Experimental Validation of Linear Damage Superposition for IGBT Power Modules Under High and Low Temperature Stress Cycles

This paper presents results from experimental tests intended to assess the validity of linear damage superposition using Miner’s rule for IGBT power modules. Such validity is crucial, for example, when applying Miner's rule in combination with power cycling lifetime models for estimating converter design lifetime. The linear combination of damage is debated, and, hence, it is important to test the validity of calculating the accumulated damages of IGBT power modules subjected to a mix of high- and low- temperature stress cycles. In total, seven power cycling experiments with commercial modules forms the basis for the assessment, involving test runs with constant stress conditions, as well as with mixed stress conditions. The analysis of the results indicates that the Miner’s rule predictions are in line with the lifetime obtained experimentally for mixed stress conditions.