ABB helps develop universal train

has supplied transformer technology to make possible the world’s first universal train - developed by Bombardier - that can run without stopping on diesel, AC and DC power supplies.

Bombardier’s AGC XBiBi (bi-mode and dual voltage) train can switch effortlessly and efficiently between the different power sources using ABB’s roof-mounted traction transformer.

Previously the traction transformer, which powers the train with AC power, and the diesel engine were mutually exclusive because they occupied the same position in the train. ABB solved the impasse by developing a traction transformer that could be installed on the roof of the train, thereby freeing up space inside for the diesel engine.

Crucially, the roof-mounted traction transformer has no impact on the speed, acceleration, performance or seating capacity of the train itself.

The AGC XBiBi was developed for the French national rail operator SNCF, whose extensive network in 21 regions uses all three power alternatives.

Of the 29,500km of track in the SNCF network, 15,800km are not electrified, 5,800km are electrified at 1.5kV DC and 7,900km at 25kV AC.

A route like Marseille to Geneva via Grenoble, for instance, is part diesel, part AC and part DC, which means that prior to the AGC XBiBi passengers had to change trains whenever the regional power system switched from, say, diesel to AC. With the AGC XBiBi, a single train can now run the entire route, regardless of power system.

The AGC XBiBi is based on Bombardier’s AGC (autorail à grande capacité) family of trains, a versatile platform that consists of diesel, diesel/AC and AC/DC variants. Bombardier is currently delivering 612 AGC trains to SNCF. ABB is supplying the traction motors for all 612 trains, the generators for the diesel variants, and the traction transformers for the AC trains.