Online condition monitoring of IGBT modules using current-change rate identification

Insulated gate bipolar transistors have gained leading position in aerospace and marine applications. However, due to the fact that the power devices are exposed to electrical, thermal and mechanical stresses, the failure rates of these components are comparatively high, and it was found to be the main reason for reducing the reliability of the whole system. Therefore, this paper investigates an IGBT current change rate as a new potential precursor parameter to identify early failure of an IGBT devices. Ageing of IGBT devices and its effect on current change rate is investigated using accelerated power cycling test in order to trigger solder die-attach degradation and bond wire lift-off damage. Experimental investigation verifies that the increase in current change rate is a reflection of die-attach degradation. Lastly, a three-phase inverter system is developed for experiments to verify the proposed method in real time operating conditions.