Research on Blind Zone Identification Method of IGBT Aliased Reflection Signals Based on STDR/SSTDR Signal Transmission Model

The degradation process of an IGBT module typically involves changes in the device impedance characteristics. Therefore, in this paper, the advantages of time-domain reflectometry (TDR) in the field of impedance parameter identification for power electronic devices are utilized to conduct device-level research on the sequence/spread spectrum time-domain reflectometry (STDR/SSTDR) signal transmission and reflection characteristics of IGBT modules. Based on studying the multiple/multipoint reflection characteristics of the incident signal, this paper proposes an identification method for IGBT reflection signals in the aliasing blind zone based on a time-domain signal transmission model. This method can effectively extract the target feature information of the IGBT in the blind zone, while accurately monitoring the impedance variation characteristics of the IGBT, providing a basis for its health assessment. Finally, this paper conducts relevant experiments to verify the proposed method, and the experimental results have achieved the expected effect.