The Filter-Compensation Device Applications to the AC 25 kV 50 Hz AC of Serbian Railways

New technologies in rail, including devices for infrastructure and transport, have meant improved safety, comfort, and speed of services. It has also brought new problems for the AC 25 kV 50 Hz traction power supply system with a specific filter-compensation device in traction substations of the Serbian Railways. These problems have resulted in some specific behavior issues during operation modes. For these reasons, research activities during last several years in engineering departments at the Railway College of Vocational Studies in Belgrade have been focused on studying the behavior of the traction system during selected operation states with traction vehicles with diode converters. The main findings of these problems are detailed in this paper.