AUTOMATED CONTROL SYSTEMS FOR TRACTION POWER SUPPLY NETWORKS ON RAILWAY LINES: STRAY CURRENT MANAGEMENT, ELECTROCORROSION MITIGATION, AND INDUSTRY 4.0 INTEGRATION

Abstract

This paper presents a systematic analysis of automated control systems (ACS) for traction power supply networks on electrified railway lines, with emphasis on the physical mechanisms, quantitative characterisation, and intelligent mitigation of stray traction currents and their electrocorrosion effects on underground metallic infrastructure. The study addresses the single-wire traction supply scheme common to all railway and urban rail systems, in which running rails serve as the return conductor, and demonstrates that rail-to-earth leakage is an inherent and unavoidable consequence of finite rail-to-earth conductance under operational loading conditions. Drawing on traction load data for 17 rolling stock types, standardised traction system parameters for six categories of electrified transport, and recent Scopus-indexed publications (2019–2025), the paper develops a quantitative analytical framework encompassing three engineering formulas: a stray current magnitude model incorporating rail-to-earth resistivity, traction feeder current, and substation spacing; a rail potential distribution model; and an ACS intelligence integration index (AII) for traction power supply systems. A comprehensive monitoring parameter matrix for smart ACS-TSS platforms is proposed, mapping nine physical measurement channels to their SCADA, IoT, and predictive maintenance applications. The study establishes that DC traction systems generate electrocorrosion risk 100 times higher than equivalent AC systems at equal leakage current density, quantifying the priority modernisation sequence for Kazakhstan’s mixed DC/AC railway network. The proposed integrated ACS architecture, combining IEC 61850 digital substation automation, GPS-synchronised real-time load modelling, machine learning-based cathodic protection optimisation, and digital twin synchronisation, is demonstrated to reduce stray current magnitudes by 35–55 % and annual electrocorrosion maintenance costs by an estimated 40–60 % relative to conventional passive protection measures.