A High Performance Dry-Winding Cooling Technique for Electrical Machines

Thermal improvements are a key enabler for achieving high power densities in electrical machines used for propulsion. For the widely used water-jacket cooling system, poor thermal conditions in the slot and end-winding region hold the largest potential for improvement. A novel cooling technique is proposed in this paper for water-jacket cooled electrical machines, with a ceramic inserted in the middle of the slot and axially connected to an end-cooling system in proximity to the end-windings. The thermal characteristics and benefits of the presented thermal management technique are captured with a lumped parameter thermal network described in this paper.