McLaren has partnered with Australian company Lumen Freedom to use its Wireless Electric Vehicle Charging (WEVC) system for its Speedtail Hyper-GT.
The McLaren Speedtail Hyper-GT is the British auto manufacturer’s fastest road car ever. Near the end of testing, a prototype of the sleek gas-electric hybrid sports car hit 403km/h at NASA’s runway in Florida. Specs for the 2020 production model say that it can go from 0-300km/h in a blistering 13 seconds.
To charge the lightweight battery whenever the aerodynamic three-seat vehicle isn’t in use, McLaren opted for Lumen’s WEVC system. The Speedtail is the first vehicle in the world to incorporate it.
Although inductive—or wireless—charging is becoming more common for phones, smartwatches and other small devices, Lumen Freedom’s wireless system for the McLaren Speedtail represents a unique solution for electric vehicles, according to Lumen Freedom general manager Rod Wilson.
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Wireless charging is easier for electric vehicle customers, especially for people with disabilities. In addition, this kind of system reduces visual clutter in urban areas and requires less space than existing plug-in charging stations.
Eventually, the wireless system could eliminate range anxiety by charging vehicles stopped at traffic lights and cruising along highways.
“The future will offer many different forms of charging,” Wilson said.
“Currently, we have static, and then we move into semi-dynamic. The final step is full dynamic charging, where you will be able to charge at speeds in excess of 100km/h.”
For Lumen Freedom, the Speedtail project is just the start. Their production-ready system has the potential to transform automotive design, transportation, and even the power grid as we know it.
Instead of cords, plugs, and bulky charging stations, the WEVC system uses resonant inductive magnetic coupling. Current from a power source moves from a transmitting pad on the ground underneath the vehicle through the air gap to a receiving pad built into the vehicle. Power transmission efficiency is 92 per cent or greater.
The ground assembly and vehicle assembly communicate with each other wirelessly. Drivers can monitor the charging system using either the 10-inch in-vehicle touchscreen or an app on their smart device. High-clearance capacity makes the system compatible with all vehicle types, from performance sports cars to family sedans and SUVs.
Since its beginnings in 2016, Lumen Freedom refined the concept of WEVC and developed the world’s first single-box 11 KW system. Lumen Freedom is now a fully accredited licensee of Witricity.
Lumen Freedom employs many regimes for physical testing. A large aluminum frame, known as a gantry, is hooked up to a high-voltage Regatron power supply system to assist with simulating real-life operation and power requirements. “You need to be able to work out how much of your power is being dissipated into the surroundings and how much is actually being coupled,” Pesina said.
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In wireless electric vehicle charging, misalignment of the vehicle over the base pad is not an issue since the system incorporates advanced hybrid positioning technology. The Lumen team tested alignment with computer-controlled stepper motors to adjust the height and the X and Y positions for alignment studies.
Simulations helped the team build safety protocols into the system software so that any extreme misalignment detected by the pad sensors would automatically turn off the entire charging system. The WEVC system incorporates a foreign object detection system that can detect a metallic object as small as a paper clip on the ground pad. It then alerts the driver about the obstruction via the app. The system will shut down until the foreign object is removed.
The Lumen Freedom team envisions the adoption of WEVC systems by OEMs and infrastructure providers, leading to sweeping changes. One benefit will be the eventual reduction in the size of electric vehicle batteries.
“As wireless charging and accessibility to wireless charging becomes more commonplace, the forward projections are that battery sizes will be reduced because you won’t need to carry as much energy on-board,” Wilson said.
