|The infrared photo shows a temperature increase of only 9.8 degrees at the junction between the pantograph and the overhead charging rail of the Opbrid Bůsbaar at 625 A. Click to enlarge.|
During recent tests of Hybricon Bus Systems’ new Arctic Whisper (HAW) urban bus in Umeå, Sweden (earlier post), the Opbrid Bůsbaar achieved ultrafast charging at 625 amps for 6 minutes. This paves the way for charging at 500 – 1000 kW or more to achieve 2- to 3-minute charges at the end stations of longer bus routes. It also allows all-electric heating and 5 – 6 minute charging for the upcoming 18 m 4WD Arctic Whisper articulated bus.
The Opbrid Bůsbaar is an overhead, pantograph-based fast-charging station for buses. In the future, this technology may enable other applications such as medium-distance electric buses or even long distance buses and trucks, the company said.
While fast charging of urban buses has already been shown to be a valuable way to achieve “infinite electric range” in bus systems by Hybricon, Proterra, Volvo, and others, bus operators want ever shorter charging times. If charging times can be reduced to just 2-3 minutes, then the operators do not have to add additional buses—and their associated costs—to a route.
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. 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.—Jonas Hansson, CEO Hybricon Bus System
The tests recently completed consisted of charging the batteries of the Arctic Whisper at 625 Amps for 6 minutes. The infrared photo above shows a temperature increase of only 9.8 degrees at the critical junction between the pantograph and the overhead charging rail of the Opbrid Bůsbaar. The Opbrid Bůsbaar uses technology borrowed from the European electric rail industry which makes these results possible.
These tests validate our approach, which uses electric rail components such as Schunk pantographs and Furrer+Frey Conductor Rail. Besides transferring very high power, our Bůsbaar charging system is cost effective, safe and durable.—Roger Bedell, CEO of Opbrid
The 12m Hybricon Arctic Whisper uses special batteries specifically designed for high charging rates and cold temperatures. The battery packs themselves are relatively small given the size of the vehicle—100 kWh in the case of the Arctic Whisper prototype. (The Arctic Whisper is configured as a series hybrid, with a 50 kW diesel backup system.) The BYD 12m (40-foot) battery-electric bus, for comparison, is equipped with a 324 kWh pack. In contrast, buses that require overnight charging must carry larger batteries. This gives the HAW more passenger capacity, more room inside the bus, and reduces weight and wear on roads.
Just a few chargers located at strategic points in Umeå can charge all of the Hybricon electric buses throughout the day. One hundred percent electric heating can also be used because there is plenty of energy available. The Umeå bus routes are relatively long and Ultrafast Charging provides sufficient power for continuous driving and heating on longer routes in this challenging climate.
The electricity in Umeå comes from renewable sources—primarily wind and hydroelectric dams. Converting the buses in Umeå from diesel to electricity using ultrafast charging saves both money and protects the environment. Hybricon Bus Systems will also be producing 4WD 18 meter electric buses for Umeå city starting this year.
HAW is the brand of the electric city buses developed and made by Hybricon Bus Systems in Umeå, Sweden. The HAW buses are modularly built and can be equipped with different battery types and pack sizes for different charging solutions. They can also be equipped with a range extender to widen the use of the buses, especially in the startup phase of electric bus fleets. However, its main focus is on Ultrafast Charging of a smaller battery pack for 24/7 electrical running in city traffic.