-05-13 Power module aging parameter quasi-online identification method and junction temperature calibration method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210524777.2A CN114924176A (en) 2022-05-13 2022-05-13 Power module aging parameter quasi-online identification method and junction temperature calibration method and system

Publications (1)

Publication Number Publication Date
CN114924176A true CN114924176A (en) 2022-08-19

Family

ID=82808868

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210524777.2A Pending CN114924176A (en) 2022-05-13 2022-05-13 Power module aging parameter quasi-online identification method and junction temperature calibration method and system

Country Status (1)

Country Link
CN (1) CN114924176A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024114279A1 (en) * 2022-12-01 2024-06-06 上海临港电力电子研究有限公司 Leakage current correction method and apparatus for power module aging test, and testing system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024114279A1 (en) * 2022-12-01 2024-06-06 上海临港电力电子研究有限公司 Leakage current correction method and apparatus for power module aging test, and testing system

Similar Documents

Publication Publication Date Title
Smet et al. Evaluation of $ V_ {\rm ce} $ Monitoring as a Real-Time Method to Estimate Aging of Bond Wire-IGBT Modules Stressed by Power Cycling
CN111337808B (en) On-line measuring circuit and system for conduction voltage drop of power semiconductor device
CN106969851B (en) On-line detection device for measuring junction temperature of IGBT power module based on saturation voltage drop
CN110765601A (en) IGBT junction temperature estimation method based on IGBT thermoelectric coupling model
Brandelero et al. Online junction temperature measurements for power cycling power modules with high switching frequencies
CN111044876B (en) IGBT module bonding wire state monitoring circuit and half-bridge structure monitoring circuit thereof
Amoiridis et al. Vce-based chip temperature estimation methods for high power IGBT modules during power cycling—A comparison
Ghimire et al. An online V ce measurement and temperature estimation method for high power IGBT module in normal PWM operation
CN109164370A (en) The thermal impedance measuring system and method for power semiconductor
CN111505475B (en) Method and device for calibrating parameters of electric heating model of power semiconductor module
CN113030682B (en) High-precision junction temperature online monitoring method and system
CN111239576B (en) Constant power cycle test circuit and method based on power loss linear control
CN114924176A (en) Power module aging parameter quasi-online identification method and junction temperature calibration method and system
Chen et al. Driver Integrated Online R ds-on Monitoring Method for SiC Power Converters
JPH06281693A (en) Measuring method for thermal resistance of semiconductor device
WO2017130573A1 (en) Power conversion device and thermal resistance measurement method for power module
CN116500400B (en) Online in-situ characterization system and method for failure state of solder layer of silicon carbide power device
Yang et al. A novel in situ IGBT and FWD junction temperature estimation technique for IGBT module based on on-state voltage drop measurement
CN112986781B (en) Junction temperature online monitoring data verification system and method
Gregorio et al. Estimation of the internal junction temperatures of resin encapsulated IGBT power modules
Jiao et al. A novel junction temperature estimation approach for high voltage IGBT modules based on pre-turn-off current
Wei et al. Research on on-line reliability state detection method of power electronic devices based on turn-off losses
Zhang et al. An In-Situ On-Board Offline Diagnostic Method of IGBT Modules for Bond Wire Degradation Within High-Power 3L-NPC Converters
CN118330414A (en) Method and device capable of measuring bonding wire aging state of MOSFET power module on line
Lu et al. Tj-Vce Calibration under Self-heating Condition for Online Junction Temperature Monitoring of IGBT Module

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination