Design of Oil-Water Hybrid Cooling Structure and Its Heat Dissipation Optimisation for Permanent Magnet Synchronous Motor in New Energy Vehicles

In response to the heat dissipation challenge encountered by a 30 kW permanent magnet synchronous motor (PMSM) operating at 3000 r/min in new energy vehicle applications, this study proposes an innovative cooling approach: the integration of an oil injection pipe at the motor winding end for oil-water composite cooling. By conducting advanced simulations of the temperature distribution within the permanent magnet synchronous motor under the oil-water composite cooling system and analyzing temperature rise characteristics, this study compares the effectiveness of the traditional water cooling system with the new oil-water composite cooling system in regulating motor temperature. Findings reveal that the oil-water hybrid cooling solution outperforms traditional water cooling by reducing the motor's peak temperature by 18°C under both operating conditions, and enhancing cooling efficiency by 15% to 19% as opposed to water cooling. Furthermore, this cooling technology demonstrates notable improvements in temperature uniformity within the motor, thereby contributing positively towards enhancing the overall performance and reliability of automotive permanent magnet synchronous motors. Additionally, these results offer valuable insights for extending motor service life, enhancing operational efficiency, and reducing maintenance costs, thus presenting significant implications for advancing technological innovation in the electric vehicle industry through the development and implementation of oil-water composite cooling technology.