DC components in pantograph arcing: mechanisms and influence of various parameters

Pantograph arcing generates a net DC voltage which create interference with the track circuit signaling, saturate transformer core, generate even harmonics, create problems on control of the switching of power electronics and drives. Experiments were conducted by Bombardier Transportation and ABB as a part of the ICE project to understand the physical processes that generates this DC component, the coupling mechanisms and the distribution paths, the identification of DC vulnerable components and their response to this DC. The amplitude of the DC voltage shows a wide variation with respect to applied voltage, train speed, type of electrical load, gap between the contact wire and the pantograph and current. In this paper, the authors analyzed those experimental data to understand the typical nature of sliding arc between the pantograph and the contact wire and possible mechanisms involved with this.