Study on the Variations in Precursor Parameters of Insulated Gate Bipolar Transistors and SiC MOSFETs for Fault Diagnosis

The reliability of power devices such as insulated gate bipolar transistor (IGBT) and SiC MOSFET has been wildly concerned with the development of the new transmission systems, electric vehicles and other industries. The condition monitor of power devices is one of the effective methods for fault rank evaluation by monitoring the changes in aging precursors. The investigation into electrical parameters of power devices used as aging precursors is of key importance. In this paper, the variations in several electrical parameters of IGBTs and SiC MOSFETs are studied to reveal the relationship between electric signals and aging stage. The static and dynamic electrical parameters are measured during accelerated aging tests and compared. The results show that the collector-to-emitter saturation voltage varies obviously with the degradation process which can be used as a promising failure precursor for the development of a condition monitoring system of power devices.