| As a typical representative of fully controlled power electronic devices,Insulated gate bipolar transistor(IGBT)has been widely used in aerospace,electromagnetic launch,rail transit and new energy power generation.These fields have high requirements for the reliability of power IGBT devices.The research shows that the failure rate of IGBT is the highest among the power electronic devices,which plays an important part in the reliability of the power electronic system.In addition,The higher junction temperature is,the higher failure efficiency of IGBT devices is.Therefore,the research on the junction temperature measurement of IGBT devices has very important practical and economic significance for ensuring the safe and reliable operation of IGBT devices,prolonging the service life,improving the overall system performance,power density and reliability.However,most of the temperature sensitive electrical parameters are affected by the fatigue of IGBT modules,and the coupling relationship between temperature sensitive electrical parameters(TSEPs)and fatigue of IGBT modules is rarely studied.Therefore,it is of great significance to propose a junction temperature measurement method of IGBT modules,which decouples the fatigue effect of IGBT modules.In this paper,IGBT module of bond-wire package is taken as the research object,and the coupling relationship between the commonly used TSEPs and the fatigue process is studied.This paper proposed a junction temperature measurement method based on dynamic parameter Ve Emax,which is not affected by IGBT module's package fatigue.The main work of this paper is as follows:To begin with,this paper established the equivalent circuit model of IGBT modules,and analysed the coupling relationship between fatigue process and the methods as below:the method of the saturation voltage drop under low current,the method of the saturation voltage drop under load current,the method of short-circuit current and the method of combined short-circuit current.This paper verified the fatigue coupling of the static TSEPs based on the saturation voltage drop experiment and short-circuit current experiment,and then established the single phase bridge inverter circuit to verify the feasibility of online junction temperature measurement by combined TSEP.This paper compared and analyzed the advantages and disadvantages of the current static TSEPs.The results show that the existing static TSEPs have some inherent problems,such as fatigue coupling,unable to be measured online,short-circuit power consumption etc,which limit its application in operational converters.Furthermore,combined with IGBT module equivalent circuit model and turn on process,this paper studied the coupling relationship between the conventional dynamic TSEPs and the fatigue process of IGBT modules.The analysis shows that most of the dynamic TSEPs are affected by the fatigue of the bond wire.Based on the turn on process of IGBT modules under constant current drive,this paper proposed a junction temperature measurement method based on dynamic parameter Ve Emax,which is not affected by IGBT module's package fatigue.Ultimately,this paper established the dynamic test platform based on the double pulse test method,and designed a special gate drive circuit.The temperature calibration experiment and simulated fatigue experiment are carried out in this paper.The results show that Ve Emax has good temperature linearity,and the temperature sensitivity is about-2m V/°C?-5.8m V/°C,the temperature sensitivity increases with the increase of load current.The maximum junction temperature error is about 27°C of the Ve Emax driven by constant voltage under different fatigue degrees,and the Ve Emaxdriven by constant current is almost not affected by the aging effect of bond wire,which has the advantages of decoupling the fatigue effect and is suitable for on-line measurement. |
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