Analysis and prediction of the stability of train control systems to ultra-wideband electromagnetic pulses of intentional action

Abstract

Problem of ensuring stability of railway automation systems to ultra-wideband pulses of an electromagnetic field is considered. These pulses can be used to intentionally affect the equipment of these systems. It is shown that modern complex systems of control and safety of train traffic are vulnerable to electromagnetic impulses of intentional action. The features that determine the difference between the problem of ensuring the stability of railway automation systems from information systems are highlighted. In particular, microprocessor-based automation systems are geographically distributed and accessible for action from a short distance. The test generators used to prove immunity to electromagnetic impulses from intentional exposure are unique installations. Therefore, to reduce the number of tests design estimates and comprehensive tests for immunity to electromagnetic interference are required. Electrostatic discharges have the widest frequency spectrum. They act on the same apertures in the housings of technical means of railway automation systems as impulses of intentional action. The level of energy absorbed in electronic nodes can be calculated using the Rayleigh theorem. The electromagnetic field inside the housing is determined by the known relations for the radiation of the antennas and depends on the spectrum of the electric component of the field in the antenna aperture. This spectrum, in turn, depends on the spectrum of the electrostatic discharge pulse and the geometric parameters of the antenna. When an electromagnetic wave of an intentional impulse is incident, the aperture releases this impulse and transmits it into the housing. Therefore, the intentional impulse emitted into the housing and the electrostatic discharge impulse can be compared in shape and amplitude. Pulses of different shapes, in turn, can be compared using the spectral-energy equivalence condition. Intentional impulse equivalent to an electrostatic discharge impulse and, accordingly, having the same energy with it, causes exactly the same failures or setback of the element base. The amplitude of the pulse received by the aperture and the amplitude of the transmitted pulse are related by the utilization of the antenna. Thus, authors have obtained a technique for indirectly assessing the influence of an electromagnetic pulse of intentional action based on the calculated prediction of the resistance of railway automation systems to electrostatic discharges. An analogue of the equation of power suppression of radioelectronic means is obtained, which allows finding the parameters of an electromagnetic pulse generator that creates dangerous pulses for railway automation systems. Also, this equation allows calculating the size of the suppression zone for a given generator.