In this paper the authors propose a feasibility analysis of the high voltage DC feeding system for an electric plant. High DC voltage application in traction power supply system may be interesting if compared with 15 KV 16. 2/3 Hz or 25 KV 50 Hz for many reasons: the lower harmonic contents and the consequent reduction of electromagnetic interference; the possibility to have higher distance between electric substations; the symmetry of power consumption from the main line. The development high cost of the test plant is not justified due to the low compatibility and possibility of integration with the other supply systems working all around the world. From the other side, high voltage in DC traction may be of some interest in many situations such as mines lines where a high power per Km supplied by a reduced number of substations is requested. This study is based on the complete model of two electric substations and of the fed traction track. Substations are made by four parallel conversion groups each of them made of two twelve pulse thyristor rectifier series connection. Simulation result analysis can demonstrate the system feasibility. The simulation program is EMTP/ATP.