Sustainability
Evolution at the Bus Stop – E-buses in SHA and HDH
Evolution at the Bus Station
The first transit buses between Schwäbisch Hall and Heidenheim are now in regular service with the Voith Electrical Drive System (VEDS), the company’s solution for the electrified drivetrain. The results so far have been just as positive as the prospects for the technology with its holistic, flexible system approach.
VEDS is extremely efficient, helping bus operators cover longer distances.
When the future rolls into the avant-garde bus station in Schwäbisch Hall, the passengers waiting there initially notice – nothing. No engine noise. No exhaust fumes. Only driver Armin Hinderer’s satisfied smile provides a clue that something here is different.
He sits at the wheel of one of three electric buses that have been in regular service for Stadtbus Schwäbisch Hall GmbH (a Transdev Group company) since the fall of 2019. “It was a completely new experience for me,” says the experienced driver, “but I’m absolutely thrilled.” In fact, he now prefers to drive electric rather than diesel-powered buses. Hinderer’s enthusiasm is based solely on the drive system. The electric buses from the Solaris Urbino 12 family are equipped with the Voith Electrical Drive System (VEDS), which combines a water-cooled, permanent-magnet motor with a particularly efficient inverter. As a result, the VEDS achieves an output of up to 340 kW and a maximum torque of 3,100 Nm – enough to power even heavy articulated buses or double-decker buses effortlessly. In the process, sophisticated control algorithms make 100 percent of the torque available as soon as the driver pulls away – a particularly helpful feature when ferrying passengers on the hilly streets of Schwäbisch Hall. And it also makes sense in Heidenheim, some 80 kilometers away, where the Transdev subsidiary Heidenheimer Verkehrsgesellschaft mbH also brought three electric buses with VEDS drivetrains into service in February 2020.
High-performance engine concept also suitable for single, articulated and double-decker buses. Optimized range due to low system weight.
Supports all common battery systems on the market and can be integrated into any vehicle.
No local NOx and particulate matter emissions thanks to regenerative braking and energy management.
When it comes to operators of local public transit systems, the most important aspect is range, emphasizes Alexander Denk, Vice President Product Management E-Mobility at Voith. “We can currently boast of having the most efficient system on the market today,” says the executive. To achieve this, both the motor and the inverter were deliberately redesigned for the automotive sector – for one thing, standard industrial components would neither meet Voith’s high standards of quality nor the safety standards applicable to passenger transport. On the other hand, this allowed the technology specialist to ensure that all of the components – from the electric motor, traction inverter, and high-voltage power distribution box to the drive control and energy management software – are perfectly compatible with each other.
The success of the VEDS can be seen in the consumption data. “We distribute recovered power efficiently and can split it effectively between the components, because the most sensible solution isn’t always to feed it back into the battery,” offers Denk as an example. The fact that the VEDS doesn’t require a separate transmission, which saves weight, further increases its range.
In Schwäbisch Hall and Heidenheim, buses equipped with the Voith Electrical Drive System are expected to clock up some 320,000 km by the end of the year. Compared to buses with conventional diesel engines, these buses have already cut CO2 emissions by approximately 320 tons alone – and in the future, it will become even more important for operators and vehicle manufacturers to further reduce their carbon dioxide emissions. This is because the European Union has defined binding targets for the procurement of low-emission and zero-emission buses in its Clean Vehicles Directive, which countries will need to implement in two stages by 2025 and 2030, respectively. The electric bus projects in Schwäbisch Hall and Heidenheim are leading the way.“
As an international mobility service provider, we also have a responsibility to combat climate change and ensure that the air in cities remains clean,” explains Stadtbus general manager Michael Dalhof. “And we want to fulfill this responsibility through Transdev GmbH’s first pilot project of this kind in rural areas.” The experience gained from the company’s collaboration with Transdev and Solaris is particularly valuable, emphasizes Alexander Denk. “Solaris explicitly highlights the power density and Transdev is excited about the range because our VEDS consumes very little energy.”
Irrespective of these benefits, the OEMs are primarily interested in the modularity and adaptability of the drive concept in addition to the extremely stringent hardware and software security requirements. This is precisely where the VEDS stands out, because its compact design means it can also be integrated into low-floor buses with improved accessibility for passengers with disabilities. And it doesn’t even make a difference whether the manufacturers equip their vehicles with a fuel cell or batteries for the power supply in the future in order to meet the EU requirements – Voith’s drive system supports both options. “Our modular inverter concept makes our system extremely flexible in this regard,” Denk makes clear. The e-volution is already underway.
