Multi-Phase Winding With In-Conductor Direct Cooling Capability For A 48v Traction Drive Design

Traction drive applications demand high power density motors with a good stator cooling design. We propose a novel multi-phase winding for a 48V traction drive design having identical preformed hollow copper conductors with in-conductor direct cooling capability. This paper studies the cooling performance of an individual conductor phase using either EGW50/50 or water as coolant. Analytical calculations and experiments are conducted on a straight conductor of the same length using 20 degrees C water as coolant. The results are then cross verified with those from the FEM simulations to validate the simulation setup. Then a final simulation is conducted at a current of 700A and a current density of 49.5A/mm(2) on the preformed conductor using 65 degrees C EGW50/50 as coolant at a pressure of 140 kPa. The results highlight the exceptional performance of the cooling design which enables a power dissipation of 710W at a maximum conductor temperature rise of only 56.9 degrees C.