In-situ diagnostics and prognostics of wire bonding faults in IGBT modules of three-level neutral-point-clamped inverters

Abstract

The reliability of power electronic converters is a major concern in industrial applications because of the use of high-power semiconductor devices, which have high-power density and higher failure rates. Potential defects inside an insulated gate bipolar transistor (IGBT) module can be seen as precursors of being about to wear out, and are important for health monitoring of the IGBT module which is used to enhance reliability. Aiming to do reliability assessment about three-level inverters, this paper proposes an appropriate method based on fault-tolerant control circuit, uniquely fine-tuned for inverter (or general converter) evaluation. The proposed prognostic approach uses terminal voltages of IGBT as a precursors to monitor the bond wire health, which can give accurate predictions and allow operators to observe unhealthy IGBT modules inside a power converter, and then take appropriate measures timely to avoid breakdown.