Online junction temperature extraction and aging detection of IGBT via Miller plateau width

The width of the Miller plateau during IGBT turnoff process is temperature sensitive and suitable for online junction temperature monitoring. In this paper, the online measurement system to detect this parameter is achieved at the gate driver side. The advantages of using the Miller plateau width for practical applications are discussed by comparison of three existing parameters. An accelerated aging test has been performed to determine the evolution of the Miller plateau width and validate the effectiveness of the method during the entire lifetime. Results show that as the bond-wire degradation develops and the junction temperature rises in the aging process, the Miller plateau width decreases, and it varies conversely with the on-state voltage. Therefore, the Miller plateau width is proposed as the indicator for online aging detection and remaining life prediction of IGBT.