|Close-up of the charging mechanism on the demo TOSA bus. Source: ABB. Click to enlarge.|
ABB has developed and is demonstrating a high-capacity “flash charging” system for electric buses. The system enables onboard batteries to be charged in 15 seconds with a 400 kW boost at selected stops using a roof-mounted system (“Flash station”). The flash stations are connected to the 50kVA electricity network and also have a 3kWh storage unit (supercap) for smoothing peaks in consumption.
At the end of the bus line (“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 supply station connected to the 50 kVA network.
ABB announced at the 60th congress of the International Association of Public Transport (UTIP) in Geneva that it is working together with the city’s public transport company (TGP), the Office for the Promotion of Industries and Technologies (OPI) and the Geneva power utility SIG on the TOSA (Trolleybus Optimisation Système Alimentation) electric bus system pilot project using the new flash charging system.
In concept, the system is similar to the Oprid Bůsbaar ultra-fast bus charging stations used to recharge the Volvo plug-in hybrid buses undergoing trials by Göteborg Energi in Sweden (earlier post)—i.e., a very high power, very rapid overhead recharge using a terminus station and not reliant upon overhead lines. The buses in the Göteborg trials use a 300 kW charger.
The new ABB boost charging technology will be deployed for the first time on a large capacity electric bus (TOSA), carrying as many as 135 passengers. The system uses a laser-controlled moving arm, which connects to an overhead receptacle for charging at bus shelters.
The flash-charging technology and the onboard traction equipment used in this project were developed by ABB and optimized for high-frequency bus routes in key urban areas, carrying large numbers of passengers at peak times.