Today, the electrical energy consumption of rail transportation accounts for 2.8% of the national consumption that is to say 12.2 TWh a year. Thus, in the context of rail traffic increase, both in freight and in people transport, the quality of the power supply becomes a critical problem. For the rail network manager, it is necessary to ensure on the one hand, a satisfactory voltage level for the correct operation of locomotives and on the other hand, an electricity consumption meeting power quality standards and reducing losses on upstream transmission lines. Thus, for eight years, the management of the rail network renovation (RFF), the Engineering Department of French Railways Company (SNCF) and the laboratory Plasma and Energy Conversion (LAPLACE) studied new power electronics solutions to improve power quality and energy efficiency on railways. The objective of this project is to enhance in short term this research work through a technology of static conversion modules which allows achieving and industrializing of these new topologies by using Si semi-conductors. This project also includes a more prospective section to assess the contribution of SiC semi-conductors in these new topologies. Concerning PROGELEC program, this project is positioned in thematic five especially in the sub theme 5.3 dedicated to smart grids. It concerns the development of power electronics for the management and the quality of electrical energy. The scientific program consists of nine tasks and takes place over a period of 30 months. The target application is a new topology of a voltage unbalance compensator for 25kV/50 Hz single phase substations. A pilot, scaled at one MW, will be implemented and validated on a test platform. Ultimately, this project will contribute to the emergence of a French technology, based on a generic power electronics which will allow building the required facilities to improve energy efficiency on electrified railways. The targeted power range is one MW at a voltage level of several kilovolts. Thus, this generic block shall be also used for connecting renewable energy either on electrified railways and electricity public network.