Abstract：Insulated gate bipolar transistor（IGBT）as an important part of wind power converter，through the

high frequency switch to achieve efficient conversion of electrical energy，its long-term complex operation will lead

to IGBT performance decline，increase the risk of failure and affect the stability of the system. By analyzing the

change trend of junction temperature of IGBT after decay，the decay degree of IGBT in wind power converters in

different years of actual operation was tested. PLECS module was used to build IGBT thermal simulation model for

doubly-fed wind turbine application scenarios to study the junction temperature characteristics of IGBT under

different working conditions. The IGBT thermal model was modified according to the measured decay data. In

addition，according to the difference of junction temperature characteristics before and after IGBT recession，the

digital twin model framework was established，and the whole process from model establishment to real-time

monitoring of IGBT recession degree was designed，and the real-time monitoring of IGBT recession degree was

finally realized.

      Key words：wind power converter；insulated gate bipolar transistor（IGBT）；decline monitoring；digital twin