Kettering University Working On More Efficient Level 2 Charger

JUL 31 2015 BY MARK KANE 4

Dr. Kevin Bai

Dr. Kevin Bai

After its project of a 10 kW on-board charger for Magna E-car and 24 kW on-board charger for Turkish automaker Derindere Motorlu Araclar (DMA), Kettering University’s researchers recently were engaged by German lighting manufacturer HELLA.

The topic of the latest project is next generation high efficiency, ultra compact and light on-board charger.

“Researchers in Kettering University’s Advanced Power Electronics Lab (APEL) have become a go-to resource for global companies seeking innovations in electric vehicle (EV) charging technology.

The latest collaboration is with HELLA, a globally positioned company that develops and manufactures lighting technology and electronic products for the automotive industry. One such product is the Level-2 EV charger. Presently, level-2 EV chargers on the market have three-stage design — converting AC grid voltage to 400 VDC, inverting this DC to high frequency AC to feed the transformer, and then rectifying AC to DC again to charge the battery. Assuming that each stage of that process leads to about a 2 percent loss of overall power, the overall wall-to-battery efficiency is 94 percent.”

Kettering University’s APEL and HELLA will develop a 2-stage design with 97% efficiency – 3% improvement. That 3% is important because almost all the energy used by electric car over its lifetime is going through the on-board charger (beside a small part of off-board DC charging). Besides it 2-stage design, we found in the press release another key word – gallium-nitride power components.

Prototype of the charger is expected to be finished by October (several patents have already been applied for related to this project). With HELLA as principal, on-board charger can enter volume production at some point in the near future we believe.

Matt McAmmond, Advanced Engineering Manager at HELLA Corporate Center in Plymouth, Michigan said:

“As an innovator, HELLA is very much a hands-on company. 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.”

Dr. Kevin Bai, associate professor of Electrical Engineering at Kettering University said:

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

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4 Comments on "Kettering University Working On More Efficient Level 2 Charger"

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protomech

Perhaps not so much for cars.. but definitely for bikes. Ultra-compact high-efficiency (= low-heat) chargers are key when space is so critical.

finecadmin

Bikes are different. The majority are way under 400V, and often under grid voltage (particularly in 240V regions of course). Different terrain, different tactics, different troops.

Bill Howland

Well they didn’t say so, but they’re using a Cycloconverter topology to eliminate the interim DC link, which lowers cost, size , and improves efficiency since one link is elminated. They have 3ph power to start with, so why not?

Kevin Bai

We figured the cycloconverter topology might not be the right choice so we went for another topology. Can’t say it now due to the IP issue and will publish the end of the year. Thanks for attention.