As coils operate closer to the road surface, coil size and weight is exponentially reduced.
Seattle, Washington (PRWEB) August 27, 2014
Business and academia around the world are analyzing not only the electrification of vehicles, but also the electrification of roads. Qualcomm demonstrated the 20kW Halo system on the Lola-Drayson EV Racing Car, and is expected to demonstrate the Wireless Halo system at Formula E September 13, 2014 in Beijing.
According to Bryan Solstin of Solstin.org, 20kW (27 bhp) is not a lot of power. The smallest 2014 Honda Accord has 185 HP, so Halo is 14% of the small car. According to Solstin.org, High-Power Wireless EVs have two problems:
1. High-power charging overheats lithium-ion batteries
2. The secondary coil (attached to the vehicle) is prohibitively heavy
“Wireless coils can get smaller by reducing the gap between the primary and secondary coil, but this is difficult with vehicles,” Solstin said. “Placing the vehicle coil close to the road on a moving vehicle is tricky. Hard-drive, read-and-writes improved with an air bearing, so what if EVs used the same trick?”
To explain the 200kW-Wireless EV, Solstin compares it to air hockey: air hockey is air bearing. The puck floats on a cushion of air while air is supplied from the table. With the 200kW-Wireless EV (U.S. Patent No. 8,556,050,), air is supplied from the vehicle. Air cushions and maintains a slippery gap between the vehicle coils over the road coils. The primary and secondary coils slide by each other with a very small gap. In regards to power transfer, Wireless EVs using an air bearing are about 10 times more powerful than the Qualcomm’s 20kW wireless system, Solstin said.
The air bearing mitigates the weight problem. As coils operate closer to the road surface, coil size and weight is exponentially reduced. High-power transfer, however, does not mitigate overheating. When is comes to lithium-ion, more power means more heat. Additional storage innovation is needed for Wireless EVs to charge fast and leverage wireless, high-power potential. Emerging supercapacitors may mitigate the overheating problem because supercapacitors charge fast without overheating.
Bryan is attending the Formula E race in Beijing and is available for media consultations. For more information, contact Bryan.Solstin at Solstin.org