Research On Thermal Structure Modeling And Aging Of IGBT Module

Environmental pollution and energy crisis have made clean,renewable wind energy received worldwide attention,and wind power is an effective use of wind energy.Because of the continuous improvement of the installed capacity of wind power generation and the harsh environment of the wind power generation system,the reliability requirements of the wind power generation system are also increasing.Wind power converter is an important part of the wind power generation system,and its reliability affects the safe operation of the entire power generation system.Relevant research shows that power devices are one of the most important factors that affect the reliability of wind power converters,so it is necessary to study the reliability of power devices.Further studies have found that thermal failure is the most important way for power devices to fail.Based on the thermal reliability of IGBT module,the thermal structure model that can reflect the working state is established by analyzing the internal heat transfer process of the IGBT module,and the aging of the module is analyzed by thermal structural function.The main contents are as follows:(1)The steady-state heat transfer and transient heat transfer process in IGBT module are studied,and the concepts of thermal resistance and thermal impedance are deduced.The linearities of different temperature-sensitive parameters are compared and the heat impedance curves of the IGBT module under different heat dissipation conditions are measured.Foster thermal network model and Cauer thermal network model,as the two most common heat network models which can reflect the heat transfer characteristics,are presented and compared.(2)According to that Cauer thermal network model parameters can be obtained accurately from the structural function,The structural function principle and the key algorithm are analyzed,and the compilation work of the whole algorithm is realized.Based on the measured transient thermal impedance curve,the IGBT module 5-order Cauer thermal network model is obtained by the compiled the program.(3)The variability characteristics of IGBT module in the aging process are analyzed.Firstly,the aging test program is designed,and the IGBT module is aged by the aging platform.secondly,based on the structure function analysis,a linear fatigue cumulative damage model and a nonlinear fatigue cumulative damage model based on the thermalresistance of solder layer of IGBT module chip are established.