Harmonic composition of the traction network current as an identifier of the operating mode

The problem of accurate identifying emergency and normal operating modes of the AC traction network is an important aspect of protecting the traction power supply system of railway transport. The paper is devoted to the study of formation of the amplitude-frequency spectrum of the current of the contact network feeders during the transition process. On the basis of the field measurements carried out at the AC operating traction substations of the Far Eastern Railway, the analysis of the harmonic components of the current was performed. Full-scale measurements were carried out by a measuring and computing complex having a discrete Fourier transform function in its software. The study of changes in the amplitudes of the harmonic components of the current and their increments at short time intervals was carried out, on the basis of which their numerical characteristics are calculated. The distinctive features of formation of harmonic current spectra in the short-circuit mode and with a sharp increase in the load of the traction network are revealed. It is proposed to use the identified features of the harmonic composition of the current as an identifier of emergency and normal modes of operation of the traction network, which will improve its protection in the future.