Stuttgart researchers develop inductive charging of EVs in motion

Inductive charging of electric vehicles could someday include use of electric coils embedded in the pavement to charge EVs as they move. (University of Stuttgart)


Researchers at the University of Stuttgart in Germany have been developing inductive charging systems that could make it easier to charge e-vehicles even as they move.

The concept would help automate the charging process so that a rechargeable vehicle battery could be recharged while sitting in a parking lot or paused at a traffic light or driving on selected sections of roads.

Similar technologies have been in development for years.  Plugless Power’s wireless stationary charging stations have been used in more than 1 million charge hours, for example.

Last October, the Society of Automotive Engineers announced a global standard for wireless electric vehicle charging for inductive charging systems up to 11 kw. The idea behind the standard is to allow interoperability between inductive charging technology and various vehicles. The lack of interoperability has held back wireless charging advances, according to experts.

WiTricity has also been developing wireless charging technology. Last year, WiTricity said it is working with vehicle manufacturers to install a resonator on a vehicle’s underside to capture energy from a resonator on a pad on the ground that is connected to a wired power outlet.  In a video, the company explained its concept.


The researchers at the Institute of Electrical Energy Conversion at Stuttgart said in a statement they are developing wireless electrical road systems so EVs can be charged without cables while driving or while stationary.

The technology would improve the range of electric vehicles now averaging 250 miles on a charge. Because a driver could charge more frequently and over a shorter time with the researchers’ approach, their vision would allow manufacturers to install smaller batteries to reduce lithium consumption used for lithium-ion batteries.

An e-vehicle could be charged on the way to work and in the parking lot. It would not longer be necessary to plug the car in for charging at night, the researchers said.

In a short statement, the researchers said the inductive charging concept would create more charging capacity at relatively comparable cost to public charging stations. President Biden has set a goal of building 500,000 charging stations in the U.S., partly as incentive to employ more workers to do the construction.

The research team at Stuttgart is headed by Dr. Nejila Parspour.  Charging coils are the basis of the technology. For dynamic charging while driving, induction coils would be installed on the road surface. When a vehicle travels over the top of the coils, the coils are activated, and a transfer is made via a magnetic field.

 The researchers have filed patents for their work, including one invention to allow for inductive charging regardless of the vehicle’s height or width. Another invention can detect when a foreign body is on the induction coil to prevent it from overheating.

The team is working on creating greater efficiency with the coils and making them lighter. The goal is to create a stable system with very few components.

Technologie-Lizenz-Buro GmbH helps Stuttgart patent and market its innovations.  For more information, engineers should contact Innovation Manager Emmerich Somlo at [email protected]

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