Abstract
In the context of increasing power of electric rolling stock and widespread application of power electronics, the problem of reliable operation of automatic locomotive signaling systems has become particularly relevant. Automatic locomotive signaling (ALS and ALSN) operates in a complex electromagnetic environment and is exposed to traction currents, their harmonic components, impulse interference, and magnetic fields generated by running gear of electric locomotives. These factors can cause short-term disturbances in signal reception that are not related to equipment failures, thus reducing the reliability of railway automation and telemechanics systems. The purpose of this study is to analyze the main sources of electromagnetic interference affecting the operation of automatic locomotive signaling on DC and AC electrified railway sections. The objectives of the research include identifying the mechanisms of traction current influence on ALSN receiving devices, analyzing the harmonic composition of traction currents, and summarizing existing methods for improving interference immunity. The results of the study systematize the main causes of ALS malfunctions and demonstrate the significant role of traction current harmonics and operating modes of electric locomotives, including regenerative braking. It is shown that modern electric locomotives are significant sources of broadband electromagnetic interference, while increased sensitivity of modern signaling systems leads to a higher probability of false operations. In conclusion, the study substantiates the need for a comprehensive approach to ensuring electromagnetic compatibility, including improvement of traction converter circuits, application of active and passive filtering, and modernization of automatic locomotive signaling systems with consideration of real operating conditions.