Wave Processes in a 10 kV High-Voltage Railway Signalling Line Subjected to Serial Lightning Strikes

the objective of this study is to investigate wave processes in a 10 kV high-voltage automatic block line under multiple lightning strokes, taking into account energy accumulation and degradation of surge arresters, as well as to assess the influence of these factors on the effectiveness of lightning protection. Methods: the study employs mathematical and numerical modeling in the time domain based on the state-space method. Lightning currents are represented using the analytical Heidler function, combined with a dynamic model of the lightning channel and an energy-dependent model of surge arresters. Results: it is shown that under multiple lightning strokes, wave processes in the line overlap in time, leading to increased overvoltage levels. It is established that the energy dissipated in surge arresters accumulates from stroke to stroke and reaches critical values after only a few events. It is demonstrated that the performance of surge arresters is determined not only by instantaneous voltage and current values, but also by the cumulative energy load, which may lead to degradation and eventual failure. Practical significance: the practical significance of the study lies in the applicability of the developed model for analyzing multiple lightning events and evaluating the energy loading of surge arresters in the design of lightning protection systems for high-voltage automatic block lines. The results substantiate the necessity of accounting for cumulative effects and transitioning to energy-coordinated protection schemes, including the implementation of protected approaches for railway automation and remote control systems.