Nowadays, the competitors of railway systems are going through a strong development phase, concerning the energy savings and the emissions in the environment, typically fields where railway vehicles assume a position of advantage. Due to the diffusion of distributed traction in railway vehicles, the recovery of braking energy, through appropriate technical solutions, represents an important purpose of research. In this work, the authors, as partner of the Tesys rail project (an Italian project which involves important academic and industrial partners), have developed an innovative model, which includes a vehicle dynamical model, coupled with an electrical model of the feeding line, using the innovative object oriented Matlab-Simscape language. The line model is made up of the contact line, the electrical substations, and stationary and on-board energy storage devices. The authors have focused their attention on the performances of high-speed trains. In particular, the proposed model has been validated through a set of experimental measurements performed on the Italian high-speed train ETR 1000 within the Firenze-Roma 3 kV direct current line. Once proved the good accuracy of the results, the model permits to perform a feasibility analysis of the energetic perspectives of a high-speed railway system, concerning different operating scenarios and various energy storage systems configurations. Through appropriate driving strategies and energy storage configurations, the results show that it is possible to recover a significant percentage of the braking energy. Finally, the proposed model proved to be characterized by a great computational efficiency: it is possible to simulate the behaviour of the train along a 250 km distance in only 5 seconds of simulation.