Evaluation of on-state voltage V<inf>CE(ON)</inf> and threshold voltage V<inf>th</inf> for real-time health monitoring of IGBT power modules

Abstract

This paper investigates by experiment and simulation the use of the real-time measurements of on-state voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE(ON)</sub> and threshold voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> for real-time health monitoring of IGBT power modules. A study of the dependencies of each parameter on temperature, wear-out mechanisms and operating conditions is presented. Online measurement circuits are developed to obtain these two parameters during the normal operation of power converters. Junction temperature estimation for health monitoring is implemented using V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> which is a thermo-sensitive electrical parameter. The data of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE(ON)</sub> , V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</sub> are combined in a residual-based health monitoring framework which allows the discrimination between two dominant failure mechanisms of power modules: wire-bond lift-off and solder fatigue.