Enhanced Thermal Management of High-Torque Electric Motors Using Embedded Microchannel Cooling

Adjustable speed motor drives are crucial components of the powertrain in electrified vehicles. With the increasing demand for higher torque and power density in electric propulsion motors and their associated power converters, efficient cooling methods for stator windings are essential. Traditional cooling systems often face challenges, including long thermal time constants for heat transfer, complex configurations for heat removal from the windings, which result in reduced filling factors, and the added volume and material requirements. To overcome these limitations, a novel cooling system for the stator windings of adjustable-speed AC drives is proposed. This system incorporates embedded microchannels within the end windings to facilitate efficient heat transfer. The proposed design allows for the effective utilization of the slot area, enabling the placement of windings at a very high filling factor, while accommodating high current density. The cooling system and end windings are designed as separate units, enabling modular assembly that simplifies repair and supports end-of-life recycling.