Design Of The DC Accelerated Aging Test Platform For High Power IGBT Modules

As an important part of new energy generation system(such as wind farm and photovoltaic power plant),the reliability of converter becomes more and more important to the safe operation of the whole system with the development of the whole application system to higher voltage level and higher power level.Current researches show that most of the converter faults originate from aging failure of IGBT modules.Therefore,extracting aging information of IGBT module is an effective way to prevent the failures happen.At present,the extraction of ASEPs are mainly focused on the static parameters of IGBT module.Few literatures have conducted in-depth research and analysis on the dynamic parameters of the transient process.Based on the above background,this paper explores a new aging electrical sensitive parameter of high-power IGBT module to better meet the application requirements.Firstly,different aging parts and mechanisms of IGBT module are analyzed and elaborated in detail from five aspects:bonding line aging,welding layer aging,DBC aging,aluminum metal reconstruction and chip aging.It is pointed out that the aging of bonding wires will not cause significant changes in the parasitic inductance of IGBT modules,but it can significantly change the resistance value of the contact resistance between bonding wires and chips,which provides a theoretical basis for extracting the aging electrical sensitive parameters.Secondly,through the research and analysis of the equivalent circuit model of IGBT module,the working principle of different stages of start-up process and the aging mechanism of IGBT module,a new aging electric sensitive parameter based on the voltage VEe between power emitter and Kelvin emitter of IGBT module is proposed,and the effective mechanism in on-state and transient state is analyzed respectively.The advantage and disadvantage of the method and the decoupling of temperature and aging factors are discussed as well.Finally,a DC accelerated aging experimental platform for two high-power IGBT modules is designed and built,corresponding tests are carried out,showing that the experimental platform meets the experimental requirements for accelerated aging of IGBT modules.Furthermore,the validation of the aging electrical sensitive parameters proposed in this paper is verified through this platform.