US Researchers Wirelessly Charge Electric Trucks at Highway Speed
Electrifying heavy-duty transport requires large batteries in trucks. A wireless high-power charging technology in roads is intended to change this.
The transmitter coils of Purdue University's dynamic high-power charging technology are embedded in the road.
(Image: Purdue University/Kelsey Lefever)
US researchers at Purdue University have developed a wireless, dynamically operating high-power charging system for integration into roads, enabling electric heavy-duty trucks and electric cars to charge while driving at 65 mph (approximately 105 km/h). The technology is being tested on a 400 m experimental highway section of U.S. Highway 52/U.S. Highway 231 in West Lafayette, Indiana. It is the first road in the USA equipped with this dynamic high-power charging technology.
Purdue University's charging technology works inductively. Power is transmitted via transmitter coils embedded in the road surface through a magnetic field to receiver coils attached to the underside of an electric truck. The problem: the distance between the transmitter and receiver coils is relatively large, and the vehicle moves over the charging units at a relatively high speed. In the USA, this is typically between 65 and 75 mph (approximately 105 to 120 km/h) on their highways.
Charging with Dynamic Power Levels
To overcome these challenges, the researchers are using high-power levels that are dynamically adjusted to demand. On the West Lafayette section, this is up to approximately 190 KW. A prototype of a battery-powered truck is being used as the test vehicle. The scientists have adapted it to their own high-power transmission system. In a statement, the researchers emphasize in a press release that wireless power transfer is not only suitable for electric trucks but can, in principle, be integrated into any electric car.
Several projects are already underway in the USA testing wireless charging systems for electric vehicles in roads. However, these systems are not suitable for charging electric heavy-duty trucks as they operate at lower power levels. Furthermore, these charging systems require multiple receiver coils housed in a trailer behind the towing vehicle. In contrast, Purdue University's charging system works with coils housed exclusively in the tractor unit in a single package. They are more compact yet highly efficient, thus simplifying the power reception system in the truck.
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The researchers have filed a patent for their charging system. They aim to electrify heavy-duty transport without relying on very large and heavy batteries in electric trucks, which take up additional space for cargo. Conventional electric cars can also be charged with this system, provided they are equipped with Purdue University's technology. They could then also manage with smaller and lighter batteries, as long as they are repeatedly charged via the charging technology embedded in roads. Purdue University provides no information on the costs of the system, which must be elaborately integrated into the road.
(olb)
