Mission Profile Based Lifetime Assessment Of IGBTS In High-speed Traction Converter System

The of high-speed railways in China has developed over a decade.With the rapid expansion of the high-speed railway network,a large number of high-speed EMUs have been put into operation.As the power system of high-speed EMUs,the electric traction converter system plays an important role.The power semiconductor devices that make up the traction converter system are very fragile under the complicated and harsh working condition.Therefore,the reliability analysis of the traction converter IGBT module for high-speed trains has become a top priority.For the power device under the actual application conditions of the system,its working state and environmental conditions are essential for detailed life prediction.Therefore,it is necessary to introduce a definition of the task profile,which is,the time sequence description of events and environments experienced by the product during the period of the specified tasks.This paper focuses on the mission-profiles-based lifetime assessment of IGBT module in traction converter systems of high-speed EMUs.The method for estimating the lifetime of IGBT modules in traction converters is given.Firstly,the traction calculation model of high-speed EMUs was established.The mission profile of the CRH3 high-speed train running on the Wuhan-Guangzhou line was analyzed.The power distribution estimation method of the traction converter was derived,and the load curves of the rectifier and the traction inverter were calculated.Secondly,the heat loss of the power module is calculated,and the thermal network model of the IGBT module of the traction converter is established.Through the joint simulation of PLECS and MATLAB/Simulink,the junction temperature fluctuation curve of IGBTs and diodes in the rectifier and traction inverter of the traction converter system are extracted.The differences in the modulation methods of rectifiers and inverters are analyzed to explain the differences in temperature changes.Finally,through the rainflow counting method,the junction temperature fluctuation curve is processed to record the data of temperature differences,average values of the junction temperature and the corresponding cycle times.Next,the data is brought into the Norris-Landzberg lifetime model of the IGBT module.The lifetime estimation results of the IGBT modules in the traction converter are given and the reliability of the estimation results is discussed.The life expectancy results are resembled to the practical data and statistics.