Fast track to the future

Moderni­sa­tion of rail travel is right at the top of the Russian government’s list of prior­i­ties: By 2030 a national campaign is aiming to make the rail­ways safer, more reli­able and more ecolog­ical in keeping with inter­na­tional stan­dards. This will require a new approach on the part of Russian manu­fac­turers who so far have always stuck to conven­tional designs: Namely diesel and elec­tric engines. But both of these have certain disad­van­tages: Elec­tric trains hardly produce any CO₂ emis­sions but the infra­struc­ture costs are high on account of the over­head wires for example.

Wide­spread elec­tri­fi­ca­tion is there­fore not a feasible option at the moment in a country the size of Russia. The use of diesel engines is attrac­tive from a finan­cial point of view but there are lots of ecolog­ical draw­backs to consider. To make the most of both tech­nolo­gies whilst minimising the nega­tive aspects, a Russian loco­mo­tive manu­fac­turer had the idea of simply combining the two systems in one engine.

The best of both worlds

An EC centrifugal fan (bottom centre) in the elec­tronic module for the elec­tric drive system ensures heat dissi­pa­tion

To be able to switch between drive systems as required in the course of a journey, the hybrid loco­mo­tive is designed for both elec­trical and diesel oper­a­tion. The engine is there­fore provided with an elec­tronic module which, by way of a frequency converter, makes it possible for the drive units at the train wheels to make use of the elec­tricity from the power line. Even at sub-zero temper­a­tures, a consid­er­able amount of heat is constantly gener­ated in the module and has to be dissi­pated as quickly as possible. This was a real chal­lenge for the devel­op­ment engi­neers, as the elec­tronics have to be housed in a confined space and are also subjected to severe vibra­tion and extreme temper­a­ture differ­ences in the train – a diffi­cult envi­ron­ment for any piece of equip­ment.

The loco­mo­tive manu­fac­turer approached the Russian branch of ebm-papst in Jeka­ter­in­burg with this problem. Thanks to a good working rela­tion­ship over the previous eight years a solu­tion was quickly found. Working on the basis of an existing Green­Tech EC centrifugal fan, the Russians got together with experts from Mulfingen to develop four new fan models capable of ensuring the neces­sary heat dissi­pa­tion in the elec­tronic module even under the toughest condi­tions. The trial run in 2012 satis­fied everyone’s expec­ta­tions. Delivery is timetabled for 2015.