Energy Saver for Transit Vehicles

This paper describes how energy storage on board of railway vehicles leads to a big step in the reduction of consumed energy and opens up a vast array of new applications. Up to 30% energy savings are measured with a prototype vehicle in daily revenue service equipped with the MITRAC Energy Saver. At the same time the peak power demand from the line has been reduced drastically. With the on board energy storage an autonomous operation on tracks with partly catenary free lines becomes reality. This was successfully demonstrated with the prototype light rail vehicle driving with lowered pantograph, disconnecting the vehicle from line. Being in daily passenger operation since September 2003, the MITRAC Energy Saver has proven its reliability and technology. In addition to energy savings aspects, several further applications benefit from an on board energy storage. Hybrid light rail vehicles (Electrical and Diesel-Electrical traction) as well as diesel multiple units benefit from the “booster” effect of the energy storage. The stored energy is adding additional power to the diesel engines during acceleration with a relatively low weight impact. Finally, the energy savings of around 30% and the corresponding emission reduction should already fulfill the targets of various local and global energy saving programs set up by e.g. European Union and big railway operators.