December 2003 - Active pantographs

By means of the revolutionary development of the electro pneumatic control of pantographs, the performance of the interaction between pantographs and overhead line dramatically is improved.

In order that the electrical current can be transferred to the vehicle preferably without any interruptions, the pantograph has to work at the overhead line with an even contact force. Less force can lead to contact interruptions (arcing) including beading at the catenary wire. A too high contact force possibly results in an exceedance of the allowed catenary wire lifting and to an increased wear of the carbon contact strip and of the catenary wire. In case of high speeds on normal tracks moreover the complete overhead line gets into high vibrations so that trailing pantographs hardly obtain a good contact.

By means of the electro pneumatic control produced by Stemmann-Technik GmbH, at all travelling speeds of the vehicle a nearly same contact force of the pantographs to the overhead line is realised. Depending on the actual speed, thereby acc. to the actual speed the control reaches back to the optimum contact force that has been determined during practical running tests at these particular speeds of the railway vehicle. The board computer controls the corresponding electrical systems of the valve plate that in turn adjusts the pneumatic pressure. Depending on the speed of the vehicle, this interaction can create the exact pneumatic contact force and the pantograph can be operated in all speed ranges with nearly same contact force to the overhead line.

Advantages of the electro pneumatic control:

Increase of the travelling speed on old tracks Improved contact gradeLong service life of contact pieces in single- and multi tractionLess arcingLess wearReduction of the noiseReduction of the measuring- and optimization efforts

With this kind of control, all pantographs of the seriesDSA can be equipped resp. upgraded.

Stemmann-Technik GmbH is manufacturer and sole supplierunder licence of Bombardier.

Further more a pneumatic control (closed loop system)is being developed right now. This system once more reduces the testingefforts in case of test runs.