Wireless Inductive Charging Technology for EVs Could Bring Convenient Charging to Cities

(Photo courtesy of Jaguar.)

While the switch to electric vehicles (EVs) continues to grow in popularity, coupled with it is the increasing problem of how to effectively make charging stations accessible and convenient to the public.

Norway currently has one of the highest EV adoption rates in the world with 50 percent of cars on its road being EVs. The country is still pushing for more solutions to combat climate change with Oslo’s ElectriCity plan that will require taxis to produce zero tailpipe emissions by 2024. This means that even gasoline-electric hybrid vehicles will be subsequently banned once the plan goes into full effect. In addition to that, Norway’s government has already announced that all new cars must be zero-emissions vehicles by 2025.

To address the inevitable demand for charging stations, a former NASA engineer at the Pennsylvania company Momentum Dynamics is proposing a new solution: wireless charging. In partnership with Jaguar, Nordic taxi operator Cabonline, and charging company Fortam Recharge, the team aims to release a fleet of Jaguar I-Pace taxis capable of charging wirelessly while waiting for passengers.

In Electric vehicle wireless charging technology: a state-of-the-art review of magnetic coupling systems, a 2014 study on electric vehicle wireless charging, explained that this kind of technology uses the principles of magnetic inductance and magnetic resonance. Currents are run through a coil of wire, inducing a magnetic current in the surrounding area. When another coil is exposed to this magnetic field, it induces an electric current back achieving wireless power transfer. Magnetic resonance improves this further by ensuring that both circuits are magnetically resonant at a similar frequency for higher efficiency.

25 I-Pace SUVs will be outfitted with Momentum Dynamics’ inductive charging pads, which are approximately 50 to 75 kilowatts and 60 square centimeters in size. A series of inductive coils embedded in the ground will provide the charging power, requiring the Jaguars to simply park over them. The coils will use resonant magnetic coupling at 85 kHz. According to the team, a charging pad is capable of adding 80 kilometers of range for every 15 minutes that the vehicles spend hovering over the inductive coils.

For more about the technology of wireless charging, read this article.

(Photo courtesy of Momentum Dynamics.)

Andrew Daga, chief executive of Momentum Dynamics, notes that the concept is to replenish the batteries in shorter bursts when needed instead. He also explains that reliance on the “one car, one plug” model can actually degrade battery life and is ultimately inefficient for congested cities, mobility fleets, and for drivers and riders themselves.

“More frequent interactions with the grid are necessary,” said Daga. “It’s all about thinking differently about how fueling is going to be done in a world of electric vehicles.”

The idea was inspired by Momentum Dynamics’ late cofounder Bruce Long’s geophysics expeditions in Antarctica to measure glacial activity, where harsh elements forced him to seek a wireless solution to recharge his electronic equipment. According to Daga, he had already envisioned a similar solution for the International Space Station’s solar power arrays back when he worked with NASA on the project in hopes of getting rid of the heavy aluminum cabling.

Four inductive charging pads mounted under a Link Transit Bus. (Photo courtesy of Momentum Dynamics.)

Momentum Dynamics first introduced and tested the idea back in 2015 in four U.S. cities with electric buses. Charging pads were installed throughout various bus routes and were capable of charging at a rate of 200 kilowatts, allowing the buses to remain in operation 24/7 without needing to return to the garage just to recharge.

The company shares that this technology will deliver 94 percent charging efficiency with a scalable capacity of 200 to 350 kilowatts. This is in contrast with most fast-charging DCs where efficiency tends to drop when charging at a higher power, which results in more energy loss. The project will be in collaboration with Geely, one of China’s largest EV companies, which also owns Volvo and Lotus. An unnamed European manufacturer will also be developing a wireless charging urban delivery truck.

Momentum Dynamics will also be developing tracking software capable of detecting charging sessions and automatically billing customers. A near-field communication system will also allow autonomous vehicles to instantly align and connect with charging pads. The company also hopes to enable bidirectional charging, which means that cars can also contribute supplementary power to the grid when necessary.

The Jaguar taxis are anticipated to begin test operations in Norway by the end of this year.

For more news and stories, check out how this device enables two-way electric vehicle charging here.