IGBT module power cycle-vibration experiment thermal resistance online testing device and method

Abstract

The present invention provides an IGBT module power cycle-vibration experiment thermal resistance online testing device and method, including an automotive-grade IGBT module, a power cycle circuit system, a vibration test bench, a special fixture for the IGBT module, a constant temperature water cooling and heat dissipation system, an IGBT gate control system, a data acquisition system, and a data analysis system. The special fixture for the IGBT module fixes the automotive-grade IGBT module on the vibration test bench, the power cycle circuit system provides current for multiple serially connected automotive-grade IGBT modules, the vibration test bench provides different excitations to the automotive-grade IGBT module to be tested, the IGBT gate control system controls the on and off of the automotive-grade IGBT module, the data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module in real time, and the data analysis system processes and analyzes the collected data based on the structure function method to obtain the junction temperature and thermal resistance data of the automotive-grade IGBT module in the power cycle-vibration comprehensive experiment. The present invention realizes real-time monitoring of thermal resistance changes and understands the thermal characteristics of automotive-grade IGBT modules.

Description

Technical Field

[0001] The invention relates to an online thermal resistance testing device and method for an IGBT module power cycle-vibration experiment, belonging to the field of thermal resistance testing devices and methods, in particular to a thermal resistance test of an automotive-grade IGBT module under a power cycle-vibration comprehensive condition experiment, to achieve online monitoring and evaluation of thermal resistance. Background Art

[0002] Insulated gate bipolar transistor (IGBT) is one of the most advanced power electronic devices that can realize the conversion and control of electric energy at the same time. It is the core device of energy conversion and transmission. Due to its high input impedance, low output impedance, relatively easy to drive and fast switching speed, it is increasingly used as the core component of the motor drive of new energy vehicles.

[0003] Compared with general IGBT modules, the service environment of automotive-grade IGBT modules is more severe, and they often have to withstand severe temperature and mechanical load tests. This requires that automotive-grade IGBT modules can achieve reliable operation under the cyclic impact of different loads. The power cycle-vibration comprehensive condition experiment takes into account the life of automotive-grade IGBT modules under both power cycle and vibration experimental conditions, providing guidance for solving reliability problems. In the problem of automotive-grade IGBT module reliability, the chip junction temperature continues to rise, and the problem of module failure caused by temperature is becoming more and more prominent. Therefore, it is very important to study the thermal characteristic parameters of automotive-grade IGBT modules. For high-power automotive-grade IGBT modules, thermal resistance is an important thermal characteristic parameter. At present, the thermal resistance cannot be monitored and evaluated online in real time during the automotive-grade IGBT module experiment. It is necessary to conduct a separate thermal resistance test experiment, which greatly increases the time cost of the experiment, and cannot monitor and evaluate the thermal resistance degradation process in a timely and accurate manner. Therefore, it is necessary to propose an IGBT module power cycle-vibration experiment thermal resistance online testing device and method under the power cycle-vibration comprehensive experimental conditions, which can realize real-time testing and online monitoring and evaluation of the thermal resistance of the automotive-grade IGBT module during the power cycle-vibration process. Summary of the invention

[0004] In view of the problems mentioned in the above background technology, the present invention provides an IGBT module power cycle-vibration test thermal resistance online testing device and method. The method can meet the two experimental conditions of power cycle and vibration, and can realize online monitoring and evaluation of the thermal resistance of the automotive-grade IGBT module to be tested, which not only improves the experimental efficiency, but also can timely understand the thermal resistance degradation process of the automotive-grade IGBT module and accurately evaluate the thermal characteristics of the automotive-grade IGBT module.

[0005] The invention provides an IGBT module power cycle-vibration experiment thermal resistance online testing device, which comprises: an automotive-grade IGBT module, a special fixture for the IGBT module, a vibration test bench, a power cycle circuit system, an IGBT grid control system, a constant temperature water cooling and heat dissipation system, a data acquisition system, and a data analysis system; the special fixture for the IGBT module, the power cycle circuit system, the IGBT grid control system, the vibration test bench, the constant temperature water cooling and heat dissipation system, and the data acquisition system are respectively connected to the automotive-grade IGBT module, and the data acquisition system is also connected to the data analysis system.

[0006] The automotive-grade IGBT module comprises three automotive-grade IGBT modules of the same model, namely, a first automotive-grade IGBT module, a second automotive-grade IGBT module and a third automotive-grade IGBT module. The first automotive-grade IGBT module is used as a switch of a power circulation circuit system, and the second automotive-grade IGBT module and the third automotive-grade IGBT module are automotive-grade IGBT modules to be tested and fixed on a vibration test bench by a special fixture.

[0007] The IGBT module-specific fixture is mainly composed of three parts, namely, a solenoid valve, a fixture body, and a fixture cover. The fixture cover includes an aluminum cover and a copper sheet, and the fixture body includes a fixture base and a cooling cavity. The solenoid valve is connected to the cooling cavity of the fixture, and the two solenoid valves are symmetrically distributed with the two cooling cavities, which are mainly used to control the flow direction and speed of the cooling water, and keep the cooling water at a constant temperature under the control of the constant temperature water cooling system. The fixture base is connected to the cooling cavity and is located at the bottom of the fixture. It can adapt to the positioning of different vibration test benches and is fixed to the vibration test bench so that the automotive-grade IGBT module to be tested can be subjected to vibration experiments according to the excitation of the vibration test bench. The fixture cover adopts a die-cast copper-type aluminum heat sink, and the aluminum cover and the copper sheet are die-cast together and connected to the upper end of the cooling cavity, and the two copper sheets are symmetrically distributed above the two cooling cavities, which not only utilizes the rapid heat absorption of copper to absorb the heat of the automotive-grade IGBT module, but also utilizes the rapid heat release of aluminum to release the heat on the copper block. When using the IGBT module special fixture, first select the appropriate through hole on the fixture base to fix the fixture to the vibration test bench with bolts, then fix the automotive-grade IGBT module to be tested to the fixture cover with bolts, and finally connect the solenoid valve and connect it to the water cooling system. During the experiment, the IGBT module special fixture can make the experimental module vibrate with the vibration test bench to achieve the required vibration conditions, and can also connect the module to the circuit for power cycle experiments, and can also achieve the effect of constant temperature water cooling by controlling the flow rate of cooling water.

[0008] The vibration test bench provides vibration excitation for the automotive-grade IGBT module to be tested through a special fixture for the IGBT module fixed to the vibration test bench. During the experiment, the vibration test bench can realize excitation signals such as random vibration and sinusoidal vibration, and can adjust parameters such as acceleration, amplitude and vibration frequency. Different vibration parameters are adjusted to meet the vibration conditions of the automotive-grade IGBT module.

[0009] The power circulation circuit system includes a main circuit and a test circuit;

[0010] The main circuit includes a first power supply, a first resistor and a first automotive-grade IGBT module, a second automotive-grade IGBT module and a third automotive-grade IGBT module to form a power circulation circuit system. The first resistor and the first automotive-grade IGBT module, the second automotive-grade IGBT module and the third automotive-grade IGBT module are connected in series at both ends of the first power supply. The first power supply can provide currents of different sizes to the power circulation circuit system as the load current of the automotive-grade IGBT module to be tested according to the needs of the power circulation conditions. The first automotive-grade IGBT module acts as a switch in the power circulation circuit system to control the conduction and disconnection of the large current in the power circulation circuit system. When the collector-emitter of the first automotive-grade IGBT module is turned on, the power circulation circuit system is turned on; when the collector-emitter of the first automotive-grade IGBT module is turned off, the power circulation circuit system is turned off.

[0011] The test circuit includes a second power supply, a second resistor, a diode, a second automotive-grade IGBT module, and a third automotive-grade IGBT module; wherein the second resistor, the diode, the second automotive-grade IGBT module, and the third automotive-grade IGBT module are connected in series at both ends of the second power supply. The second power supply provides a test current of 10 mA for the automotive-grade IGBT module to be tested. The test current is very small compared to the current of the power cycle circuit system of the power cycle experiment, and the effect of the test current on the junction temperature change of the automotive-grade IGBT module can be ignored. The diode ensures that the test current is in a disconnected state when the power cycle circuit system is turned on. At the moment when the power cycle circuit system is turned off, the test circuit is turned on to provide a test current to the automotive-grade IGBT module to be tested. The collector-emitter ends of the second automotive-grade IGBT module and the third automotive-grade IGBT module to be tested are respectively connected to the data acquisition system.

[0012] The IGBT gate control system uses the pulse signal released by the single-chip microcomputer to control the on and off of the switch module of the first automotive-grade IGBT module. When the pulse signal is at a high level, the gate-emitter of the first automotive-grade IGBT module is connected to a 15V voltage, and the collector-emitter of the first automotive-grade IGBT module is turned on; when the pulse signal is at a low level, the gate-emitter is connected to a 0V voltage, and the collector-emitter of the first automotive-grade IGBT module is turned off. A 15V constant voltage source is used to provide a 15V voltage to the gate-emitter of the second automotive-grade IGBT module and the third automotive-grade IGBT module, so that the collector-emitter of the second automotive-grade IGBT module and the third automotive-grade IGBT module are always kept in a conducting state.

[0013] The constant temperature water cooling system adjusts the temperature of the cooling water and the switch of the solenoid valve according to the conditions of the power cycle-vibration experiment to independently heat each automotive-grade IGBT module at a constant temperature. When the collector-emitter of the first automotive-grade IGBT module is turned on, the solenoid valve is closed, the automotive-grade IGBT module stops cooling, and the junction temperature of the second automotive-grade IGBT module and the third automotive-grade IGBT module rises rapidly. When the first automotive-grade IGBT module is turned off, the solenoid valve is opened to heat each automotive-grade IGBT module, so that the junction temperature of the second automotive-grade IGBT module and the third automotive-grade IGBT module is quickly reduced.

[0014] The data acquisition system collects the voltage across the collector and emitter of the automotive-grade IGBT module to be tested, the current of the test circuit, and the shell temperature of the automotive-grade IGBT module. The frequency of voltage signal acquisition reaches 1×10 6 The voltage across the collector and emitter of the automotive-grade IGBT module to be tested and the current in the test circuit are collected and displayed in the Labview software program for real-time monitoring, and the collected data are transmitted to the data analysis system. The collected collector-emitter voltage of the automotive-grade IGBT module to be tested is divided into two cases. One is the collector-emitter voltage of the automotive-grade IGBT module to be tested during the power cycle-vibration comprehensive test, and the other is the collector-emitter voltage when the power cycle circuit system is turned off when measuring the thermal resistance of the automotive-grade IGBT module.

[0015] The data analysis system analyzes and calculates the junction temperature and thermal resistance of the automotive-grade IGBT module to be tested.

[0016] The K coefficient method is used to calculate the junction temperature change of the automotive-grade IGBT module to be tested during the power cycle-vibration comprehensive experiment and the change of the junction temperature during the thermal resistance test. It is known that the functional relationship between the collector-emitter voltage and the junction temperature of the automotive-grade IGBT module to be tested is obtained under the test circuit current. The collector-emitter voltage of the automotive-grade IGBT module to be tested is obtained through the data acquisition system, and the junction temperature of the automotive-grade IGBT module to be tested is calculated and displayed in real time in the Labview software program to achieve online monitoring.

[0017] Based on the structure function method, the thermal resistance of the automotive-grade IGBT module to be tested is measured. The process of the structure function is to obtain the thermal transient thermal impedance curve, process the noise signal, perform logarithmic time derivation on the transient thermal impedance curve, deconvolve the derivative value with the weight function to obtain the time constant spectrum, convert the Foster thermal network model into the Cauer thermal network model, and finally obtain the structure function. Among them, the thermal impedance curve is obtained by the data acquisition system after the junction temperature of the automotive-grade IGBT module to be tested rises to a stable state, and the voltage across the collector and emitter at the moment when the main circuit system is turned off is obtained to obtain the cooling curve. The cooling curve, the collected current of the test circuit to be tested, the heat dissipation temperature of the constant temperature water cooling heat dissipation, and the K curve are combined to analyze and calculate the thermal impedance curve of the automotive-grade IGBT module to be tested. The MATLAB software is used to perform numerical derivation of the thermal impedance curve and other subsequent calculation processes, and finally the thermal resistance and heat capacity parameters of each material layer of the automotive-grade IGBT module to be tested are obtained through the obtained structure function.

[0018] The present invention provides an online thermal resistance test method under the power cycle-vibration comprehensive condition experiment of an automotive-grade IGBT module, and its main implementation steps include: connecting an automotive-grade IGBT module, turning on the IGBT gate control system, turning on the test circuit, turning on the data acquisition system, checking whether the collector-emitter voltage of the automotive-grade IGBT module under the collected test circuit meets the experimental requirements, and if not, performing a correction check until the experimental requirements are met, and combining the initial module junction temperature calculated by the K curve. Turn on the vibration test bench debugging parameters, then turn on the constant temperature water cooling and heat dissipation system, turn on the power cycle circuit system, turn on the data analysis system to perform a power cycle-vibration comprehensive experiment, the data acquisition system monitors the collector-emitter voltage of the automotive-grade IGBT module to be tested under the current of the power cycle circuit system in real time, and the data analysis system calculates and monitors the junction temperature of the automotive-grade IGBT module to be tested in real time. After a certain number of power cycles, the thermal resistance of the automotive-grade IGBT module to be tested is measured and calculated by the data analysis system, and recorded and saved.

[0019] The specific steps are:

[0020] First, the automotive-grade IGBT module is in a preset state by turning on the IGBT gate control system, and then the automotive-grade IGBT module is powered by the test circuit. The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module in real time to detect whether it is within the allowable error required by the experiment. If the collector-emitter voltage of the automotive-grade IGBT module is abnormal, check whether the module is damaged. If the collector-emitter voltage of the module is normal, start measuring the initial junction temperature and initial thermal resistance.

[0021] The IGBT gate control system controls the collector-emitter of the first automotive-grade IGBT module to be in the on state, the power circulation circuit system is turned on, and the junction temperature of the automotive-grade IGBT module begins to rise. When the junction temperature reaches stability through the data analysis system, the power circulation circuit system is turned off. At this time, the current of the test circuit supplies power to the automotive-grade IGBT module to be tested. The current of the test circuit hardly generates heat in the automotive-grade IGBT module to be tested, and its influence on the junction temperature of the automotive-grade IGBT module can be ignored. The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module after the power circulation circuit system is turned off, and stores the collected data. The data analysis system is used to combine the collected voltage with the K curve to obtain the junction temperature change, and the transient thermal impedance curve of the automotive-grade IGBT module to be tested is obtained by combining the definition of thermal resistance. The transient thermal impedance curve is numerically derived, deconvolved and other mathematical transformations, as well as the conversion of the thermal network model to obtain the structure function of the automotive-grade IGBT module to be tested. Through the structure function, the thermal resistance of each material layer inside the module and the contact surface of the material layer can be understood, and the thermal resistance data can be saved. The thermal resistance recorded at this time is the initial thermal resistance of the automotive-grade IGBT module.

[0022] Debug the vibration test bench to the preset parameters, turn on the vibration test bench, then set the IGBT gate control system to the conditions required for the power cycle-vibration comprehensive experiment, turn on the power cycle circuit system, obtain the initial junction temperature of the automotive-grade IGBT module to be tested through the data analysis system, and record and save it, and then conduct subsequent power cycle-vibration comprehensive experiments. The automotive-grade IGBT module power cycle-vibration comprehensive experiment needs to be stopped for a period of time after each certain number of cycles. When each power cycle experiment reaches the expected number of times, stop the vibration test bench, set the switch automotive-grade IGBT module gate to normally open, and after a period of time, monitor the junction temperature through the data acquisition system to reach stability and immediately turn off the power cycle circuit system, repeat the initial thermal resistance test process to obtain the thermal resistance of the automotive-grade IGBT module after the power cycle-vibration comprehensive experiment, and record and save it.

[0023] When the collector-emitter voltage change of the automotive-grade IGBT module obtained by online monitoring of the data acquisition system meets the failure criterion of the automotive-grade IGBT module, the power cycle-vibration comprehensive experiment is stopped, the thermal resistance of the automotive-grade IGBT module is measured at this time, and the power cycle circuit system, vibration test bench, IGBT gate control system, and constant temperature water cooling system are turned off. The thermal resistance of the automotive-grade IGBT module measured at multiple shutdown times of the power cycle circuit system during the power cycle-vibration comprehensive experiment of the automotive-grade IGBT module is compared with the initial thermal resistance of the automotive-grade IGBT module to obtain the thermal resistance degradation process of the automotive-grade IGBT module during the power cycle-vibration comprehensive experiment.

[0024] The device of the present invention combines the two experimental conditions of power cycling and vibration, and obtains the transient thermal signal of the automotive-grade IGBT module to be tested by using the voltage across the collector and emitter of the automotive-grade IGBT module to be tested at the moment when the power cycling circuit system is turned off, and obtains the thermal resistance result based on the structure function method, so as to monitor and evaluate the thermal resistance degradation process of the automotive-grade IGBT module in time.

[0025] The present invention can realize real-time monitoring of thermal resistance changes, improve work efficiency, and clearly understand the thermal characteristics of automotive-grade IGBT modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an implementation structure diagram provided by the present invention;

[0027] Figure 2 is a circuit diagram of a power circulation device provided by the present invention;

[0028] Figure 3 It is a general schematic diagram of the special fixture for IGBT module provided by the present invention;

[0029] Figure 4 It is a schematic diagram of the main body of the special clamp for IGBT module provided by the present invention;

[0030] Figure 5 This is a flow chart of the online test of thermal resistance of IGBT module in the power cycle-vibration comprehensive experiment provided by the present invention;

[0031] Figure 6 It is a diagram of the gate voltage signal of the automotive-grade IGBT module provided by the present invention;

[0032] Figure 7 It is a thermal transient response curve diagram provided by the present invention. DETAILED DESCRIPTION

[0033] The specific implementation steps of the present invention are described in detail below in conjunction with the accompanying drawings.

[0034] The present invention provides an IGBT module power cycle-vibration experiment thermal resistance online testing device, such as Figure 1 As shown, the test device includes: an automotive-grade IGBT module, a special fixture for the IGBT module, a vibration test bench, a power circulation circuit system, an IGBT gate control system, a constant temperature water cooling system, a data acquisition system, and a data analysis system; the special fixture for the IGBT module, the power circulation circuit system, the IGBT gate control system, the vibration test bench, the constant temperature water cooling system, and the data acquisition system are respectively connected to the automotive-grade IGBT module, and the data acquisition system is also connected to the data analysis system.

[0035] The automotive-grade IGBT module, such as Figure 2As shown. It contains three automotive-grade IGBT modules of the same model, namely the first automotive-grade IGBT module IGBT1, the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3. The first automotive-grade IGBT module IGBT1 is used as a switch of the power circulation circuit system, and the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3 are automotive-grade IGBT modules to be tested and fixed on the vibration test bench through a special fixture.

[0036] The IGBT module dedicated fixture, such as Figure 3 and Figure 4 As shown. It is mainly composed of three parts, namely the solenoid valve 1, the fixture body, and the fixture cover. Among them, the fixture cover includes an aluminum cover 2 and a copper sheet 3, and the fixture body includes a fixture base 44 and a cooling cavity 5. The solenoid valve 1 is connected to the cooling cavity 5 of the fixture, and the two solenoid valves 1 and the two cooling cavities 5 are symmetrically distributed, which is mainly used to control the flow direction and speed of the cooling water, and keep the cooling water at a constant temperature under the control of the constant temperature water cooling system. The fixture base 4 is connected to the cooling cavity 5 and is located at the bottom of the fixture. It can adapt to the positioning of different vibration test benches and is fixed to the vibration test bench, so that the automotive-grade IGBT module to be tested can be subjected to vibration testing according to the excitation of the vibration test bench. The clamp cover adopts a die-cast copper-type aluminum heat sink. The aluminum cover 2 and the copper sheet 3 are die-cast together and connected to the upper end of the cooling cavity 5, and the two copper sheets 3 are symmetrically distributed above the two cooling cavities 5, which not only utilizes the rapid heat absorption of copper to absorb the heat of the automotive-grade IGBT module, but also utilizes the rapid heat release of aluminum to release the heat on the copper block. When using the special clamp for the IGBT module, first select the appropriate through hole on the clamp base 4 to fix the clamp on the vibration test bench with bolts, and then fix the automotive-grade IGBT module to be tested to the clamp cover with bolts, and finally connect the solenoid valve 1 and connect it to the water cooling system. During the experiment, the special clamp for the IGBT module can make the experimental module vibrate together with the vibration test bench to achieve the required vibration conditions, and can also connect the module to the circuit for power cycle experiments, and can also achieve the effect of constant temperature water cooling by controlling the flow rate of cooling water.

[0037] The vibration test bench provides vibration excitation for the automotive-grade IGBT module to be tested through a special fixture for the IGBT module fixed to the vibration test bench. During the experiment, the vibration test bench can realize excitation signals such as random vibration and sinusoidal vibration, and can adjust parameters such as acceleration, amplitude and vibration frequency. Different vibration parameters are adjusted to meet the vibration conditions of the automotive-grade IGBT module.

[0038] like Figure 2 As shown, the power circulation circuit system includes a main circuit and a test circuit;

[0039] The main circuit includes a first power supply V1, a first resistor R1, and a first automotive-grade IGBT module IGBT1, a second automotive-grade IGBT module IGBT2, and a third automotive-grade IGBT module IGBT3 to form a power circulation circuit system. Among them, the first resistor R1 and the first automotive-grade IGBT module IGBT1, the second automotive-grade IGBT module IGBT2, and the third automotive-grade IGBT module IGBT3 are connected in series at both ends of the first power supply V1. The first power supply V1 can provide currents of different sizes to the power circulation circuit system as the load current of the automotive-grade IGBT module to be tested according to the needs of the power circulation conditions. The first automotive-grade IGBT module IGBT1 acts as a switch in the power circulation circuit system to control the conduction and shutoff of the large current in the power circulation circuit system. When the collector-emitter of the first automotive-grade IGBT module IGBT1 is turned on, the power circulation circuit system is turned on; when the collector-emitter of the first automotive-grade IGBT module IGBT1 is turned off, the power circulation circuit system is turned off.

[0040] The test circuit includes a second power supply V2, a second resistor R2, a diode, a second automotive-grade IGBT module IGBT2, and a third automotive-grade IGBT module IGBT3; wherein the second resistor R2, the diode, the second automotive-grade IGBT module IGBT2, and the third automotive-grade IGBT module IGBT3 are connected in series at both ends of the second power supply V2. The second power supply V2 provides a test current of 10 mA for the automotive-grade IGBT module to be tested. The test current is very small compared to the current of the power cycle circuit system of the power cycle experiment, and the effect of the test current on the junction temperature change of the automotive-grade IGBT module can be ignored. The diode ensures that the test current is in a disconnected state when the power cycle circuit system is turned on. At the moment when the power cycle circuit system is turned off, the test circuit is turned on to provide the test current to the automotive-grade IGBT module to be tested. The collector-emitter ends of the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3 to be tested are respectively connected to the data acquisition system.

[0041] The IGBT gate control system uses the pulse signal released by the single chip microcomputer to control the on and off of the first automotive-grade IGBT module IGBT1 switch module. Figure 6 As shown, when the pulse signal is at a high level, a 15V voltage is applied to the gate-emitter of the first automotive-grade IGBT module IGBT1, and the collector-emitter of the first automotive-grade IGBT module IGBT1 is turned on; when the pulse signal is at a low level, a 0V voltage is applied to the gate-emitter, and the collector-emitter of the first automotive-grade IGBT module IGBT1 is turned off. A 15V constant voltage source is used to provide a 15V voltage to the gate-emitter of the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3, so that the collector-emitter of the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3 remain in a conducting state.

[0042] The constant temperature water cooling system adjusts the temperature of the cooling water and the switch of the solenoid valve 1 according to the conditions of the power cycle-vibration experiment to independently heat each automotive-grade IGBT module at a constant temperature. When the collector-emitter of the first automotive-grade IGBT module IGBT1 is turned on, the solenoid valve 1 is closed, the automotive-grade IGBT module stops cooling, and the junction temperature of the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3 rises rapidly. When the first automotive-grade IGBT module IGBT1 is turned off, the solenoid valve 1 is opened to heat each automotive-grade IGBT module, so that the junction temperature of the second automotive-grade IGBT module IGBT2 and the third automotive-grade IGBT module IGBT3 is quickly reduced.

[0043] The data acquisition system collects the voltage across the collector and emitter of the automotive-grade IGBT module to be tested, the current of the test circuit, and the shell temperature of the automotive-grade IGBT module. The frequency of voltage signal acquisition reaches 1×10 6 The voltage across the collector and emitter of the automotive-grade IGBT module to be tested and the current in the test circuit are collected and displayed in the Labview software program for real-time monitoring, and the collected data are transmitted to the data analysis system. The collected collector-emitter voltage of the automotive-grade IGBT module to be tested is divided into two cases. One is the collector-emitter voltage of the automotive-grade IGBT module to be tested during the power cycle-vibration comprehensive test, and the other is the collector-emitter voltage when the power cycle circuit system is turned off when measuring the thermal resistance of the automotive-grade IGBT module.

[0044] The data analysis system analyzes and calculates the junction temperature and thermal resistance of the automotive-grade IGBT module to be tested.

[0045] The K coefficient method is used to calculate the junction temperature change of the automotive-grade IGBT module to be tested during the power cycle-vibration comprehensive experiment and the change of the junction temperature during the thermal resistance test. It is known that the functional relationship between the collector-emitter voltage and the junction temperature of the automotive-grade IGBT module to be tested is obtained under the test circuit current. The collector-emitter voltage of the automotive-grade IGBT module to be tested is obtained through the data acquisition system, and the junction temperature of the automotive-grade IGBT module to be tested is calculated and displayed in real time in the Labview software program to achieve online monitoring.

[0046] Based on the structure function method, the thermal resistance of the automotive-grade IGBT module to be tested is measured. The process of the structure function is to obtain the thermal transient thermal impedance curve, process the noise signal, perform logarithmic time derivative of the transient thermal impedance curve, deconvolute the derivative value with the weight function to obtain the time constant spectrum, convert the Foster thermal network model into the Cauer thermal network model, and finally obtain the structure function. Among them, the thermal impedance curve is obtained in that after the junction temperature of the automotive-grade IGBT module to be tested rises to a stable state, the data acquisition system obtains the voltage across the collector and emitter at the moment the power cycle circuit system is turned off, and obtains the cooling curve. The cooling curve, the collected current of the test circuit to be tested, the heat dissipation temperature of the constant temperature water cooling, and the K curve are combined to analyze and calculate the thermal impedance curve of the automotive-grade IGBT module to be tested, such as Figure 7 MATLAB software is used to perform numerical derivation and other subsequent calculation processes on the thermal impedance curve, and finally the thermal resistance and heat capacity parameters of each material layer of the automotive-grade IGBT module to be tested are obtained through the obtained structure function.

[0047] like Figure 5 As shown, the present invention provides an online thermal resistance test method under the power cycle-vibration comprehensive condition experiment of an automotive-grade IGBT module, and its main implementation steps include: connecting the automotive-grade IGBT module, turning on the IGBT gate control system, turning on the test circuit, turning on the data acquisition system, checking whether the collector-emitter voltage of the automotive-grade IGBT module under the collected test circuit meets the experimental requirements, if not, performing a correction check until the experimental requirements are met, and combining the initial module junction temperature calculated by the K curve. Turn on the vibration test bench debugging parameters, then turn on the constant temperature water cooling system, turn on the power cycle circuit system, turn on the data analysis system to perform a power cycle-vibration comprehensive experiment, the data acquisition system monitors the collector-emitter voltage of the automotive-grade IGBT module to be tested under the current of the power cycle circuit system in real time, and the data analysis system calculates and monitors the junction temperature of the automotive-grade IGBT module to be tested in real time. After a certain number of power cycles, the thermal resistance of the automotive-grade IGBT module to be tested is measured and calculated by the data analysis system, and recorded and saved.

[0048] First, the automotive-grade IGBT module is in a preset state by turning on the IGBT gate control system, and then the automotive-grade IGBT module is powered by the test circuit. The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module in real time to detect whether it is within the allowable error required by the experiment. If the collector-emitter voltage of the automotive-grade IGBT module is abnormal, check whether the module is damaged. If the collector-emitter voltage of the module is normal, start measuring the initial junction temperature and initial thermal resistance.

[0049] The IGBT gate control system controls the collector-emitter of the first automotive-grade IGBT module IGBT1 to be in the on state, the power circulation circuit system is turned on, and the junction temperature of the automotive-grade IGBT module begins to rise. When the junction temperature reaches stability through the data analysis system, the power circulation circuit system is turned off. At this time, the current of the test circuit supplies power to the automotive-grade IGBT module to be tested. The current of the test circuit hardly generates heat in the automotive-grade IGBT module to be tested, and its influence on the junction temperature of the automotive-grade IGBT module can be ignored. The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module after the power circulation circuit system is turned off, and stores the collected data. The data analysis system is used to combine the collected voltage with the K curve to obtain the junction temperature change, and the transient thermal impedance curve of the automotive-grade IGBT module to be tested is obtained by combining the definition of thermal resistance. The transient thermal impedance curve is numerically derived, deconvolved and other mathematical transformations, as well as the conversion of the thermal network model to obtain the structure function of the automotive-grade IGBT module to be tested. Through the structure function, the thermal resistance of each material layer inside the module and the contact surface of the material layer can be understood, and the thermal resistance data can be saved. The thermal resistance recorded at this time is the initial thermal resistance of the automotive-grade IGBT module.

[0050] Debug the vibration test bench to the preset parameters, turn on the vibration test bench, then set the IGBT gate control system to the conditions required for the power cycle-vibration comprehensive experiment, turn on the power cycle circuit system, obtain the initial junction temperature of the automotive-grade IGBT module to be tested through the data analysis system, and record and save it, and then conduct subsequent power cycle-vibration comprehensive experiments. The automotive-grade IGBT module power cycle-vibration comprehensive experiment needs to be stopped for a period of time after each certain number of cycles. When each power cycle experiment reaches the expected number of times, stop the vibration test bench, set the switch automotive-grade IGBT module gate to normally open, and after a period of time, monitor the junction temperature through the data acquisition system to reach stability and immediately turn off the power cycle circuit system, repeat the initial thermal resistance test process to obtain the thermal resistance of the automotive-grade IGBT module after the power cycle-vibration comprehensive experiment, and record and save it.

[0051] When the collector-emitter voltage change of the automotive-grade IGBT module obtained by online monitoring of the data acquisition system meets the failure criterion of the automotive-grade IGBT module, the power cycle-vibration comprehensive experiment is stopped, the thermal resistance of the automotive-grade IGBT module is measured at this time, and the power cycle circuit system, vibration test bench, IGBT gate control system, and constant temperature water cooling system are turned off. The thermal resistance of the automotive-grade IGBT module measured at multiple shutdown times of the power cycle circuit system during the power cycle-vibration comprehensive experiment of the automotive-grade IGBT module is compared with the initial thermal resistance of the automotive-grade IGBT module to obtain the thermal resistance degradation process of the automotive-grade IGBT module during the power cycle-vibration comprehensive experiment.

Claims

1. IGBT module power cycle-vibration experiment thermal resistance online test device, characterized in that: include: Automotive-grade IGBT modules, IGBT module-specific fixtures, vibration test benches, power cycle circuit systems, IGBT gate control systems, constant temperature water cooling systems, data acquisition systems, and data analysis systems; The IGBT module-specific fixture, power cycle circuit system, IGBT gate control system, vibration test bench, constant temperature water cooling system, and data acquisition system are connected to the automotive-grade IGBT module respectively, and the data acquisition system is also connected to the data analysis system; The automotive-grade IGBT module comprises three automotive-grade IGBT modules of the same model, namely a first automotive-grade IGBT module (IGBT1), a second automotive-grade IGBT module (IGBT2) and a third automotive-grade IGBT module (IGBT3); wherein the first automotive-grade IGBT module (IGBT1) is used as a switch of a power circulation circuit system, and the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) are automotive-grade IGBT modules to be tested and are fixed on a vibration test bench by a special fixture; The IGBT module-specific fixture comprises a solenoid valve (1), a fixture body, and a fixture cover; the fixture cover comprises an aluminum cover (2) and a copper sheet (3); the fixture body comprises a fixture base (4) and a cooling cavity (5); the solenoid valve (1) is connected to the cooling cavity (5), and the two solenoid valves (1) and the two cooling cavities (5) are symmetrically distributed, and are used to control the flow direction and speed of cooling water, and keep the cooling water at a constant temperature under the control of a constant temperature water cooling system; The fixture base (4) is connected to the cooling cavity (5), is located at the bottom end of the fixture, and is fixed to the vibration test table; The clamp upper cover adopts a die-cast copper-type aluminum heat sink, and the aluminum cover (2) and the copper sheet (3) are die-cast together and connected to the upper end of the cooling cavity (5), and the two copper sheets (3) are symmetrically distributed above the two cooling cavities (5).

2. The IGBT module power cycle-vibration experiment thermal resistance online testing device according to claim 1, characterized in that: The vibration test bench provides vibration excitation for the automotive-grade IGBT module to be tested through a special fixture for the IGBT module fixed to the vibration test bench.

3. The IGBT module power cycle-vibration experiment thermal resistance online testing device according to claim 1, characterized in that: The power circulation circuit system includes a main circuit and a test circuit; The main circuit comprises a first power supply (V1), a first resistor (R1) and a first automotive-grade IGBT module (IGBT1), a second automotive-grade IGBT module (IGBT2) and a third automotive-grade IGBT module (IGBT3); wherein the first resistor (R1) and the first automotive-grade IGBT module (IGBT1), the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) are connected in series at both ends of the first power supply (V1); the first power supply (V1) provides current to the power circulation circuit system as a load current of the automotive-grade IGBT module to be tested; the first automotive-grade IGBT module (IGBT1) serves as a switch in the power circulation circuit system to control the conduction and shutoff of a large current in the power circulation circuit system, and when the collector-emitter of the first automotive-grade IGBT module (IGBT1) is turned on, the power circulation circuit system is turned on; when the collector-emitter of the first automotive-grade IGBT module (IGBT1) is turned off, the power circulation circuit system is turned off; The test circuit comprises a second power supply (V2), a second resistor (R2), a diode, a second automotive-grade IGBT module (IGBT2), and a third automotive-grade IGBT module (IGBT3); wherein the second resistor (R2), the diode, the second automotive-grade IGBT module (IGBT2), and the third automotive-grade IGBT module (IGBT3) are connected in series at both ends of the second power supply (V2); the second power supply (V2) provides a test current for the automotive-grade IGBT module to be tested; the diode ensures that the test current is in a disconnected state when the power circulation circuit system is turned on; at the moment when the power circulation circuit system is turned off, the test circuit is turned on to provide a test current to the automotive-grade IGBT module to be tested; the collector-emitter ends of the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) to be tested are respectively connected to a data acquisition system.

4. The IGBT module power cycle-vibration experiment thermal resistance online testing device according to claim 1, characterized in that: The IGBT gate control system adopts a pulse signal released by a single-chip microcomputer to control the on and off of the switch module of the first automotive-grade IGBT module (IGBT1). When the pulse signal is at a high level, a 15V voltage is applied to the gate-emitter of the first automotive-grade IGBT module (IGBT1), and the collector-emitter of the first automotive-grade IGBT module (IGBT1) is turned on; when the pulse signal is at a low level, a 0V voltage is applied to the gate-emitter, and the collector-emitter of the first automotive-grade IGBT module (IGBT1) is turned off; a 15V constant voltage source is adopted to provide a 15V voltage to the gate-emitter of the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3), so that the collector-emitter of the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) is always kept in a conducting state.

5. The IGBT module power cycle-vibration experiment thermal resistance online testing device according to claim 1, characterized in that: The constant temperature water cooling system adjusts the temperature of the cooling water and the switch of the solenoid valve (1) according to the conditions of the power cycle-vibration experiment to independently perform constant temperature cooling on each automotive-grade IGBT module; when the collector-emitter of the first automotive-grade IGBT module (IGBT1) is turned on, the solenoid valve (1) is closed, the automotive-grade IGBT module stops cooling, and the junction temperatures of the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) increase rapidly; when the first automotive-grade IGBT module (IGBT1) is turned off, the solenoid valve (1) is opened to cool each automotive-grade IGBT module, so that the junction temperatures of the second automotive-grade IGBT module (IGBT2) and the third automotive-grade IGBT module (IGBT3) decrease rapidly.

6. The IGBT module power cycle-vibration experiment thermal resistance online testing device according to claim 1, characterized in that: The data acquisition system collects the voltage across the collector and emitter of the automotive-grade IGBT module to be tested, the current of the test circuit, and the shell temperature of the automotive-grade IGBT module; wherein the frequency of voltage signal acquisition reaches 1×10 6 times, and store and transmit the collected data; collect the voltage across the collector and emitter of the automotive-grade IGBT module to be tested, the current in the test circuit, display it in the Labview software program, perform real-time monitoring, and transmit the collected data to the data analysis system; the collected collector-emitter voltage of the automotive-grade IGBT module to be tested is divided into two situations, one is the collector-emitter voltage of the automotive-grade IGBT module to be tested during the power cycle-vibration comprehensive test, and the other is the collector-emitter voltage when the power cycle circuit system is turned off when measuring the thermal resistance of the automotive-grade IGBT module; The data analysis system analyzes and calculates the junction temperature and thermal resistance of the automotive-grade IGBT module to be tested.

7. IGBT module power cycle-vibration test thermal resistance online test method, characterized in that: The IGBT module power cycle-vibration experiment thermal resistance online test device according to any one of claims 1 to 6 comprises the following steps: connecting an automotive-grade IGBT module, turning on an IGBT gate control system, turning on a test circuit, turning on a data acquisition system, checking whether the collector-emitter voltage of the automotive-grade IGBT module under the collected test circuit meets the experimental requirements, if not, performing a correction check until the experimental requirements are met, and combining the initial module junction temperature calculated by the K curve; turning on the vibration test bench debugging parameters, then turning on the constant temperature water cooling system, turning on the power cycle circuit system, turning on the data analysis system to perform a power cycle-vibration comprehensive experiment, the data acquisition system real-time monitoring of the collector-emitter voltage of the automotive-grade IGBT module to be tested under the current of the power cycle circuit system, the data analysis system real-time calculation and monitoring of the junction temperature of the automotive-grade IGBT module to be tested; after a certain number of power cycles, the thermal resistance of the automotive-grade IGBT module to be tested is measured and calculated by the data analysis system, and recorded and saved.

8. The IGBT module power cycle-vibration experiment thermal resistance online testing method according to claim 7, characterized in that: The specific steps include: First, the automotive-grade IGBT module is in a preset state by turning on the IGBT gate control system, and then the automotive-grade IGBT module is powered by the test circuit. The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module in real time to detect whether it is within the allowable error required by the experiment; if the collector-emitter voltage of the automotive-grade IGBT module is abnormal, check whether the module is damaged; if the collector-emitter voltage of the module is normal, start measuring the initial junction temperature and initial thermal resistance; The IGBT gate control system controls the collector-emitter of the first automotive-grade IGBT module (IGBT1) to be in the on state, the power circulation circuit system is turned on, and the junction temperature of the automotive-grade IGBT module begins to rise. When the data analysis system monitors that the junction temperature reaches stability, the power circulation circuit system is turned off. At this time, the current of the test circuit supplies power to the automotive-grade IGBT module to be tested; The data acquisition system collects the collector-emitter voltage of the automotive-grade IGBT module immediately after the power cycle circuit system is turned off, and stores the collected data; the data analysis system combines the collected voltage with the K curve to obtain the junction temperature change, and combines the thermal resistance definition to obtain the transient thermal impedance curve of the automotive-grade IGBT module to be tested; the transient thermal impedance curve is numerically derived, deconvoluted mathematically, and converted into a thermal network model to obtain the structure function of the automotive-grade IGBT module to be tested; through the structure function, the thermal resistance of each material layer inside the module and the contact surface of the material layer is understood, and the thermal resistance data is saved; the thermal resistance at this time is recorded as the initial thermal resistance of the automotive-grade IGBT module; Debug the vibration test bench to the preset parameters, turn on the vibration test bench, then set the IGBT gate control system to the conditions required for the power cycle-vibration comprehensive experiment, turn on the power cycle circuit system, obtain the initial junction temperature of the automotive-grade IGBT module to be tested through the data analysis system, and record and save it, and then conduct subsequent power cycle-vibration comprehensive experiments; the automotive-grade IGBT module power cycle-vibration comprehensive experiment needs to be stopped for a period of time after a certain number of cycles; When each power cycle test reaches the expected number of times, stop the vibration test bench, set the gate of the switch automotive-grade IGBT module to normally open, and immediately shut down the power cycle circuit system after the junction temperature reaches stability through the data acquisition system after a period of time, repeat the initial thermal resistance test process to obtain the automotive-grade IGBT module thermal resistance after the power cycle-vibration comprehensive test, and record and save; When the collector-emitter voltage change of the automotive-grade IGBT module obtained by online monitoring of the data acquisition system meets the failure criterion of the automotive-grade IGBT module, the power cycle-vibration comprehensive experiment is stopped, the thermal resistance of the automotive-grade IGBT module is measured at this time, and the power cycle circuit system, vibration test bench, IGBT gate control system, and constant temperature water cooling system are turned off; the thermal resistance of the automotive-grade IGBT module measured at multiple shutdown times of the power cycle circuit system during the power cycle-vibration comprehensive experiment of the automotive-grade IGBT module is compared with the initial thermal resistance of the automotive-grade IGBT module to obtain the thermal resistance degradation process of the automotive-grade IGBT module during the power cycle-vibration comprehensive experiment.

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