NREL Science and Technology Highlights

Wide Bandgap Technology Enhances Performance of Electric-Drive Vehicles

Wide bandgap (WBG) power electronics devices reduce component size, increase efficiency, and improve performance for hybrid and all-electric vehicles.

A drawing of the DC-Link Capacitor with a circuit board on the left hand side and 3-D rectangular neon-colored boxes to the right.
DC-link capacitor and busbar temperatures. Graphic by Gilbert Moreno, NREL

Present-day silicon-based traction drive inverters for electric-drive vehicle (EDV) applications require two separate radiators and thermal management systems for the electric-drive components and the conventional internal combustion engine (ICE). This added weight, bulk, complexity, cost, and lack of efficiency is one hurdle to widespread consumer adoption of hybrid electric and plug-in hybrid electric vehicles in a competitive market dominated by ICE vehicles.

WBG-based components, incorporating devices made from materials such as silicon carbide, can reduce power electronics component size and potentially reduce system or component-level cost, while improving performance and reliability, to give EDVs a competitive advantage in the marketplace. NREL researchers are characterizing the thermal performance and reliability of these emerging WBG-based packaging technologies that could potentially operate more efficiently and reliably under higher temperatures than current silicon-based components. NREL's ongoing research and development of thermal management strategies for WBG power electronics systems led to the world's first commercial high-temperature (140° C ambient), high-power density automotive traction drive inverter.

NREL collaborated with Wolfspeed, Toyota, the National Center for Reliable Electric Power Transmission at the University of Arkansas, and DOE's Vehicle Technologies Office on this project, providing expertise for the thermal management, thermomechanical, and reliability aspects of the inverter development. This resulting R&D 100 Award-winning technology is now being utilized by industry in components such as Wolfspeed's High-Temperature, Wide Bandgap Underhood Inverter for EDVs.

The WBG inverter developed by Wolfspeed in partnership with NREL has proven to be a smaller, lighter, higher power density, and more efficient system in comparison to the silicon-based inverter design used in EDVs currently on the road.

Technical Contacts

Sreekant Narumanchi

Kevin Bennion