Delivering fast charging for hybrid trains

This new traction battery is delivering whole new levels of energy density and fast charging for hybrid trains.

As reflected in Innotrans 2024’s theme “The future of mobility,” the global rail market is poised for steady growth due to rapid urbanisation, rising road congestion and favourable eco credentials over other forms of transport, like air travel. As such, the railways of the future are starting to take shape, with electrification offering the promise of zero-emission trains. But to meet this challenge head on, new and existing networks must be able to adapt to evolving technologies in order to maintain efficient and sustainable transportation networks.

ABB has been an active technology leader in the rail sector for more than a century, offering the market innovative solutions to speed up its decarbonisation journey. When it comes to rail infrastructure, the key focus areas are DC and AC traction power supply applications.

“ABB is at the forefront of supporting efforts to decarbonise the global rail industry by developing cutting-edge traction systems and solutions through intense research and development,” says Edgar Keller, president of ABB’s Traction Division. “Our commitment to reducing energy consumption and introducing cleaner, more efficient technologies further supports the creation of a more sustainable rail industry, helping to meet ambitious global sustainability targets.”

GROWING TRACTION

The latest advancement in this area from ABB was debuted at the Innotrans show in Berlin. The company launched the third generation of its Pro series traction battery, designed specifically for demanding hybrid and fully electric rail applications. The innovative battery pack is the latest addition to the company’s extensive traction battery family, designed to offer a range of benefits from scalability and modularity to enhanced energy density.

“This new design is still modular and flexible but is even more compact, and has a higher energy density than previous generations,” says Keller. “Charging to 80% is possible in just 10 minutes, and the battery is capable of enabling crucial regenerative braking which is a key element in hybrid trains. When there isn’t the time or ability to refuel the diesel tank, you can charge the battery through braking and use the energy again for acceleration. We see this as a big advantage.”

Alongside its rapid charging capabilities, the new traction battery provides a long lifetime with over 20,000 cycles. The Traction Battery Pro’s fast charging element also yields significant fuel savings for hybrid trains, thanks to an accompanying high-performance lithium-ion based onboard energy storage system.

“We have proven that you can achieve more than 30% fuel savings - depending on the network – which equates to around one in three trains running for free,” Keller explains. “From a comfort perspective, this is also a benefit for passengers as there is low noise levels, acceleration is smooth, and there are no fumes or emissions in tunnels, and so on. The passenger can feel like they are on a fully electric train, despite being on a hybrid one. The new battery is able to charge and discharge very fast with limited losses, and can also operate in very low temperatures. The compactness of the battery also allows for more space for passengers.”

The new generation of the Traction Battery Pro is engineered to provide both modularity and scalability to operators, as well as best-in-class performance. The battery is also designed with high levels of safety in mind, and features enhanced energy density in a compact design. Combined with ABB’s efficient propulsion system and advanced digital tools, the entire system is optimised for better performance.

According to Keller, the battery’s capabilities will help to bridge the time before hydrogen – or something better – becomes more available to take decarbonisation to the next level.

“There’s much hype around hydrogen, but many are realising that this will take time,” he says. “It’s expensive, especially if we’re talking about green hydrogen, and it will take a huge effort to bring this through. And then there is the question of transportation, it’s not like diesel that you can fill up in a tank, it’s more complex than that. So, today we need to bridge the time until we have sufficient green hydrogen infrastructure. This is where hybridisation of diesel trains is key, especially with the fuel savings we are able to achieve with the Traction Battery Pro.”

Alongside applications in hybrid trains, ABB is also exploring the use of traction batteries in trams which can run without catenaries for short distances, in a bid to improve infrastructure flexibility. According to Keller, the near-term focus should be on efficient solutions that meet the increasing demand for public transport, without overloading the grid.

“Regarding electrification, everyone is talking about the electric car, but the railway has been electric for 100 years - this is nothing new for us,” Keller adds. “Now, it’s a question of balance; what you can run with batteries, when does it make sense to have a catenary on top, and so on. It’s an evolution, and we certainly should not wait for hydrogen fuel to change everything as it will not happen overnight. Electric technology is available today, and there is huge potential in these projects to improve the sustainability of rail.”