A new cooling approach for traction motors in hybrid drives

This paper presents a new cooling approach for traction motors which are mounted in hybrid electric vehicle (HEV) or battery electric vehicle (BEV). For this vehicle powertrain application the permanent magnet synchronous machines (PMSM) is a very popular choice, because of high power density, a high efficiency and the small package. However, this machine is susceptible to suffer insulations failures of coils and demagnetization of magnets under severe thermal condition. Therefore, it is important to have an efficient cooling for the PMSM to generate high heat dissipation. The configuration of a new cooling method is presented in this paper. The new cooling approach is based on a vortex tube that generates a -40 °C air stream. Also a simulation is done to give an outlook on the possibilities of the new cooling method. To make the simulation very accurate and comprehensive a finite volume Computational Fluid Dynamic (CFD) model is applied. This is a useful tool to analyze the cooling flow in a traction motor with regard to fluid velocity, flow quantity and pressure drop.