The Research Of IGBT Module On-state Voltage Monitoring And Aging Diagnosing

In recent years,power electronics technology has developed rapidly;it has been widely used in new energy power generation,electric vehicles,ship manufacturing,and aerospace.In these fields,power electronics systems perform an important task of power conversion,which increases the requirements for their reliability.An insulated gate bipolar transistor(IGBT)module,a widely used semiconductor device,plays an important role in the reliability of power electronics systems.The on-state voltage of the IGBT module is the voltage between the collector and the emitter in on-state status.It is a thermo-sensitive electrical parameter which can be used in junction temperature measurement of the IGBT module.When concerning the aging diagnosis of IGBT module,both bond wire fatigue and solder fatigue have influence on on-state voltage.Thus,it is possible to diagnose the aging modes of IGBT module by monitoring on-state voltage.This paper proposes a model of the on-state voltage across IGBT modules and a calculation method of the on-state voltage.Based on this model,an aging diagnosis strategy is proposed.The research content of this paper is listed as follows:1.Propose an IGBT module on-state voltage separation strategy.Starting from the physical structure and conduction mechanism,this paper studies the threshold voltage of the IGBT module and the motion modes of the carries in on-state status.The on-state voltage separation strategy is proposed after studying the component of the on-state voltage.The feasibility of the proposed method is proved by experiments.After acquiring the extraction and measurement methods to each part of the on-state voltage,an IGBT module on-state voltage calculation model is proposed.2.Analyze the influence factors of each part of the on-state voltage.Studying the influence of junction temperature and aging on the on-state voltage.Based on the separation strategy,this paper analyzes the junction temperature influence on collector-emitter threshold voltage,on-state chip voltage and package voltage independently.After acquiring their relationship with junction temperature,the on-state voltage calculation method is updated which realizes the calculation of the on-state voltage in on-line conditions.Studying the aging mechanism,the paper analyzes the influence of different aging modes which is benefit to diagnosis the aging of the IGBT module though the on-state voltage.3.Propose an IGBT module aging diagnosis strategy based on the on-state voltage separation method.It is possible to diagnosis the bond wire fatigue by comparing the measurement and the calculation result of the package voltage which is proved by the experimental results in this paper.What is more,the change of the package resistance can be used in solder fatigue and is a supplement to the existing diagnosis methods.