A Fault Detection Method for Partial Chip Failure in Multichip IGBT Modules Based on Turn-Off Delay Time

Multichip IGBT module has been widely used in high-power converters. Detecting the status of the IGBT chip is a cost-effective approach to improving the reliability of power devices. This article proposes a novel method based on turn-off delay time to detect chip fault in multichip IGBT modules. First, the effect of chip failure on the turn-off process is analyzed, which causes a decrease in turn-off delay time. Then, a detection method of chip failure based on turn-off delay is proposed, which is validated by experimental results. Furthermore, the effects of chip failure on turn-off delay time in different working conditions are investigated through effective experimental results. The tested results show that the proposed method not only has high linearity and sensitivity to chip failure, but can also eliminate the influence of working environments on detection. The proposed method can be used to monitor the health status of multichip modules and is of great significance for enhancing operation reliability.