Voith Delivers Complete Driveline for Helsinki Tram
Helsinki City Transport (HKL) has placed an order with the Finnish vehicle manufacturer Transtech for the delivery of 40 new trams. As a partner of Transtech, Voith will supply the entire traction equipment from pantograph to the wheels. The first trams will be delivered in 2013.
For the first time, Voith Turbo will supply both the mechanical and the electrical drive components. These include the high-voltage equipment, the traction converter, motor-gear units, axles, wheels and the vehicle control system with diagnosis unit. The new HKL trams combine conventional bogie mechanics with modern low-floor technology. Extra attention was paid to Helsinki’s climatic and track conditions. Through specific measures, the accumulation of snow on the vehicle roof area is successfully prevented.
The drive consists of two double traction inverters and eight motor-gear units. Each inverter supplies two motor-gear units. The two inverters of a double traction inverter are installed separately, allowing a three-quarter redundancy in the drive system. If one drive fails (one inverter, two motor-gear units), driving operation can be continued without any restriction.
The fully sprung motor-gear unit is fitted externally and allows low floor heights, as well as high driving comfort for the freely turning bogies. The gearbox is a fully sprung two-stage KSH-217 bevel gear. At the heart of the drive system is the Voith-developed EmCon DI1000-5AR double traction inverter. It has a continuous output of 2 x 180kVA and a peak capacity of 2 x 400kVA, a requirement for efficient tram operation.
An all-axle drive system combined with a highly dynamic anti-slip control ensures optimum traction under any operating condition. Particularly high energy efficiencies are achieved through low-loss drive operation during rolling phases and the recuperation of braking energy, which is fed back to the net. If the electric network is unable to take up this energy, it is redirected to a thermal storage unit to supply the vehicle heating system.