Abstract
Insulated Gate Bipolar Transistor (IGBT) modules used in electric locomotive traction converters are key components of power electronics, particularly under intensive freight-operating conditions. The current study presents an analysis of dominant failure mechanisms and thermal modeling of semiconductor systems, using the example of CM900HC-90H modules employed in UzEL series electric locomotives (operated by JSC "Oʻzbekiston Temir Yoʻllari"), based on a comprehensive approach that integrates compact thermal models with three-dimensional numerical modeling. The novelty of this study lies in the integration of a compact electrothermal model, three-dimensional FEM simulation, and field measurements obtained from an operating UzEL-series electric locomotive. Unlike previous studies focused mainly on laboratory-based IGBT thermal characterization, this work validates the thermal behavior of high-power traction converter modules under real railway operating conditions. Experimental verification was also conducted using the cooling curve comparison method, along with field tests on a UzEL-0304 locomotive, during which thermal and electrical parameters were recorded under real traction operating modes. Correlation analysis was performed to establish the relationship between the thermal field and the converter's load profile. As a result of numerical modeling and processing of experimental data, validated thermal models were obtained, a quantitative dependence of the cooling system temperature differential on the current load was established, and a comparison of calculated and experimental parameters showed a discrepancy of 6.2%. The developed models and methodology enable the prediction of thermal operating regimes and the assessment of IGBT module reliability under real-world service conditions.