Traction Converting Substation from Viewpoint of Feeding Interlocking Plant at Czech Railwayes

This paper presents analyses current and voltage harmonic in traction converting substation 3 kV. It researches their rise and influence to three-phase cable line 6 kV, 50 Hz that is used for feeding interlocking plant. Processing of this task is arisen from requirement practice for line Pěčky - Poříčany - Rostoklaty where happened to adverse ratio in particular transmission line of feeding system. It is meant especially about backward influence traction substation rectifier Pečky to three - phase cable line 6 kV, 50 Hz. At the determinate lenght of the cable line, when resonace frequency of circuit transformer 22 kV/6 kV and the cable line 6 kV, 50 Hz is approached frequency 550 Hz and 650 Hz (i.e. 11 and 13 harmonic) are happened to socalled "annulations input reactance of this circuit". That is caused by the leakage of current resonace frequency from traction converting substation to cable line. That proceduces additional losses and deformation waveform of voltage too. This deformation can be reflected on how interlocking plant is working. <br /