Active power cycling and condition monitoring of IGBT power modules using reflectometry

Abstract

High thermal and electrical stress, over a period of time tends to deteriorate the health of power electronic switches. Being a key element in any high-power converter systems, power switches such as Insulated Gate Bipolar Junction Transistors (IGBTs) and Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are constantly monitored to predict when and how they might fail. A huge fraction of research efforts involves the study of power electronic device reliability and development of novel techniques with higher accuracy in health estimation of such devices. Through this paper, a new method for online condition monitoring of IGBTs and IGBT modules using spread spectrum time domain reflectometry (SSTDR) has been proposed. Unlike traditional methods, this research work concentrates at the gate terminals (low voltage) of the device instead of looking at the collector side. The IGBT collector-emitter ON voltage or V CEON was chosen as the failure precursor parameter as the reference, and the auto-correlated magnitudes of the SSTDR signal for the new and the aged IGBTs were plotted and compared.