Pantograph‐catenary arc fault is the primary factor threatening the stability of the power transmission for high‐speed railway. The motion characteristics of the pantograph‐catenary arc under low air pressure and strong airflow is significantly different from the case under atmospheric pressure. In this paper, an experimental platform of pantograph‐catenary arc was built to investigate arc root position‐time and arc column longitudinal drift height‐time characteristic curves under different air pressures and airflow velocites. Via analysing the corresponding results, it can be found that there are different arc root–arc column traction mechanisms at different stages of arc development. The arcing time and arc root stagnation time under low air pressure are significantly longer than the case under atmospheric pressure, resulting in more serious electrode ablation. The arc column longitudinal drift velocity and height are greater with the increase of airflow velocity. Two typical irregular arc motion phenomena—arc root jumping and arc reignition are observed. To clarify the internal mechanism of the above phenomenon, a magnetohydrodynamics (MHD) model of the pantograph‐catenary arc was lauched, the influence mechanism of the pantograph‐catenary arc temperature and voltage are studied, and the physical process of arc temperature oscillation is analysed. The research results provide theoretical support for arc protection in high‐altitude areas.

Currently, the detection equipment for offline arcing on high-speed trains is of great interest because it can evacuate the contact state between the contact wire and the strip. In order to ensure the safety of the train under the effect of the arcing, the self-designed fourth-order Hilbert curve fractal antenna is chosen to detect the arcing, in this paper, based on its electromagnetic radiation signal. Aspects of time-, frequency-, and joint time–frequency-domain analyses of the signals were considered. Meanwhile, the experiments were conducted several times with different circuit currents and different electrode gaps, and the electromagnetic pulses under different moments were studied. Results indicated that the electromagnetic radiation pulses were corresponding to the abrupt variations of voltage during arcing, and all the characteristic frequencies were located at similar values (18 MHz). Mechanisms of using the short-time Fourier transform method to obtain an accurate arcing moment, extinguished time, and arcing duration have been explained in detail. Thus, the characteristics of arcing electromagnetic radiation could become the significant and efficient parameters to detect the pantograph–catenary operation state of high-speed trains.

The sliding electric contact of pantograph/contact wire systems plays a significant part in the current collection stability and operation life of pantograph/contact wire systems. This paper addresses the evolutionary process of sliding electric contact of pantograph/contact wire systems by analyzing three key characteristics including contact resistance, temperature distribution and microstructure. The influence of electric current on contact resistance was interpreted. Furthermore, the evolution of the spatial temperature distribution of the carbon strip was obtained in the zigzag movement, while the dominant role of electric effect in temperature rise was demonstrated. In the end, the wear morphology differences under pure friction and current-carrying conditions were analyzed. The formation of radial cracks was illustrated and its influenced on the wear process was discussed.

As common electric contact materials, copper‐carbon electrode pairs are widely used in the field of electric contact such as in high‐speed railways, motor collector rings and grounding brushes. They play a key role in energy transmission in the above‐mentioned systems. Arc erosion has become a key issue threatening system safety. In this work, a dedicated arc erosion platform was built to study the polarity effect of copper‐carbon electrode pairs. It was found that arc dynamics and electrodes erosion behaviours were significantly different under different polarities, which could be understood from the mechanism of heat transfer, cooling and electron emission of the electrode. Then, when the carbon material was used as an anode, the arc caused carbon transfer: the carbon material sublimated quickly due to electron condensation and thermal conduction and quickly condensed on the low‐temperature metal electrode, while the carbon material transfer could partly inhibit the oxidation of the cathode metal electrode. In addition, the rapid sublimation of the carbon material produced high‐temperature airflow, which would make the arc impedance fluctuate and cause the arc voltage to jump. Finally, the anode heat transfer and cathode cooling mechanism directly affected the material state, and the erosion of the anode material was more serious.