Comparative Damage Analysis of Critical Sub-Profiles in Random Mission Profile of Electric Drive Power Converters Under Controlled Thermal Conditions

This paper presents a signal-processing methodology for assessing thermal stress and fatigue damage in IGBT modules. This study utilizes junction temperature data from operational frequency converters at a belt conveyor station rather than conventional approaches. These in situ measurements ensure that thermal profiles accurately reflect actual loading conditions. A reliability framework based on mission profiles assesses the contribution of each operational regime. We examine transient overloads, steady-state operation, and periods of low load specifically. We apply Miner’s rule and rainflow counts to the analyzed temperature profiles. This enables the assessment of accumulated damage in each operational segment. The primary finding indicates that a minimal duration of operational time constitutes the majority of total lifetime utilization. This disproportionate impact is attributable to transient overloads. This study quantitatively evaluates this phenomenon using Rainflow analysis to disaggregate mission profiles. The proposed framework enhances the precision of reliability engineering. It provides a valuable foundation for enhancing maintenance planning and control strategies in practical scenarios.