Session: 17-01-01: Research Posters

Paper Number: 144321

144321 - Thermal Analysis of Capacitive Charging Pads for Electrified Roadways 

Roadways with charging capabilities would allow electric vehicles to carry smaller batteries, eliminate the need for frequent charging stops, potentially help the practicality of electric buses and trucks, and reduce the consumption of non-renewable energy sources. In 2021, 28% of the total energy consumed by the United States was used by transporting people or goods, with every-day commuter vehicles being 54.2% of the total transportation energy. Gasoline powered vehicles are a major contributor to greenhouse gas emissions, and gasoline is costly. On average, the United States consumed 376 million gallons of gasoline a day in 2023. Although electric vehicles still produce some carbon emissions, they contribute less than the average gasoline vehicle. Reducing the amount of gasoline consumption would be a step in the right direction for the health of the environment.

For many, electric vehicles are inconvenient because of their frequent charging needs. Larger electric vehicles such as buses or trucks are unpractical because of the large battery required to power them. To begin solving these issues, development started on wirelessly charging vehicles through the road itself. Inductive electrified roadways are a mature technology that combats the excessive and inconvenient charging needs of electric vehicles. However, the costs to build inductive charging pads are substantial, which restricts the ability to widely implement them.

This study examines a capacitive charging system to reduce costs and make a future with electrified roadways more attainable. Capacitive systems use common materials such as copper and Teflon that are more cost effective than the inductive counterparts such as coils and ferrite magnetic components. The study also explores capacitive wireless charging at higher power levels, because capacitive charging is less developed and explored than inductive charging in practical applications such as transportation.

To compare effectiveness to the inductive systems, the study thermally analyzes the capacitive system with finite element analysis methods in ANSYS Mechanical. The thermal model is first simulated in stationary air with 6 kW and 10 kW power transfer to compare to laboratory experiment data. Assumptions made about the heat transfer modes and coefficients were validated after preliminary simulation testing with alternating assumptions. The model is used both to show temperature gradients throughout the charging pad, but also to extrapolate to higher power levels.

After refining the model based on experimental data, the model is simulated embedded in asphalt. The asphalt material properties were obtained through experimental testing. To remain conservative and capture the most heat, the simulation assumed free convection on the asphalt instead of forced convection from a passing vehicle.

Results show that the highest temperature gradient through the charging pad is only 1.62 °C. The highest temperature reached is 23.99 °C with 10 kW power transfer. The results imply that the capacitive charging pad can be scaled up further to supply more power to car batteries without significantly increasing heat loss.

Presenting Author: Karmen Teuscher Utah State University

Presenting Author Biography: Karmen is pursuing a bachelor’s degree in Mechanical and Aerospace Engineering with a minor in Leadership and Management at Utah State University. Teuscher has four summers of experience as an intern at Northrop Grumman and one summer as an intern at Pratt and Whitney. Teuscher's most recent internships have been working as a Mechanical Design Intern, and as a Thermal Analysis Intern. Teuscher is the former President of the American Society of Mechanical Engineers student section at Utah State University, and she continues her fourth year in the club presidency, now supporting as the Outreach Director. Teuscher plans to start her masters degree in Mechanical Engineering after graduating with her bachelors in the Spring of 2025.

Authors:

Karmen Teuscher Utah State University
Dheeraj Kumar Reddy Etta Cornell University
Khurram Khan Afridi Cornell University
Nicholas Roberts Utah State University