Multi-physics optimization of high power density induction machines for railway traction drives

This paper applies a multi-physics optimization exemplary considering electromagnetic and aero-/ thermo-dynamic performance. Today, electrical drives used for railway traction face limited space constrains which leads to high power density machines. That requires advanced cooling concepts that are able to highly effectively discharge heat without adding more volume and weight in the boggy. A novel optimization approach for internal forced air-cooled traction drives will be presented. The optimization method integrates multi-physic performance evaluations. As an example, here, the coupling of aero- and thermodynamic cooling performance with electromagnetic performance evaluation is presented. However, the method is made to be easily extended to consider additional physics e. □g. material strength or acoustic objectives, production cost functions or additional limiting constraints. FEA (finite element analysis) is used for obtaining electromagnetic properties whether analytical code is used to rate the amount of heat discharged by the cooling fluid. The aero-/ thermodynamic performance of the optimized solution is finally validated by full CFD (computational fluid dynamics) with conjugate heat transfer.