Kettering, Hella Working To Improve EV Chargers

FLINT — Researchers in Kettering University’s Advanced Power Electronics Lab have become a go-to resource for global companies seeking innovations in electric vehicle charging technology.

That’s according to the lab’s latest partner, Hella KgaA Hueck & Co., the Lippstadt, Germany-based developer of lighting and electronics systems for the automotive industry.

Kettering and Hella’s Plymouth-based U.S. subsidiary are working together to improve the company’s Level 2 electric vehicle charger.

Level-2 EV chargers currently on the market have a three-stage design — converting AC grid voltage to 400 VDC; inverting the DC to high frequency AC to feed the transformer, and then converting AC back to DC to charge the battery. Assuming each results in a two percent loss of power, overall wall-to-battery efficiency is 94 percent.

A research team led by Dr. Kevin Bai, associate professor of electrical engineering at Kettering, is working with Hella to develop a next-generation charger that has a two-stage design which would offer 97 percent efficiency for an overall improvement of 3 percent.

“By using gallium-nitride devices, the charger switching frequency also is significantly higher, nearly double the present charger,” Bai said. “The design will make the charger ultra compact and light, which eventually will be a game changer for the EV charging industry.”

Kettering’s research team includes Bai, a research graduate and a research engineer working on the system design and testing. A prototype of the charger is expected to be finished by October and several patents related to the project already have been applied for.

Said Matt McAmmond, advanced engineering manager at the Hella Corporate Center in Plymouth: “Engaging with the students and staff at Kettering University allows us to get a fresh perspective while sharing our knowledge of real world applications in technology.”

Bai and researchers in his lab have worked with numerous industry partners to develop charging technology, including development of a 24-kilowatt charger for Turkish automaker Derindere Motorlu Araclar and development of a 10-kilowatt charger for Magna E-car.

Hella has more than 5,800 people working in research and development among its more than 30,000 employees at 100 locations in more than 35 countries. The company posted sales of 5.3 billion Euros in its 2013-14 fiscal year.

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