Modeling of Electromagnetic Heating of Multi-coil Inductors in Railway Traction Systems

Sammanfattning: Inductors are frequently used in railway electrical tractions systems in filtering and current limiting operations. Magnetic fields are generated due to the flow of large AC currents through the coils, which intend induce currents on the coils as well as the metallic components in the vicinity, causing electromagnetic heating. The heating may cause temperatures to exceed project temperature requirements and in the worst case distort the functionality of drive system. The purpose of this work is to simulate the Electromagnetic Heating effect of inductors in 3D using COMSOL Multiphysics. First a 3D CAD model of the inductor geometry is imported to COMSOL and the magnetic fields for a giving current excitation are estimated. Then the power losses are fed in to a heat flow simulation to predict the temperature distributions. Cooling is simulated by driving cool air through the heated coils and the surrounding metal objects. The temperature distributions for different current excitations and air flow velocities are estimated. Simulation is performed on conceptual project inductor model. The 3D inductor modeling approach established in this thesis work could be used to characterize the electromagnetic heating issues early in the project design phase.