RT Journal Article SR Electronic A1 Altus, Juraj A1 Novak, Milan A1 Otcenasova, Alena A1 Pokorny, Michal A1 Szelag, Adam T1 Quality Parameters of Electricity Supplied to Electric Railways JF Communications - Scientific Letters of the University of Zilina YR 2001 VO 3 IS 2 SP 48 OP 60 DO 10.26552/com.C.2001.2-3.48-60 UL https://komunikacie.uniza.sk/artkey/csl-200102-0005.php AB The paper analyses the most relevant unfavourable impact of AC electric traction on the quality parameters of supplied electric energy. These are: power factor of fundamental harmonic and power factor, voltage a current harmonic components, unbalance and power factors in asymmetrically loaded lines and flicker. To confirm some propositions, the paper presents results of measurements in traction transformer substation ŽSR Nové Zámky. Also, the possibilities of unfavourableimpact elimination using filtering and compensating substation and power active filters are mentioned.