The railway transport system is a key factor supporting industrialization in all aspects of human activity. However, in order not to lose its importance, it must meet the challenge of modern civilization. The safety, reliability, and efficiency of railway transport, to a large degree, depend on using highly integrated electronics, which are very sensitive to various disturbances generated in the electric traction system and train or coming from the environment. One of the sources of electromagnetic disturbances are high-voltage (HV) power lines running close to the railway infrastructure. The purpose was to assess the electromagnetic impact of overhead HV transmission lines on buried signaling cables of the railway traffic control system crossbreeding with them. The levels of voltage induced in the cable under steady state and the earth fault in the HV line at various soil resistivity were estimated. A software tool based on a hybrid numerical method that combines circuit theory and electromagnetic field theory was used for computations. It was found that very high voltages may be induced in the signaling cables during earth faults in the HV lines, which may lead to serious interference or damage to the equipment. The results provide useful knowledge for implementing modern railway traffic control systems and protection measures.

Lightning discharge becomes a serious source of interference and damage for electronic and electrical power systems. Safe and reliable operation of railway traffic control systems requires proper protection against the effects of lightning. However, the current standards on lightning protection, PN-EN/EN/IEC 62305, do not cover railway objects. Moreover, there are no other standards or recommendations dedicated to the railway. The paper is an attempt to apply the procedure of lightning risk management according to PN-EN 62305-2 to select the proper protection measures in railway objects. A case study for the signal box with installed relaying and digital stations of the railway traffic control system is analyzed. The analysis comprises calculations based on the current standard PN-EN 62305-2:2012 but including the issues specific to railway traffic control. The risks of lightning losses have been calculated for two cases: without lightning protection measures and with protection measures proposed to decrease the risks below the tolerable values. The results show that a practically effective solution to reduce the risks is applying surge protective devices with proper characteristics. Another way is replacing unshielded incoming lines with shielded ones of given shield bonding way, and supplementing it with surge protective devices when necessary.

Electronic systems with extensive underground cable installations are endangered by damage or interference during lightning as a result of current and voltage surges induced in the installations. The paper presents the study on the lightning threat to the electronic intrusion detection system based on underground cable sensors during a nearby lightning strike to the pole of the lighting system installed in parallel with the sensory cables. In the extensive intrusion detection system working in a network composed of several controller-sensor-terminator units, a problem arises whether the neighbouring units should or should not be connected galvanically in order the system is less vulnerable to the effects of a lightning electromagnetic pulse. The problem is complex since the threat level may depend on many factors, i.e. the point of the strike, the lightning current, soil parameters, and configurations of the affected systems. The problem has been studied using numerical simulations based on the electromagnetic field theory and method of moments. The results show that the isolated configuration, i.e. without the galvanic continuity between the units, may be better as far as relatively low soil resistivity and low steepness of the lightning current waveform are considered.

The static and surge properties of the pole grounding system at various soil parameters has been analyzed, taking into account the frequency characteristics, surge parameters, and nonlinear phenomena related to soil ionization during the dissipation of high-intensity surge currents. The analysis is based on the results of numerical calculations that use electromagnetic field theory and method of moments, and known analytical model of high-current phenomena.