CN115616367A - Power electronic device state information online monitoring method and system - Google Patents

Abstract

The invention discloses a method and system for online monitoring of state information of power electronic devices, relating to the field of power electronic device monitoring, including: determining the first estimated junction temperature of power electronic devices based on a junction temperature estimation method based on temperature-sensitive electrical parameters; The junction temperature estimation method of the power terminal temperature determines the second estimated junction temperature of the power electronic device; the junction temperature estimation method based on the case temperature determines the third estimated junction temperature of the power electronic device; based on the first estimated junction temperature, the second estimated junction temperature The junction temperature and the third estimated junction temperature are used to monitor the state information of the power electronic device online in real time. The invention can accurately monitor the status information of the power electronic device in real time.

Description

A method and system for online monitoring of status information of power electronic devices

technical field

The invention relates to the field of power electronic equipment monitoring, in particular to an online monitoring method and system for status information of power electronic devices.

Background technique

Most of the electric energy in the world, such as electric vehicle drive equipment, rail transit traction equipment, new energy power generation equipment, communication power supply equipment, etc., is converted and controlled by power electronic devices. Power electronic devices are almost the most fault-prone components in all electrical equipment. Therefore, online monitoring of the reliability status or aging evolution status of power electronic devices is very important for mastering the status information of power electronic devices, ensuring operation safety, and realizing electrical equipment health management/life. Management matters.

The reliability state or aging evolution state monitoring of power electronic devices has always been a hot spot in the research of power electronic equipment at home and abroad. Synthesizing the state monitoring methods of power electronic equipment currently researched at home and abroad, they can be roughly summarized as: methods based on external sensors and circuits at the end of the device, methods based on the characteristics of the end of the device, and methods based on models.

Based on the method of externally connecting sensors and circuits at the end of the device, for example, a terminal is drawn out at the emitter lead of the IGBT to access auxiliary measurement circuits such as external resistance, and the IGBT lead-off fault can be monitored. For example, resistors are connected in parallel on both sides of the emitter lead terminal of the IGBT, and the change in the voltage drop on the resistor is used to trigger the auxiliary circuit and issue an alarm. Although this type of method based on external sensors and circuits at the end of the device can effectively monitor the occurrence of faults, the introduction of auxiliary circuits and/or sensor elements will change the internal structural layout of the converter IGBT, and the auxiliary circuits and/or sensor elements will Power loss can also affect the accuracy of status detection for power electronics.

Based on the method of device end characteristics, such as through electrothermal loading experiments, the characteristics of on-state voltage drop, transconductance, and gate threshold voltage of power electronic devices before and after fatigue are studied, so as to infer the aging of power electronic devices. However, in practical applications, since most power electronic devices are packaged in modules, it is difficult to directly measure terminal characteristics such as on-state voltage drop, transconductance, and gate threshold voltage, and due to factors such as measurement errors and weak signal changes, this It is very difficult to accurately measure the method based on the characteristics of the end of the device, which limits the practical engineering application.

Model-based methods, such as the thermal resistance model method, estimate the change of the internal thermal resistance of the power electronic device by analyzing the change of power loss in the entire operating range of the power electronic device, thereby judging the degree of fatigue of the solder layer under the chip; such as the junction temperature model method, using the characteristic relationship between the aging of power electronic devices and the change of junction temperature to infer the aging of power electronic devices; such as the method of combining the thermal resistance model and the junction temperature model, comparing the two junction temperature parameters obtained by the junction temperature model and the thermal resistance model to determine the aging type of power electronic devices. However, this type of model-based method may introduce certain errors, resulting in inaccurate measurement accuracy. In addition, the accuracy requirements for the corresponding thermal resistance model and/or junction temperature model are relatively high.

To sum up, the method based on the external sensor and circuit at the end of the device needs to consider the sensor measurement error and its impact on the hardware structure. The method based on the characteristics of the end of the device is not suitable for online measurement, and the model-based method will affect the accuracy of the model and the algorithm. higher requirements have been put forward.

Contents of the invention

The object of the present invention is to provide an online monitoring method and system for status information of power electronic devices, so as to achieve the purpose of real-time and accurate monitoring of status information of power electronic devices.

To achieve the above object, the present invention provides the following scheme:

A method for online monitoring of state information of power electronic devices, comprising:

A junction temperature estimation method based on temperature-sensitive electrical parameters is used to determine a first estimated junction temperature of the power electronic device; the power electronic device includes a chip, a power terminal, and a solder layer under the chip;

determining a second estimated junction temperature of the power electronic device based on a junction temperature estimation method of a device power terminal temperature;

determining a third estimated junction temperature of the power electronic device based on a case temperature estimation method;

Based on the first estimated junction temperature, the second estimated junction temperature, and the third estimated junction temperature, the state information of the power electronic device is monitored online in real time; the state information includes chip aging and chip aging , The bonding wire is aged, the bonding wire is not aged, the solder layer under the chip is aged, and the solder layer under the chip is not aged.

Optionally, the method for estimating the junction temperature based on temperature-sensitive electrical parameters determines the first estimated junction temperature of the power electronic device, specifically including:

Obtain temperature-sensitive electrical parameters of power electronic devices;

Estimate a first estimated junction temperature of the power electronic device online according to the temperature-sensitive characteristic relationship and the temperature-sensitive electrical parameter; the temperature-sensitive characteristic relationship is a mapping relationship between the temperature-sensitive electrical parameter and the junction temperature.

Optionally, the method of estimating the junction temperature based on the temperature of the power terminal of the device determines the second estimated junction temperature of the power electronic device, which specifically includes:

Acquiring parameters of a thermal resistance network from a chip to a power terminal in the power electronic device;

Acquiring the temperature of the power terminals of the power electronic device;

calculating the loss corresponding to the second estimated junction temperature of the power electronic device; the loss corresponding to the second estimated junction temperature is determined according to the operating point information of the power electronic device; the power electronic device is installed on the power electronic device on the device;

determining the second estimated junction temperature of the power electronic device according to the formula T _B =P _B *Z _{th_jt} + T _t ;

Wherein, T _B represents the second estimated junction temperature, P _B represents the loss corresponding to the second estimated junction temperature, T _t represents the power terminal temperature, and Z _{th_jt} represents the thermal resistance network parameter from the chip to the power terminal.

Optionally, the method for estimating the junction temperature based on the case temperature determines the third estimated junction temperature of the power electronic device, which specifically includes:

Obtaining the parameters of the thermal resistance network from the chip to the solder layer in the power electronic device;

Acquiring the case temperature of the power electronic device; the case temperature is the temperature of the shell or copper base of the power electronic device;

calculating the loss corresponding to the third estimated junction temperature of the power electronic device; the loss corresponding to the third estimated junction temperature is determined according to the operating point information of the power electronic device; the power electronic device is installed on the power electronic device on the device;

determining the third estimated junction temperature of the power electronic device according to the formula T _C =P*Z _{th_jc} +T _case ;

Among them, T _C represents the third estimated junction temperature, P represents the loss corresponding to the third estimated junction temperature, T _case represents the case temperature, and Z _{th_jc} represents the thermal resistance network parameter from the chip to the solder layer.

Optionally, the real-time online monitoring of status information of the power electronic device based on the first estimated junction temperature, the second estimated junction temperature, and the third estimated junction temperature specifically includes:

When the difference between the first estimated junction temperature and the second estimated junction temperature is within a set interval, it is determined that the state information of the power electronic device is that the chip is not aging and the bonding wire is not aging;

When the difference between the first estimated junction temperature and the second estimated junction temperature is greater than the maximum value of the set interval, it is determined that the state information of the power electronic device is that the chip is aging;

When the difference between the first estimated junction temperature and the second estimated junction temperature is smaller than the minimum value of the set interval, it is determined that the state information of the power electronic device is that the bonding wire is aging;

When the difference between the second estimated junction temperature and the third estimated junction temperature is less than or equal to a set threshold, it is determined that the state information of the power electronic device is that the solder layer under the chip has not aged;

When the difference between the second estimated junction temperature and the third estimated junction temperature is greater than the set threshold, it is determined that the state information of the power electronic device is that the solder layer under the chip is aging.

An online monitoring system for state information of power electronic devices, comprising:

The first estimated junction temperature determination module is used to determine the first estimated junction temperature of the power electronic device based on the junction temperature estimation method of temperature-sensitive electrical parameters; the power electronic device includes a chip, a power terminal, and a solder layer under the chip;

A second estimated junction temperature determining module, configured to determine a second estimated junction temperature of the power electronic device based on a junction temperature estimation method of the device power terminal temperature;

A third estimated junction temperature determination module, configured to determine a third estimated junction temperature of the power electronic device based on a case temperature estimation method for junction temperature;

A state information monitoring module, configured to monitor the state information of the power electronic device online in real time based on the first estimated junction temperature, the second estimated junction temperature and the third estimated junction temperature; the state information includes chip Aging occurs, chip does not age, bonding wires ages, bonding wires does not age, solder layer under the chip ages, and solder layer under the chip does not age.

Optionally, the first estimated junction temperature determination module specifically includes:

A temperature-sensitive electrical parameter acquisition unit, configured to acquire temperature-sensitive electrical parameters of power electronic devices;

The first estimated junction temperature determination unit is configured to estimate online the first estimated junction temperature of the power electronic device according to the temperature-sensitive characteristic relationship and the temperature-sensitive electrical parameter; the temperature-sensitive characteristic relationship is the temperature-sensitive electrical parameter Mapping relationship with junction temperature.

Optionally, the second estimated junction temperature determination module specifically includes:

a thermal resistance network parameter acquisition unit, configured to acquire the thermal resistance network parameters from the chip to the power terminal in the power electronic device;

a power terminal temperature acquisition unit, configured to acquire the power terminal temperature of the power electronic device;

A loss calculation unit corresponding to the second estimated junction temperature, configured to calculate the loss corresponding to the second estimated junction temperature of the power electronic device; the loss corresponding to the second estimated junction temperature is determined according to the operating point information of the power electronic device The power electronic device is installed on the power electronic device;

A second estimated junction temperature determining unit, configured to determine the second estimated junction temperature of the power electronic device according to the formula T _B =P _B *Z _{th_jt} +T _t ;

Wherein, T _B represents the second estimated junction temperature, P _B represents the loss corresponding to the second estimated junction temperature, T _t represents the power terminal temperature, and Z _{th_jt} represents the thermal resistance network parameter from the chip to the power terminal.

Optionally, the third estimated junction temperature determination module specifically includes:

a thermal resistance network parameter acquisition unit, configured to acquire thermal resistance network parameters from the chip to the solder layer in the power electronic device;

A shell temperature acquisition module, configured to acquire the shell temperature of the power electronic device; the shell temperature is the temperature of the shell or copper base plate of the power electronic device;

A loss calculation unit corresponding to the third estimated junction temperature, configured to calculate the loss corresponding to the third estimated junction temperature of the power electronic device; the loss corresponding to the third estimated junction temperature is determined according to the operating point information of the power electronic device The power electronic device is installed on the power electronic device;

A third estimated junction temperature determining unit, configured to determine a third estimated junction temperature of the power electronic device according to the formula T _C =P*Z _{th_jc} +T _case ;

Among them, T _C represents the third estimated junction temperature, P represents the loss corresponding to the third estimated junction temperature, T _case represents the case temperature, and Z _{th_jc} represents the thermal resistance network parameter from the chip to the solder layer.

Optionally, the status information monitoring module specifically includes:

The chip has not occurred aging and the bonding wire has not occurred aging determining unit, configured to determine the power electronic device when the difference between the first estimated junction temperature and the second estimated junction temperature is within a set interval The status information is that the chip has not aged and the bonding wire has not aged;

A chip aging determination unit, configured to determine that the state information of the power electronic device is Chip aging;

A bonding wire aging determination unit, configured to determine the state of the power electronic device when the difference between the first estimated junction temperature and the second estimated junction temperature is smaller than the minimum value of the set interval The information is that the bonding wire has aged;

The under-chip solder layer has no aging determination unit, configured to determine the state information of the power electronic device when the difference between the second estimated junction temperature and the third estimated junction temperature is less than or equal to a set threshold The solder layer under the chip has not aged;

Aging occurrence determination unit of the solder layer under the chip, configured to determine that the state information of the power electronic device is when the difference between the second estimated junction temperature and the third estimated junction temperature is greater than the set threshold The solder layer under the chip has aged.

According to the specific embodiments provided by the invention, the invention discloses the following technical effects:

The invention discloses an on-line monitoring method and system for state information of power electronic devices. Based on the characteristics of different junction temperatures measured by different methods under different aging modes of power electronic devices, the present invention establishes an aging diagnosis model based on junction temperature, specifically according to the electric-thermal data in the actual working conditions of power electronic devices, combined with temperature-sensitive The junction temperature estimation method of electrical parameters, the junction temperature estimation method based on the device power terminal temperature, and the junction temperature estimation method based on the case temperature are respectively used to estimate the junction temperature of power electronic devices, and then compare the three estimated junction temperatures to realize real-time Accurately monitor the status information of power electronic devices online, and then realize the identification of aging types of power electronic devices, including package aging (mainly referring to the aging of the solder layer under the chip), chip aging, and bonding wire aging.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is a schematic flow chart of the online monitoring method for status information of power electronic devices of the present invention;

Fig. 2 is a flow chart for realizing the determination of the type of aging of the power electronic device of the present invention;

3 is a schematic structural diagram of an online monitoring system for status information of power electronic devices of the present invention;

Fig. 4 is a schematic diagram of the junction temperature estimation and calibration experiment platform based on temperature-sensitive electrical parameters of the present invention;

Fig. 5 is the schematic diagram of the junction temperature estimation and calibration experiment system based on temperature-sensitive electrical parameters of the present invention;

Fig. 6 is the electrical symbol schematic diagram of IGBT device of the present invention;

Fig. 7 is the structural representation of IGBT device of the present invention;

Fig. 8 is a schematic diagram of the waveform of the collector-emitter voltage v _ce and the collector current ic of the IGBT device in one switching period of the present invention; Fig. 8 (a) is a schematic diagram of the grid-emitter voltage waveform of the present invention; Fig. 8 ( _b ) is the Schematic diagram of the waveform of the collector current i _c of the invention; Figure 8 (c) is a schematic diagram of the waveform of the collector-emitter voltage v _ce of the invention;

9 is a schematic diagram of the junction temperature estimation method based on the device power terminal temperature in the present invention;

Figure 10 is a schematic diagram of the basis for judging the type of aging in the present invention; Figure 10(a) is a schematic diagram of the basis for judging the aging of the chip of the present invention; Figure 10(b) is a schematic diagram of the basis for judging the aging of the bonding wire in the present invention; Figure 10(c) is a schematic diagram of the basis for judging the aging of the chip of the present invention Schematic diagram of the basis for judging the aging of the lower solder layer;

FIG. 11 is a schematic diagram of the present invention based on the estimated junction temperature change curve of the power terminal of the power electronic device.

Symbol Description:

1. Thermostat, 2. Control board, 3. High-power DC power supply, 4. Host computer, 5. Mixed signal oscilloscope (MSO), 6. High-voltage differential probe and high-precision circuit probe, 7. Cooling fan, 8. Device under test (DUT), 9 inductive loads (8mh).

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to overcome the deficiencies of the prior art, the present invention proposes a method to characterize and judge the chip and bonding wire by using the information of the chip junction temperature T _j , the power terminal temperature T _t , and the case temperature T _case (or the relationship between the three). , The on-line monitoring method for the aging state of the solder layer under the chip has the advantages of simple implementation, novel principle, scientific and reasonable judgment of aging of power electronic devices, and high confidence. With the support of big data, hidden dangers of power electronic devices can be quickly discovered, and effective support can be provided for the extended operation of power electronic devices.

Another object of the present invention is to improve the safety and economic benefits of power electronic devices, which is a new idea in the field of aging pre-diagnosis of power electronic devices.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

In order to achieve the above invention creation purpose, the present invention adopts the following technical solutions:

Embodiment one

Please refer to Fig. 1 and Fig. 2, this embodiment provides a kind of online monitoring method for the state information of power electronic device for power electronic device (such as inverter), and described power electronic device includes chip, power terminal and solder under the chip layer; includes the following steps:

Step 101: Determine the first estimated junction temperature T _A of the power electronic device based on the junction temperature estimation method of temperature-sensitive electrical parameters; specifically:

Step 1011: Obtain the temperature-sensitive electrical parameters of the power electronic devices in the power electronic device.

Among them, various temperature-sensitive electrical parameters can be measured and obtained through calibration experiments according to the actual situation, such as: turn-on voltage drop v _ce(on) , turn-off delay time t _{d_off} , voltage rise time t _rv when turn-off, voltage when turn-on Fall time t _fv etc.

Step 1012: Estimate the first estimated junction temperature T _A of the power electronic device online according to the previously calibrated temperature-sensitive characteristic relationship between the temperature-sensitive electrical parameter and temperature and the acquired temperature-sensitive electrical parameter.

The temperature-sensitive characteristic relationship is determined according to a temperature-sensitive electrical parameter characteristic calibration experiment.

Taking IGBT as an example, the determination process of the temperature-sensitive characteristic relationship is as follows:

First select an IGBT and place the IGBT on the temperature calibration platform.

Secondly, the control variable method is used to measure the collector current _{ic signal and collector-emitter voltage v ce signal} of the IGBT in a single switching cycle under a certain current gradient and junction temperature gradient.

Then based on the collector current _{ic signal and the collector-emitter voltage v ce signal} , the experimental sample data is established by offline data processing method.

Finally, based on the experimental sample data, the temperature-sensitive electrical parameter-junction temperature mapping relationship table of power electronic devices is determined, that is, the temperature-sensitive characteristic relationship.

Step 102: Determine the second estimated junction temperature T _B of the power electronic device based on the junction temperature estimation method of the power terminal temperature of the device; specifically:

Step 1021: Obtain the thermal resistance network parameter Z _{th_jt} from the chip to the power terminal in the power electronic device by means of experimental calibration or finite element simulation calculation.

Step 1022: Online measurement and acquisition of the power terminal temperature T _t of the power electronic device.

Step 1023: Calculate the loss P _B of the power electronic device corresponding to the second estimated junction temperature.

Step 1024: Estimate the second estimated junction temperature of the power electronic device according to the thermal resistance network parameter Z _{th_jt} , the power terminal temperature T _t , the loss P _B corresponding to the second estimated junction temperature, and the electrothermal model of the power electronic device chip-power terminal T _B .

The estimation formula of the electrothermal model of the power electronic device chip-power terminal is T _B =P _B *Z _{th_jt} +T _t .

Among them, according to the power electronic device manual or the device loss model established by the calibration experiment, and the online measurement of the operating point information of the power electronic device (including DC voltage, output current, duty cycle and case temperature T _case , etc.) B. Estimate the junction temperature loss P _B .

Step 103: Determine the third estimated junction temperature T _C of the power electronic device based on the junction temperature estimation method of the case temperature; specifically:

Step 1031: Obtain the thermal resistance network parameter Z _{th_jc} from the chip to the solder layer in the power electronic device, such as the temperature of the NTC thermistor integrated at the liner of the power electronic device, through power electronic device manuals or calibration experiments.

Step 1032: Online measurement and acquisition of the case temperature T _case of the power electronic device. The case temperature T _case is the temperature of the case of the power electronic device or the copper base plate.

Step 1033: Calculate the loss P of the power electronic device corresponding to the third estimated junction temperature.

Step 1034: Based on the thermal resistance network parameter Z _{th_jc} , the case temperature T _case , the loss P corresponding to the third estimated junction temperature, and the electrothermal model of the power electronic device chip-chip solder layer, estimate the third estimated junction temperature of the power electronic device Warm T _C .

The expression T _C =P*Z _{th_jc} +T _case of the electrothermal model of the power electronic device chip-chip solder layer.

Among them, according to the power electronic device manual or the device loss model established by the calibration experiment, and the online measurement of the operating point information of the power electronic device (including DC voltage, output current, duty cycle and case temperature T _case , etc.) 3 Estimated junction temperature losses P.

Step 104: based on the first estimated junction temperature T _A , the second estimated junction temperature T _B and the third estimated junction temperature T _C , monitor the state information of the power electronic device online in real time; the state information Including the aging of the chip, the aging of the chip, the aging of the bonding wire, the aging of the bonding wire, the aging of the solder layer under the chip and the non-aging of the solder layer under the chip.

By comparing the junction temperature of power electronic devices estimated by different methods, the aging type of power electronic devices can be judged, and the characterization and status information online monitoring of power electronic device aging evolution can be realized.

The determination of the aging type of power electronic devices is realized as follows:

(1) A method for judging (or characterizing) chip aging of power electronic devices.

Two junction temperature parameters are used: the first estimated junction temperature T _A (when the chip ages, the turn-off process of power electronic devices will slow down and the loss will increase, that is, it is estimated based on the temperature-sensitive electrical parameters such as turn-off time The first estimated junction temperature T _A will be greater than the actual chip junction temperature) and the second estimated junction temperature T _B (when the chip is aging, it will hardly affect the thermal resistance network parameters from the chip to the power terminal, that is, the estimated second estimated junction temperature Temperature T _B is equal to or nearly equal to the actual chip junction temperature). Under the same operating point, when the change trend of the first estimated junction temperature T _A will gradually deviate from the change trend of the second estimated junction temperature T _B and the difference between the two △T ₁ =T _A -T _B increases, It can be determined that the chip of the power electronic device is aging.

(2) A method for judging (characterizing) the aging of bonding wires of power electronic devices.

Two junction temperature parameters are used: the first estimated junction temperature T _A (when the bond wire is aged but the chip is not aged, the first estimated junction temperature T _A is equal to or nearly equal to the actual chip junction temperature) and the second estimated junction temperature Temperature _TB (when the bonding wire is aging but the chip is not aging, the equivalent internal resistance of the bonding wire will increase and cause the heat to increase, and the second estimated junction temperature _TB will be greater than the actual chip junction temperature). Under the same operating point, when the change trend of the second temperature T _B will gradually deviate from the change trend of the first estimated junction temperature T _A and the difference between the two △T ₁ =T _A -T _B decreases, the power can be determined The bonding wires of electronic devices age.

(3) A method for judging (characterizing) the aging of the solder layer under the chip of a power electronic device.

Two junction temperature parameters are used: the second estimated junction temperature T _B (when the solder layer under the chip is aged and the chip and bonding wire are not aged, the second estimated junction temperature T _B is equal to or almost equal to the actual chip junction temperature) , and the third estimated junction temperature T _C (when the aging of the solder layer under the chip occurs, the actual thermal resistance will become larger, and the third estimated junction temperature T _C is smaller than the actual chip junction temperature). Under the same operating point, when the variation trend of the third estimated junction temperature T _C will gradually deviate from the variation trend of the second estimated junction temperature T _B and the difference between the two ΔT ₂ =T _B -T _C increases, It can be judged that the solder layer under the chip of the power electronic device is aging.

Step 104 described in this embodiment specifically includes:

When the difference between the first estimated _junction temperature _TA and the second estimated junction temperature TB is within the set interval, it is determined that the state information of the power electronic device is that the chip has not aged and the bonding wire has not occurred. Aging occurs.

When the difference between the first estimated _junction temperature _TA and the second estimated junction temperature TB is greater than the maximum value of the set interval, it is determined that the state information of the power electronic device is that the chip is aging.

When the difference between the first estimated junction temperature T _A and the second estimated junction temperature T _B is smaller than the minimum value of the set interval, it is determined that the state information of the power electronic device is a bonding wire occurrence Ageing.

When the difference between the second estimated junction temperature T _B and the third estimated junction temperature T _C is less than or equal to a set threshold, it is determined that the state information of the power electronic device is that the solder layer under the chip has not aged .

When the difference between the second estimated junction temperature TB and the third estimated junction temperature _{T C is} greater than the set threshold, it is determined that the state information of the power electronic device is that the solder layer under the chip is aging.

Compared with the existing technology, it has the following obvious outstanding substantive features and significant advantages:

1. The online monitoring method provided in this embodiment is to diagnose the aging type by the key state variable "junction temperature" of the power electronic device, which has the advantages of directness and reliability.

2. In this embodiment, the junction temperature estimation method based on temperature-sensitive electrical parameters, the junction temperature estimation method based on device power terminal temperature, and the junction temperature estimation method based on case temperature are respectively used for junction temperature monitoring. By comparing the monitored junction temperatures, Realize the determination of the aging type of power electronic devices, and then realize the diagnosis of aging degree and life estimation, improve the safety and economic benefits of power electronic devices, and provide a new idea for the online diagnosis research of power electronic device aging.

3. The online monitoring method provided in this embodiment has the advantages of simple method, novel principle, scientific and reasonable determination of device aging, and high confidence. With the support of big data, it can quickly find hidden dangers of devices and provide effective services for extending the life of power electronic devices. support.

Embodiment two

Please refer to FIG. 3. This embodiment provides an online monitoring system for status information of power electronic devices, including:

The first estimated junction temperature determining module 301 is configured to determine a first estimated junction temperature of the power electronic device based on a junction temperature estimation method based on temperature-sensitive electrical parameters; the power electronic device includes a chip, a power terminal, and a solder layer under the chip.

The second estimated junction temperature determination module 302 is configured to determine a second estimated junction temperature of the power electronic device based on a junction temperature estimation method of the device power terminal temperature.

The third estimated junction temperature determining module 303 is configured to determine a third estimated junction temperature of the power electronic device based on a junction temperature estimation method based on case temperature.

A state information monitoring module 304, configured to monitor the state information of the power electronic device online in real time based on the first estimated junction temperature, the second estimated junction temperature and the third estimated junction temperature; the state information includes The chip is aged, the chip is not aged, the bonding wire is aged, the bonding wire is not aged, the solder layer under the chip is aged, and the solder layer under the chip is not aged.

The first estimated junction temperature determination module 301 specifically includes:

The temperature-sensitive electrical parameter acquisition unit is used to acquire the temperature-sensitive electrical parameters of the power electronic device.

Among them, the temperature-sensitive electrical parameters are obtained by measuring the DC voltage of the busbar of the power electronic device and the current sensor of the power electronic device (such as an inverter) and its peripheral circuits.

The first estimated junction temperature determination unit is configured to estimate online the first estimated junction temperature of the power electronic device according to the temperature-sensitive characteristic relationship and the temperature-sensitive electrical parameter; the temperature-sensitive characteristic relationship is the temperature-sensitive electrical parameter Mapping relationship with junction temperature.

The second estimated junction temperature determination module 302 specifically includes:

The thermal resistance network parameter acquisition unit is configured to acquire the thermal resistance network parameters from the chip to the power terminal in the power electronic device.

The power terminal temperature acquisition unit is configured to acquire the power terminal temperature of the power electronic device collected by the power terminal temperature sensor.

A loss calculation unit corresponding to the second estimated junction temperature, configured to calculate the loss corresponding to the second estimated junction temperature of the power electronic device; the loss corresponding to the second estimated junction temperature is determined according to the operating point information of the power electronic device and the power electronic device is mounted on the power electronic device.

The second estimated junction temperature determining unit is configured to determine the second estimated junction temperature of the power electronic device according to the formula T _B =P _B *Z _{th_jt} + T _t .

Wherein, T _B represents the second estimated junction temperature, P _B represents the loss corresponding to the second estimated junction temperature, T _t represents the power terminal temperature, and Z _{th_jt} represents the thermal resistance network parameter from the chip to the power terminal.

The third estimated junction temperature determination module 303 specifically includes:

The thermal resistance network parameter acquisition unit is configured to acquire the thermal resistance network parameters from the chip to the solder layer in the power electronic device.

The shell temperature acquisition module is used to acquire the shell temperature of the power electronic device collected by the shell temperature sensor; the shell temperature is the temperature of the shell or the copper base plate of the power electronic device.

A loss calculation unit corresponding to the third estimated junction temperature, configured to calculate the loss corresponding to the third estimated junction temperature of the power electronic device; the loss corresponding to the third estimated junction temperature is determined according to the operating point information of the power electronic device and the power electronic device is mounted on the power electronic device.

The third estimated junction temperature determining unit is configured to determine the third estimated junction temperature of the power electronic device according to the formula T _C =P*Z _{th_jc} +T _case .

Among them, T _C represents the third estimated junction temperature, P represents the loss corresponding to the third estimated junction temperature, T _case represents the case temperature, and Z _{th_jc} represents the thermal resistance network parameter from the chip to the solder layer.

The status information monitoring module 304 specifically includes:

The chip has not occurred aging and the bonding wire has not occurred aging determining unit, configured to determine the power electronic device when the difference between the first estimated junction temperature and the second estimated junction temperature is within a set interval The status information is that the chip has not aged and the bonding wire has not aged.

A chip aging determination unit, configured to determine that the state information of the power electronic device is The chip is aging.

A bonding wire aging determination unit, configured to determine the state of the power electronic device when the difference between the first estimated junction temperature and the second estimated junction temperature is smaller than the minimum value of the set interval The message is that the bond wire has aged.

The under-chip solder layer has no aging determination unit, configured to determine the state information of the power electronic device when the difference between the second estimated junction temperature and the third estimated junction temperature is less than or equal to a set threshold The solder layer under the chip has not aged.

Aging occurrence determination unit of the solder layer under the chip, configured to determine that the state information of the power electronic device is when the difference between the second estimated junction temperature and the third estimated junction temperature is greater than the set threshold The solder layer under the chip has aged.

Embodiment three

This embodiment provides an online monitoring method for IGBT device state information used in inverters, and the state of the IGBT device is determined by comparing the junction temperature of the IGBT device collected by the three junction temperature estimation methods.

Fig. 6 is a schematic diagram of electrical symbols of the IGBT device, C is the collector of the IGBT device, E is the emitter of the IGBT device, and G is the gate of the IGBT device.

Please refer to Fig. 7, the IGBT device described in this embodiment includes: a chip, an anti-parallel diode chip, a bonding wire, a solder layer under the chip, a copper layer on the DBC, a DBC ceramic substrate, a copper layer under the DBC, a solder layer under the DBC, Copper base plate and power terminals.

Among them, the chip is connected to the bonding wire, the bonding wire is connected to the anti-parallel diode chip, the bonding wire is connected to the copper layer on the DBC, the copper layer on the DBC is connected to the power terminal, the chip is connected to the solder layer under the chip, and the anti-parallel diode chip is connected. Connected to the solder layer under the chip, the solder layer under the chip is connected to the upper copper layer of DBC, the upper copper layer of DBC is connected to the DBC ceramic substrate, the DBC ceramic substrate is connected to the lower copper layer of DBC, the lower copper layer of DBC is connected to the lower solder layer of DBC, and the DBC The lower solder layer is connected to the copper baseplate.

At the same time, the upper copper layer of the DCB is divided into three lines, which are respectively connected to the three output terminals C\E\G of the IGBT device, and the three upper copper layers are not connected to each other (no electrical connection).

The online monitoring method for IGBT device status information of an inverter described in this embodiment includes: firstly collect the power terminal temperature T _t of the IGBT device, the case temperature T _case of the IGBT device, and the collector-emitter voltage V of the IGBT device _ce , the inverter DC bus voltage U _d and the inverter output current signal i; then use the junction temperature estimation method based on temperature-sensitive electrical parameters, the junction temperature estimation method based on device power terminal temperature and the junction temperature estimation method based on case temperature The junction temperature of the IGBT device is estimated by the method respectively, and finally the aging type of the IGBT device is judged by comparing the three estimated junction temperatures with each other, so as to realize the online monitoring of the characterization and status information of the IGBT device aging evolution.

Among them, the junction temperature monitoring method of IGBT devices includes:

(1) Junction temperature estimation method based on temperature-sensitive electrical parameters: collect the collector-emitter voltage V _ce of the IGBT device and the inverter output current signal i online, and select the voltage rise time t _rv when the IGBT device is turned off as the temperature-sensitive electrical parameter , and estimate the first estimated junction temperature T _A of the IGBT device according to the previously calibrated temperature-sensitive characteristic relationship between the temperature-sensitive electric parameter and temperature.

The temperature-sensitive characteristic calibration test is realized on the temperature calibration platform shown in Figure 4 (the schematic diagram is shown in Figure 5), using a single-phase inverter circuit for double-pulse testing, and selecting Infineon's IGBT device (model: FF50R12RT4) for testing. During the experiment, start after heating the chips on both sides of the device under test 8 (i.e., the IGBT device). Change the pulse width of the first pulse to realize the adjustable collector current of 10A, 15A, 20A, 25A, 30A, 35A, and 40A at the turn-off time, and test the IGBT devices at 30°C, 60°C, 90°C, and 120°C in a single Collector-emitter voltage V _ce , collector current ic within a switching cycle, and record experimental data (i.e. collector-emitter voltage V _ce , collector current _{ic )} , collector-emitter voltage V _ce , collector current _ic within a single switching cycle The waveform is shown in Figure 8.

(2) Junction temperature estimation method based on device power terminal temperature: First, obtain the thermal resistance network parameter Z _{th_jt} from the chip to the power terminal in the IGBT device by means of experimental calibration or simulation calculation, and then measure the power terminal temperature T of the IGBT device online _t and the loss P _B corresponding to the second estimated junction temperature, and finally estimate the second estimated junction temperature T _B of the IGBT device according to the IGBT device electrothermal model T _B =P _B *Z _{th_jt} + T _t .

The schematic diagram of the junction temperature estimation method based on the device power terminal temperature is shown in FIG. 9 . The power electronic device is used as the tested component and installed inside the power electronic device; the power terminal of the power electronic device is connected to an external load or power supply through a terminal block. The infrared temperature sensor is installed near the power electronic device (distance between 1mm and 100m), the temperature measurement point is the power terminal of the power electronic device, and the measured temperature T _t of the power terminal of the power electronic device is sent to the electrothermal model of the power electronic device in the MCU unit to calculate the second estimated junction temperature T _B online. The results show that the power terminal of the power electronic device is located outside the power electronic device, which is convenient for online temperature measurement, and the heat capacity from the power terminal to the chip is small, that is, the temperature of the power terminal can be used to accurately measure the internal chip junction temperature of the power electronic device in time, and it is not affected by the power electronic device. The influence of fatigue on the solder layer under the device chip can be combined with the thermal resistance network method and the temperature-sensitive electrical parameter method to establish a joint model to finally determine the aging state of the IGBT device.

(3) Junction temperature estimation method based on case temperature: first obtain the thermal resistance network parameter Z _{th_jc} from the IGBT device chip to the device case through IGBT device manuals or calibration experiments, and then measure the case temperature (T _case ) of the IGBT device online and the loss P corresponding to the third estimated junction temperature, and finally estimate the third estimated junction temperature T _C according to the IGBT device electrothermal model T _C =P*Z _{th_jc} +T _case .

Among them, the loss P corresponding to the third estimated junction temperature is calculated according to the device loss model provided in the IGBT device manual and the inverter operating point information (including DC voltage, output current, duty cycle and case temperature T _case ) measured online owned.

According to the schematic diagram of the basis for determining the type of aging shown in Figure 10, it can be found that the actual junction temperature and the measured temperature inside the power electronic device are affected by the aging state and degree of aging, but the first estimated junction temperature T _A and the second estimated junction temperature can be estimated by comparing _The junction temperature TB , the second estimated junction temperature TB and the third estimated junction temperature _{T C are} used to judge the aging state of the power electronic device. When the value of △T ₁ = _{TA -TB} becomes larger, it indicates that the chip of the power electronic device is aging; when the value of △T ₁ = _{TA -TB} becomes smaller, it indicates that the bonding wire of the power electronic device is aging; when When the value of ΔT ₂ =T _B -T _C becomes larger, it indicates that the solder layer under the chip of the power electronic device is aging.

In this embodiment, according to the electrical data of the IGBT device in the actual working condition, the junction temperature estimation method based on the temperature-sensitive electrical parameters, the junction temperature estimation method based on the device power terminal temperature, and the junction temperature estimation method based on the case temperature are used to perform the IGBT device respectively. Junction temperature estimation, through the comparison of three estimated junction temperatures, the judgment of the aging type of the IGBT device is realized.

For example: The temperature of the IGBT device in a 380V/7.5kW three-phase inverter was experimentally measured. During the experiment, the inverter drives a 380V/3kW permanent magnet synchronous motor for rated operation, and an infrared thermal imager is used to measure the temperature of the power terminal and the chip of the IGBT device online simultaneously. In order to facilitate the infrared thermal imager to measure the chip temperature of the IGBT device, the shell of the IGBT device in phase A of the inverter is removed, so that the internal chip is exposed to the measurement range of the infrared thermal imager.

The experimentally measured temperature variation curves of the IGBT device at different positions are shown in FIG. 11 . _The junction temperature TB estimated in Fig. 10 is determined by using the method provided by the present invention. The experimental results show that the temperature of the IGBT device at different positions increases gradually with the increase of the inverter running time. The junction temperature estimated by the present invention is basically consistent with the junction temperature measured by the infrared thermal imager.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.

In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in specific implementation methods and application ranges. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A method for on-line monitoring state information of a power electronic device is characterized by comprising the following steps:

determining a first estimated junction temperature of the power electronic device based on a junction temperature estimation method of the temperature-sensitive electrical parameter; the power electronic device comprises a chip, a power terminal and a chip lower solder layer;

determining a second estimated junction temperature of the power electronic device based on a junction temperature estimation method of the device power terminal temperature;

determining a third estimated junction temperature of the power electronic device based on a shell temperature junction temperature estimation method;

monitoring state information of the power electronic device in real time on line based on the first estimated junction temperature, the second estimated junction temperature and the third estimated junction temperature; the state information comprises chip aging, chip non-aging, bonding wire non-aging, chip lower solder layer aging and chip lower solder layer non-aging.

2. The method for on-line monitoring of state information of a power electronic device according to claim 1, wherein the determining of the first estimated junction temperature of the power electronic device by the junction temperature estimation method based on the temperature-sensitive electrical parameter specifically comprises:

acquiring temperature-sensitive electrical parameters of the power electronic device;

estimating a first estimated junction temperature of the power electronic device on line according to the temperature-sensitive characteristic relation and the temperature-sensitive electrical parameter; the temperature-sensitive characteristic relation is a mapping relation between the temperature-sensitive electrical parameter and the junction temperature.

3. The method for on-line monitoring of state information of a power electronic device according to claim 1, wherein the determining of the second estimated junction temperature of the power electronic device by the junction temperature estimation method based on the device power terminal temperature specifically comprises:

acquiring thermal resistance network parameters from a chip to a power terminal in the power electronic device;

acquiring the temperature of a power terminal of the power electronic device;

calculating a loss of the power electronics corresponding to a second estimated junction temperature; the loss corresponding to the second estimated junction temperature is determined from operating point information of the power electronic device; the power electronics are mounted on the power electronics device;

according to the formula T _B ＝P _B *Z _{th_jt} +T _t Determining a second estimated junction temperature of the power electronics;

wherein, T _B Representing the second estimated junction temperature, P _B Representing the loss, T, corresponding to the second estimated junction temperature _t Indicating power terminal temperature, Z _{th_jt} Representing the thermal resistance network parameters from chip to power terminal.

4. The method for online monitoring of state information of a power electronic device according to claim 1, wherein the determining of the third estimated junction temperature of the power electronic device by the case temperature-based junction temperature estimation method specifically includes:

acquiring thermal resistance network parameters from a chip to a solder layer in the power electronic device;

acquiring the shell temperature of the power electronic device; the shell temperature is the temperature of the shell of the power electronic device or the copper bottom plate;

calculating a loss of the power electronic device corresponding to a third estimated junction temperature; the loss corresponding to the third estimated junction temperature is determined from operating point information of the power electronic device; the power electronics are mounted on the power electronics device;

according to the formula T _C ＝P*Z _{th_jc} +T _case Determining a third estimated junction temperature of the power electronics;

wherein, T _C Representing a third estimated junction temperature, P representing a loss corresponding to the third estimated junction temperature, T _case Indicates the shell temperature, Z _{th_jc} Representing the thermal resistance network parameter from chip to solder layer.

5. The on-line monitoring method for state information of a power electronic device according to claim 1, wherein the real-time on-line monitoring of the state information of the power electronic device based on the first estimated junction temperature, the second estimated junction temperature, and the third estimated junction temperature specifically comprises:

when the difference value between the first estimated junction temperature and the second estimated junction temperature is in a set interval, determining the state information of the power electronic device as that the chip is not aged and the bonding wire is not aged;

when the difference value between the first estimated junction temperature and the second estimated junction temperature is larger than the maximum value of the set interval, determining the state information of the power electronic device as that the chip is aged;

when the difference value between the first estimated junction temperature and the second estimated junction temperature is smaller than the minimum value of the set interval, determining the state information of the power electronic device as that the bonding wire is aged;

when the difference value between the second estimated junction temperature and the third estimated junction temperature is smaller than or equal to a set threshold value, determining that the state information of the power electronic device is that the solder layer under the chip is not aged;

and when the difference value between the second estimated junction temperature and the third estimated junction temperature is larger than the set threshold value, determining the state information of the power electronic device as the aging of a solder layer under the chip.

6. An on-line monitoring system for status information of power electronic devices, comprising:

the first estimated junction temperature determination module is used for determining a first estimated junction temperature of the power electronic device based on a junction temperature estimation method of the temperature-sensitive electrical parameter; the power electronic device comprises a chip, a power terminal and a chip lower solder layer;

the second estimated junction temperature determining module is used for determining a second estimated junction temperature of the power electronic device based on a junction temperature estimation method of the device power terminal temperature;

a third estimated junction temperature determination module, configured to determine a third estimated junction temperature of the power electronic device based on a junction temperature estimation method of the case temperature;

a state information monitoring module, configured to monitor state information of the power electronic device in real time on line based on the first estimated junction temperature, the second estimated junction temperature, and the third estimated junction temperature; the state information comprises chip aging, chip non-aging, bonding wire non-aging, chip lower solder layer aging and chip lower solder layer non-aging.

7. The system for online monitoring of state information of power electronic devices according to claim 6, wherein the first estimated junction temperature determining module specifically includes:

the temperature-sensitive electrical parameter acquisition unit is used for acquiring temperature-sensitive electrical parameters of the power electronic device;

the first estimated junction temperature determining unit is used for estimating a first estimated junction temperature of the power electronic device on line according to the temperature-sensitive characteristic relation and the temperature-sensitive electrical parameter; the temperature-sensitive characteristic relation is a mapping relation between the temperature-sensitive electrical parameter and the junction temperature.

8. The system for on-line monitoring of state information of a power electronic device according to claim 6, wherein the second estimated junction temperature determining module specifically includes:

the thermal resistance network parameter acquisition unit is used for acquiring thermal resistance network parameters from a chip to a power terminal in the power electronic device;

a power terminal temperature acquisition unit for acquiring a power terminal temperature of the power electronic device;

a loss calculation unit corresponding to a second estimated junction temperature, configured to calculate a loss of the power electronic device corresponding to the second estimated junction temperature; the loss corresponding to the second estimated junction temperature is determined from operating point information of the power electronics device; the power electronics are mounted on the power electronics device;

a second estimated junction temperature determination unit for determining a junction temperature according to the formula T _B ＝P _B *Z _{th_jt} +T _t Determining a second estimated junction temperature of the power electronics;

wherein, T _B Representing a second estimated junction temperature, P _B Representing the loss, T, corresponding to the second estimated junction temperature _t Indicating power terminal temperature, Z _{th_jt} Representing the thermal resistance network parameters from chip to power terminal.

9. The system for online monitoring of state information of power electronic devices according to claim 6, wherein the third estimated junction temperature determining module specifically includes:

the thermal resistance network parameter acquisition unit is used for acquiring thermal resistance network parameters from a chip to a solder layer in the power electronic device;

the shell temperature acquisition module is used for acquiring the shell temperature of the power electronic device; the shell temperature is the temperature of the shell of the power electronic device or the copper bottom plate;

a loss calculation unit corresponding to a third estimated junction temperature, configured to calculate a loss of the power electronic device corresponding to the third estimated junction temperature; the loss corresponding to the third estimated junction temperature is determined from operating point information of the power electronic device; the power electronics are mounted on the power electronics device;

a third estimated junction temperature determination unit for determining a junction temperature according to the formula T _C ＝P*Z _{th_jc} +T _case Determining a third estimated junction temperature of the power electronics;

wherein, T _C Representing a third estimated junction temperature, P representing a loss corresponding to the third estimated junction temperature, T _case Indicates the shell temperature, Z _{th_jc} Representing the thermal resistance network parameter from chip to solder layer.

10. The system for on-line monitoring of status information of power electronic devices according to claim 6, wherein the status information monitoring module specifically comprises:

a chip non-aging and bonding wire non-aging determining unit, configured to determine, when a difference between the first estimated junction temperature and the second estimated junction temperature is within a set interval, that the state information of the power electronic device is chip non-aging and bonding wire non-aging;

a chip aging occurrence determination unit, configured to determine that the state information of the power electronic device is chip aging occurrence when a difference between the first estimated junction temperature and the second estimated junction temperature is greater than a maximum value of the set interval;

a bonding wire aging determining unit, configured to determine that the state information of the power electronic device is the aging of the bonding wire when a difference between the first estimated junction temperature and the second estimated junction temperature is smaller than a minimum value of the set interval;

a unit for determining that the solder layer under the chip is not aged, the unit being configured to determine that the state information of the power electronic device is that the solder layer under the chip is not aged when a difference between the second estimated junction temperature and the third estimated junction temperature is less than or equal to a set threshold;

and the under-chip solder layer aging determining unit is used for determining that the state information of the power electronic device is the under-chip solder layer aging when the difference value between the second estimated junction temperature and the third estimated junction temperature is greater than the set threshold value.

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