Abstract |
Today’s innovative technologies for Railway Electrification and Rolling Stock enable an energy efficient operation of railway vehicles supplied by the overhead contact line. In case there is no possibility to recover the braking energy, an onboard energy storage unit allows absorption of this energy for re-use. Therefore the energy consumption and the emission of “Greenhouse gasesâ€, e.g. CO2, can be reduced significantly. But a second operation mode realized by an onboard energy storage unit is possible – the operation of such equipped rail vehicles on tracks without overhead contact lines. The introduction of the new Hybrid Energy Storage system Sitras® HES based on a new electrical connection to the common power supply voltage offers extended possibilities of the operation mode driving without overhead contact line. Consequently, increasingly arising requirement of customers due to aesthetical, environmental or operational reasons can be satisfied by the technology of onboard energy storage units. For both operating modes – energy-efficient operation and operation without overhead contact lines – valuable results and experiences in revenue service at MTS (Metro Transportes do Sul, S.A.) south of Lisbon, Portugal demonstrates the benefits of the new connection concept and the new energy storage system certified according to BOStrab (German Construction and Operating Code) by TÜV Süd GmbH, Germany. |