Surrogate-based heat transfer modeling for important parts in a fully enclosed traction motor

Abstract The aim of this paper is to present a heat transfer modeling method that combines analytical calculation with numerical simulation. This method can be referred to as hybrid modeling or surrogate-based modeling. The object under study is a fully enclosed water-cooled traction motor. The selected investigated regions that are adjusted by numerical simulation are the end-winding region and the interface of the stator core and water jacket. The end-winding region is investigated because end windings are located at the enclosed inner part, where it is difficult to analytically determine the airflow velocity (velocity distribution). The transition between the stator core and the water jacket is also important, as it directly determines the cooling efficiency due to the cooling method where the water jacket is placed on the stator core. This paper presents a heat transfer calculation example for these two critical areas, along with validation using real motor data obtained temperature rise test, comparing the calculated results with measurements.