Charging Ahead
Tennessee is home to more than 20,000 workers in the hybrid and electric vehicle (EV) industry, making it the top state in the Southeast for EV manufacturing and investment. However, the installation of public fast chargers—the powerful direct-current (DC) chargers capable of fully charging an EV in about 20 minutes—is trailing behind. Without them, EV owners often have to charge cars at home, which can take more than eight hours.
“The traditional on-board charger technologies in many existing EVs have very limited power management capability, resulting in very slow charging speed from common power sources,” said JiangBiao He, an associate professor in the Min H. Kao Department of Electrical Engineering and Computer Science who is also affiliated with UT’s Center for Ultra-Wide-Area Resilient Electric Energy Transmission Networks (CURENT) and Institute for Future Mobility. “The insufficient deployment of fast chargers has been a challenge constraining wider adoption of EVs, especially in small cities and remote areas.”
When plugged in to a suitable energy source, modern EV chargers channel direct current (DC) power from the grid into the car battery. When traction energy is needed, a traction inverter transforms that DC power into alternating current (AC) that the traction motor can use to propel the vehicle forward.
To improve the convenience and speed of EV charging, He and his collaborators at Western Michigan University have proposed a design for an integrated charger-inverter (ICI) concept. This technology would harness the existing traction power components onboard EVs, giving them additional utility as fast chargers.
Led by Western Michigan University (WMU) Professor Sandun Kuruppu, the research group also includes experts from Oak Ridge National Laboratory (ORNL), the University of Kentucky, and two industry partners, BorgWarner and John Deere.
The team was awarded more than $3 million by the United States Department of Energy (DOE) in the fall of 2024 to develop a working, 15-kilowatt (kW) ICI prototype and test it across a range of EV charging, driving, and grid interaction profiles.
He and his group at the University of Tennessee are receiving about $565,000 of the project funding to develop the full-scale 150-kW ICI system.
“Thanks to the DOE’s support, I have been able to hire UT graduate students dedicated to this project,” He said. “These students are being intensively trained in cutting-edge technologies and gaining hands-on experience with EV traction and charger development.”
UT Leads Nation in Transportation Electrification
Over the first half of the project, Kuruppu and his lab members at WMU led the team’s efforts to create a scaled-down ICI prototype. In the summer of 2026, they passed the baton to He’s group at UT, which is now spearheading development of the full-scale system.
“In addition to having dedicated high-power lab facilities where we can test the high-power prototype, UT is home to one of the best research groups in the nation for the fields of electric power and transportation electrification,” He said. “UT also has comprehensive undergraduate and graduate courses focusing on electric vehicles, electric drives, and power electronics, making our student body uniquely capable of contributing to this project.”
UT’s proximity to ORNL will also make it easy to collaborate with He’s research partners at the ORNL Vehicle and Mobility Systems Research Group, who will support prototype development and testing.
He’s team at UT will investigate advanced hardware and control techniques to enable the ICI to efficiently achieve fast charging from almost any standard power source, leading to lower charging bills and better mileage between charges.
Removing EV reliance on dedicated charging stations may be the most impactful aspect of the ICI technologies, representing a game changer for electrified transportation.
“Charging flexibility is one of the major advantages of our ICI concept,” He said. “For existing EVs on the market, drivers have to drive to one of very few fast charging stations, which is very inconvenient. They also have to plan their trips carefully around where fast charging stations are available. With the ICI, you would be able to charge the vehicle anywhere there is an AC or DC power source.”
Contact
Izzie Gall (egall4@utk.edu)