Heat transfer analysis of a traction machine with directly cooled laminated windings

A directly enhanced cooled winding in an electrical traction machine has the potential to extend the operation range, which is in particular attractive for a traction application when operating near peak power for extended periods of time. This paper presents the heat transfer analysis of a modular machine segment with a laminated winding. The laminated winding has a great potential when it comes to production of the winding and the thermal management of the excessive power losses in the winding. The prototype is built and assessed based on experimental measurements and finite element analysis. The results indicate some practical challenges of integrating the combined heat exchanger and winding and controlling the coolant flow through the machine construction. The prototype machine shows a limited enhanced cooling capability mostly due to flow leakage while the results from the simulation models indicate the great potential of direct cooled windings.