The Application Of Junction Temperature Measurement Of IGBT Module Based On Electrothermal Coupling

IGBT means Insulated Gate Bipolar Transistor,which combines the advantages of MOSFET and bipolar devices.On the o ne hand,like MOSFET,it has high input resistance,easy drive system and fast switching speed;on the other,like bipolar devices,it has high current ratings and low saturation voltage,etc.It is widely applied in many key areas,such as railway transpo rt,wind power,electric cars and industrial drive.However,IGBT is operating in high voltage,high current ratings and high-frequency switching state for long term.So fatigue and aging are always caused by frequent fluctuation of power dissipation and ju nction temperature,then it will cause failure.In the module failure,the reason related to high temperature accounts for 60%.Therefore,measuring the junction temperature of IGBT module in a accurate,convenient and harmless way becomes a key question t o assess system reliability.researching the power loss,junction temperature and lifetime prediction of IGBT is significant for choosing device model,designing dissipation and enhancing reliability.This thesis focuses on the research of IGBT power model,building a model to measure electric-heat coupling model of IGBT,exploitingjunction temperature measurement system and researching the application of junction temperature measurement on lifetime prediction.Firstly,the basic structure and operating prin ciple of IGBT were introduced,the stacking packaging configuration and material properties of IGBT power module was analyzed.The failure modes and failure causes in IGBT were summarized,then followed by an introduction of main failure mode of the solder fatigue and the bonding wire lift-off caused by junction temperature fluctuation,which revealed that temperature is one of main reasons affecting the reliability of power module and life table.Secondly,due to the reason that the control parameters of c onvertor which needed by electric-heat coupling model are hard to get,and real time change is hard to unify,this thesis improved a aelectric-heat coupling model which is for engineering application.PWM control strategy parameters are not needed in this model,which can use the current,voltage data to switch current,calculate module loss.Then,use the shell temperature to calculate real-time junction temperature and the fluctuation of junction temperature on the basis of thermal source 's movement and properties of IGBT,and it has very important application value.Then,based on Labview software,accomplish the system development of junction temperature measurement.Using IGBT's power module to assemble a three-phase inverter module and build a hardware test platform to simulate reality.By comparing the software simulation's results with module manufacturers,it verifies that accuracy of electric-heat coupling model and junction temperature measurement system,and laid a foundation for lifetime predicti on.Finally,the thesis states the relationship between the change of junction temperature and device service life.Compare and analyze the advantages and disadvantages of different kinds of analytical life model.Introduce Two stage rain flow counting method which is extracted from Stress load spectrum and its Ergodic logic.At the end of the thesis,it introduces the data of Junction Temperature Measurement of IGBT Module based on Electrothermal Coupling,states the specific steps,and reflects its application value.