A new bus generation

ABB is contributing to a low-carbon future by developing technologies to encourage large-scale adoption of e-buses without the need for overhead wires.

ABB is contributing to bringing about a low-carbon future by developing technologies to encourage large-scale adoption of electric buses without the need for overhead wires.

The uptake of electric vehicles on our roads signals a shift towards a low-carbon, less polluting environment. In some cities, we are now seeing electric buses powered entirely by batteries. One of the challenges with battery driven vehicles today is the time that it takes to recharge the batteries.  We are still some way from charging as quickly as a car’s tank fills with petrol.

Buses present a particular challenge as operators want the vehicles on the road transporting passengers, not waiting at charging stations. Until recently, one option was for operators to use additional electric buses on a bus line – but this inevitably increases the cost of the electric bus fleet. Today, ABB has a “flash-charging” solution that can quickly charge a battery in the same time it takes for passengers to get on and off the bus – around 20 seconds.

The first buses with this technology will take to the road on a major city route in Geneva, Switzerland, Line 23. Referred to as TOSA (Trolleybus Optimisation Système Alimentation), the buses receive a quick, flash-charge at selected passenger stops, in addition to charging buses for four to five minutes at the end of their routes.  Several valuable seconds are saved at each flash-charging stop, so it takes less time at the end terminal to return the battery to its 100 percent state – and keeps the buses aligned with the timetable.

Of course, different buses will have different routes that will require varying amounts of energy. Factors will depend on the length and topography of the route, the size of the bus, heating or cooling in the bus and the number of passengers. The technology is able to adapt to this by simply varying the number of flash-charging stations–offering  a uniform charging system for a city’s entire fleet.

With the same focus on saving time, the TOSA buses have a simple interface between the bus and wayside which does not require any dialogue between the battery management system and the wayside feeding station – something which takes some time to establish. Another time-saving feature is that the connection arm on the roof automatically aligns and connects in less than a second, making it the world’s fastest flash-charging connection technology.