Preliminary field testing of a servoactuated pantograph

摘要

One of the main problems concerning high speed running on Italian railways is the current pick up. The contact force between the pantograph and the overhead contact line increases its amplitude and frequency as the speed increases. The frequent detachments generated by this situation cause not only the temporary interruption of power transmission and wire and contact shoe erosion and produce electromagnetic pollution. A frequent method to reduce detachments is based on the progressive increase of uplift force with the increasing speed. This solution can't be used in high speed running as the excessive contact force necessary to avoid detachments causes a very quick erosion of contact shoes. Furthermore, operating in the above mentioned conditon, the amplitude of contact shoe oscillations may cause impact with the suspension devices of overhead line. An alternative approach to solve these problems is the use of a servo actuated pantograph able to maintain the contact force at a given value. In order to obtain the above mentioned result a FS pantograph was modified applying a brushless servomotor connected by a wire to the contact strip. This actuator, adding its force to the effect of the traditional air bellow, is able to properly regulate the contact force. In the paper the preliminary experimental results, obtained by a special test rig in a FS laboratory, are reported and discussed.