(Updated 4/19/2014 -12:00PM EDT with added comments from Boh Westerlund, Hybricon Founder & CTO, clarifying technical details.)
Hybricon Bus Systems has been testing its new Arctic Whisper electric bus in its hometown of Umeå, Sweden, near the Arctic Circle. Using the company’s Ultrafast Charging system with the Opbrid Bůsbaar, which features a pantograph and an overhead charging rail. The buses charged at 625 amps (400 V DC) for 6 minutes in recent tests, and infrared photos showed a temperature increase of only 9.8 degrees at the critical junction between the pantograph and the overhead charging rail.
The company’s goal is to charge at 500-1000 kW, to enable 2-3 minute charges at the end stations of longer bus routes.
“We have been using 400 V DC up until now, but we will now switch to 700 (672) V DC nominal,” Boh Westerlund, Hybricon Founder & CTO told Charged. “We have today built a 300 kW charging station for the basic tests, but will this year build two 650 kW stations and plan for 950 kW stations next year.”
“The local bus operator only has a few minutes to charge at the ends of the route, so we developed this bus to satisfy this demand,” said Hybricon CEO Jonas Hansson. “We live close to the Arctic Circle and keeping passengers warm is also a top priority. Ultrafast Charging lets us heat with clean electricity instead of a diesel fuel-burning heater.”
“These tests validate our approach, which uses electric rail components such as Schunk pantographs and Furrer+Frey Conductor Rail,” said Roger Bedell, CEO of Opbrid. “Besides transferring very high power, our Bůsbaar charging system is cost effective, safe and durable.”
The 12-meter Arctic Whisper uses batteries specifically designed for high charging rates and cold temperatures. The HAW buses use a modular design, and can be delivered with different battery types and pack sizes for different charging solutions. They can also be equipped with a diesel range extender.
“On the currently running Ultrafast Charged HAW 12 LE, we only need a 50 kWh battery pack for the 14 km airport route,” explained Westerlund. “On our former retrofitted buses we had 100 kWh packs. In the 400 V charging system we used 25 kWh pack size as a base, but this will now increase to 40 kWh packs for each string as a base with the 672 V system.”
A few chargers located at strategic points in Umeå can charge all of the buses throughout the day.