IGBT Module Junction Temperature Measurement And Electromagnetic Interference Research

Power electronic systems have high energy conversion efficiency and controllability.They have been widely used in aerospace,industrial automation,transportation,renewable energy power generation and other fields.Due to the complicated working conditions and the harsh working environment,the power electronic system has high reliability requirements.Power devices are the key components of power electronics systems,and their safety and reliability determine whether the entire system operates efficiently and whether energy is fully utilized.The junction temperature is closely related to the reliability of the power device.The evaluation of the state of power devices by measuring junction temperature is a relatively common method at present.With the application of power electronic systems under high-frequency and high-voltage conditions,electromagnetic interference generated by power devices cannot be ignored.In order to improve the reliability and security of power devices,the research on electromagnetic interference of power devices is also indispensable.IGBT is a widely used power device,so this paper takes IGBT module as the research object.This paper takes the IGBT power module as the research object,and mainly conducts research on IGBT junction temperature measurement and electromagnetic interference.The specific research content is as follows:1.Analyze the effect of IGBT thermal characteristics on reliability.Firstly,the working principle and transmission characteristics of IGBT chip are analyzed.The relationship between IGBT power loss and junction temperature is studied.The general method of power loss calculation in IGBT switching process is analyzed.On the basis of studying the basic structure of the IGBT module,the heat transfer is analyzed,and the factors causing the failure are explained.It is pointed out that the junction temperature fluctuation is the main cause of the fatigue aging of the solder layer and the lift off of the bonding wire.2.A junction temperature measurement method based on dynamic thermo-sensitive electrical parameters is proposed.The parasitic parameters between the auxiliary emitter and the power emitter in the IGBT module encapsulated structure are analyzed,and the parasitic parameters are extracted to simulate the influence of parasitic parameters on the switching process.Analyze the change of electrical parameters during the turn-off process,clarify the formation process of V_eE-peak.The variation of V_eE-peakE-peak with junction temperature during the turn-off process and the change of V_eE-peakE-peak with the collector current are analyzed in detail.The experimental platform was built for the offline test of the IGBT module.The junction temperature prediction model of the IGBT module based on V_eE-peakE-peak was obtained.Through experiments and analysis,the verification model is feasible and effective,and the junction temperature measurement accuracy is high.3.Explore the electromagnetic interference of the IGBT module under the junction temperature change.Firstly,the generation mechanism of electromagnetic interference and the measurement method of conducted electromagnetic interference in power electronic system are analyzed.Then the influence of the junction temperature rise on the IGBT switching process is analyzed,and the frequency domain analysis of the IGBT working transient is carried out.Finally,an experimental platform is built to measure the electromagnetic interference under the change of IGBT junction temperature.The relationship between junction temperature and electromagnetic interference of IGBT is obtained.