Enhancing E-motor design, thermal efficiency with advanced cooling

The acceleration of 800V permanent magnet radial flux e-motors marks a significant leap in the automotive industry. This motor architecture offers increased power density through smaller, lighter designs that spin at higher rpm. However, this advancement brings with it the challenge of efficient thermal management, especially in dissipating heat from the magnet wire within the stator.

Effective thermal management is crucial for improving e-motor efficiency. The primary heat sources are the copper-insulated magnet wires, with heat spreading to the slot liners. Engineers have explored various cooling methods, including traditional water jackets using ethylene glycol and water. However, the trend is shifting towards using automatic transmission fluid (ATF) or oilbased fluids for direct cooling, driven by its integration convenience with the e-motor gearbox and inverter systems.