Abstract
This article is focused on the analysis of impacts on the cross-border transmissions between Slovakia and Hungary and between Slovakia and Ukraine after the completion of the new 400 kV transmission lines on the cross-border profile Slovakia – Hungary. A simulation model of the Slovak transmission system in software ETAP was created, which is set for exploring the impacts of the new Slovak – Hungarian transmission lines 447, 480 and 481 on the cross-border and national transmissions. Correctness of the created simulation model was confirmed by the match of the measured values from winter nationwide measurement with the calculated values from the simulation model. Subsequently, several variants of the Slovak transmission system operation before and after completion of the new power lines to Hungary were evaluated.