Research on Electromagnetic-Thermal-Mechanical Multiphysics Coupling Simulation Analysis of Converter Transformers

Addressing the limitations of conventional single-physics analysis methods in accurately revealing the internal electro-thermal-mechanical interaction mechanisms, this study established a fully coupled electro-magnetic-thermal-mechanical model for converter transformer windings. This model comprehensively accounts for the effects of harmonic currents and DC bias, employing bidirectional coupling calculations to elucidate the complete propagation process from electromagnetic losses to temperature distribution and structural stresses. Simulation results indicate that harmonic losses constitute the primary factor driving localised hotspot temperature rise. The resulting non-uniform thermal expansion, coupled with electromagnetic forces, generates significant stress concentrations in regions such as the winding ends.