Wear-Out Condition Monitoring of IGBT and mosfet Power Modules in Inverter Operation

In this article, a condition monitoring system for the degradation assessment of power semiconductor modules under switching conditions is presented. The proposed monitoring system is based on the online measurement of two damage indicators: the on-state voltage of the semiconductor and the voltage drop in the bond wires. The on-state voltage of a semiconductor can be employed for temperature estimation, in order to anticipate failures in the solder joints that increase the thermal resistance of the cooling path. Moreover, by measuring the voltage drop in the bond wires, the degradation of the bond wires can be detected. The described monitoring system has been implemented in an inverter prototype, and tests have been performed in different scenarios to verify its capabilities in healthy and degraded states. Furthermore, a monitoring routine has been proposed in order to perform the required measurements in high switching frequency applications.