Influencing Factors of Electrical Sectioning Arcs in Rail Transit and Their Correlation Analysis

Objective The frequent occurrence of electric arcs in the electrical sections of rail transit directly affects the current collection quality of the pantograph-catenary system. Therefore, it is necessary to analyze the correlation between the arc-related electrical parameters and the factors such as the operating speed of electric multiple units (EMU), the structural type of overlap-type electrical sections, and the voltage difference between the contact lines on the section both sides. The arc generation mechanism and influencing factors as the EMU exits the electrical section are further clarified.

Method An arc model suitable for overlap-type electrical sections is established by extending the Cassie–Mayr series arc model. The model considers the dynamic interaction between the pantograph head and the contact line as the EMU exits the electrical section, and its effectiveness is validated based on experimental data from previous studies. In addition, a simulation platform is used to further analyze the impacts of different EMU operating conditions on the electrical characteristic parameters of electrical section arcing and their correlations.

Result & Conclusion The positive steady-state arcing voltage generated as the EMU exits the electrical section increases with the rise of train speed and the voltage difference on the section both sides, showing a significant positive correlation. By contrast, the peak value of the pantograph-catenary positive arcing current decreases gradually, exhibiting a significant negative correlation. Moreover, the influence of different overlap-type electrical sections on pantograph-catenary arcing is mainly caused by the angle between the non-working contact wire and the horizontal plane. A larger angle corresponds to a higher positive steady-state arcing voltage and a lower peak arcing current. Therefore, the ablation of the pantograph-catenary contact wire caused by arcing can be mitigated by reducing the EMU exiting speed and the voltage difference between the contact lines on the section both sides, or by optimizing the mechanical structure of the electrical section.