Research And Implementation Of Online Monitoring Technology For IGBT Key Devices Of High-power Power Supply

High-power power supplies are increasingly used in various aspects such as national defense,industry,and transportation,and have become the core and key important technologies in many fields.As the most critical power device in high-power power supply,IGBT module has reliability problems such as aging failure during long-term operation,which will directly affect the safe and stable operation of power supply equipment.In order to improve the reliability of high-power power supply operation,avoid the sudden failure of the IGBT module,which will bring serious consequences to the entire power supply system.Researching on-line monitoring technology of IGBT module,judging the health status of the device,timely discovering and replacing the aging failure device,is of great significance to equipment maintenance.The difficult points of the online monitoring technology of IGBT device failure parameters are analyzed in this thesis:one is to select the appropriate online monitoring characteristic parameters,the other is to eliminate the influence of temperature during the monitoring process,and the third is the design and realization of the saturation voltage drop online monitoring program.Firstly,the relationship between various failure characteristic parameters and IGBT aging failure and the difficulty of realizing online monitoring are analyzed.The working characteristics and aging failure mechanism of IGBT modules are studied,and the failure factors are discussed in depth.Compare the pros and cons of various IGBT device state monitoring parameters,and select the method of monitoring V_CE(sat).Secondly,an on-line monitoring method of the IGBT module aging failure status under the condition of the inflection collector current is proposed,and the influence of temperature on the status monitoring parameters is analyzed theoretically and experimentally.This method only needs to monitor the V_CE(sat)of the IGBT device under the condition of the collector current of the inflection point,without considering the influence of the junction temperature,to realize the monitoring and evaluation of the health status of the IGBT module.Then,an online monitoring program for IGBT aging failure in the three-phase high-power inverter power supply topology circuit is designed,and the driving circuit and V_CE(sat)accurate measurement circuit of the system are designed.Simulation verification shows the feasibility of the program.Then the software part of the online monitoring system is designed to realize the control of the inverter power supply and the collection and monitoring of the V_CE(sat)of the IGBT device.Finally,the feasibility of the online monitoring program of IGBT devices proposed in this thesis is verified through experiments.An online monitoring platform for IGBT modules based on three-phase high-power inverter power supply equipment is built.On this online monitoring experimental platform,a comparative experimental analysis of IGBT devices after accelerated aging experiments and under normal operating conditions is performed.Experiments show that this scheme can effectively and accurately realize online monitoring of the aging failure status of IGBT devices.