ABB has developed a new flash charging system for city buses, and is working with the city of Geneva’s public transport company and electric power utility SIG on a pilot project. The TOSA (Trolleybus Optimisation Système Alimentation) will be deployed for the first time on a 135-passenger electric bus.
The system enables onboard batteries to be charged in 15 seconds with a 400 kW boost at selected stops (“flash stations”), using a laser-controlled moving arm mounted on the roof, which connects to an overhead receptacle. The flash stations are connected to the 50 kVA electricity network, and each has a 3 kWh supercapacitor storage unit for smoothing peaks in consumption.
At the end of the bus line (the “terminus station”) a 3 to 4 minute boost at 200 kW tops up the batteries. At the depot station, the bus plugs into a multi-bus charging station.
The system is similar one that Göteborg Energi in Sweden is testing, which uses 300 kW Oprid Bůsbaar charging stations to recharge Volvo plug-in hybrid buses.
“Through flash charging, we are able to pilot a new generation of electric buses for urban mass transport that no longer relies on overhead lines,” said Claes Rytoft, ABB’s Chief Technology Officer. “This project will pave the way for switching to more flexible, cost-effective, public transport infrastructure while reducing pollution and noise.”