Design and analysis of a high loss density motor cooling system with water cold plates

Aiming at reducing the difficulty of cooling the interior of high-density motors, this study proposed the placement of a water cold plate cooling structure between the axial laminations of the motor stator. The effect of the cooling water flow, thickness of the plate, and motor loss density on the cooling effect of the water cold plate were studied. To compare the cooling performance of water cold plate and outer spiral water jacket cooling structures, a high-speed permanent magnet motor with a high loss density was used to establish two motor models with the two cooling structures. Consequently, the cooling effects of the two models were analyzed using the finite element method under the same loss density, coolant flow, and main dimensions. The results were as follows. (1) The maximum and average temperatures of the water cold plate structure were reduced by 25.5% and 30.5%, respectively, compared to that of the outer spiral water jacket motor; .(2) Compared with the outer spiral water jacket structure, the water cold plate structure can reduce the overall mass and volume of the motor. Considering a 100 kW high-speed permanent magnet motor as an example, a water cold plate cooling system was designed, and the temperature distribution is analyzed, with the result indicating that the cooling structure satisfied the cooling requirements of the high loss density motor.