Electric Motor Thermal Management

A photo of a piece of laboratory equipment.

NREL research in electric motors is helping to improve the performance and reliability of electric-drive vehicles.
Photo by Kevin Bennion, NREL

NREL's electric motor thermal management research generates experimental data and simulation processes for the modeling, analysis, design, and construction of new electric motors.

Electric motor thermal management involves a multifaceted interaction of motor operating conditions, heat load distribution, material temperature limitations, passive thermal heat spreading, and active convective cooling.

Industry partners are looking to better understand heat transfer in electric motors in their efforts to develop motors that reliably operate with reduced size and cost. NREL research is addressing this challenge and supporting broad industry demand for data, analysis methods, and experimental techniques to improve motor thermal management.

Research to characterize and improve motor thermal management includes the following:

  • Developing fluid-based (transmission oil, water-ethylene glycol) cooling technologies for the stator and the rotor

  • Characterizing automatic transmission fluid impingement and flow on geometrically representative surfaces and providing validated computational fluid dynamics models

  • Performing passive stack thermal characterization and improvements for the stator and the rotor, including laminations, end-windings, and slot-windings

  • Collaborating with other national laboratories and industry partners to measure thermal performance of materials, improve motor performance and thermal management, and facilitate future bench-level thermal evaluation of electric motor components

  • Supporting thermal management design for motors developed by NREL partners.