Automotive

Oak Ridge's wireless charging system comparable to plug-in high power fast chargers

Oak Ridge's wireless charging ...
The latest ORNL wireless charging device managed to transfer 120 kW of power over a 6-inch air gap at 97 percent efficiency
The latest ORNL wireless charging device managed to transfer 120 kW of power over a 6-inch air gap at 97 percent efficiency
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"We used finite element and circuit analyses to develop a novel co-optimization methodology," said ONRL project lead Veda Galigeker
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"We used finite element and circuit analyses to develop a novel co-optimization methodology," said ONRL project lead Veda Galigeker
The ORNL wireless charging system makes use of a brand new coil design
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The ORNL wireless charging system makes use of a brand new coil design
The latest ORNL wireless charging device managed to transfer 120 kW of power over a 6-inch air gap at 97 percent efficiency
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The latest ORNL wireless charging device managed to transfer 120 kW of power over a 6-inch air gap at 97 percent efficiency
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The US Department of Energy's Oak Ridge National Laboratory (ORNL) built and demonstrated a 20 kW wireless charging system in April 2016, reported capable of operating at 90 percent efficiency. Now ORNL has taken another giant leap towards meeting the DofE's goal of making electric vehicles as practical and affordable as gas guzzlers by 2022 with the creation of a 120 kW wireless charging prototype.

ORNL's latest wireless charging system takes energy from the grid, converts it to high-frequency AC before transferring power across a 6-inch air gap to a secondary coil, where it's converted for storage in a battery pack. Though the system is built around a brand new coil design, it remains lightweight and compact.

"It was important to maintain the same or smaller footprint as the previous demonstration to encourage commercial adoption," said project lead Veda Galigeker. "We used finite element and circuit analyses to develop a novel co-optimization methodology, solving the issues of coil design while ensuring the system doesn't heat up or pose any safety issues, and that any loss of power during the transfer is minimal."

The ORNL wireless charging system makes use of a brand new coil design
The ORNL wireless charging system makes use of a brand new coil design

In its laboratory demo, the project team managed to transfer 120 kW of power with 97 percent efficiency, which is said to be comparable to plug-in fast chargers in operation today. But the researchers are not stopping there. They plan to look for ways to increase power transfer to 200 kW and beyond, eventually delivering 350 kW systems capable of charging an electric vehicle in 15 minutes or less.

There's also talk of developing dynamic charging systems, where wireless charging pads are installed under road surfaces that will allow for top-ups at highway speeds.

Source: ORNL

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6 comments
MartinVoelker
A few years ago wireless charging was ignored by EV advocates as woefully wasteful, especially when extrapolated to a world with a majority of electric cars. This development is a huge step, and it also highlights that wired charging isn't without losses, either.
paul314
Not to minimize this accomplishment, but rather to give an idea of the really serious power levels involved: 3 percent of 120 KW is 3600 watts, or about the heat output of the broiler in an electric oven. Will take some serious cooling to handle that.
Derek Howe
Hopefully in the near future this tech gets licensed out to all automakers. and all public level 3 charging spots, have this built in, no need for any cords, and have a smaller wimpier one for your home. So you can just set the charging mat under where your vehicle sits, and never again think about plugging it in. The future's looking bright!
Grumpyrelic
Please correct me if I am wrong. My house power is limited to 200 amps @ 220 volts or about 44 Kwatts. If everyone on my street had one of these chargers and charged their vehicles when they got home and proceeded to cook supper, the pole transformers would get sucked inside out and the grid would melt. While we have reduced our electrical needs with the invention of LED lights, solid state electronics, improved house insulation and efficient heating systems, we have not produced a really good storage battery in 200 years - "but it is just around the corner!". Some reality. 1. There is not enough lithium on the planet to supply just the United States auto industry - never mind other countries. 2. There is just not enough power on the planet to run these cars either. This is not the only industry with supply problems. My neighbours are all buying standby natural gas generators. These things use a lot of gas as it contains a lot less energy than gasoline or diesel. If everyone on my road had a power failure, the last few homes would be sucking a vacuum and in winter nobody would have heat. I have a gasoline generator. It is more work but I get peace of mind.
WaywardPatriot
@Grumpyrelic
You're wrong.
At least, on the lithium availability front. Check your numbers! Here you go:
https://blog.energybrainpool.com/en/is-there-enough-lithium-to-feed-the-need-for-batteries/
to quote:
The bottom line, according to Argonne National Laboratory, is that “the available materials will not be depleted in the foreseeable future. … Known lithium reserves could meet world demand to 2050.”
If you read the rest of the article, it says that we don't even have a good estimate of how much total lithium is available. Could be 3.9 million tons, or 39 million tons...or more. Point is. we are GOOD on lithium for now.
Worry more about cobalt and other rare elements that ARE in short supply.
Wingnut
The first thing I thought when I read this article was that city based cars could have much smaller batteries, charged at traffic lights for example (with some car id recognition to levy costs to specific accounts). An enabling technology for 24 hour 'on-call' autonomous cars in particular.